September 2005
NSF05/17/EPADWCTR
EPA/600/R-05/120
Environmental Technology
Verification Report
Removal of Arsenic in Drinking Water
Pall Corporation
Microza Microfiltration System
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
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September 2005
Environmental Technology Verification Report
Removal of Arsenic in Drinking Water
Pall Corporation
Microzaฎ Microfiltration System
Prepared for:
NSF International
Ann Arbor, Michigan 48105
Prepared by:
NSF International
And
Scherger Associates
Under a cooperative agreement with the U.S. Environmental Protection Agency
Jeffrey Q. Adams, Project Officer
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development, has financially supported and collaborated with NSF International (NSF) under
Cooperative Agreement No. R-82833301. This verification effort was supported by the Drinking
Water Systems (DWS) Center, operating under the Environmental Technology Verification
(ETV) Program. This document has been peer reviewed, reviewed by NSF and EPA, and
recommended for public release.
11
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites, sediments and ground water; prevention and control
of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public
and private sector partners to foster technologies that reduce the cost of compliance and to
anticipate emerging problems. NRMRL's research provides solutions to environmental problems
by: developing and promoting technologies that protect and improve the environment; advancing
scientific and engineering information to support regulatory and policy decisions; and providing
the technical support and information transfer to ensure implementation of environmental
regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan.
It is published and made available by EPA's Office of Research and Development to assist the
user community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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Table of Contents
Notice ii
Foreword iii
Table of Contents iv
Appendices vii
Acknowledgements x
Chapter 1 Introduction 1
1.1 ETV Purpose and Program Operation 1
1.2 Testing Participants and Responsibilities 1
1.2.1 NSF International 2
1.2.2 Field Testing Organization 2
1.2.3 Manufacturer 3
1.2.4 Analytical Laboratory 3
1.2.5 U.S. Environmental Protection Agency 4
1.3 Verification Testing Site 4
1.3.1 Site Background Information 4
1.3.2 Test Site Description 6
Chapter 2 Equipment Description and Operating Process 8
2.1 Description of Equipment 8
2.2 Engineering and Scientific Concepts 8
2.3 Description of Treatment Train and Unit Processes 9
2.4 Description of Physical Construction/Components 11
2.5 Chemical Consumption and Production of Waste Material 12
2.5.1 Chemical Consumption 12
2.5.2 Waste Production and Physical and Chemical Nature of Wastes 13
2.6 Licensing Requirements 13
2.7 Statement of Performance Objectives 13
2.8 Advantages of the Pall Microza System Process 13
2.9 Limitations of Equipment 14
Chapter 3 Methods and Procedures 15
3.1 Quantitative and Qualitative Evaluation Criteria 15
3.2 Key Filtrate Water Quality Parameters 16
3.2.1 Key Groundwater Quality Parameters the Equipment is Designed to Address.... 16
3.2.2 Key Filtrate Water Quality Parameters for Evaluating Equipment Performance. 16
3.3 Calculations 16
3.3.1 Calculation of Statistical Uncertainty 16
3.3.2 Definition of Operational Parameters 17
3.4 Operation and Maintenance 18
3.5 Field Operations Procedures 19
3.6 Environmental Technology Verificaition Testing Plan 19
3.6.1 Task A: Raw Water Characterization 20
3.6.2 TaskB: Initial Test Runs 20
3.6.3 Task C: Verification Test Procedures 20
3.7 Task A: Raw Water Characterization 21
iv
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3.7.1 Site Background Information 21
3.7.2 Additional Analytical Data 21
3.7.3 Evaluation Criteria 22
3.8 TaskB: Initial Test Runs 22
3.8.1 Objectives 22
3.8.2 Work Plan 22
3.8.3 Arsenic Loss Test 23
3.8.4 Analytical Schedule 23
3.8.5 Evaluation Criteria 24
3.9 Task C: Verification Test 24
3.9.1 Introduction 24
3.9.2 Experimental Objectives 25
3.9.3 Task 1: Verification Testing Runs 25
3.9.4 Task 2: Feed Water and Filtrate Water Quality 27
3.9.5 Task 3: Operating Conditions and Treatment Equipment Performance 32
3.9.6 Task 4: Arsenic Removal 34
3.9.7 Task 5: Data Management 37
3.9.8 Task 6: Quality Assurance 38
3.10 Operation and Maintenance 40
3.10.1 Maintenance 40
3.10.2 Operation 40
3.10.3 Operability Evaluation 42
Chapter 4 Results and Discussion 43
4.1 Introduction 43
4.2 Equipment Installation, Startup, and Shakedown 43
4.3 Raw Water Characterization 44
4.4 Arsenic Loss Test 45
4.5 Verification Test 48
4.5.1 Operating Results 48
4.5.2 Verification Test Arsenic Results 54
4.5.3 Raw, Feed, and Filtrate Water Quality Results 57
4.5.4 Chemical Use, Backwash Quality, and Chemical Cleaning 69
4.6 Other Operating Information 72
4.7 Quality Assurance/Quality Control 75
4.7.1 Documentation 76
4.7.2 Quality Audits 76
4.7.3 Data Quality Indicators 77
4.7.3.1 Representativeness 77
4.7.3.2 Accuracy 77
4.7.3.3 Precision 79
4.7.3.4 Field Blanks and Method Blanks 82
4.7.3.5 Completeness 83
Chapter 5 References 85
Chapter 6 Vendor Comments 86
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List of Figures
Figure 2-1. Photograph of the Microza System [[[ 12
Figure 4-1. Transmembrane Pressure and Specific Flux at 20ฐC ................................................. 52
Figure 4-2. Verification Test Arsenic Results [[[ 56
Figure 4-3. Verification Test pH Results [[[ 58
Figure 4-4. Verification Test Bench-top Turbidity Results [[[ 60
Figure 4-5. Alkalinity Results [[[ 63
Figure 4-6. Iron Results [[[ 65
List of Tables
Table 1-1. Raw Water Quality Data [[[ 6
Table 2-1. Test System Typical Operating Conditions [[[ 11
Table 2-2. Microfilter Membrane Specifications [[[ 11
Table 3-1. Quantitative and Qualitative Evaluation Criteria [[[ 15
Table 3-2. Operating Range of the Microza System [[[ 16
Table 3-3. Key Filtrate Water Quality Parameters [[[ 16
Table 3-4. Water Quality Parameters for Raw Water Characterization ....................................... 22
Table 3-5. Water Quality Parameters - Arsenic Loss Test [[[ 24
Table 3-6. On-site Equipment Operation Parameter Monitoring and Data Collection Schedule 26
Table 3-7. Weekly Sampling Schedule [[[ 28
Table 3-8. Analytical Methods [[[ 29
Table 3-9. Sample Bottles, Preservation, and Holding Time [[[ 30
Table 3-10. Parameter List for Arsenic Intensive Sampling Program .......................................... 36
Table 4-1. Raw Water Characterization Data -August 19,2004 ................................................ 45
Table 4-2. Operating Data Arsenic Loss Test [[[ 46
Table 4-3. Arsenic Loss Test Water Quality Results [[[ 47
Table 4-4. Arsenic Loss Test Daily Water Quality Results [[[ 48
Table 4-5. Verification Test Operating Data [[[ 50
Table4-6. Flux, TMP, and Specific Flux Data [[[ 53
Table 4-7. Arsenic Results [[[ 55
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Appendices
Appendix A - Operation and Maintenance Manual, Flow Diagrams, Specifications
Appendix B - Clean In Place (CIP) Procedure
Appendix C - Photographs
Appendix D - Integrity Test and Startup/Shakedown Procedures and Data
Appendix E - Field Logbooks, Field Log Sheets, Field Calibration Records
Appendix F - NSF Laboratory Data Reports
Appendix G - Spreadsheets
Appendix H - Pall Corporation's Pilot Test Report
vn
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Abbreviations and Acronyms
BGL
CIP
ฐC
CAWET
DWS
DWTS
DQO
EPA
ETV
Ft2
FTO
g
gfd
gfd/psi
gpd
gpm
gpm/ft2
hr
hp
ID.
L
LCS
m
MCL
MDEQ
Microza System
ml
mg
mg/L
mm
NBR
NIST
NRMRL
NSF
NTU
OCDC
O&M
Pall
PLC/PC
psi
PSTP
PVC
PVDF
QA/QC
Below Ground Level
Clean In Place
Degree(s) Celsius
California Waste Extraction Test
Drinking Water Systems
NSF International Drinking Water Treatment Systems Laboratory
Data Quality Objectives
Environmental Protection Agency
Environmental Technology Verification
square feet or square foot
Field Testing Organization
Gram(s)
Gallon(s) per day per square foot
Gallon(s) per day per square foot per pounds per square inch
Gallon(s) per day
Gallon(s) per minute
Gallon(s) per minute per square foot
Hour(s)
Horsepower
Inside Diameter
Liter
Laboratory Control Sample
Meter(s)
Maximum Contaminant Level
Michigan Department of Environmental Quality
Pall Corporation Microzaฎ Microfiltration System
Milliliter(s)
Milligram(s)
Milligram(s) per liter
Millimeter(s)
Nitrile Butadiene Rubber
National Institute of Standards and Technology
National Risk Management Research Laboratory
NSF International
Nephelometric turbidity unit(s)
Oakland County Drain Commissioner
Operation and Maintenance
Pall Corporation
Programmable Logic Controller/Personal Computer
Pounds per square inch
Product Specific Test Plan
Polyvinyl chloride
Polyvinylideneflouride
Quality Assurance/Quality Control
Vlll
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QAPP Quality Assurance Project Plan
RCRA Resource Conservation and Recovery Act
RSD Relative Standard Deviation
SCADA Supervisory control and data acquisition
SCFH Standard cubic feet per hour
SCFM Standard cubic feet per minute
TCLP Toxicity Characteristics Leaching Procedure
IMP Transmembrane Pressure
TOC Total organic carbon
TSS Total suspended solids
|ig/L Microgram(s) per liter
IX
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Acknowledgements
The Field Testing Organization (FTO), NSF International Drinking Water Treatment Systems
Laboratory (DWTS) and its consultant, Scherger Associates, was responsible for all elements in
the testing sequence, including collection of samples, calibration and check of instrumentation,
data collection and analysis, data management, data interpretation and the preparation of this
report.
NSF International Drinking Water Treatment Systems Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Rob Herman
Scherger Associates
3017 Rumsey Drive
Ann Arbor, Michigan 48105
Contact Person: Dale Scherger, P.E.
The laboratory selected for the analytical work for this test was:
NSF International Chemistry Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 4810
Contact Person: Kurt Kneen
The manufacturer of the equipment was:
Pall Corporation
2200 Northern Boulevard
East Hills, New York 11548
Contact Person: William Sellerberg, P.E.
The NSF International DWTS wishes to thank the following participants:
Mr. Bruce Bartley and Ms. Angela Beach of the NSF International Environmental Technology
Verification (ETV) Drinking Water Systems (DWS) Center for their support, guidance, and
program management.
Oakland County Drain Commissioner Office, especially Ms. Connie Sims, for help in selecting
the test site, managing the public contact, and supplying requested information on water quality.
Mr. Lloyd Lewis and his staff provided invaluable field support to Pall and NSF by arranging all
site installation requirements and checking on the test system throughout the installation, startup,
and testing program.
Pall Corporation for supplying the verification test unit and support services during the startup
period. Mr. William Sellerberg, P.E. and Mr. Carlos Lopez presence at the site to optimize the
operation of the system and provide training to the NSF field operators is greatly appreciated.
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Chapter 1
Introduction
1.1 ETV Purpose and Program Operation
The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative or improved
environmental technologies through performance verification and dissemination of information.
The goal of the ETV Program is to further environmental protection by accelerating the
acceptance and use of improved and more cost-effective technologies. ETV seeks to achieve this
goal by providing high-quality, peer-reviewed data on technology performance to those involved
in the design, distribution, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; with stakeholder
groups consisting of buyers, vendor organizations, and permitters; and with the full participation
of individual technology developers. The program evaluates the performance of innovative
technologies by developing test plans responsive to the needs of stakeholders, conducting field
demonstrations, collecting and analyzing data, and preparing peer-reviewed reports. All
evaluations are conducted in accordance with rigorous quality assurance protocols to ensure that
data of known and adequate quality are generated and that the results are defensible.
The EPA has partnered with NSF International (NSF) under the ETV Drinking Water Systems
(DWS) Center to verify the performance of small drinking water systems that serve small
communities. A goal of verification testing is to enhance and facilitate the acceptance of small
drinking water treatment equipment by state drinking water regulatory officials and consulting
engineers, while reducing the need for testing of equipment at each location where the
equipment's use is contemplated. NSF meets this goal by working with manufacturers and NSF-
qualified Field Testing Organizations (FTOs) to conduct verification testing under the approved
protocols. It is important to note that verification of the equipment does not mean the equipment
is "certified" by NSF or "accepted" by EPA. Rather, it recognizes that the performance of the
equipment has been determined and verified by these organizations for those conditions tested by
the FTO.
The DWS Center evaluated the performance of the Pall Corporation Microzaฎ Microfiltration
System (Microza System), which is a microfiltration system used in drinking water treatment
system applications. The statement of performance objective evaluated during field-testing of
the system was that the system is capable of removing arsenic to less than 5 micrograms per liter
(ug/L) in drinking water. This document provides the verification test results for the Microza
System.
1.2 Testing Participants and Responsibilities
The ETV testing of the Microza System was a cooperative effort among the following
participants:
NSF International
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NSF International Drinking Water Treatment Systems Laboratory (DWTS) and its
consultant, Scherger Associates
Pall Corporation
Oakland County Drain Commissioner (OCDC)
U.S. Environmental Protection Agency
The following is a brief description of all of the ETV participants and their roles and
responsibilities.
1.2.1 NSF International
NSF is an independent, not-for-profit testing and certification organization dedicated to public
health and safety and to the protection of the environment. Founded in 1946 and located in Ann
Arbor, Michigan, NSF has been instrumental in the development of consensus standards for the
protection of public health and the environment. NSF also provides testing and certification
services to ensure products bearing the NSF Name, Logo and/or Mark meet those standards. The
EPA partnered with NSF to verify the performance of drinking water treatment systems through
the EPA's ETV Program.
NSF provided technical oversight of the verification testing and conducted an audit of the field
analytical and data gathering and recording procedures. NSF also provided review of the
Product Specific Test Plan (PSTP) as well as this report.
Contact Information:
NSF International
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact: Bruce Bartley, Project Manager
Phone: (734) 769-8010
Fax: (734) 769-0109
Email: bartley@nsf.org
1.2.2 Field Testing Organization
The DWTS conducted the verification testing of the Microza System. The DWTS is an NSF-
qualified FTO for the ETV DWS Center.
The FTO was responsible for conducting the verification testing for 30 calendar days. The FTO
provided all needed logistical support, established a communications network, and scheduled and
coordinated activities of all participants. The FTO was responsible for ensuring the testing
location and feed water conditions were such that the verification testing could meet its stated
objectives. The FTO and its consultant, Scherger Associates, prepared the PSTP; oversaw the
pilot testing; managed, evaluated, interpreted, and reported on the data generated by the testing;
and evaluated and reported on the performance of the technology.
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FTO employees conducted the on-site analyses and data recording during the testing. The FTO's
Project Manager and Project Director provided oversight of the daily tests.
Contact Information:
NSF International Drinking Water Treatment Systems Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Rob Herman
Phone: (734) 769-5349
Fax: (734)827-7143
Email: herman@nsf.org
Scherger Associates
3017 Rumsey Drive
Ann Arbor, Michigan 48105
Contact Person: Dale Scherger, P.E.
Phone:(734)213-8150
Fax: (734)213-8150
Email: daleres@aol.com
1.2.3 Manufacturer
The treatment system was the Pall Corporation Microzaฎ Microfiltration System for the
treatment of drinking water.
The manufacturer was responsible for supplying a field-ready microfiltration system equipped
with all necessary components, including treatment equipment, instrumentation and controls and
an operation and maintenance (O&M) manual. The manufacturer was responsible for providing
logistical and technical support, as needed, as well as technical assistance to the FTO during
operation and monitoring of the equipment undergoing field verification testing.
Contact Information:
Pall Corporation
2200 Northern Road
East Hills, New York 11548
Contact Person: William Sellerberg, P.E.
Phone:(516)484-5400
Fax: (516)484-3548
Email: william_sellerberg@pall.com
1.2.4 Analytical Laboratory
The NSF International Chemistry Laboratory in Ann Arbor, Michigan performed all water
quality analyses.
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Contact Information:
NSF International Chemistry Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Kurt Kneen
Phone: (734) 827-6874
Fax: (734)827-7765
Email: kneen@nsf.org
1.2.5 U.S. Environmental Protection Agency
The EPA, through its Office of Research and Development, has financially supported and
collaborated with NSF under Cooperative Agreement No. R-82833301. This verification effort
was supported by the DWS Center operating under the ETV Program. This document has been
peer reviewed, reviewed by NSF and EPA, and recommended for public release.
1.3 Verification Testing Site
1.3.1 Site Background Information
Two production wells are installed at the Plum Creek Development in Oakland Township,
Oakland County, Michigan. The well house address is 2714 Long Winter Lane, Oakland,
Michigan 48363. These wells supply potable water to approximately thirty-six homes (maximum
design for fifty-one homes). The Plum Creek Development is a suburban residential
development northeast of Detroit, Michigan, located in the Paint Creek Watershed, which
discharges into the Clinton River. The area is a mix of suburban residential developments with
some agriculture.
Basic well information was obtained from the OCDC office and the well installation records.
The wells are installed in the same aquifer, with both wells being drilled to a depth of 99 feet
below ground level (BGL). One well is cased with an 8-inch inside diameter (ID.) well casing
and the other is cased with a 12-inch ID. well casing, and both have 20 feet of stainless steel
well screen. The well screens are located between 79 and 99 feet BGL. The geology at the site
consists of glacial tills, and sand and gravel outwash lithologies from the ground surface to
approximately 250 feet (BGL). Productive water bearing sand and gravel lithologies are
encountered between 25 and 97 feet BGL. The well screens are placed just below this contact
point. Approximately 16 feet of gray clay barrier protection is present above the defined aquifer.
After installation, pump tests were performed to indicate how 100 days of continuous pumping
would affect safe yield. The estimated safe yield for an 8-inch production well was 1,472 gallons
per minute (gpm). This safe aquifer yield is well in excess of the 500-gpm design basis for each
well. The well with an 8-inch well casing has a maximum well screen intake of 500 gpm and the
well with a 12-inch well casing has a maximum well screen intake of 1,000 gpm.
The water supply system uses both wells and a single pressurized water supply tank to deliver
water to the development. The water supply tank is a fixed wall tank and does not have a bladder
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insert in the tank. When the water level in the supply tank drops to a preset level, one well is
activated and refills the tank. Once the tank is filled, the pump shuts off. When the tank level
drops again, the second pump turns on and refills the tank. This alternating cycle is the standard
operating mode for the system. Therefore, the raw water taken from the supply tank for the
verification test will be a blend of the two wells. Since the wells are within a few feet of each
other and screened at the same depth, the water quality of both wells is expected to be similar.
There are no chemicals added to the well water delivered by the wells to the supply tank or to the
water delivered to the homes.
The average daily water use for the community is 29,700 gallons per day (gpd) based on weekly
meter readings from June 2003 through June 2004. The average maximum water use based on
the weekly readings is 93,000 gpd. Well #1 typically reaches a maximum pumping rate of
approximately 500 gpm when it is operating, whereas Well #2 typically reaches a maximum
pumping rate of approximately 1,000 gpm during its cycle. Records are maintained of the time
each pump operates and the flow rates during each cycle. A review of the pump records for May
22-30, 2004 shows that Well #1 normally pumps for four to five minutes and Well #2 normally
pumps for two to three minutes to refill the supply tank. The supply tank is replenished based on
level control and the time between pump activation will depend on the demand for water. The
records for May 22-30, 2003 indicate that the "normal" time between well activation is two to
four hours (alternating between wells #1 and #2), with some cycles as short as once per hour at
high demand and as long as once in six hours at low demand over night. It appears that on an
overall average basis, a well pump is actively pumping (either #1 or #2) for approximately three
to four minutes every two to three hours (this will vary widely depending on demand). The
supervisory control and data acquisition (SCADA) system monitors the pumping times and flow
rates on a minute-by-minute basis. These data are available for the verification test period.
Table 1-1 presents raw water quality for samples taken from the water supply tank. These data
were collected by OCDC as part of their regular monitoring program for this public drinking
water supply site. The water has moderate total hardness of 250-290 milligrams per liter (mg/L)
and the pH is normally about 7.4. Water quality data for total arsenic are available for the period
between August 2002 and May 2004. In May 2004, the raw water was also analyzed for volatile
organic compounds, semivolatile organics and pesticides/herbicides. The results showed no
detectable concentrations of any of these organics.
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Table 1-1. Raw
Parameter
Hardness
Sodium
Chloride
Sulfate
Fluoride
Iron
Total Arsenic
Turbidity
Manganese
Water Quality
Units
mg/L as
CaCO3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
nephelometric
turbidity units
(NTU)
mg/L
Data
August November February
2002 2002 2003
0.014 0.011 0.011
June
2003
288
13
12
17
0.6
0.9
January May
2004 2004
247
13
13
16
0.6
1.0
0.009
<1
0.021
1.3.2 Test Site Description
Structural
The entire water supply system, two wells, supply tank, controls, and piping, are located inside a
secure building. There was room in the building to add the needed piping to supply the Microza
System, house the chemical addition pumps and tanks (sodium hypochlorite, sulfuric acid, ferric
chloride), and store basic supplies and equipment needed by the FTO. The building was not large
enough to house the Microza System, but there was a large paved area immediately adjacent to
the building. The Microza System was housed under a tent outside of the building on the paved
area. The water supply was piped through the wall of the building, where it flowed into the
mixing/coagulation tank, which supplied the chemically treated feed water to the microfiltration
membrane. This test site provided the following advantages:
Full electrical supply;
Building enclosing the wells and pressure holding tank;
Ease of accessibility; and
All required utilities, including raw water supply, power, and drain locations for the
discharge of the filtrate and backwash water to either ground water or to the sanitary
sewer system.
Handling of Filtrate and Residuals
All treated water (filtrate) was discharged to a drainpipe that then discharged onto the land at the
side of the building. The water flowed over the land and either entered the soil or reached a small
tributary to Paint Creek. Backwash water was discharged through a separate drainpipe that was
parallel to the filtrate discharge pipe and also discharged directly to the soil.
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Discharge Permits
According the State of Michigan regulations and discussion with the Michigan Department of
Environmental Quality (MDEQ), no special discharge permits were required for the discharge of
the filtrate and backwash water from the Microza System test unit.
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Chapter 2
Equipment Description and Operating Process
2.1 Description of Equipment
The Microza System used during the verification test was a skid mounted test rig supplied by
Pall Corporation for testing the application of its microfiltration system. The test equipment was
the Microza System Single Station test rig, which was designed to demonstrate the efficiency
and performance of the Microza System. The test rig was designed to test one microfiltration
module. Full-scale installations use multiple modules to attain the design flow rates needed by
public drinking water supply systems. The single-module test unit holds a pilot-scale module to
reduce the quantity of water required for testing.
The test rig is a self-contained, complete system that connects to a pressurized water supply. The
unit delivers filtered product to either a site supplied collection tank or other drainage location.
At Plum Creek, the filtrate from the Microza System discharged over the land, where it seeped
into the soil. Any excess water entered a nearby surface water tributary of Paint Creek. The test
rig is designed to treat flows up to 10 gpm using the microfiltration module selected for this
verification test. A flow schematic is presented in Appendix A along with additional information
on the test rig.
Similar to the Pall full-scale systems, the test system is automated and programmed to control all
aspects of the filter operation. Clean In Place (CIP) maintenance is operator initiated with
computer aided cleaning functions. The control system automatically initiates backwash cycles
based on the time set by the operator. The backwash cycle time is dependent on the water
quality conditions and the amount of solids generated in the coagulation process. The test rig
controls provide the same full functionality and operator interface as Pall provides with full-scale
public water supply systems. The control system is a programmable logic controller/personal
computer (PLC/PC) based controller with data logging, trend display graphs, and a remote
monitoring modem connection for off-site technical support.
The computer monitors and records transmembrane pressure (TMP), flow rates, temperature, air
scrub parameters, and turbidity. All this information is available to the on-site operator and to
remote users.
2.2 Engineering and Scientific Concepts
Coagulation and precipitation of arsenic using iron as a coagulant is a well-known basic
technology for arsenic removal. Various forms of iron (e.g., ferric sulfate or ferric chloride) are
added to water, and the pH is adjusted to an optimal level to form iron floe. As part of the
coagulation process, arsenic is co-precipitated with the iron. The mixing process helps to build
the floe into larger particles that can then be removed by various forms of particle removal
(settling, filtration etc.). Some equipment trains use flocculation tanks and clarifiers with or
without post filtration to remove the precipitated iron and arsenic particulate. Other process
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trains use only chemical coagulation, mixing, and media filtration. The Pall process is based on
chemical coagulation, mixing, and microfiltration with no intermediate solids separation process.
It is widely accepted in the scientific community that the precipitation of arsenic (V) with iron or
similar coagulants is effective for arsenic removal, while arsenic (III) is not removed as easily to
the low concentrations required to meet drinking water regulations. Therefore, water that
contains arsenic (III) is often pre-treated with an oxidization step to convert the arsenic (III) to
arsenic (V). The Pall system uses chlorine (fed as sodium hypochlorite) as a pretreatment step to
convert any arsenic (III) to arsenic (V). The Pall system is compatible with several different
oxidants in addition to chlorine.
2.3 Description of Treatment Train and Unit Processes
The Microza System includes pretreatment with sodium hypochlorite to oxidize any arsenic (III)
to arsenic (V), and iron present in the water supply. Ferric chloride is then added to augment any
natural occurring iron and optimize the iron dose. Sulfuric acid is added to adjust the pH to an
optimal level, as determined during shakedown testing at the site. This chemically treated water
(feed water) enters the feed tank supplied as part of test rig.
The coagulated water in the feed tank is mixed with an installed mixer and then is pumped
directly to the microfiltration module. Flow enters the module on the outside of the membrane,
passes through the membrane, and flows on the inside of the membrane to the outlet of the
module. The microfiltration membrane filters the water, removing the precipitate, including
arsenic, iron, and any other precipitated constituents. A portion of the filtrate is collected in a
tank (reverse filtration tank) for use during the backwash process. The microfiltration system is
designed to filter all of the water under normal operating conditions, [i.e., there is no reject
(concentrate) water from the system]. In certain applications, small amounts of reject water may
occur in a microfiltration system. No reject water was generated at the Plum Creek Site.
The raw water was obtained from the pressure tank at the site (both wells feed the tank on an
alternating cycle basis), which normally operates at 55 to 90 pounds per square inch (psi). A
flow control valve was installed downstream of a back flow preventer to control the flow rate of
raw water. A flow meter was used to monitor the flow rate and total flow of raw water to the
chemical treatment portion of the process.
The piping installed to carry the raw water to the test unit feed tank incorporated the chemical
feed part of the process. Chemical feed ports along the pipe provided for injection of sodium
hypochlorite, ferric chloride, and acid. Each chemical was stored in a five-gallon container at the
site. Chemical metering pumps were used to inject the chemicals into the water. Sampling ports
were located before any chemical addition (raw water), and after the chemical addition points
and the mixing tank. These sampling ports were manual valves placed in the line. Small
diameter tubing was attached to the valves so that samples of the raw water and the feed water
could be collected directly into the sample bottles.
The chemically treated water flowed into the 30-gallon feedwater holding tank. The water in this
tank was continuously mixed with an installed mixer. The water was pumped to the
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microfiltration module at flow rate of approximately 6.3 gpm. The raw water flow rate to the
feed tank was set slightly higher than the feed to the microfiltration module to ensure water was
always present for continuous feed to the module. At the established flow of 6.3 gpm, the
mixing time in the feed water holding tank was less than five minutes.
A variable speed pump controls the flow rate to the filter module. The flow meter measures the
flow in both directions so that both filtrate flow and backwash flow are monitored. Pressure
gauges are mounted on both the feed water line and the filtrate line to monitor pressure in the
system and to monitor the pressure differential across the membrane. A full schematic of the
system is presented in Appendix A.
The Microza System uses a combination of air and water to backwash the microfiltration
membrane. Water is supplied from the reverse filtration tank (30 gallon tank), which holds
filtrate from the system. A compressor with a fully automated control system supplies air for the
air scrub. When a backwash is initiated, the air system is activated and supplies air to the feed
side of the module. The reverse filtration pump pumps filtrate in a reverse flow through the
membrane as well. The combination of air scrubbing and reverse water flow removes the
particles that have been trapped by the microfiltration module. Backwash water from the test
system is discharged either directly to a wastewater collection system or to another appropriate
disposal outlet. For the verification test, the backwash water was discharged through a drainpipe
to the soil behind the well house. Airflow and water flow are monitored during the backwash
cycles.
Occasionally, microfiltration membranes require chemical cleaning to remove materials that are
not removed during the backwash process. Chemical CIP is typically required on a two or three
month basis. A CIP was not required during the 30-day verification test. Therefore, the CIP
demonstration was done at the end of the test, manually. When the CIP was performed, the feed
water tank was used to hold water that contained sodium hydroxide (caustic) and sodium
hypochlorite. The mixture was recirculated through the system for approximately two hours.
The system was then flushed with raw water to remove any residual chemicals. A citric acid
cycle followed the caustic/chlorine cycle. The entire process was monitored once at the end to
the verification test. The chemical CIP water was collected and discharged to the sanitary sewer
system. Appendix B presents the Pall procedure for chemical cleaning of the module.
The Microza System had two inline turbidimeters to monitor turbidity on a continuous basis.
Turbidity was monitored and recorded for the feed water and the filtrate.
A summary of typical operating conditions is provided in Table 2-1.
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Table 2-1. Test System Typical Operating Conditions
Parameter Specification
Flux 120 gallons per day per square foot (gfd)
Filtrate Flow Rate 6.3 gpm
Air Scrub Filtrate Rate 0.5 gpm
Air Scrub Air Rate 1.1 SCFM (66 SCFH)
Air Scrub Duration 60 seconds
Forward Flush Rate 3 gpm
Forward Flush Duration 30 seconds
Filtration Duration 28 minutes^
Waste per Air Scrub and Forward Flush 2.0 gallons
Excess Recirculation None
Source Water Pressure 55-90 psi
^ Actual filtrate production time was approximately 28 minutes out of every 30 minutes, with
two minutes needed to complete the backwash cycle.
The microfiltration membrane used for the verification test was a Pall polyvinylideneflouride
(PVDF) hollow fiber Microzaฎ microfilter. The nominal pore size was 0.1 micron.
Specifications for the membrane are given in Table 2-2.
Table 2-2. Microfilter Membrane Specifications
Name Pall PVDF Hollow Fiber Microzaฎ Microfilter
Model USV-3003
Diameter 7.62 cm (3 inches)
Length 1126 millimeters (mm) (44.3 inches)
Number of filters 1800
Nominal pore size 0.1 microns
Operational pH 1-10
Filter Area 7 m2 (75 ft2)
2.4 Description of Physical Construction/Components
The Microza System test rig was a skid mounted, self-contained unit. The membrane was
housed in a polyvinyl chloride (PVC) module with nitrile butadiene rubber (NBR) gasket and
epoxy resin potting. Maximum operating pressure was approximately 3 bar. The test rig was 96"
(L) x 34" (D) x 125" (H). The air compressor was a separate unit that was 30" (L) x 36" (W) x
70" (H). The main components of the Microza System were:
2 horsepower (hp) feed centrifugal pump;
2 hp reverse filtration pump;
Feed water tank (30 gallons);
Reverse filtration tank (30 gallons);
Schedule 80 PVC piping for water, stainless steel tubing for air;
One module holder for the membrane;
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Air compressor;
Pressure, level, temperature transmitters;
Flow meters (two);
Inline turbidimeters (two); and
Automated PLC/PC based control system.
A detailed set of specifications is provided in Appendix A. Figure 2-1 is a photograph of the
Microza System used in this verification test.
Figure 2-1. Photograph of the Microza" System
2.5 Chemical Consumption and Production of Waste Material
2.5.1 Chemical Consumption
Three chemicals were used during normal operation of the testing equipment. Sodium
hypochlorite was fed to oxidize any arsenic (III) to arsenic (V) and any iron in the raw water.
The target dose for chlorine was approximately 1 mg/L. Ferric chloride was added for arsenic
removal by coagulation. The final feed rate for ferric chloride was approximately 3 mg/L as
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ferric chloride. Sulfuric acid was added to adjust pH as needed. All chemical use was recorded
during the verification test.
2.5.2 Waste Production and Physical and Chemical Nature of Wastes
Backwash water containing the solids (iron and arsenic) generated during the coagulation and
precipitation process was produced at the rate of approximately 96 gpd during continuous
operation. This backwash volume represented approximately 1.2% of the filtrate volume
produced each day. This water in a full-scale system may need to be disposed of to a sanitary
sewer system or may need a liquid-solids separation process to clean the backwash water prior to
discharge. If solids are settled or filtered, they will contain higher levels of iron and arsenic, and
may require special handling for disposal. For the test system, the backwash water was
discharged to the ground at the same location as the filtrate.
The Pall CIP chemical process was performed three times during this verification test; once after
initial startup and shakedown before the arsenic loss test, once at the start of the 30-day
verification test, and once at the conclusion of the 30-day verification test. The water from this
caustic/sodium hypochlorite (bleach) cleaning had a high pH and chlorine content. It was
neutralized before disposal to the sanitary sewer system. The second part of the cleaning waste
had a low pH, which was also neutralized and discharged to the sanitary sewer.
2.6 Licensing Requirements
Based on conversations with the MDEQ, there were no special licensing requirements to operate
the Pall equipment during the test. Larger systems may require licensed water treatment
operators and wastewater permits for disposal of backwash water or cleaning chemicals.
2.7 Statement of Performance Objectives
The Microza System is a chemical coagulation and microfiltration system used in drinking water
treatment system applications for reduction of arsenic. This document provides the verification
test results for the Microza System.
2.8 Advantages of the Pall Microza System Process
According to the Pall Corporation, the main advantages of the Microza System microfiltration
process for removing arsenic from water are as follows:
The process is simple, compact, and can be operated on-demand;
The hollow fiber filter membranes have a long service life;
Each module provides a high filtration surface area;
Fully automated control system allows operation with only periodic operator attention;
Unique air scrub and flush system maintains long membrane runs between chemical
cleaning;
System is compatible with chlorine and other common treatment chemicals; and,
Modular construction on skids provides for ease of installation and expansion.
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2.9 Limitations of Equipment
Potential limitations of the microfiltration process for the treatment of raw drinking water with
respect to source water quality are:
Poor source water quality can cause high backpressure and plugging of the filters,
increasing backwash frequency and chemical cleaning requirements.
A disposal location, such as a sanitary sewer system, is needed to handle the low volume
of backwash water generated on a daily basis.
While the system is automated and operation should be easy, a moderate level of operator
skill maybe required for successful use of the system. If the water quality of the source
water varies it may require adjustment of the chemical feeds in order to maintain optimal
removal efficiency.
A heated structure is recommended when freezing temperatures are encountered. A roof
may be needed in other areas to protect the equipment from sunlight and high
temperature.
Routine maintenance includes checking hoses, fittings and valves for leaks by a brief
visual inspection. Chemicals need replenishment to ensure adequate supplies are
available for injection to the system.
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Chapter 3
Methods and Procedures
3.1 Quantitative and Qualitative Evaluation Criteria
The objectives of the verification test were to evaluate equipment in the following areas:
Report the actual results obtained by the equipment as operated under the conditions at
the test site,
Assess any impacts on performance of any variations in feed water quality or process
variation,
Determine the logistical, human and other resources necessary to operate the equipment,
and
Assess reliability, ruggedness, ranges of usefulness and ease of operation of the
equipment.
In order to address these objectives, the verification employed the quantitative and qualitative
factors listed in Table 3-1 in evaluating the microfiltration equipment performance.
Table 3-1. Quantitative and Qualitative Evaluation Criteria
Quantitative Factors Qualitative Factors
Flux Ease of operation
Feed water flow rate Safety
Finished water quality Susceptibility to environmental conditions
Length of operating cycle Impact of operator experience on
Frequency of backwash cycles successful operation
Power consumption
Chemical use
Maintenance requirements
Required level of operator attention
(time required for system maintenance)
Spatial requirements
Discharge requirements
Waste disposal
The primary application of the coagulation and microfiltration system is the removal of dissolved
inorganic chemicals. In the case of this verification, the primary application was total arsenic
removal. The microfiltration system can also be used for the removal of bacteria and cysts and
oocysts, which was not part of this verification test.
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3.2 Key Filtrate Water Quality Parameters
3.2.1 Key Groundwater Quality Parameters the Equipment is Designed to Address
The operating range of the Microza System, as stated by Pall Corporation is summarized in
Table 3-2.
Table 3-2. Operating Range of the Microza System
Parameter Range
Total Arsenic( )
pH
Turbidity
Less than 200 |ig/L
2tolOS.U.
0- 1000NTU
0)
During verification testing, the range of total arsenic in the feed water was <20
3.2.2 Key Filtrate Water Quality Parameters for Evaluating Equipment Performance
Key filtrate water quality parameters employed for evaluation of the Microza System are listed in
Table 3-3. The Water Quality and Inorganic Parameter columns were the key parameters for
evaluating the treatment process and water quality. The Other Parameters were not expected to
have immediate impact on the treatment process, but were considered important parameters in
drinking water supplies.
Table 3-3. Key Filtrate Water Quality Parameters
Water Quality Inorganic Parameters
Other Parameters
Temperature
Alkalinity
Hardness
pH
Turbidity
Residual Chlorine
Arsenic
Iron
Total Suspended
Solids (TSS)
(backwash water)
Manganese
True Color
Total Organic Carbon
(TOC)
Chloride
Sulfate
Fluoride
Barium
Dissolved Oxygen
3.3 Calculations
3.3.1 Calculation of Statistical Uncertainty
The count, average, minimum, and maximum values were tabulated for all data sets. For the
water quality parameters described in Table 3-3, 95% confidence intervals were calculated for
parameters with more than eight data points (total arsenic, iron, turbidity, chlorine, and
alkalinity). Equation 3-1 was used for confidence interval calculation:
Confidence Interval = X +1
(3-1)
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where: X = sample mean;
S = sample standard deviation;
n = number of independent measurements included in the data set;
t = Student's t distribution value with n-1 degrees of freedom; and
a = significance level, defined for 95% confidence as: 1 - 0.95 = 0.05.
According to the 95% confidence interval approach, the a term is defined to have the value of
0.05, thus simplifying the equation for the 95% confidence interval in the following manner:
95% Confidence Interval = ~X ฑ tn 1 0 975 \-=\ (3-2)
With input of the analytical results for pertinent water quality parameters into Equation 3-2, the
output is reported as the sample mean value plus or minus the second term. The results of this
statistical calculation are presented as a range of values falling within the 95% confidence
interval. For example, the results of the confidence interval calculation provide the following
information: 520 +/- 38.4 mg/L, with a 95% confidence interval range described as (481.6,
558.4).
3.3.2 Definition of Operational Parameters
The following are definitions used for the verification report and designation of sampling
locations:
Filtrate is defined as the water produced by the microfiltration membrane process, the treated
water.
Feed water is defined as the water introduced to the membrane element after all chemical
additions.
Raw water is the source water supply. In this test, the water from the pressurized supply tank.
Membrane flux is the average flux across the microfiltration membrane surface calculated by
dividing the flow rate of filtrate by the surface area of the membrane.
Membrane flux is calculated according to Equation 3-3:
J'=f (3-3)
where: Jt = filtrate flux at time t (gfd or L/(h-m2))
Qp = filtrate flow (gpd or L/h)
S = membrane surface area (ft2 or m2)
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Temperature Adjustment for Flux Calculation: Temperature corrections to 20ฐC for filtrate flux
and specific flux will be made to correct for the variation of water viscosity with temperature.
The following empirically derived equation will be used to provide temperature corrections for
specific flux calculations:
-0.0239 (T-20)
/t (at 20 ฐC) = pXC
S 2 (3.4)
where: Jt = filtrate flux at time t (gfd, L/(h-m ))
Qp = filtrate flow (gpd, L/h)
S = membrane surface area (ft2, m2)
T = temperature of the feed water (ฐC)
Transmembrane Pressure is the pressure across the membrane, equal to the average feed water
pressure on the membrane (average of inlet pressure and outlet pressure) minus the filtrate
(permeate) pressure:
TMP=
(Pf+Pc)
f c
(3.5)
where: TMP = transmembrane pressure (psi, bar)
Pf = inlet pressure to the feed side of the membrane (psi, bar)
Pc = outlet pressure on the concentrate side of the membrane (psi, bar)
Pp = filtrate pressure on the treated water side of the membrane (psi, bar)
Specific flux is used to refer to filtrate flux that has been normalized for the TMP. The equation
used for calculation of specific flux is given by the formula provided below. Specific flux is
usually discussed with use of flux values that have been temperature-adjusted to 20 or 25ฐC per
equation 3.4 above:
tm ~ IMP '
where: TMP = Transmembrane pressure across the membrane (psi, bar)
Jt = filtrate flux at time t (gfd, L/(h-m2)). Temperature-corrected flux values will be
employed. Temperature correction is to 20ฐC.
Jtm = specific flux at time t (gfd/psi, (L/(h-m2))/bar)
3.4 Operation and Maintenance
The manufacturer's O&M documentation for a typical full-scale system was reviewed. NSF, as
part of the verification testing, performed this review and the results of this review are included
in this report. In addition, the following aspects of operability were evaluated:
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Fluctuation of flow rates and pressures through unit - the time interval at which resetting
is needed (i.e., how long can feed pumps hold on a set value for the feed rate?)
Presence of devices to aid the operator with flow control adjustment.
Is pressure measurement provided?
Is rate of flow of raw water measured?
Is chemical feed paced with raw water flow?
Adequacy and ease of use of the PLC/PC control system.
The test unit used a pilot-size module, which allowed observation of the design and operation of
this part of the system. The control system was also the same system used in larger applications.
The backwash and chemical cleaning cycles were identical to larger multiple module systems.
Therefore, it was possible to evaluate the following operability issues directly during the
verification test:
Length of filter runs between backwash cycles;
Change in pressure across the membrane over time;
Frequency and ease of backwash;
Chemical cleaning cycle requirements;
Ease of operating the computer control system;
Availability of process data to the operator; and
Requirements for control and maintenance of the chemical feed systems.
3.5 Field Operations Procedures
The DWTS, as the FTO, conducted the testing of the Microza System. The NSF Chemistry
Laboratory performed water quality analytical work. DWTS field personnel performed field
analytical work, using field laboratory equipment and procedures for pH, temperature, chlorine,
turbidity, dissolved oxygen, and true color.
The following sections describe the tasks completed for the verification. The Microza System
was operated 24 hours a day, seven days a week with staff on-site each day to operate the system
and collect water quality data.
3.6 Environmental Technology Verification Testing Plan
A PSTP was prepared for the Microza System verification test in accordance with ETV
Protocols. The PSTP divided the work into three main tasks (A, B, C) with Task C, the
verification test itself, divided into six (6) tasks. These tasks were:
Task A: Raw Water Characterization
Task B: Initial Test Runs
Task C: Verification Test
Task 1: Verification Testing Runs
Task 2: Raw Water, Feed Water, and Filtrate (Treated) Water Quality
Task 3: Operating Conditions and Performance
Task 4: Arsenic Removal
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Task 5: Data Management
Task 6: Quality Assurance/Quality Control
The PSTP, which included a Quality Assurance Project Plan (QAPP), specified the procedures
that were used to ensure the accurate documentation of both water quality and equipment
performance.
An overview of each task is provided below with detailed information on the testing procedures
presented in the following sections.
3.6.1 Task A: Raw Water Characterization
The objective of Task A, an initial operations task, was to obtain a chemical and physical
characterization of the feed water. Information on the groundwater supply that provided the raw
water was obtained from the OCDC to aid in interpretation of feedwater characterization.
3.6.2 TaskB: Initial Test Runs
During Task B, initial test runs, Pall Corporation evaluated the equipment operation to determine
the optimal chemical dosages and other pretreatment conditions that were needed to provide
effective treatment of the feed water. Pall Corporation performed all startup and shakedown
testing.
3.6.3 Task C: Verification Test Procedures
Task 1: Verification Testing Run
The Microza System was operated for 30 days to collect data on equipment performance and
water quality for the verification test. The 30-day test period was selected based the
microfiltration process being used by the Microza System and the ETV Protocol requirement for
testing such filtration processes.
Task 2: Raw Water, Feed Water, and Filtrate (Finished) Water Quality
During verification testing, raw, feed, and filtrate water samples were collected, and appropriate
analyses were performed. For example, iron analyses were performed to monitor the coagulation
process, in addition to arsenic analyses for the evaluation of arsenic removal.
Task 3: Operating Conditions and Performance
During verification testing, operating conditions and performance of the water treatment
equipment were documented. Operating conditions include pretreatment chemistry for
coagulation, a listing of treatment processes used, and their operating conditions. Equipment
performance information included data on rate of filter head loss change, duration of filter runs,
and the frequency and duration of backwash and filter cleaning. The operating conditions
included plant flow rates and chemical dosages.
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Task 4: Total Arsenic Removal
The objective of this task was to evaluate total arsenic removal during verification testing by
measuring total arsenic in the raw, feed and filtrate water. In addition, detailed data on coagulant
dosages and pre-oxidants were collected.
Task 5: Data Management
The objective of this task was to establish an effective field protocol for data management at the
field operations site and for data transmission between the FTO and the ETV DWS Center.
Prepared master field logs and field data sheets were used to ensure all scheduled activities were
performed. These logs were delivered to the ETV DWS Center project coordinator on a weekly
basis.
Task 6: Quality Assurance/Quality Control
An important aspect of verification testing was the development of specific quality assurance and
quality control (QA/QC) procedures and measures. The objective of this task was to assure
accurate measurement of operational and water quality parameters during the verification test. A
project specific QAPP was prepared with the PSTP to identify data quality objectives (DQO) for
the test. Appropriate QA/QC measures for both field and laboratory data were used by the NSF
staff and reported as part of the field logs and laboratory reports.
3.7 Task A: Raw Water Characterization
3.7.1 Site Background Information
Section 1.3 provided a description of the area and basic information on the wells. This
information was obtained from OCDC and the well installation records. In the past, the site
operator (OCDC) collected samples periodically, which were used for general characterization of
the water quality. The historical data were presented in Table 1-1.
3.7.2 Additional Analytical Data
During Task A, grab samples of the raw water were collected for characterization purposes.
These samples were collected and analyzed to confirm the historical data. The analyses included
arsenic speciation to determine the distribution of arsenic (III) and arsenic (V) in the raw water.
These analyses also included parameters that were part of verification test as described in Task
C. Table 3-4 shows the parameters that were analyzed on these initial samples. Information on
sampling and analysis methods and procedures is provided in later sections. These data, along
with historical data for the groundwater source, provided characterization of the untreated water
source.
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Table 3-4. Water Quality Parameters for Raw Water Characterization
pH Manganese
Temperature Barium
Turbidity Chloride
Alkalinity Sulfate
Residual Chlorine TOC
Dissolved Oxygen Fluoride
Total Arsenic Calcium(1)
Arsenic (speciation) Magnesium(1)
Iron
Hardness was calculated from calcium and magnesium measurements.
3.7.3 Evaluation Criteria
The raw water characteristics were evaluated in context of the Pall statement of performance to
confirm that the water source was appropriate for verification testing.
3.8 Task B: Initial Test Runs
3.8.1 Objectives
The primary objective of this task was to determine the proper chemical dose for the chlorine
pretreatment, iron addition, and pH adjustment to properly co-precipitate arsenic present in the
raw water. The Microza System was set up and operated to check system integrity and ensure the
unit was properly installed for the verification test.
3.8.2 Work Plan
Pall technical support staff worked with OCDC site staff to install the equipment and ready the
Microza System for operation. Pall staff was on-site to direct final connections and the startup
for the equipment. Once ready for operation, Pall Corporation ran the initial startup and
shakedown tests.
Pall Corporation provided a basic outline of the testing that was planned to determine the optimal
iron dose and optimal pH for the coagulation process. This outline was presented in the PSTP,
Appendix C. These tests included varying the chlorine and iron concentrations, and the pH.
Samples for total and soluble iron and total arsenic were collected. Pall also monitored pH on the
samples. The testing plan followed the basic outline provided, and the startup proceeded
smoothly. Pall arranged with a local laboratory to perform the analyses of samples collected
during the shakedown testing.
Once Pall had confirmed the operating conditions and chemical feed rates recommended for the
verification test, they informed NSF that the Microza System was ready for the verification test.
These operating conditions defined by Pall were used for the verification test.
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Pall has a standard integrity test procedure that is used to check the microfiltration membrane
after installation. The integrity test procedure, based on pressurizing the system, is presented in
Appendix D. Pall performed this test to ensure that the membrane was free of major defects. The
integrity test also functioned as a leak check on the test system to ensure that all connections
were tight and that the seals on the module did not leak.
3.8.3 Arsenic Loss Test
Prior to starting the verification test, the unit was flushed for two hours using raw water with no
chemical feed. It should be noted that the raw water contained naturally occurring iron at a
concentration of approximately 1 mg/L. Normal backwash cycles were performed and all
operating conditions (flow rate, pressure, etc.) were monitored and confirmed by the NSF field
staff. Following the flushing of the system, an initial test run was performed to determine if there
is any total arsenic loss in the system when coagulants were not being used. This test run lasted
for 24 hours with samples of raw water, feed water, and filtrate being collected after 6, 12, 18,
and 24 hours of continuous operation. Once this testing was completed and all operating
parameters confirmed, the verification test began.
3.8.4 Analytical Schedule
The samples collected during the arsenic loss test were grab samples collected at the times
specified. The four sets of samples (three sampling locations per set) were analyzed for basic
water quality parameters and for total arsenic, as shown in Table 3-5. The first and last samples
(6 hours and 24 hours) had arsenic speciation tests run to confirm the distribution of arsenic
species in the water.
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Table 3-5. Water Quality Parameters - Arsenic Loss Test
Parameter Frequency(1) Location
pH 4/24 hours Raw, feed, filtrate
Temperature 4/24 hours Raw, feed, filtrate
Turbidity 4/24 hours Raw, feed, filtrate
Alkalinity 4/24 hours Raw, feed, filtrate
Residual Chlorine 4/24 hours Raw, feed, filtrate
True Color 1/24 hours Raw, feed, filtrate
Calcium(2) 4/24 hours Raw, feed, filtrate
Magnesium(2) 4/24 hours Raw, feed, filtrate
Total Arsenic 4/24 hours Raw, feed, filtrate
Arsenic (speciation) 2/24 hours Raw, feed, filtrate
Iron 4/24 hours Raw, feed, filtrate
Manganese 1/24 hours Raw, feed, filtrate
Barium 1/24 hours Raw, feed, filtrate
Chloride 1/24 hours Raw, feed, filtrate
Sulfate 1/24 hours Raw, feed, filtrate
Fluoride 1/24 hours Raw, feed, filtrate
TOC 1/24 hours Raw, feed, filtrate
Dissolved Oxygen 4/24 hours Raw, filtrate
"^ Samples were collected after 6, 12, 18, and 24 hours of operation.
(2) Hardness was calculated from calcium and magnesium measurements.
3.8.5 Evaluation Criteria
During startup and shakedown testing, Pall determined the optimal chemical doses (chlorine and
ferric chloride) and the system operating conditions to achieve arsenic removal. NSF reviewed
this information and determined that the data indicated that the total arsenic removal
performance and operating conditions met the stated performance objective. Therefore, the
recommended chemical feed rates and system operating conditions were used for the verification
test.
3.9 Task C: Verification Test
3.9.1 Introduction
The verification test was run for a 30-day period from September 9, 2004 through October 8,
2004. The Microza System was operated continuously, 24 hours a day, seven days per week,
except for a power outage that occurred overnight on September 27-28. Water quality data for
the raw, feed and the filtrate were collected in accordance with the PSTP, as described in the
following sections. All samples were grab samples collected from the sampling ports installed on
the test rig.
The PSTP described six tasks to be performed to achieve a successful verification test. Each of
these tasks was performed in accordance with the approved PSTP as outlined below.
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3.9.2 Experimental Objectives
The objective of Task C was to assess the ability of the Microza System to demonstrate the
treatment capability of reducing arsenic from a groundwater source, as indicated in the Statement
of Performance Objectives (Section 2.7). The verification test was designed to collect and
analyze arsenic performance data, equipment operating performance data and characteristics, and
other water quality information in order to achieve the objective. Statistical analyses (standard
deviation and confidence intervals) were performed on all analytes with eight or more discrete
samples collected over the 30-day verification period.
3.9.3 Task 1: Verification Testing Runs
Introduction
The verification test was designed to use the optimal configuration and filtration operating
conditions determined by the shakedown testing. The 30-day test was designed to measure the
performance of the system for an extended operating period. The test was typical of operating
conditions expected at a public water supply site using groundwater as the supply source. The
quality of the raw water did not vary significantly over the test period.
The filtrate produced during the verification was not used for public supply purposes. The filtrate
was discharged to the ground.
Operating Schedule
The Microza System was operated continuously during the verification test. Flow was
maintained to the system 24 hours a day, seven days per week, except during the short routine
backwash cycles that are part of the normal system operating procedure. Two CIP cleanings
were performed during the Task C verification. One chemical CIP procedure was performed at
the start of the verification test and the procedure was repeated at the end of the 30-day period to
demonstrate the effectiveness of the chemical CIP procedure.
During the 30-day test, the DWTS field operators recorded daily measurements of the routine
operating parameters, as shown in Table 3-6. In addition the PLC/PC system was also collecting
and recording operating data for the system. Sampling and analysis included one intensive 58-
hour sample collection period.
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Table 3-6. On-site Equipment Operation Parameter Monitoring and Data Collection
Schedule
Parameter
Monitoring Frequency
Monitoring Method
Raw water flow rate
Check and record once per day. Raw water flow meter.
Feed/filtrate water production Check and record once per day. Raw water totalizer meter.
Feed/filtrate water flow rate Check and record once per day
(adjust when 5% above or
below target; record before and
Feed/filtrate water flow
meters.
Feed water pressure
Filtrate water pressure
after adjustment).
Check and record once per day.
Check and record once per day.
Concentrate water pressure Check and record once per day
Backwash volume per cycle Check and record once per day.
Total backwash volume Check and record once per day.
Chemical feeds:
tank volume and pump
metering rate of the
three chemicals: acid,
chlorine, ferric chloride
Chemicals used
Rapid Mixer
Operating hours
In Line Turbidimeters
Check and record once per day.
As needed.
Check once per day.
Record the total hours of
operation since last site visit
once per day.
Verify these meters are
operating and data are recorded.
Feed water pressure
gauge.
Filtrate water pressure
gauge.
Concentrate water
pressure gauge.
Bucket and stop watch.
Number backwashes per
day multiplied by the
backwash volume.
Measure with measuring
tape depth of chemical
remaining and, as
required, quantity of
chemical refill.
Record name of chemical,
supplier, commercial
strength, and dilution used
for making batch solution.
Visual observation that
mixer is properly working.
Based on PLC/PC and
total volume meters,
determine total hours.
Compare to bench-top
meter; calibrate as needed.
26
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Evaluation Criteria
Field logs were used to record all of the information shown in Table 3-6. The hours of operation
needed to meet the protocol requirements of 30 days continuous operations were documented.
Backwash cycles and times were recorded. All data are summarized in Chapter 4, Results and
Discussion. The field logs and log sheets are presented in Appendix E.
3.9.4 Task 2: Feed Water and Filtrate Water Quality
Introduction
Water quality data were collected for raw water, feed water, and filtrate for a 30-day period from
September 9 through October 8, 2004. One intensive 58-hour sampling period was performed
from September 20 through 22, 2004. These data provided the basis for determining the total
arsenic removal performance of the system and documenting the water quality achieved. The
sampling and analysis also included data collection to monitor the changes or impacts of the
coagulant addition (ferric chloride) on water quality.
Work Plan
Monitoring of water quality parameters in the feed water and filtrate water streams was
performed on a regular basis as shown in Table 3-7. These data were used to calculate the change
in the total arsenic concentration and changes in other inorganic chemicals. In addition to the
regular sample collection schedule, there was one intensive sampling and analysis period, which
focused on total arsenic removal, pH and turbidity variability, and the concentration of related
process chemicals, such as iron, and residual chlorine. The intensive sampling period is
described further in Section 3.9.6.
27
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Table 3-7. Weekly Sampling Schedule
Sampling
Parameter Frequency Test Streams Sampled
Temperature
pH
Alkalinity
Turbidity
Hardness(1)
Calcium
Magnesium
TOC
Total Iron
Manganese
Total Arsenic(2)
Sulfate
Chloride
True Color
Residual Chlorine
Barium
Fluoride
Dissolved Oxygen
Total Arsenic(3)
Total Iron(3)
pH(3)
Daily
Daily
3 /week
Daily
Weekly
Weekly
Weekly
Weekly
3 /week
Weekly
3 /week
Weekly
Weekly
Weekly
Daily
Weekly
Weekly
Daily
Weekly
Weekly
Weekly
Weekly
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw Water
Backwash water
Backwash water
Backwash water
Backwash water
Hardness was calculated from calcium and magnesium measurements.
(2) Arsenic samples were speciated once per week for raw, feed, and filtrate samples.
(3) Samples were collected during a backwash cycle.
The field staff analyzed samples on-site for pH, temperature, turbidity, total and free chlorine,
dissolved oxygen, and true color. The NSF Chemistry Laboratory performed analyses of the
remaining water quality parameters. The methods used for measurement of water quality
parameters are identified in Table 3-8. Further discussion of analytical methods is presented in
the PSTP and in the QAPP.
28
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Table 3-8. Analytical Methods
Parameter Facility
Standard EPA
Method(1) Method(2)
Hach
Method(3)
Field Tests
pH On-site 4500-FT B
True Col or On-site 2120B
Turbidity On-site
Temperature On-site 2550
Chlorine (total and free) On-site 4500-C1
Dissolved Oxygen On-site 4500-G
180.1
8167 (total)
8021 (free)
NSF Lab Tests
Arsenic (total)
Arsenic [As (III) and
dissolved]
Calcium
Magnesium
Iron
Manganese
Sulfate
Chloride
TOC
TSS
Barium
Fluoride
Alkalinity
Hardness
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory 53 IOC
Laboratory 2540 D
Laboratory
Laboratory
Laboratory 2320B
Laboratory(4) 2340 B
200.8
200.8
200.7
200.7
200.7
200.8
300.0
300.0
200.7
300.0
0)
(3)
(4)
Standard Methods for the Examination of Water and Wastewater. 1999. 20m edition. APHA, AWWA, and
WEF, Washington D.C.
EPA Methods Source: EPA Office of Ground Water and Drinking Water. EPA Methods are available from the
National Technical Information Service (NTIS).
Hach Water Analysis Handbook (1992). Hach Company, Loveland, Colorado.
Hardness was calculated from calcium and magnesium measurements.
Water samples submitted to the NSF Chemistry Laboratory were collected in appropriate
containers (containing necessary preservatives as applicable) prepared by the NSF Chemistry
Laboratory. The samples were stored in a cooler with ice, delivered to the laboratory (no
commercial shipping used), and analyzed in accordance with appropriate procedures and holding
times. Table 3-9 summarizes the preservation and holding times applicable to the various
analyses.
29
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Table 3-9. Sample Bottles, Preservation, and Holding Time
Parameter Bottle Type Preservation
Field Tests
pH
True Color
Turbidity
Temperature
Chlorine (total and free)
Dissolved Oxygen
NSF Lab Tests
Arsenic (total)
Arsenic [As (III) and
dissolved]
Calcium
Magnesium
Iron
Manganese
Sulfate
Chloride
TOC
TSS
Barium
Fluoride
Alkalinity
Hardness
Plastic, glass
Plastic, glass
Glass vial
Plastic, glass
Plastic, glass
BOD glass bottle
Plastic, glass
Plastic
Plastic
Plastic,
Plastic
Plastic
Plastic, glass
Plastic, glass
Glass
Plastic, glass
Plastic, glass
Plastic, glass
Plastic, glass
Plastic, glass
None
Cool to 2-6ฐC
None
None
None
None
HNO3,
Cool to 2-6ฐC
HNO3,
Cool to 2-6ฐC
HNO3,
Cool to 2-6ฐC
HNO3,
Cool to 2-6ฐC
HN03,
Cool to 2-6ฐC
HNO3,
Cool to 2-6ฐC
Cool 2-6ฐC
Cool 2-6ฐC
H2S04,
Cool 2-6ฐC
Cool 2-6ฐC
HNO3,
Cool to 2-6ฐC
Cool 2-6ฐC
Cool 2-6ฐC
HNO3,
Cool to 2-6ฐC
Holding time
Analyze immediately
24 hours
Analyze immediately
Analyze immediately
Analyze immediately
Analyze immediately
6 months
6 months
6 months
6 months
6 months
6 months
14 days
14 days
28 days
7 days
6 months
14 days
14 days
6 months
Analytical Schedule
The analytical parameter list and frequency shown in Table 3-7 was designed to frequently
monitor the parameters that are critical to the coagulation and filtration process. The parameters
monitored on a less frequent basis are general water quality parameters to provide water quality
characteristics. Dissolved oxygen concentration in the raw water was considered important, as
30
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the treatment system depends on the oxidation of iron to achieve the proper conditions for
arsenic coagulation and removal.
It should be noted that pH was monitored on all three water types, raw, feed, and filtrate. The pH
adjustment step was an important part of the process; therefore, monitoring the pH before
adjustments, after adjustment, and after filtration was an important operating parameter.
Turbidity measurements were made continuously within inline turbidimeters. The inline
turbidimeters were checked daily using a bench-top turbidimeter. If the inline units required
calibration, it was performed by the DWTS field staff and recorded in the logbook.
The backwash water was sampled once per week during a backwash cycle to obtain information
on the TSS concentration in the backwash. Backwash samples were also analyzed for the
concentration of total arsenic, total iron, and pH. The PSTP also called for residual chlorine
analyses on the backwash water, but these analyses were not performed. The backwash water
residual chlorine was approximately the same as the filtrate water, since filtrate water was
collected in a tank for backwashes that occurred every 15 to 30 minutes.
The protocol and PSTP called for measuring the metals leached from any sludge produced from
the system using the Toxicity Characteristics Leaching Procedure (TCLP) and California Waste
Extraction Test (CAWET) leaching procedures. The Microza System would typically produce
sludge only if the backwash water was stored in a tank and passed through a solids separator to
remove suspended solids prior to discharge. This was not the method of handling backwash at
the site. Backwash was directly discharged onto the ground. Therefore, no residues accumulated
during the test and no solids testing was performed.
Water Quality Sample Collection
All raw water, feed water, and filtrate samples were grab samples collected from the sampling
valves installed in the test system. The raw water sample tap was located prior to any chemical
addition. The feed water sample port was located after all chemical additions and mixing just
prior to the filtration unit. The filtrate (treated water) sample tap was located downstream of the
microfiltration module. Prior to collecting the sample, each valve and sample tube (tubing
attached the valve) was flushed for at least five seconds to be sure fresh water was obtained from
the process lines. The samples were collected directly into a clean large container. Aliquots of
sample were then poured into the required containers for laboratory analysis or on-site analysis.
Samples from all three locations were collected within a short period of time (less than 30
minutes) so that data were representative of the current conditions. Backwash samples were grab
samples collected from the backwash line as it discharged from the system during the backwash
cycle.
Special sampling procedures were employed for bench-top turbidity samples. The method for
collecting grab samples consisted of running a slow, steady stream from the sample tap, triple-
rinsing a dedicated sample beaker in this stream, allowing the sample to flow down the side of
the beaker to minimize bubble entrainment, double-rinsing the sample vial with the sample,
carefully pouring from the beaker down the side of the sample vial, wiping the sample vial clean,
inserting the sample vial into the turbidimeter, and recording the measured turbidity.
31
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Temperature measurements were performed by collecting a sample into a clean container and
immediately immersing the thermometer into the water.
Evaluation Criteria and Minimum Reporting Criteria
Performance was evaluated in the context of the manufacturer's statement of performance
objectives.
Since iron was used as the coagulant, the filtered water data were tabulated and the concentration
of iron in filtered water was compared to the secondary Maximum Contaminant Level (MCL) of
0.3 mg/L.
Given that the verification test was for a ground water source, turbidity results were analyzed to
determine the percentage of turbidity data in the range of 0.50 NTU or lower, the percentage in
the range of 0.51 NTU to 1.0 NTU, the percentage in the range between 1.1 NTU and 2.0 NTU,
and the percentage exceeding 2.0 NTU.
Other water quality data were summarized and are presented in the Chapter 4 in either graphical
or tabular format. Daily analyses were plotted against time, while weekly parameters were
summarized in a tabular format. Information includes:
A graph plotting the daily turbidity, pH, alkalinity, and iron for the raw, feed and filtrate
over the test period.
A table summarizing the raw, feed, and filtrate concentrations of hardness, manganese,
TOC, sulfate, chloride, and true color.
A table summarizing the residual chlorine data.
An appendix containing all data collected during the verification test.
3.9.5 Task 3: Operating Conditions and Treatment Equipment Performance
Introduction
Operating conditions were documented during each day of verification testing, including
descriptions of chemicals used for coagulation and operating conditions. The performance of the
water treatment equipment was documented, including flow rates through the microfilter,
pressure drop across the filter, frequency and duration of filter backwash cycles, and any
maintenance required.
The objective of this task was to accurately document the operating conditions during treatment
and the equipment performance. This task was intended to result in operational data describing
the operation of the equipment.
Work Plan
A description of the equipment, microfiltration membrane characteristics, and test system
operating conditions was presented in Chapter 2. During verification testing, operating
32
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parameters such as those defined by Pall (Table 2-1) were monitored. Table 3-6 presented a list
of the normal operating parameters that were monitored to document the equipment performance
during the verifications test.
The following items were monitored, collected, recorded, or analyzed:
Treatment equipment operating parameters for both pretreatment and filtration, including:
- Monitoring iron dose and pH for the coagulation system,
Monitoring the chlorine pre-oxidation step,
Observing the operation of the mixing in the feed water tank, and
- Calculating process detention time in the feed water tank based on system flow rate
data.
Filter pressure drop before and after backwash cycles, and backwashing data (frequency,
flow rate, volume), cleaning data.
Chemical dosages for all chemicals used, including oxidants. Sodium hypochlorite was
used as an oxidant. Free and total residual chlorine were measured daily, including when
total arsenic samples are collected. The feed rate of iron coagulant chemical, the strength
of the solution, and the specific gravity for liquid coagulant, were documented. The
quantity of sulfuric acid used for pH adjustments was monitored, and the strength of the
solution, and the specific gravity were documented.
Electrical energy consumed by the treatment equipment based on aggregate horsepower
of all pumps in operation (based on operating time estimate), air compressor, and mixer
was calculated and reported.
Effectiveness of the chemical CIP procedure was monitored by comparing post cleaning
membrane pressure drop to original clean membrane pressure drop at the start of the test.
Chemical use, flow rates, and waste generated were recorded.
Schedule for Operating Parameter Data Collection
Table 3-6 shows the list of operating parameters that were monitored during the verification test
and the frequency of the observations.
Evaluation Criteria
The data developed from this task were used to present operating data on system flow rate,
membrane flux, pressure drop across the filter module, frequency and duration of filter backwash
cycles, and information on the chemical CIP procedure at the end of the test.
The results of operating and performance data were tabulated and are included in Chapter 4. The
results include:
Average volume of flow treated, expressed as gpd;
Average filtrate water flow rate, expressed as gpm;
Average filtration rate, expressed as gallons per minute per square foot (gpm/ft2);
Flux as gfd, and specific flux as gallons per day per square foot per pounds per square
inch (gfd/psi);
33
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Chemical usage over the duration of the test;
Daily TMP across the module;
Typical backwash water production;
Typical suspended solids in the backwash; and
Effectiveness of the chemical in place cleaning procedure.
3.9.6 Task 4: Arsenic Removal
Introduction
Total arsenic removal was the primary objective of coagulation and microfiltration process being
evaluated in this verification. The effectiveness of the coagulation and filtration treatment
processes for total arsenic removal was evaluated in this task. Assessment of treatment efficacy
was made on the basis of total arsenic removal, by measuring total arsenic naturally present in
the raw water, the feed water (after coagulation with iron), and in the filtrate (treated) water.
Work Plan
Task 4 was performed simultaneously with the verification testing runs described in Task 1. The
treatment equipment was operated using the chemical treatment conditions and system operating
conditions established by Pall during the shakedown test.
Evaluation of total arsenic removal was performed by analyzing total arsenic in the raw, feed and
filtered waters. The total arsenic evaluation included monitoring total arsenic concentration on a
frequency of three times per week, as shown in Table 3-7, and during one intensive sampling
period over 58 hours. The intensive sampling period started on the 12th day of the verification
test. Samples were collected at the start (time zero), 1, 3, 6, 10, 24, 29, 34, 48, 53, and 58 hours
after time zero (11 sets of samples). The collection of total arsenic samples during this intensive
program provided verifiable total arsenic removal data.
Chlorine dose and residual chlorine were monitored throughout the verification. During the
intensive total arsenic test, residual chlorine was analyzed on every sample. The Pall process
includes a pre-oxidation step with chlorine to convert any arsenic (III) to arsenic (V) and also
oxidize iron species in the raw water. It has been demonstrated by many researchers that arsenic
(V) removal by coagulation and filtration is much more effective than arsenic (III) removal.
Thus, Pall has implemented the preferred approach and uses pre-oxidation to convert all arsenic
to arsenic (V) to attain the most effective results. Pre-oxidation used sodium hypochlorite as the
chlorine source and pre-oxidation operating conditions were documented.
Analytical Schedule
Turbidity in the feed water and filtered water was monitored using continuous flow turbidimeters
equipped with recording capability, so data were available on a 24-hour-per-day basis during
verification testing. Raw water, feed water and filtrate turbidity were also monitored once per
day using a bench-top turbidimeter. The bench-top results were used to verify the calibration of
the inline units.
34
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The regular daily and weekly sample analyses for total arsenic and other water quality
parameters are discussed in Section 3.9.4, Task 2. Total arsenic samples were collected three
times per week and one sample each week was speciated. The sampling schedule was
summarized in Table 3-7.
For the 58-hour intensive sampling period, samples were collected from the raw water (before
chemical addition), from the feed water (after chemicals addition and mixing), and from the
filtrate (the filter effluent). Total arsenic samples were collected at times, resulting in collection
of 11 sets of total arsenic samples in a 58-hour period. The total concentration of iron, used as
the coagulant to co-precipitate arsenic, was also determined in each raw water, feed water, and
filtered water sample.
The complete list of parameters that were monitored during the 58-hour intensive sampling
period is shown in Table 3-10.
35
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Table 3-10. Parameter List for Arsenic Intensive Sampling Program
Parameter
Sampling
Frequency
Test Streams Sampled
Total Arsenic
Arsenic Speciation
Temperature
PH
Alkalinity
Turbidity
Turbidity
Hardness(2)
Calcium
Magnesium
TOC
Iron
Manganese
Barium
Sulfate
Chloride
Fluoride
True color
Residual Chlorine
Dissolved Oxygen
Total Arsenic(3)
Total Iron(3)
pH(3)
All samples(1)
0, 10, 24, 48 hours
0, 10, 24, 48 hours
All samples
0, 24, 48 hours
Daily
For all arsenic samples
by continuous meter
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
All samples
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
All samples
0, 24, 48 hours
Once between 24-48 hrs
Once between 24-48 hrs
Once between 24-48 hrs
Once between 24-48 hrs
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Feed and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw, Feed, and Filtrate Water
Raw and Filtrate Water
Backwash water
Backwash water
Backwash water
Backwash water
All samples means time zero and 1, 3, 6, 10, 24, 29, 34.
(2) Hardness was calculated from calcium and magnesium
(3) Samples were collected during a backwash cycle.
48, 53, 58 hrs after time zero.
measurements.
36
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Evaluation Criteria
Performance evaluation was conducted in the context of the manufacturer's statement of
performance objectives with respect to total arsenic removal. The following information is
provided in Chapter 4:
Valence of the arsenic being treated by the process [i.e., arsenic (III) or arsenic (V)];
pH of coagulated water;
Turbidity levels associated with each sample for total arsenic;
Coagulant chemical used;
Coagulant dosage or concentration of iron coagulant; and
Concentration of chlorine added.
Since iron was used as the coagulant, the filtered water data were tabulated and the concentration
of iron in filtered water was compared to the secondary MCL of 0.3 mg/L.
The following data are also presented in the Chapter 4:
The total arsenic data plotted against sample time to show trends or variations
performance.
A graph plotting the turbidity, pH, and iron for the raw, feed and filtrate over the 58-
hours test period.
A table summarizing the raw, feed, and filtrate concentrations of hardness, manganese,
TOC, sulfate, chloride, and true color.
A table summarizing the residual chlorine data.
An appendix containing all data collected during the verification test.
3.9.7 Task 5: Data Management
Introduction
The data management system used in the verification testing plan included the use of computer
spreadsheets and manual recording of operational parameters for the microfiltration equipment
on a daily or weekly basis. DWTS field staff, their consultant, and DWS Center staff collected
the information and entered it into the appropriate spreadsheets and logbooks. All field activities
were documented. Field documentation included field logbooks, field data sheets, and chain of
custody forms. The procedures for logbook format and entries were as follows:
Field notes were kept in a bound logbook;
Field log sheets were used to record all water treatment equipment operating data;
Each page in bound log books were sequentially numbered;
Each data log sheet page was labeled with the date and time;
Completed pages were initialed and dated by the individual responsible for the entries;
and
Errors were noted by drawing a line through them.
37
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Original field sheets and chain of custody forms accompanied all samples delivered to the
analytical laboratory. Copies of field sheets and chain of custody forms for all samples are
included in Appendix F.
Experimental Objectives
The objectives of this task were to: 1) establish a viable structure for the recording and
transmission of field testing data such that the NSF provided sufficient and reliable data for
verification purposes, and 2) develop a statistical analysis of the data, as described in the
document: EPA/NSF ETV Protocol for Equipment Verification Testing for Arsenic Removal:
Requirements For All Studies and Chapter Three of the same document, and the PSTP.
Work Plan
DWTS site operators recorded on-site data and calculations (e.g., calculating calibration flow
rates using the bucket and stop watch and other similar routine calculations) by hand in field and
laboratory logbooks. Daily measurements were recorded on specially prepared data log sheets.
The original logbooks were stored on-site during the test; copies were delivered to the DWS
Center project coordinator at NSF at least once per week during the testing period. Operating
logs included a description of the equipment (description of test runs, names of visitors,
description of any problems or issues, etc.), in addition to experimental calculations and other
items.
A database for the project was setup in the form of custom-designed spreadsheets. The
spreadsheets were capable of storing and manipulating each monitored water quality and
operational parameter from each task, each sampling location, and each sampling time. All data
from the on-site laboratory logbooks and data log sheets were entered into the appropriate
spreadsheet. Following data entry, the spreadsheets were printed out and the printouts were
checked against the handwritten data sheet. All spreadsheets were then proof read by the DWS
Center staff to provide a 100% check of the data.
Samples collected and sent to the NSF Chemistry Laboratory were tracked by use of chain of
custody forms. Each sample had a location name, date, time of collection, and the parameters
written on the label. Data from the NSF Chemistry Laboratory were received and reviewed by
the NSF coordinator. These data were entered into the data spreadsheets, corrected, and verified
in the same manner as the field data. Copies of the spreadsheets are presented in Appendix G.
3.9.8 Task 6: Quality Assurance
QA/QC of the operation of the Microza System equipment and the measured water quality
parameters was maintained during verification testing by following the QAPP developed as part
of the PSTP. The QAPP included accuracy and precision objectives for the analytical work. The
need to meet representativeness and completeness criteria is also discussed in the QAPP.
Calibration requirements for field meters and for analytical equipment/methods are detailed in
the QAPP, Chapter 5 of the PSTP.
38
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On-site Equipment Checks
Equipment flow rates were documented and recorded on a daily basis. A routine daily walk
through during testing was established to verify that each piece of equipment or instrumentation
was operating properly. Inline monitoring equipment such as flow meters, etc. were checked to
confirm that the readout matches with the actual measurement.
The items listed below were performed in addition to any specified checks outlined in the
analytical methods.
Weekly QA/QC Verifications:
Inline flow meters (cleaned any fouling buildup as needed, and verified flow rate
volumetrically, bucket and stop watch or tank fill time);
Inline totalizer meter (cleaned any material buildup as needed and verified production
rate volumetrically, monitored volume recorded over time based on calibrated flow rate);
Tubing/piping (verified good condition of all tubing and connections, replace as
necessary); and,
Confirmed calibration of each metering pump by using a graduated cylinder to determine
the flow rate of each pump.
Daily QA/QC Verifications:
Turbidity calibration of the inline meters were verified daily by comparison with bench-
top turbidimeter results.
Sampling and Analytical Methods
The analytical methods utilized in this verification-testing plan for laboratory samples and for
on-site monitoring of water quality are shown in Table 3-8.
Sampling procedures are described in Section 3.9.4. All samples were grab samples taken at
designated sampling ports. The sampling valves were flushed for a minimum of five seconds
before a grab sample was collected.
The QAPP provided specific calibration procedures for the on-site analytical methods performed
on-site and also a summary of the laboratory calibration requirements based on the analytical
methods.
The NSF Chemistry Laboratory performed all water quality analyses using EPA or Standard
Methods procedures as shown in Table 3-8. All of the required calibration curves and quality
control procedures were documented in accordance with the published methods, and as described
in the QAPP in Section 5 of the PSTP.
39
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3.10 Operation and Maintenance
NSF obtained the O&M manual from Pall to evaluate the instructions and procedures for their
applicability during the verification test and for overall completeness. NSF reviewed the Pall
O&M manual. Results of the O&M manual review are reported in Chapter 4.
3.10.1 Maintenance
Some of the items that were evaluated during the verification test and review of the O&M
manual included:
Did the manufacturer provide readily understood information on the recommended or required
maintenance schedule for each piece of operating equipment, such as:
Pumps;
Valves;
Pressure gauges;
Flow meters;
Chemical feeders;
Mixers;
Motors;
Membrane cleaning; and
Continuous turbidimeters?
Did Pall Corporation provide readily understood information on the recommended or required
maintenance for non-mechanical or non-electrical equipment, such as:
Tanks;
Piping; and
Filter vessels?
3.10.2 Operation
Among the operating aspects that were evaluated are:
Pre-oxidant generation/feed:
Measurement of pre-oxidant concentration generated; and
Measurement of pre-oxidant concentration fed into treatment equipment.
Chemical feeder pumps:
Calibration check;
Settings and adjustments - how they should be made; and
Dilution of chemicals - proper procedures.
40
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Microfiltration:
Control of filtration flow and rate;
Observation and measurement of pressure drop across the membrane during filter run;
and
Feed flow control in response to temperature changes.
Membrane backwashing:
Programming automated frequency;
Proper backwash venting and disposal;
Appropriate backwash rate; and
Monitoring during return of filter to service.
Chemical cleaning:
Selection of proper chemical washing sequence;
Proper procedures for dilution of chemicals;
Monitoring of pH through chemical cleaning cycle;
Rinsing of membrane system following chemical clean; and
Return of filter to service.
Monitoring and observing operation:
Observation of floe;
Filtered and feedwater water turbidity;
Filter pressure differential;
Measuring the iron coagulant dose; and
Measuring and controlling pH of coagulated water.
The ETV Protocol recommends that a manufacturer should provide a troubleshooting guide, a
simple checklist of what to do for a variety of problems, in the O&M manual including:
No raw water (feed water) flow to plant;
Cannot control rate of flow of water through equipment;
No chemical feed;
Loss of pre-oxidant feed;
Calibration and maintenance of inline pH monitoring instruments, problems of erratic pH
or drifting pH readings;
Mixer will not operate (will not rotate);
Filter cannot be backwashed or backwash rate of flow cannot change;
No reading on turbidimeter;
Automatic operation (if provided) not functioning;
Filtered water turbidity too high;
Filter head loss builds up excessively rapid;
41
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Valve stuck or will not operate;
Low feed pump pressure;
Reduced filtrate flux;
Pump cavitation; and
No electric power.
The O&M manual was reviewed for the detail and information provided on these and other
operating conditions observed during the verification test.
3.10.3 Operability Evaluation
The following were the basis of the review and evaluation for operability aspects of the
equipment.
During verification testing attention was given to equipment operability aspects. The following
are some of the factors considered:
Fluctuation of chemical feed rate from desired value - the time interval at which re-
setting is needed (i.e., how long can feed pumps hold on a set value for the feed rate?).
Ability to maintain desired pre-oxidant feed rate.
Presence of devices to aid the operator with chemical dosage selection:
influent and filtered water continuous turbidimeters provided?
inline pH meter provided?
Can automatic backwash be initiated by reaching a set value for head loss?
Does plant have multiple feed points for chemicals:
- for pH adjustment?
- for coagulant chemical feed?
for oxidants?
Is membrane pressure differential measurement provided?
Is rate of flow of raw water measured?
Is chemical feed paced with raw water flow?
Can coagulation pH be maintained automatically if raw water flow changes?
Is backwash rate of flow measured and variable?
Is backwash duration (time) variable?
Other factors and questions included:
Does the equipment have sensors or monitoring equipment that can detect an equipment
malfunction, unsatisfactory filtrate water quality, or operating conditions that exceed
allowable limits? If so, can the equipment be automatically shut down?
Upon automatic shutdown, can a means of operator notification be provided, if the
operator is not present on the site where the equipment is located?
42
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Chapter 4
Results and Discussion
4.1 Introduction
The verification test program for the Microza System was conducted from June 22 through
October 13, 2004. The equipment was installed the week of June 22 and Pall conducted startup
and shakedown testing through July 1, 2004. Raw water characterization tests and an arsenic
loss test were performed in August 2004. The 30-day verification test, including a 58-hour
intensive arsenic sampling period, was performed from September 9 through October 8, 2004.
The membranes were chemically cleaned in place at the beginning and end of the 30-day
verification test. The verification test site was located at the OCDC Plum Creek Development in
Oakland Township, Oakland County, Michigan, which has two production wells supplying a
residential neighborhood. The test site was described in Section 1.3. The Microza System was
described in detail in Chapter 2 of this report.
Chapter 4 presents a summary of the water quality and operating data collected during the
verification test. Activities and data collected during the startup and shakedown of the
equipment, raw water characterization, and the arsenic loss test are presented to describe
activities performed prior to the actual 30-day verification test. The results for the 30-day
verification test are presented including data on raw water, feed water, and treated water arsenic
concentrations and for other water quality parameters. Operating data are presented to describe
the flow rates, volume of treated water produced, backwash volumes and frequency, pressure
differential across the membranes and related operating information. Information describing the
chemical CIP procedure performed at the beginning and end of the test is also presented. QA/QC
information as described by the QAPP in the PSTP for this verification test is presented at the
end of the chapter.
4.2 Equipment Installation, Startup, and Shakedown
Pall personnel installed the equipment at the Plum Creek site with assistance from OCDC staff
the week of June 21, 2004. The unit was shipped as a complete skid mounted unit with all
components in one package except for the air compressor needed for the air scrub backwash.
Piping was installed to route raw water from the pressure supply tank inside the building to the
Microza System, which was placed outside the building. The raw water line included inline
locations to inject sodium hypochlorite (source of chlorine), ferric chloride (coagulant), and
sulfuric acid (pH adjustment) using chemical metering pumps supplied by Pall. The raw water
piping also included a water meter to provide both raw water flow rate and total volume. The air
compressor was housed next to the membrane system and also outside the OCDC building. The
compressor was initially in the open, but after noise complaints from nearby homes, a temporary
wooden structure was erected around the compressor to suppress the noise. The system
installation was completed in a two to three day period.
Pall has developed a startup and shakedown procedure, which includes an integrity test for the
unit and a series of operating tests to optimize chemical feeds and flow rates for the system.
These procedures were included as appendices to the PSTP and are also included in Appendix D.
43
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The integrity test was conducted at the end of the equipment installation. This test is an air
pressure test where the unit is subjected to air pressure of 20 to 30 psi and then the pressure
decay is monitored. A pressure decay rate less than 0.2 psi/min demonstrates that the membranes
do not have significant flaws and that the system piping connections are leak free. The unit was
tested by Pall on June 24, 2004 and found to meet the specifications on the first test.
Over a two-day period from June 30 through July 1, 2004, Pall ran a series of tests that included
operating at varying doses of ferric chloride and residual chlorine (in the feed water to the unit),
and at different pH levels in the feed water. The inline analyzers for pH and turbidity were used
to monitor the system, along with a field test kit to check the iron concentration in the feed and
treated water. Samples of raw water, feedwater (after chemical addition), and filtrate water were
collected for laboratory analysis for iron, arsenic, and turbidity. The data obtained by Pall was
summarized and shown in Appendix D. This shakedown period data are provided for
informational purposes only and were not verified. The shakedown tests required only two days
because of the rapid response of this type of technology to changes in operating conditions.
Thirteen sets of test run combinations were completed in this two-day period. Based on the data,
Pall set the basic operating conditions that were used for the verification test.
Results of the shakedown tests showed that arsenic could be removed using the naturally
occurring iron in the raw water (approximately 1.0 mg/L), a residual chlorine dose concentration
of 1.0 mg/L, and without pH adjustment. However, there was still a detectable level of arsenic in
the filtrate at 2-3 |ig/L. The addition of ferric chloride at 3-5 mg/L (1.0-1.7 mg/L as Fe) and
lowering the pH to 6.8 resulted in a non-detectable (<2 |ig/L) level of arsenic in the filtrate. The
data also suggested that lower dosages of ferric chloride could achieve similar results, Pall
determined that the best operating condition for this water was to use 3 mg/L of ferric chloride,
1.0 mg/L residual chlorine, and a pH of 6.8 (range of 6.6 - 7.0). These were the target chemical
concentrations used for the 30-day verification test.
The Microza System was operated from July 2 until August 23, 2003, when the unit was
chemically cleaned prior to the arsenic loss test. During this time, Pall monitored the system
from their office using the PLC and phone line connection. The OCDC staff checked on the unit
on a regular basis and filled the chemical feed tanks as needed. Operator attention required
during this time was minimal (<15 minutes/day). Pall monitored the flow rate and TMP change
during this seven-week period to confirm the final operating conditions for the verification test.
The flow rate was steady at 6.3 gpm and the TMP increased from approximately 8.8 psi to 12.5
psi. Based on these results, Pall confirmed the final operating conditions for the 30-day
verification test. Flow rate was targeted to be 6.3 gpm (120 gfd), with the backwash set to occur
every 30 minutes for 90 seconds (60 second air scrub, 30 second forward flush).
4.3 Raw Water Characterization
Historical water quality data for the combined water from the two production wells at the Plum
Creek Development site were obtained from the OCDC in the initial planning stage for this
verification test. As shown in Table 1-1, the total arsenic concentrations was in the range of 9 to
14 |ig/L and total iron ranged from 0.9 to 1.0 mg/L. An additional set of water quality samples
were collected on August 19, 2004 and included samples for the individual wells and the
44
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combined well water, which was the raw water source for this verification test. The chemical
analyses included total arsenic and arsenic speciation [arsenic (III) and (V)] and other water
quality parameters.
The results of the initial raw water characterization test are presented in Table 4-1. These data
confirm that the raw water quality is similar to the historical water quality that was used to plan
the verification test with the exception that turbidity data were higher in the combined well
sample from the pressure tank. Dissolved oxygen present in the water from the tank, most likely
oxidized the some of the naturally occurring iron, causing the iron to form a precipitate and
increase the turbidity. Most of the arsenic is present as arsenic (III). The water quality of the
individual wells is similar as was expected.
Table 4-1. Raw Water Characterization Data - August 19, 2004
Combined
Parameter Units Well #1 Well #2 Wells
pH
Temperature
Turbidity
Free Chlorine
Total Chlorine
Dissolved Oxygen
Apparent Color
Alkalinity
Total Arsenic
Dissolved Arsenic
Arsenic (III)
Arsenic (V)
Iron
Manganese
Barium
Chloride
Sulfate
TOC
Fluoride
Calcium
Magnesium
Hardness
S.U.
ฐC
NTU
mg/L
mg/L
mg/L
C.U.
mg/L as CaCOs
Hg/L
Hg/L
Hg/L
Hg/L
mg/L
Hg/L
Hg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L as CaCOs
7.17
11.5
0.20
<0.05
<0.05
1.74
<5
240
10
10
8
2
0.94
20
160
16
14
0.6
0.5
72
24
280
7.17
10.5
0.20
0.05
<0.05
1.63
<5
240
10
9
7
2
0.95
22
150
15
14
0.6
0.5
72
24
280
7.18
11.0
5.5
<0.05
<0.05
7.05
<5
240
9
8
7
<2
1.0
19
150
16
14
0.7
0.6
74
25
290
4.4 Arsenic Loss Test
The arsenic loss test, a test to determine if arsenic is removed and retained by the system without
chemical addition, was performed over a 24-hour period beginning on August 24, 2004. The
Microza System had been operating since late June 2004, and the arsenic loss test requires that
the system be clean prior to starting the test. Therefore, the system was cleaned using the
45
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chemical CIP procedure. The IMP had increased from the typical clean system startup IMP of 8
to 9 psi at 6.3 gpm to over 12.0 psi during this pretest, operating period.
The Pall CIP is a cleaning procedure that uses warm water in the range of 90-104ฐF. Sodium
hydroxide is added to the water to produce a concentration of 1.0% NaOH and sodium
hypochlorite is added to produce a concentration of 1,000 mg/L total residual chlorine. The water
is recirculated through the system for about two hours. After a rinse step to remove the caustic
and bleach solution, an acid cleaning is performed with a 2% citric acid solution for one to two
hours. A final rinse step is performed and the unit TMP checked to determine that the cleaning
was effective. The standard operating procedure for the Pall CIP is in Appendix B. Pall
personnel performed this procedure on August 23, 2004. The TMP after cleaning was 8.9 psi,
similar to clean startup condition.
The operating data and results from the 24-hour arsenic loss test are shown in Table 4-2. This
test was run with no chemical addition to the system. It should be noted that the raw water
contained naturally occurring iron at a concentration of approximately 1 mg/L. The flow rate
was steady during the test run at 6.3 gpm. The total volume processed during the 24-hour period
was 8,619 gallons, giving a flux of 118 gfd. The TMP only increased from 8.3 psi to 8.8 psi.
Table 4-2. Operating Data Arsenic Loss Test
Date
8/24/2004
8/25/2004
Time
9:25
14:57
21:00
3:00
8:44
Feed
Pressure
psi
13.9
15.7
15.8
16.0
17.0
Filtrate
Pressure
psi
4.9
6.5
6.4
6.5
7.1
TMP
psi
8.3
8.4
8.6
8.7
8.8
Flow
Rate
gpm
6.3
6.3
6.3
6.3
6.3
Total
Volume
Treated
gal
225
372
4149
6123
8619
Total
Backwash
Volume
gal
0
23.5
51.4
65.3
110.1
Tables 4-3 and 4-4 show the water quality for the arsenic loss test. There was no significant loss
of arsenic through the system over the 24-hour test with feed water total arsenic averaging 11
Hg/L and the filtrate averaged 9 |ig/L. Arsenic (III) is the predominant arsenic species in the raw
water and only a slight oxidation of the arsenic was observed as the water came in contact with
oxygen and passed through the system. Turbidity, iron, and color were removed by filtration
system as expected. All other water quality indicators remained steady and passed through the
membranes.
46
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Table 4-3. Arsenic Loss Test Water Quality Results
Parameter
PH
Temperature
Bench-top
Turbidity(1)
Alkalinity
Free Residual
Chlorine
Residual
Chlorine
Dissolved
Oxygen
Calcium
Magnesium
Hardness
Total Arsenic
Dissolved
Arsenic
Arsenic (III)
Arsenic (V)
Iron
Units
S.U.
ฐc
NTU
mg/L as
CaCO3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L as
CaCOs
Hg/L
Hg/L
Hg/L
Hg/L
mg/L
Raw
8/24/2004
14:57 21:00
6.90
12.4
9.8
250
<0.05
<0.05
3.3
70
24
260
11
9
9
<2
1.0
7.31
12.6
5.8
260
<0.05
<0.05
4.8
69
24
260
11
NA
NA
NA
0.97
Water
8/25/2004
3:00 8:44
7.18
12.3
7.4
240
<0.05
<0.05
5.4
70
24
260
11
NA
NA
NA
1.0
7.30
11.7
3.5
250
<0.05
<0.05
5.3
70
24
260
10
11
8
<2
0.96
Feed
8/24/2004
14:57 21:00
6.89 7.20
13.6 13.3
9.1 5.0
250 250
<0.05 0.05
<0.05 <0.05
NA NA
69 72
24 24
260 260
11 10
9 NA
7 NA
2 NA
0.95 0.97
Water
8/25/2004
3:00 8:44
7.08
11.4
7.8
250
0.07
<0.05
NA
69
24
260
11
NA
NA
NA
1.0
7.15
12.1
5.2
250
<0.05
<0.05
NA
70
25
260
10
11
8
O
0.93
Filtrate
8/24/2004
14:57 21:00
6.93 7.20
15.6 13.8
0.55 0.25
250 250
<0.05 0.05
<0.05 <0.05
3.3 4.2
70 69
24 25
260 260
9 9
10 NA
7 NA
3 NA
0.38 0.47
8/25/2004
3:00 8:44
7.05
12.0
0.40
250
<0.05
<0.05
4.1
72
24
260
8
NA
NA
NA
0.31
7.12
12.6
0.35
250
0.05
0.05
4.4
69
24
260
10
10
7
O
0.55
Turbidity monitored at start of test (9:25 AM) - Raw water 3.9 NTU; Feed Water 3.7 NTU; Filtrate 0.20 NTU.
NA = Not analyzed.
47
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Table 4-4. Arsenic Loss Test Daily Water Quality Results
August 25, 2004
9:00 AM
Parameter Units Raw Water Feed Water Filtrate
Manganese
Barium
Chloride
Sulfate
Fluoride
TOC
True Color
Hg/L
Hg/L
mg/L
mg/L
mg/L
mg/L
C.U.
19
150
15
13
0.5
0.6
30
20
150
15
13
0.6
0.9
20
22
150
15
13
0.6
0.6
<5
During the arsenic loss test of August 24 and 25, color in the raw water was higher than in the
feed water (note that color was measured directly and samples were not filtered because the raw
water was groundwater). Color in water typically occurs when organic matter degrades forming
dissolved organic carbon. The TOC results did not decline throughout the arsenic loss test
whereas the color was reduced after the filtration. There is some amount of carbon in the water
that is not removed and may not have affected the color of the water. The fact that the wells
drew from 97 to 99 feet below grade and are not under the influence of surface water suggests
that the difference in color originates from colloidal formation of iron and manganese (US EPA.
July 1976. Quality Criteria For Water). Table 4-4 shows that the manganese levels were similar
in the raw, feed and filtrate indicating that the manganese was in the dissolved and not colloidal
form, otherwise the membrane filter would have removed the colloidal manganese. However,
iron may have been in a colloidal form as indicated by the lower concentrations of iron in the
filtrate (see Table 4-3). Only total, and not dissolved iron, was measured in the raw and feed
water (Table 4-3) which does not allow confirmation of whether the differences seen in color
were due to colloidal iron.
4.5 Verification Test
4.5.1 Operating Results
The Microza System was cleaned using the Pall CIP procedure on September 7, 2004 just before
the start of the 30-day verification test. The test began on September 9 and ended on October 8,
2004. During this period, the Microza System operated continuously 24-hours per day, seven
days per week, except for a 10.5-hour period during a power outage. Basic operating parameters
were monitored on a daily basis by the DWTS field team in accordance with the PSTP.
The Microza System was set to the operating criteria established by Pall during the shakedown
testing. Chemical feeds were established to feed 1.0 mg/L of total chlorine in order to maintain
total residual chlorine in the feed water of approximately 0.5 to 1.0 mg/L. The ferric chloride
feed rate was set to deliver 3 mg/L of ferric chloride to raw water. The sulfuric acid feed system
48
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was set to maintain a pH of 6.8 in the feed water. Based on the previous operating data, the flow
rate for filtrate was set at 6.3 gpm to give a targeted flux rate of 120 gfd. The backwash system
was set to backwash the membranes every 30 minutes. The backwash included a one minute air
scrub period, followed by a 30 second forward flush period.
Table 4-5 shows the daily operating data for the verification test. The filtrate flow rate remained
steady throughout the test at an average of 6.3 gpm. The total filtrate volume produced each day
was also consistent, except for September 28, 2004. The system shut down at 23:45 on
September 27 and remained off until 10:30 on September 28 when the operator reset the system.
The cause of the shut down is uncertain, but it appears there was a temporary power outage at the
site.
49
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Table 4-5. Verification Test Operating Data
Total
Date
9/9/2004
9/10/2004
9/11/2004
9/12/2004
9/13/2004
9/14/2004
9/15/2004
9/16/2004
9/17/2004
9/18/2004
9/19/2004
9/20/2004
9/21/2004
9/22/2004
9/23/2004
9/24/2004
9/25/2004
9/26/2004
9/27/2004
9/28/2004
9/29/2004
9/30/2004
10/1/2004
10/2/2004
10/3/2004
10/4/2004
10/5/2004
10/6/2004
10/7/2004
10/8/2004
Number of
Samples
Average
Minimum
Maximum
Std. Dev.
95% Conf. Int.
Feed Flow
Rate
gpm
6.3
6.2
6.2
6.2
6.3
6.3
6.2
6.2
6.3
6.3
6.3
6.3
6.3
6.2
6.3
6.2
6.2
6.3
6.2
6.3
6.2
6.2
6.3
6.3
6.3
6.3
6.3
6.2
6.2
6.3
30
6.3
6.2
6.3
0.05
(6.3, 6.2)
Filtrate
Flow Rate
gpm
6.3
6.3
6.2
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
30
6.3
6.2
6.3
0.02
(6.3,6.3)
Filtrate
Volume
gal
8142
7993
8141
8156
8061
8160
8156
8143
8135
8135
8133
8015
8135
8132
8121
8135
8130
8134
7978
4738
8119
8128
8128
8133
8133
7967
8130
8125
8127
3647
30
7850(2)
3647
8160
1006
(7475, 8226)
Feed
Pressure
psi
11.0
16.8
17.2
17.5
18.0
21.3
20.5
21.2
20.9
21.2
21.5
21.8
22.0
22.4
22.5
22.5
22.8
23.2
23.1
23.0
23.1
23.3
23.7
23.7
24.1
23.4
25.2
25.1
24.8
25.0
N/A
N/A
N/A
N/A
N/A
N/A
Filtrate
Pressure
psi
4.8
6.6
6.7
7.0
6.5
9.4
8.1
8.1
8.2
8.1
8.1
8.0
8.2
8.1
8.1
8.2
8.2
8.3
8.2
8.4
8.4
8.5
8.3
8.4
8.4
8.3
8.7
8.7
8.7
8.7
N/A
N/A
N/A
N/A
N/A
N/A
Concentrate
Pressure(1)
psi
14.8
14.9
15.6
15.9
16.2
19.5
18.9
19.2
19.2
19.6
19.9
20.2
20.4
20.8
21.0
20.7
21.2
21.5
21.3
21.4
21.6
21.8
22.0
22.0
22.3
22.3
23.5
23.5
23.0
23.4
N/A
N/A
N/A
N/A
N/A
N/A
Operating
Hours
hours
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
24
23.75
13.5
24
24
24
24
24
24
24
24
24
10.5
30
23.6
13.5
24
N/A
N/A
N/A - Not Applicable.
(1) System operated with no concentrate flow. Water was processed through the membranes and there was no
recycle stream. The concentrate pressure was measured on the closed concentrate line to allow for the
calculation of TMP.
(2) If the average volume of filtrate produced is calculated for all days except September 28 and October 8, then the
average is 8110 gpd.
50
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It should be noted that the flow rate readings (gpm) in Table 4-5 are once per day instantaneous
readings from the flowmeters. The filtrate volume data are the actual volume of filtrate produced
for each twenty-hour period (no filtrate produced during the total of four minutes of backwashing
per hour). The average volume of filtrate produced for all days except September 28 and October
8 is 8110 gpd. Accounting for the backwash cycle of four minutes each hour, the average flow
rate is calculated to be 6.03 gpm. This rate is within 4% of the instantaneous rate recorded of 6.3
gpm. The volumetric data are within 1% of the flow rate based on the calibration data shown in
Table 4-17 in Section 4.7 (QA/QC), which shows the flow rate averaged 6.05 gpm. All hydraulic
calculations are performed based on the daily volume of filtrate produced, as the daily volume
data account for fluctuations in flow over the 24 hour period whereas the flow rate measurements
represent one time each day.
The pressure on the system was monitored at three locations, feed water (inlet to the
membranes), filtrate (exit of the membranes), and on the concentrate side of the membrane unit.
It should be noted that this system operated with no concentrate flow, all water was processed
through the membranes and there was no recycle stream. The concentrate pressure was measured
on the closed concentrate line to allow for the calculation of TMP. The pressure on the feed
water line slowly, steadily increased over the 30-day period, while the filtrate pressure remained
steady, as expected. The TMP steadily increased indicating the membranes were accumulating
materials in the pores that were not removed by the backwash. Figure 4-1 shows a graph of TMP
for the 30-day period and Table 4-6 shows the daily, calculated TMP. Pall recommends that the
Microza System be cleaned using the CIP procedure when TMP exceeds 35 psi (filter maximum
TMP specification is 43.5 psi). After 30 days of operation, the TMP was 15.5 psi, indicating that
cleaning was not yet required. However, in accordance with PSTP, the membranes were
chemically cleaned at the end of the test, as described later in Section 4.5.4.
The hydraulic flow conditions for membrane systems, such as the Microza System, are typically
described by calculating the flux, the temperature corrected flux, and the specific flux. All of
these measures of flow are based on daily volume produced as function of membrane surface
area. The equations used for the calculation of these hydraulic characteristics were presented in
Section 3.3.2. Table 4-6 shows the daily flux, temperature corrected flux (corrected to 20ฐC),
and specific flux at 20ฐC. The daily volumes are based on the volume data collected by the PLC,
which was for the period midnight to midnight of each operating day. Since flux values are
reported on a per day basis, the volumes used in the calculations for September 27, 28, and
October 8 were normalized to a 24-hour period by calculating the volume that would have been
produced in a full 24-hour period. The data were also adjusted for the approximately four
minutes in each hour when the unit was in backwash mode and not producing filtrate.
The flux remained constant throughout the test as would be expected given the steady total
volumes of filtrate produced. The specific flux decreased as the TMP increased. While the
increase in TMP may not follow a liner relationship as the pressure increases, the steady rise in
TMP can be used to project when the TMP would reach 35 psi. It is projected that the TMP
would approach 35 psi at between 90 and 120 days. Thus, it could be expected that the
membranes would require chemical cleaning in this site application about once every 12 to 17
weeks.
51
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18.0
20.0
V)
Q.
Date
IMP
Specfic Flux
Figure 4-1. Transmembrane Pressure and Specific Flux at 20ฐC
52
-------
Table 4-6. Flux,
Date
9/9/2004
9/10/2004
9/11/2004
9/12/2004
9/13/2004
9/14/2004
9/15/2004
9/16/2004
9/17/2004
9/18/2004
9/19/2004
9/20/2004
9/21/2004
9/22/2004
9/23/2004
9/24/2004
9/25/2004
9/26/2004
9/27/2004
9/28/2004
9/29/2004
9/30/2004
10/1/2004
10/2/2004
10/3/2004
10/4/2004
10/5/2004
10/6/2004
10/7/2004
10/8/2004
Number of Samples
Average
Minimum
Maximum
Std. Dev.
95% Conf. Int.
TMP, and
Flux
(gfd)
114.0
111.9
114.0
114.2
112.9
114.2
114.2
114.0
113.9
113.9
113.9
112.2
113.9
113.8
113.7
113.9
113.8
113.9
111.7
113.7
113.7
113.8
113.8
113.9
113.9
111.5
mo
.8
mo
.8
113.8
116.7
30
113.7
111.5
116.7
0.9
Specific Flux Data
Feed
Temperature
(ฐC)
11.7
11.1
11.5
10.5
11.2
11.0
10.7
11.5
10.4
10.4
10.2
10.3
10.6
10.9
10.7
10.4
10.4
10.6
10.1
10.4
10.4
10.3
10.5
9.9
9.9
9.4
9.7
10.7
10.2
10.3
30
10.5
9.4
11.7
0.52
(113.3,114.0) (10.3,10.7)
Temp
Corrected
Flux(1)
(gfd)
139.0
138.4
139.6
143.3
139.3
141.7
142.6
139.7
143.3
143.3
143.9
141.5
142.6
141.5
142.0
143.3
143.2
142.6
141.5
143.0
143.0
143.5
142.8
144.9
144.9
143.7
145.6
142.1
143.8
147.2
30
142.6
138.4
147.2
2.0
(141.8, 143.3)
TMP
(psi)
8.1
9.3
9.7
9.7
10.6
11.0
11.6
12.1
11.9
12.3
12.6
13.0
13.0
13.5
13.7
13.4
13.8
14.1
14.0
13.8
14.0
14.1
14.6
14.5
14.8
14.6
15.7
15.6
15.2
15.5
30
13.0
8.1
15.7
2.0
N/A
Specific Flux(1)
(gfd/psi)
17.2
14.9
14.5
14.7
13.1
12.9
12.3
11.5
12.1
11.6
11.4
10.9
11.0
10.5
10.4
10.7
10.4
10.1
10.1
10.4
10.2
10.2
9.8
10.0
9.8
9.9
9.3
9.1
9.5
9.5
30
11.3
9.1
17.2
1.9
N/A
(1) Temperature corrected flux and specific flux at 20ฐC.
N/A - Not applicable
53
-------
4.5.2 Verification Test Arsenic Results
The determination of arsenic removal using the Microza System was the primary objective of the
verification test. This section presents the results for the raw, feed, and filtrate water from
analysis of arsenic samples performed three times per week. Also included are the results from
the 58-hour intensive sampling period, when samples for arsenic analysis were collected on a
more frequent basis. Arsenic speciation data are also included with the data presented in Table 4-
7. Figure 4-2 shows the arsenic results plotted for the entire 30-day test.
The Microza System removed total arsenic to less than the detection limit (2 |ig/L) for all filtrate
samples collected during the 30-day verification test. The total arsenic in the raw water and feed
water averaged 11 |ig/L and 13 |ig/L, respectively, during the test with little variation. The
arsenic speciation data for the raw water showed that all of the arsenic was present as arsenic
(III), with no detectable concentrations of arsenic (V) in any sample collected.
With pH adjustment to 6.6 to 7.0, the chemical addition of sodium hypochlorite (target feed of 1
mg/L) and ferric chloride (target feed of 3 mg/L in addition to the naturally occurring iron, which
average 0.95 mg/L) was effective in precipitating and coagulating the arsenic in the raw water.
As shown in Table 4-7, most of the arsenic present in the raw water was in the soluble form, as
arsenic (III). The feed water data show that after chemical oxidation and coagulation, all of the
arsenic was present in the paniculate form and there were no detectable levels of soluble arsenic
in the feed water. The effectiveness of this oxidation and coagulation process was key to the
results obtained by the Microza System. With all or most of the arsenic in the particulate form
after chemical treatment, and the membrane filtration system removing the particulate, the result
was a filtrate with no detectable arsenic in any sample.
The data collected during the intensive 58-hour sampling period were consistent with the data
collected during the regular three times per week sampling program. There was no indication of
any transient or short time changes in the arsenic concentration or in any other monitored
parameter. The frequent short duration backwashes provided a stable membrane condition. TMP
increased over the 30-day period, as discussed in Section 4.5.1, but chemical cleaning was not
needed during the 30-day test period. The Microza System produced consistent results
throughout the verification test.
54
-------
Table 4-7. Arsenic Results
Raw
Total
Arsenic
Date (ng/L)
9/9/04
9/13/04
9/15/04
9/17/04
9/20/04 Hour 0
Hourl
Hour3
Hour 6
Hour 10
9/21/04 Hour 24
Hour 29
Hour 34
9/22/04 Hour 48
Hour 53
Hour 58
9/24/04
9/27/04
9/29/04
10/1/04
10/4/04
10/5/04
10/6/04
10/8/04
Number of Samples
Average
Minimum
Maximum
Std. Dev.
95% Conf. Int.
10
12
12
12
12
11
12
11
11
10
9
10
10
10
10
10
11
12
12
12
12
12
12
23
11
9
12
1.0
(11,12)
Soluble
Arsenic
(ng/L)
10
10
11
10
10
11
11
12
8
11
10
12
0.74
(10,11)
As (III)
(ng/L)
10
9
10
8
8
9
13
9
8
10
8
13
1.6
(8,11)
As(V)
(calculated)
(ng/L)
<2
<2
...
<2
...
...
...
2
2
...
2
...
<2
...
3
...
8
<2
<2
3
N/C
N/C
Feed
Total
Arsenic
(ng/L)
11
12
12
13
12
16
12
15
16
10
12
12
10
10
11
10
13
16
12
12
14
16
13
23
13
10
16
2.0
(12, 13)
Soluble
Arsenic
(ng/L)
<2
<2
<2
<2
<2
<2
<2
<2
8
<2
<2
<2
N/C
N/C
As (III)
(ng/L)
<2
<2
<2
<2
<2
<2
<2
<2
8
<2
<2
<2
N/C
N/C
As(V)
(calculated)
(ng/L)
<2
<2
<2
<2
<2
<2
<2
<2
8
<2
<2
<2
N/C
N/C
Filtrate
Total
Arsenic
(ng/L)
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
<2
23
<2
<2
<2
N/C
N/C
Soluble
Arsenic As (III)
(ng/L) (ng/L)
<2 <2
<2 <2
<2 <2
<2 <2
<2 <2
<2 <2
<2 <2
<2 <2
8 8
<2 <2
<2 <2
<2 <2
N/C N/C
N/C N/C
As(V)
(calculated)
(ng/L)
<2
<2
<2
<2
<2
<2
<2
<2
8
<2
<2
<2
N/C
N/C
N/C - Not calculated
55
-------
I
Ol
o
o
o
o
18 -,
16 -
14
12 -
10 -
8 -
6 -
4
2 -
0
Arsenic Intensive Test
September 20-22
lf
h*
All filtrate arsenic results = < 2 ug/L
-AAA-
-AAA-
Date
Total Arsenic-Raw -
(ug/L)
Total Arsenic-Feed
(ug/L)
- Total Arsenic-Filtrate
(ug/L)
Figure 4-2. Verification Test Arsenic Results
56
-------
4.5.3 Raw, Feed, and Filtrate Water Quality Results
Water quality data were collected on a daily basis for pH, temperature, turbidity, and chlorine
(total and free residual). Samples for iron and alkalinity analyses were collected three times per
week. These parameters are key water quality indicators and important to this technology, which
used chlorine oxidation, iron coagulation, and pH adjustment as part of the technology process.
Dissolved oxygen was monitored daily in the raw water because it can impact the oxidation of
iron and arsenic (III). Other water quality parameters were also monitored on a weekly basis,
including calcium, magnesium, total hardness, manganese, barium, sulfate, chloride, fluoride,
TOC, and true color. All of the laboratory and field data reports are included in Appendices E
and F.
Figure 4-3 shows the pH for the raw, feed, and filtrate water. The raw water pH was steady in the
range of 7.0 to 7.4 for most of the test period. Sulfuric acid was added in small quantities to
adjust the pH in the feed water in the range of 6.6 to 7.0. The pH in the feed water was controlled
on most days within the target range. On October 3, 2004, the manually collected filtrate water
pH was reported as 7.42, which is out of the normal range. There is no indication of any changes
in the system on or near this date, so it is believed that this datum point is an outlier. The feed pH
was in the normal range on that day and the inline pH meter was reading pH 6.75.
57
-------
7.6 -,
7.4 -
7.2 -
7 -
3
w. 6.8 -
6.6 -
6.4 -
6.2 -
<~ <~ <~ <~ c ^ v5 v5 ^ ^ ^ ^ ^
Date
Raw ^^^^Feed 'Filtrate
Figure 4-3. Verification Test pH Results
58
-------
Figure 4-4 shows the turbidity for the raw, feed, and filtrate water. The raw water turbidity
averaged 4.9 NTU and was higher than the historical data indicated. Dissolved oxygen
concentrations in the raw water ranged from 6.5 to 9.3 mg/L. It is likely that the elevated
dissolved oxygen levels caused the naturally occurring iron to oxidize and precipitate, thus
increasing turbidity in the raw water. Feed water turbidity only increased slightly after the
addition of the oxidation and coagulation chemicals. The filtrate turbidity was low, averaging
0.25 NTU based on the bench-top turbidimeter. In addition to the bench-top turbidity meter used
by the field personnel, the Microza System had inline turbidity meters on the raw and filtrate
water lines. The filtrate meter was a Hach laser unit that could measure turbidity at a lower level
than the bench-top meter. This inline turbidimeter showed the filtrate averaged 0.021 NTU.
Table 4-8 shows the daily turbidity levels. Based on the bench-top meter measurements, the
filtrate was below 0.5 NTU in 93% of samples, had no values between 0.5 and 1 NTU, and 7%
of the readings were between 1 and 2 NTU. There were no turbidity levels above 2 NTU. The
inline turbidimeter indicated the filtrate water never exceeded 0.10 NTU.
59
-------
ฃ
3
Q.
O
12
10 -
6
4-
2
"A
V.
;\
/
\
\
i.-V
:! \
- -. ^ /
'/ \v'' ^- A
1 ^^ ป *
Date
--- Raw
'Feed
Filtrate
Figure 4-4. Verification Test Bench-top Turbidity Results
60
-------
Table 4-8. Turbidity Results (NTU)
Date
9/09/2004
9/10/2004
9/1 1/2004
9/12/2004
9/13/2004
9/14/2004
9/15/2004
9/16/2004
9/17/2004
9/18/2004
9/19/2004
9/20/2004
9/21/2004
9/22/2004
9/23/2004
9/24/2004
9/25/2004
9/26/2004
9/27/2004
9/28/2004
9/29/2004
9/30/2004
10/1/2004
10/2/2004
10/3/2004
10/4/2004
10/5/2004
10/6/2004
10/7/2004
10/8/2004
Number of Samples
Average
Minimum
Maximum
Std. Dev.
95% Conf. Int.
Raw
5.46
6.59
4.78
6.54
3.26
3.54
8.41
3.53
4.34
4.13
3.86
3.43
5.87
4.79
5.57
6.38
4.15
3.60
4.33
4.64
3.63
5.36
6.92
6.19
3.73
4.15
5.02
4.47
5.78
4.89
30
4.9 (2)
3.3
8.4
1.3
(4.4, 5.4)
Feed
6.87
6.67
5.67
2.62
3.31
4.31
4.64
4.87
4.47
4.50
4.65
3.70
6.67
5.62
6.96
4.53
2.99
5.62
4.21
11.6
5.23
4.71
6.37
6.81
5.21
5.92
6.18
4.40
5.73
8.46
30
5.5
2.6
11.6
1.7
(4.8,6.1)
Filtrate
1.26
0.16
0.17
1.03
0.22
0.29
0.18
0.18
0.10
0.28
0.14
0.15
0.18
0.12
0.41
0.18
0.18
0.48
0.10
0.27
0.14
0.11
0.09
0.24
0.08
0.08
0.08
0.44
0.18
0.18
30
0.25
0.10
1.3
0.25
(0.15,0.35)
Filtrate
In Line Meter(1)
0.021
0.023
0.022
0.031
0.021
0.024
0.021
0.022
0.022
0.020
0.053
0.026
0.020
0.020
0.021
0.021
0.020
0.019
0.019
0.018
0.017
0.017
0.016
0.016
0.018
0.016
0.018
0.016
0.019
0.020
30
0.021
0.016
0.053
0.007
(0.019, 0.024)
Instantaneous readings taken when samples were collected for bench-top turbidity analysis.
(2) Bench-top turbidity statistics have been rounded according to the Standard Method guidelines.
61
-------
Figure 4-5 presents the alkalinity for the raw, feed, and filtrate water. The raw water averaged
250 mg/L as CaCOs and was stable throughout the test with a maximum concentration of 270
mg/L and minimum of 230 mg/L. Sulfuric acid was added to the feed water to lower the pH,
which lowered the alkalinity. The alkalinity in the feed water averaged 230 mg/L with a
maximum of 250 mg/L and minimum of 200 mg/L. There was no change in alkalinity through
the membranes with the filtrate alkalinity averaging 230 mg/L with a maximum of 250 mg/L and
minimum of 200 mg/L.
62
-------
290
270
ซ 250
O
O
re
O
jg 230 ^
210
190
170
150
">A \ '
sv v /
V **
-------
Figure 4-6 shows the total iron concentrations measured in the raw, feed, and filtrate water. The
raw water contained natural occurring iron, averaging 0.99 mg/L with a maximum of 1.9 mg/L
and minimum of 0.81 mg/L. The pre-testing by Pall showed that this amount of iron was not
sufficient to provide the desired arsenic removal performance so additional iron was added to the
system to achieved the needed iron concentrations for coagulation of the arsenic. The feed water
averaged 2.3 mg/L as Fe with a median concentration of 2.1 mg/L. The maximum iron
concentration in the feed water was 4.2 mg/L. The iron concentrations were typically in the 1.8
to 2.9 mg/L range.
The Microza System removed the iron present in the feed water, producing treated water that had
less than 0.02 mg/L for all but two samples. On October 6, when the iron concentration in the
feed was measured at a maximum concentration of 3.5 mg/L, the filtrate concentration was 0.1
mg/L. There was also one sample during the intensive arsenic sample test that showed iron in the
filtrate at 3.6 mg/L, which was higher than both the feed and raw water concentrations. This
datum point appears to be an outlier, as the samples collected 12 hours before and five hours
after this sample showed filtrate iron concentrations of <0.02 mg/L. These data show that the
Microza System can achieve the statement of performance objective of producing a filtrate with
<0.02 mg/L of iron.
64
-------
"B>
4.5
4
3.5
3
2.5
2
1.5
1 -
__---*-
X
Date
* Raw - - - - Feed
Filtrate
Figure 4-6. Iron Results
65
-------
The field staff measured total and free residual chlorine daily. Table 4-9 shows the residual
chlorine data for the raw, feed, and filtrate water. The raw water is a non-chlorinated source and
should have no residual chlorine. These data show this was the case on most days with total and
free residual chlorine being below the detection limits. On four days, however, the data indicated
the presence of free residual chlorine, even though on two of those days the total residual
chlorine was below the detection limit. It is not known why these data show chlorine present in
the raw water samples, but the data appear to be anomalous readings. There is no known reason
to believe that chlorine is present in the raw water source.
The feed water averaged 0.60 mg/L of total residual chlorine and the filtrate water averaged 0.58
mg/L. Most of the data points were clustered in the range of 0.5 to 0.7 mg/L. The free residual
chlorine results show that 20 to 30% of the residual chlorine was free chlorine with the feed
averaging 0.13 mg/L and the filtrate 0.16 mg/L. The bleach solution was fed at a target rate of
1.0 mg/L, which indicates the raw water had a chlorine demand of approximately 0.4 mg/L.
66
-------
Table 4-9. Total and Free Residual Chlorine (mg/L)
Date
9/9/2004
9/10/2004
9/1 1/2004
9/12/2004
9/13/2004
9/14/2004
9/15/2004
9/16/2004
9/17/2004
9/18/2004
9/19/2004
9/20/2004
9/21/2004
9/22/2004
9/23/2004
9/24/2004
9/25/2004
9/26/2004
9/27/2004
9/28/2004
9/29/2004
9/30/2004
10/1/2004
10/2/2004
10/3/2004
10/4/2004
10/5/2004
10/6/2004
10/7/2004
10/8/2004
Number of
Samples
Average
Minimum
Maximum
Std. Dev.
95% Conf.
Int.
Raw
<0.05
0.21
<0.05
<0.05
<0.05
<0.05
0.20
0.26
<0.05
<0.05
0.05
<0.05
<0.05
0.29
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
30
<0.05
<0.05
0.29
0.08
N/C
Free Chlorine
Feed
0.12
0.35
0.17
0.22
<0.05
0.23
0.26
0.23
0.08
0.14
0.16
0.17
0.15
0.33
0.11
<0.05
<0.05
0.08
0.06
0.31
0.06
<0.05
0.10
0.17
0.12
0.11
0.14
0.05
<0.05
0.12
30
0.13
<0.05
0.35
0.10
(0.10,0.17)
Filtrate
0.05
0.25
0.28
0.09
0.40
0.23
0.46
0.49
0.10
0.12
0.12
0.45
0.42
0.35
0.16
<0.05
<0.05
<0.05
<0.05
0.15
<0.05
<0.05
0.34
0.07
<0.05
0.19
0.09
<0.05
<0.05
0.05
30
0.16
<0.05
0.49
0.16
(0.10,0.22)
Raw
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
0.13
<0.05
<0.05
0.05
0.06
<0.05
<0.05
0.16
<0.05
0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
0.05
<0.05
<0.05
0.05
<0.05
<0.05
<0.05
0.05
30
<0.05
<0.05
0.16
0.04
N/C
Total Chlorine
Feed Filtrate
0.63
0.79
0.73
0.66
0.40
0.79
0.55
0.63
0.72
0.68
0.65
0.68
0.60
0.79
0.66
0.47
0.53
0.62
0.34
0.74
0.50
0.48
0.55
0.57
0.56
0.42
0.53
0.81
0.49
0.47
30
0.60
0.34
0.81
0.13
(0.55, 0.
0.73
0.66
0.67
0.58
0.55
0.81
1.16
0.64
0.81
0.54
0.60
0.64
0.66
0.71
0.68
0.46
0.47
0.54
0.46
0.76
0.49
0.53
0.52
0.44
0.45
0.37
0.47
0.39
0.32
0.36
30
0.58
0.32
1.16
0.17
65) (0.52, 0.65)
Dissolved
Oxygen
Raw
3.85
9.23
6.52
4.78
6.88
6.22
8.67
8.50
6.16
6.80
4.65
8.86
5.65
9.22
6.53
8.98
9.04
3.82
9.28
7.16
6.45
6.20
7.34
7.45
4.47
6.35
7.50
8.60
7.30
6.86
30
6.98
3.82
9.28
1.63
(6.37, 7.59)
N/C - Not calculated.
67
-------
The results for the other water quality parameters are shown in Table 4-10 and Table 4-11. The
raw concentrations were stable throughout the test. The hardness did appear to increase on
September 27 primarily due to an increase in magnesium concentration. The next data set
obtained on October 5 showed hardness and magnesium levels back to the typical concentrations
found earlier in the test run and are similar to the data collected prior to the verification test. The
feed and filtrate water showed similar average concentrations of chloride, sulfate, TOC, fluoride,
calcium, magnesium, and barium. The Microza System had little or no impact on these water
quality parameters. Sulfate in the feed and filtrate was increased by an average of 20 to 22 mg/L
due to the addition of sulfuric acid for pH control for this treatment system. Sulfate was not
removed by the membrane filtration system. The Microza System did appear to reduce the
manganese concentration. The raw and feed waters averaged 23 |ig/L and 29 |ig/L, respectively.
The filtrate average concentration was 15 |ig/L indicating a removal of 35 to 48 percent of the
manganese in the water. Manganese was present at an elevated level in the filtrate water on one
day, September 21. The manganese was reported as 100 |ig/L, much higher than the raw or feed
water. The cause of this increase on manganese for one day is not known. The TOC results in
Table 4-10 did not decline throughout the verification test. TOC apparently is not removed by
the treatment process. The nature of the source of TOC is unknown.
Table 4-10. Other Water Quality Parameters
Date
9/9/2004
9/13/2004
9/21/2004
9/27/2004
10/5/2004
Number of Samples
Average
Minimum
Maximum
Chloride (mg/L)
Raw Feed Filtrate
18
19
19
19
21
5
19
18
21
22 22
22 22
21 22
21 22
20 24
5 5
21 22
20 22
22 24
Raw
13
15
14
14
14
5
14
13
15
(Sulfate mg/L)
Feed Filtrate
61 59
39 24
40 57
17 17
21 14
5 5
36 34
17 14
61 59
Date
9/9/2004
9/13/2004
9/21/2004
9/27/2004
10/5/2004
Number of Samples
Average
Minimum
Maximum
Raw
0.7
0.6
0.8
0.6
0.7
5
0.7
0.6
0.8
TOC (mg/L)
Feed Filtrate
0.7 1.0
0.6 0.6
0.7 0.7
0.6 0.6
0.6 0.6
5 5
0.6 0.7
0.6 0.6
0.7 1.0
Fluoride (mg/L)
Raw Feed Filtrate
0.6
0.6
0.6
0.5
0.6
5
0.6
0.5
0.6
0.6 0.6
0.6 0.6
0.6 0.6
0.5 0.6
0.6 0.5
5 5
0.6 0.6
0.5 0.5
0.6 0.6
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Table 4-11. Other Water Quality Parameters
Date
9/9/2004
9/13/2004
9/21/2004
9/27/2004
10/5/2004
Number of
Samples
Average
Minimum
Maximum
Calcium
Raw Feed
69
72
69
67
69
5
69
67
72
90
64
69
69
69
5
72
64
90
(mg/L)
Filtrate
71
70
72
71
68
5
70
68
72
Magnesium
Raw Feed
22
22
19
42
20
5
25
19
42
24
22
21
43
21
5
26
21
43
(mg/L)
Filtrate
24
22
21
42
21
5
26
21
42
Hardness
Raw
260
270
250
340
260
5
280
250
340
(mg/L
Feed
320
250
260
350
260
5
290
250
350
as CaCO3)
Filtrate
280
270
270
350
260
5
280
260
350
Date
9/9/2004
9/13/2004
9/21/2004
9/27/2004
10/5/2004
Number of
Samples
Average
Minimum
Maximum
Barium (
Raw Feed
160
170
140
160
160
5
160
140
170
160
160
130
170
160
5
160
130
170
ng/L)
Filtrate
150
160
130
140
170
5
150
130
170
Manganese (
Raw Feed
19
22
23
23
26
5
23
19
26
27
27
30
28
32
5
29
27
32
Hg/L)
Filtrate
12
10
100
17
21
5
10
100
True
Raw
5
18
15
5
N/C
18
Color
Feed
5
12
22
20
5
N/C
22
(C.TJ.)
Filtrate
5
5
7
5
N/C
7
(1) Average does not include 9/21/04 outlier.
N/C - Not calculated.
4.5.4 Chemical Use, Backwash Quality, and Chemical Cleaning
As described in Chapter 2, the Microza System uses a short duration (90 seconds) backwash
cycle to remove solids that accumulate on the membranes. The backwash water generated from
the air scrub and a forward flush cycle is discharged from the unit to an appropriate disposal
location. The backwash water is discharged through a separate backwash line that was sampled
during the verification test.
The backwash water quantity was preset by setting the flow rate of the water used for the air
scrub and forward flush (0.5 and 3 gpm, respectively), and setting the duration of the air scrub
and forward flush in the PLC (60 and 30 seconds, respectively). This resultant backwash volume
was approximately 2 gallons per backwash cycle. The backwash volume was checked each day
during the verification test by collecting the backwash water in a tared container and weighing
the filled container. The weight was then converted to gallons of backwash water produced for a
cycle. While the actual volume measured on a given day varied from 1.2 to 2.9 gallons, the
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average of the 30 measurements was 2.0 gallons with a median of 2.0 gallons. The variation in
some measurements may be a more function of the difficulty of using a "bucket" collection
method with an open discharge pipe, than any real variation in the backwash volume per cycle.
The average and mean data show the volume of 2.0 gallons is identical to the target backwash
volume. This backwash volume represented approximately 1.2% of the filtrate volume produced
each day during the verification test.
The backwash water was sampled and analyzed on weekly basis during the verification test.
Table 4-12 shows the results for total arsenic, total iron, and TSS. The backwash water was
enriched in arsenic, iron, and TSS as would be expected given the removal of arsenic and iron as
measured in the filtrate. Local disposal requirements determine whether this water is acceptable
for discharge to a sanitary sewer system, some other discharge location, or if it will require
further treatment prior to discharge. The backwash water is not considered a hazardous waste
based on the arsenic concentrations, which is below the 5,000 |ig/L limit under the Resource
Conservation and Recovery Act (RCRA).
Table 4-12. Backwash Water - Water Quality Results
Total Arsenic Total Iron TSS
Date (ng/L) (mg/L) (mg/L)
9/9/2004
9/13/2004
9/21/2004
9/27/2004
10/4/2004
10/5/2004
Average
Median
Minimum
Maximum
340
420
420
370
220
1,700
580
390
220
1,700
78
79
87
93
37
310
114
83
37
310
140
240
190
120
NA
760
290
190
120
760
NA = Not analyzed.
The Microza System used a 6% sodium hypochlorite (bleach) as the stock chemical for adding
chlorine to the system. The targeted chlorine feed was 1 mg/L. The chemical metering pump was
set to feed approximately 0.38 milliliters/minute (ml/min) from the five-gallon container [8.5
inches (W) by 11.5 inches (D) by 12 inches (H)] of bleach solution. The metering pump stroke
rate was checked daily and the calibration was checked four times during the verification test.
The volume of bleach solution used from the container was estimated based on the change in
liquid depth in the container. A total of 3.9 gallons of 6% bleach solution was used over the 30-
day test to treat 252,600 gallons of raw water. This equates to an average water concentration
added to the raw water of 0.92 mg/L.
Iron was added to the raw water using a 40% ferric chloride solution stored in a five-gallon
container [8.5 inches (W) by 11.5 inches (D) by 12 inches (H)]. The ferric chloride was fed with
a chemical metering pump that was set to deliver approximately 0.125 ml/min. The pump
calibration checks showed the average was closer to 0.106 ml/min. The volume of ferric
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chloride solution used from the container was estimated based on the change in liquid depth in
the container. A total of 1.3 gallons (15.2 pounds) of ferric chloride solution was used over the
30-day test to treat 252,600 gallons of raw water. Based on the total amount of solution fed, the
average concentration of ferric chloride in the feed water was calculated to be 2.89 mg/L, close
to the target of 3 mg/L of ferric chloride (1.0 mg/L as Fe). The iron added was in addition to the
0.95 mg/L (as Fe) of natural occurring iron in the raw water.
Sulfuric acid solution was also stored in a five-gallon container [8.5 inches (W) by 11.5 inches
(D) by 12 inches (H)] at the site and feed with a chemical metering pump. The feed rate was
monitored in the same manner as for the iron and chlorine feeds. Acid addition was based on the
need to lower pH to an operating range of 6.6 to 7.0. Approximately 5.4 gallons of sulfuric acid
was used over the 30-day test to treat 252,600 gallons of raw water.
The chemical CIP procedure used by Pall to clean membranes is described in Appendix B. The
process uses a sodium hydroxide and bleach solution that is recirculated through the system for
two hours. After a rinse, a citric acid solution used to further clean the membranes with low pH
water, followed by a rinse. Pall performed a CIP before the start of the verification test and again
at the end of the test. DWTS field staff observed both cleaning procedures and recorded the
chemical use and TMPs before and after the final cleaning. The CIP procedure took
approximately five hours to complete. This time includes the time to drain the feed water tank,
make the chemicals used for cleaning, perform the entire procedure, and reset the unit for
operation.
The chemicals used for the post verification test CIP procedure on the filter membrane (surface
area 75 ft2) included:
Sodium Hydroxide: 1.25 Ibs;
Bleach (6% solution): 942 ml;
Sodium Hydroxide and Bleach were diluted into 15 gallons of water; and
Citric Acid: 1.668 Ibs dilute into 10 gallons of water.
The recirculation and air scrub cycle for the caustic/bleach solution was run for two hours and
ten minutes, followed by a rinse with raw water for approximately 30 minutes. The citric acid
scrub was run for one hour and was followed by a 20-minute rinse with raw water. During the
rinse cycle between the caustic and acid cleaning, the TMP was checked at various flow rates,
and then checked again during the acid rinse. Table 4-13 shows the TMP data. At the end of the
CIP, the TMP had returned to the original TMP for the unit at the beginning of the verification
test. These data indicated that the unit was cleaned and restored to original operating condition.
The final check was an integrity test to demonstrate that the membranes were still in good
condition. The integrity test data are presented in Table 4-14. These data demonstrate the
membrane was in good condition after cleaning and met the same integrity specifications
measured during installation of the equipment.
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Table 4-13. TMPs Before and After the CIP
Flow Rate
(gpm)
1.0
2.0
3.0
4.0
5.0
6.0
6.3
TMP Before
Cleaning (psi)
3.2
5.5
7.8
10.4
12.7
15.1
15.7
TMP After
High pH
Cleaning (psi)
2.6
4.3
6.0
7.7
9.4
11.1
11.6
TMP After Low
pH Cleaning -
Final (psi)
2.0
3.0
4.2
5.4
6.5
7.7
8.0
Table 4-14. Integrity Test Pressure Drop Data
Time (seconds) Pressure (psi)
0
30
60
90
120
150
180
210
240
270
300
25.8
25.7
25.6
25.5
25.4
25.3
25.3
25.2
25.1
25.0
24.9
After completion of the CIP, the Microza System was placed back in operation to verify that the
system was producing similar results to the clean system at the beginning of the verification test.
Flow rate, turbidity, and TMP were recorded before and after the CIP. These data are presented
in Table 4-15. As can be seen, the turbidity results for the filtrate were good and the results
similar to clean system at the beginning of the verification test.
Table 4-15. Operating Data
Time
Before CIP
After CIP
One hour and 20 min after
normal operation
Before and After the CIP
Flow Rate TMP
(gpm) (psi)
6.3 15.9
6.3 8.4
6.3 9.0
Feed Inline
Turbidity
(NTU)
4.83
10.5
4.78
Filtrate Inline
Turbidity
(NTU)
0.016
0.077
0.016
4.6 Other Operating Information
The Microza System was operated for the 30-day verification period by the DWTS staff. The
system was found to be easy to operate and required little time for daily maintenance. The field
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staff was on-site for approximately two to three hours per day. Most of the time on-site was spent
performing ETV related activities, including daily chemical analyses, flow checks, calibrations,
etc. In a normal operation, the inline pH meters and turbidimeters would be used for system
checks. The PLC records all of the flow data, pressure information, backwash cycles, etc.
Therefore, it would be anticipated that the time to check the system on-site would be minimal,
possibly less than 30 minutes, except when chemical feed stocks needed to be replenished or
inline instruments calibrated. The PLC can be set up for remote access; so main system
parameters can be monitored without a site visit.
The chemical feed system used well-designed chemical metering pumps and five-gallon
containers for the acid, bleach, and ferric chloride solutions. The chemicals were fed in the
concentration purchased, so it was not necessary to make dilutions or perform other potentially
dangerous handling activities. An operator does need to pour the solutions into the feed
containers. For larger systems, the size of the containers can be expected to be larger and
possibly used as the actual feed containers (totes, etc.). The chemical feed rates were steady over
the duration of the test. As can be seen by the data presented earlier, the concentrations of
chlorine, iron, and the pH stayed within the anticipated ranges during the test. The chemical
meter pumps held the same stroke per minute settings throughout the test.
The Microza System has a computer for reading and checking current and historical data for all
key operating parameters. The unit also has manual readouts on the feed and filtrate flow rate,
the pressures for feed, filtrate and concentrate, and on the inline pH meters and turbidimeters.
The readings were easy to see and were used during this test for the manually recorded
verification data.
Backwash for this system is based on a preset time and backwash cycle. As compared to other
filtration devices, the membrane system backwashes regularly and is not designed to backwash
based on a pressure differential. The TMP is monitored by the PLC and when TMP reaches 35
psi, a CIP is scheduled to clean the unit. Based on the data for this site, the CIP would be
expected to occur about every 90 to 120 days. The CIP would be initiated by an operator and
require an operator to be on-site.
The Microza System operated continuously during the verification test expect for one day,
September 28, 2004. When the site operator arrived on-site the unit was shut down and the
computer indicated it needed to be reset. Based on the PLC record the unit had shut down at
23:45 the night before. The operator reset the system, a simple series of steps using the PLC, and
the unit came back on line with all flows, pressure, and feeds at the same setting as the day
before. The reason for this shut down is not known, but it is suspected that there was a short
power outage that caused the system to shut down. In a full-scale system, a shutdown of this type
could signal an alarm or notify an operator through standard PLC or security systems. The
system can also be set up to shut down based on loss of flow, high filtrate turbidity or pH, or
other PLC monitored parameters. If the system were shut down, the PLC monitoring system can
be setup to send an alarm to an operator. Assuming power is on, the operator could review the
PLC data from a remote location and determine if a site visit was needed.
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The only maintenance performed on the Microza System was the replacement of one pH meter
cable that failed on September 25, after being inadvertently damaged during a calibration
procedure. The cable was shipped to the site and the DWTS field staff was able to install the
cable and recalibrate the pH meter.
Overall, the Microza System appears well suited to small or medium scale installations where an
operator is not present at all times, or even infrequently. The system is automated and all
equipment appeared sturdy and properly selected for the process.
Pall provides an O&M manual for each system that is installed at a site. The generic O&M
manual for a full-scale system is presented in Appendix A. The O&M manual provides a good
description of the system, appropriate safety precautions, and detailed descriptions of operating
procedures, capability and operation of the computer control system, and specific instructions for
utility operators. The maintenance section of the manual includes descriptions of components
that require maintenance. Maintenance checklists including example forms for daily and periodic
maintenance activities are included along with a troubleshooting section in a tabular format. The
review of the O&M manual shows that the manual is well organized and easy to read.
The O&M manual provides instruction for membrane cleaning (CIP) using a bleach, caustic, and
acid. The actual process is automated and controlled by the PLC/PC system with the system
prompting the operator when chemicals need to be changed or added to the system. The control
system also monitors flow rates, TMP, backwash cycles, and related operating parameters. If any
of these parameters is outside of the "normal" range an alarm will be noted for operator
attention. The troubleshooting guide provides information on how to correct the problem. Pall
also provides phone numbers for technical support, if the operator needs assistance in
troubleshooting the system or general information on the unit operation.
Maintenance guidelines and instructions are also provided for checking and cleaning various
filters on the feed water tank and the reverse filtration tanks. These filters, the strainer on the
feed water tank and the vent filter on the reverse filtration tank, need to be checked on a regular
basis to protect the membranes from large particles and to ensure proper operation. The O&M
manual also describes the tanks, piping, and membrane housing with information on the
connections for each vessel.
As stated in Section 4.6.3 of the PSTP, the system was evaluated for overall operability based on
the actual conditions observed during the verification test and on the capabilities of the system
equipment and control system. The Microza System was found to be easy to operate, provided
all needed information and controls to operate the system, and provided flexibility for multiple
chemical feeds and adjustment of operating and backwash cycles.
The system design provides for multiple feed ports in the raw water feed line to add several
chemicals, including acid/caustic for pH control, coagulant (in this case iron), and oxidants
(bleach). Each chemical feed pump is controlled through the PLC/PC. In the test unit, the
chemical feed pumps were not paced to raw water flow, but were set up to shut down if raw
water flow was interrupted or stopped. In a utility application the capability to control chemical
feeds based on raw water flow can be provided. The chemical feed pumps were very stable
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throughout the test and did not need adjustment to maintain the selected feed rate. The system
included inline pH and turbidimeters to monitor the raw and filtrate water, thus providing data to
show that effective chemical feed rates were being delivered to the system. The PLC/PC
provided both real time display of the pH and turbidity and also provided historical data that
could be displayed in a trend plot for any time interval selected.
The Microza System includes flow totalizers and flow rate meters for the raw, feed, and filtrate
water. The system has pressure gauges on the feed, filtrate, and concentrate/recycle lines that
provide pressure data for monitoring TMP. All of this information is recorded and monitored by
the PLC/PC and is available to the operator for review. Both instantaneous current readings and
trend plots can be displayed on the operator console. The system also monitors hours of
operation and will activate an alarm if any operating parameter is outside of preset "normal"
operating limits. The PLC/PC can be programmed to shut down the unit if turbidity, pH, or any
other operating parameter exceeds the preset acceptable limits.
The backwash cycle including air scrub time, backwash water flow and time, and the use of
either feed forward or reverse filtration flow can be adjusted by the operator, if needed. The
PLC/PC activates and controls the backwash cycle based on the time set by the operator and
performs each set of the backwash cycle based on the preset flows and times.
The Microza System used for the verification test was a smaller unit (single module) than a
typical multiple module unit used in utility applications. Therefore, the actual power
consumption for the test unit may be slightly higher than the standard systems described in the
O&M manual. The test system used a 230 VAC, 1 Phase, 30-ampere electrical supply. The test
system had two 2 hp centrifugal pumps, one for feed water flow to the membrane and one for
backwash (reverse filtration). The test system had one small 1A hp mixer. The air compressor was
a 3 hp unit similar to a multiple module unit. The chemical feed pumps (3 pumps) were all small
units using 150 watts each. The PLC/PC power consumption was considered small. Based on
one of the two hp pumps always being in operation (feed pump producing filtrate or forward
backwash water, or the reverse filtration pump in operation during backwash), the mixer running
continuously, and estimating that the air compressor runs approximately ten minutes per hour, it
is estimated that approximately 2.75 hp-hr of electrical power was used by this equipment.
Unadjusted horsepower (not adjusted for efficiency factor) is equal to 746 watts per hp.
Therefore, it is estimated that approximately 2.05 kilowatt-hr was used for the pumps, air
compressor and mixer. The other equipment (chemical pumps and PLC/PC) used an estimated
0.5 kilowatt-hr; bring the total estimated electrical power use to 2.55 kilowatt-hr.
A full-scale system with multiple modules, as described in the O&M manual (Appendix A), uses
a 460 VAC, 60 hertz, 3 Phase electrical supply with larger pumps than the test system. A typical
system with two 5 hp pumps, a 3 hp air compressor, and accessories would be expected to use
approximately 8 to 10 hp or 6 to 8 kilowatt-hr of electrical power.
4.7 Quality Assurance/Quality Control
As described in Task 6, Section 3.9.8, a structured QA/QC program was implemented as part of
this verification to ensure the quality of the data being collected. A QAPP was developed as part
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of the PSTP and was followed by the field staff and laboratory during the testing period. Careful
adherence to the established procedures ensured that the data presented in this report is of sound
quality, defensible, and representative of the equipment performance.
4.7.1 Documentation
DWTS site operators recorded on-site data and calculations (e.g., calculating calibration flow
rates using the bucket and stop watch and other similar routine calculations) in a field logbook.
Daily measurements were recorded on specially prepared data log sheets. The original logbook
was stored on-site and copies were forwarded to the project coordinator at NSF offices once per
week during the verification test. The operating logbook included calibration records for the
field equipment used for on-site analyses. Copies of the logbook, the daily data log sheets, and
calibration log sheets are in Appendix E.
Data from the on-site laboratory and data log sheets were entered into Excel spreadsheets. These
spreadsheets were used to calculate various statistics (average, median, standard deviation, etc.)
and to calculate operating parameters such as flux, temperature corrected specific flux, and TMP.
The data in the spreadsheets were proof read by the initial data entry person. NSF DWS Center
staff then checked nearly 100% of the data entered into the spreadsheets to confirm the
information was correct. The spreadsheets are presented in Appendix G.
Samples collected and delivered to the NSF Chemistry Laboratory for analyses were tracked
using chain of custody forms. Each sample was assigned a location name, date, time of
collection, and the parameters were written on the label. The laboratory reported the analytical
results using the NSF Chemistry Laboratory management system reports. These reports were
received and reviewed by the NSF DWS Center coordinator. These data were entered into the
data spreadsheets, corrected, and verified in the same manner as the field data.
4.7.2 Quality Audits
The NSF QA department performed an on-site audit on September 13, 2004 to review the field
procedures, including the collection of operating data and performance of on-site analytical
methods. The audit was based on observing the actual collection of operating data on Day 5 of
the test and the collection and analysis of samples. The PSTP requirements and QAPP were used
as the basis for the audit. The NSF QA auditor prepared an audit report. All deficiencies were
corrected immediately.
The NSF QA Department reviewed the NSF Chemistry Laboratory analytical results for
adherence to the QA requirements for calibration, precision, and accuracy detailed in the project
QAPP and for compliance with the laboratory quality assurance requirements. The laboratory
raw data records (run logs, bench sheets, calibrations records, etc.) are maintained at NSF and
are available for review.
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4.7.3 Data Quality Indicators
The data quality indictors established for the ETV project and described in the QAPP included:
Representativeness
Accuracy
Precision
Completeness
4.7.3.1 Representativeness
Representativeness refers to the degree to which the data accurately and precisely represent the
conditions or characteristics of the parameter represented by the data. In this verification testing,
representativeness was ensured by executing consistent sample collection procedures in
accordance with established approved procedures, and following specific sample preservation,
packaging, and delivery procedures. Representativeness was ensured by using approved
analytical methods to provide results that represent the accurate and precise measurements of
drinking water. For equipment operating data, representativeness entailed collecting and
documenting a sufficient quantity of data during operation to be able to detect a change in
operations. For most water treatment processes involving total arsenic removal, detecting a +/-
10% change in an operating parameter (i.e., pressure drop, pressure) was sufficient. None of the
primary operating parameters including feed water and filtrate flow rate, pressure or pressure
drop across the membrane (on a daily basis) or backwash flow rate or times varied by more than
10% at any time during the verification test.
4.7.3.2 Accuracy
On-Site Equipment Accuracy and Calibration
On-site equipment, including Microza System flow meters and on-site analytical equipment, was
checked for accuracy through regular calibration checks. Meters and gauges were checked at the
frequencies presented in Table 4-16.
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Table 4-16. Field Instrument Calibration Schedule
Instrument Calibration Method
. A , Volumetric "bucket and stop
Flow Meters . , r
watch"
_ ,,_,,._,. Secondary turbidity standards
Portable Turbidimeter _. / .... : , ,
Primary turbidity standards
Frequency
Weekly
Daily
Weekly
Acceptable
Accuracy
ฑ 10%
+ 25%
Portable pH/ISE Meter
with Combination pH/
Temperature Electrode
Dissolved Oxygen Meter
Thermometer [National
Institute of Standards and
Technology (NIST)-traceable]
Spectrophotometer
Three-point calibration using
4.0, 7.0 and 10.0 buffers
Based on known air saturation
concentrations of dissolved
oxygen at the measured air
temperature
Calibration against NIST
traceable
Chlorine check standard
Daily
Daily
Monthly
Daily
ฑ5%
N/A
+ 5%
+ 25%
N/A - Not Applicable
The Microza System had a raw water flow rate and totalizer meter, and a feed water and filtrate
flow rate meter. The "bucket and stopwatch" technique was used to determine the accuracy of
the flow meters. Table 4-17 shows the calibration data. All calibrations were within the defined
objective of + 10%.
Table 4-17. Flow Meter Calibration Data
Date
8/24/04
9/10/04
9/13/04
9/20/04
9/27/04
10/04/04
Feed and Filtrate Flow Meter
Calibration
Result (gpm)
6.2
6.0
6.0
6.0
6.0
6.1
Flow Meter
Reading (gpm)
6.3
6.3
6.3
6.3
6.3
6.3
Raw Water Flow Meter
Calibration Flow Meter
Result (gpm) Reading (gpm)
6.1 6.4
6.0 6.3
6.0 6.2
6.1 6.3
6.0 5.9
6.1 6.2
The calibrations records for pH, turbidity, total and free residual chlorine, and dissolved oxygen
were recorded in the field calibration log (Appendix E). All calibrations were performed at the
frequency required. The only calibration data that were outside of the established requirements
was for turbidity on September 26, 2004 when the secondary standard check fell below 75% of
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the true value. The turbidimeter was recalibrated the next day with primary standards and all
subsequent calibrations were within the established QC objective.
Laboratory Analyses
Accuracy for the laboratory analyses is quantified as the percent recovery of a parameter in a
sample to which a known quantity of that parameter was added. Equation 4-1 is used to calculate
accuracy:
Accuracy = Percent Recovery = 100 x [(Xkn0wn - Xmeasured) ^ Xknown] (4-1)
where: Xkn0wn = known concentration of measured parameter
= measured concentration of parameter
Accuracy also incorporates calibration procedures and use of certified standards to ensure the
calibration curves and references for analysis are near the "true value". Accuracy of analytical
readings is measured through the use of spiked samples and lab control samples. The percent
recovery is calculated as a measure of the accuracy.
The QAPP and the NSF Chemistry Laboratory QA/QC requirements established the frequency
of spike sample analyses at 10% of the samples analyzed. Laboratory control samples (LCS) are
also run at a frequency of 10%. The recovery limits specified for the parameters in this
verification were 70 to 130% for laboratory fortified samples and 85-115% for LCS. The NSF
QA department reviewed the laboratory records and found all analyses for all sample groups
were within the QC requirements for recovery. Calibration requirements were also achieved for
all analyses.
The arsenic speciation resin columns were tested to ensure proper separation and recovery of the
arsenic species. Each lot of the arsenic speciation resin was checked once against samples with
known concentrations of arsenic (III) and arsenic (V). This QC check assured that the resin was
properly prepared. The NSF Chemistry Laboratory maintained the documentation for the column
checks.
4.7.3.3 Precision
Precision refers to the degree of mutual agreement among individual measurements and provides
an estimate of random error. Analytical precision is a measure of how far an individual
measurement may be from the mean of replicate measurements. The relative standard deviation
recorded from sample analyses was used to quantify sample precision. The percent relative
standard deviation was calculated using the equation presented as Equation 4-2:
Percent Relative Standard Deviation = S(l 00) / Xaverage (4-2)
where: S = standard deviation
= the arithmetic mean of the recovery values
79
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Standard Deviation is calculated as follows:
Standard Deviation = ^ (Xi-X)z (4-3)
where: X; = the individual measured values
X = the arithmetic mean of the measured values
n = the number of determinations
Acceptable analytical precision under the verification testing program was set at a percent
relative standard deviation for drinking water samples of 30%. Field duplicates were collected to
incorporate both sampling and analytical variation to measure overall precision against this
objective. The laboratory precision for the methods selected was tighter than the 30% overall
requirement, generally set at 20% based on the standard NSF Chemistry Laboratory method
performance.
Field Duplicates
Field duplicates were collected for all analyses (field lab and analytical laboratory) to monitor
overall precision. The field duplicates were collected at a frequency of 10% of samples collected
for each parameter. The field duplicates included samples for all three sample locations: raw,
feed, and filtrate water.
Tables 4-18 and 4-19 summarize the results for the field duplicate samples. The overall precision
as measured by these field duplicates was excellent. All results were within the overall QC
objective of 30% relative standard deviation (RSD), except for one turbidity set of replicates at
34% and one free chlorine duplicate at 37%. There was some scatter in the free and total residual
chlorine data near the detection limit, which is typical of results near the detection limit. The raw
water samples that showed elevated free or total chlorine were flagged as anomalous data, as
mentioned earlier in the report.
Laboratory precision was also monitored during the verification test in accordance with QAPP
and the NSF QA program. Laboratory duplicates were analyzed at 10% frequency of samples
analyzed. The NSF QA department reviewed the precision information and determined that the
laboratory data met QC precision requirements. No laboratory data were flagged or qualified.
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Table 4-18. Precision Data - Field Duplicates for Field Analytical Tests
pH (S.U.)
Date
Raw Water
Feed Water
Filtrate
9/16/04
9/22/04
9/24/04
10/05/04
Repl
7.42
7.51
7.48
7.24
Rep 2
7.22
7.46
7.47
7.24
%RSD
1.9
0.5
0.1
0.0
Repl
6.92
6.91
6.82
6.69
Rep 2
6.95
6.91
6.77
6.61
%RSD
0.3
0.0
0.5
0.9
Repl
6.89
6.97
7.08
6.73
Rep 2
6.89
6.98
6.88
6.74
%RSD
0.0
0.1
2.0
0.1
Turbidity (NTU)
Date
Raw Water
Feed Water
Filtrate
9/16/04
9/22/04
9/24/04
10/05/04
Rep 1
3.5
4.8
6.4
5.0
Rep 2
4.1
4.8
3.9
5.1
%RSD
11
0.0
34
1.4
Rep 1
4.9
5.6
4.5
6.2
Rep 2
4.9
5.7
4.8
6.2
%RSD
0.0
1.3
4.6
0.0
Rep 1
0.20
0.10
0.20
0.10
Rep 2
0.20
0.15
0.20
0.10
%RSD
0.0
28
0.0
0.0
Free Residual Chlorine (mg/L)
Date
Raw Water
Feed Water
Filtrate
9/16/04
9/22/04
9/24/04
10/05/04
Rep 1
0.26
0.29
0.05
0.05
Rep 2
0.05
0.17
0.05
0.05
%RSD
N/C
37
N/C
0.0
Rep 1
0.23
0.33
0.05
0.14
Rep 2
0.16
0.23
0.06
0.15
%RSD
25
25
N/C
4.9
Rep 1
0.49
0.35
0.05
0.09
Rep 2
0.35
0.25
0.05
0.12
%RSD
24
24
0.0
20
Total Residual Chlorine (mg/L)
Date
Raw Water
Feed Water
Filtrate
9/16/04
9/22/04
9/24/04
10/05/04
Repl
O.05
0.16
0.05
O.05
Rep 2
0.05
0.12
O.05
O.05
%RSD
N/C
20
N/C
0.0
Repl
0.63
0.79
0.47
0.53
Rep 2
0.61
0.83
0.47
0.55
%RSD
2.3
3.5
0.0
2.6
Repl
0.64
0.71
0.46
0.47
Rep 2
0.70
0.84
0.48
0.48
%RSD
11
12
3.0
1.5
Temperature (ฐC)
Date
Raw Water
Feed Water
Filtrate
9/16/04
9/22/04
9/24/04
10/05/04
Repl
12.1
10.8
10.8
9.7
Rep 2
10.7
10.9
10.5
9.7
%RSD
8.7
0.7
2.0
0.0
Repl
11.5
10.9
10.4
9.7
Rep 2
11.4
11.0
10.9
9.7
%RSD
0.6
0.6
3.3
0.0
Repl
10.9
11.2
10.9
9.7
Rep 2
11.0
11.2
10.8
9.7
%RSD
0.6
0.0
0.7
0.0
N/C-Not Calculated.
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Table 4-19. Precision Data - Field Duplicates for Laboratory Parameters
Total Arsenic (>ig/L)
Date
Raw Water
Feed Water
Filtrate
9/13/04
9/22/04
10/05/04
Rep 1
12
10
12
Rep 2
12
10
12
%RSD
0.0
0.0
0.0
Rep 1
12
10
14
Rep 2
17
10
14
%RSD
24
0.0
0.0
Rep 1
<2
<2
<2
Rep 2
<2
<2
<2
%RSD
0.0
0.0
0.0
Dissolved Arsenic Qig/L)
Date
Raw Water
Feed Water
Filtrate
9/13/04
9/22/04
10/05/04
Repl
10
11
12
Rep 2
11
10
11
%RSD
6.7
6.7
6.1
Repl
<2
<2
<2
Rep 2
<2
<2
<2
%RSD
0
0
0
Repl
<2
<2
<2
Rep 2
<2
<2
<2
%RSD
0.0
0.0
0.0
Arsenic (III) Qig/L)
Date
Raw Water
Feed Water
Filtrate
9/13/04
9/22/04
10/5/04
Repl
9
9
9
Rep 2
9
9
8
%RSD
0
0
8.3
Repl
<2
<2
<2
Rep 2
<2
<2
<2
%RSD
0
0
0
Repl
<2
<2
<2
Rep 2
<2
<2
<2
%RSD
0
0
0
Alkalinity (mg/L as CaCO3)
Date
9/22/04
10/05/04
Repl
240
240
Raw Water
Rep 2
250
240
%RSD
2.9
0.0
Repl
220
230
Feed Water
Rep 2
220
230
%RSD
0.0
0.0
Repl
220
240
Filtrate
Rep 2
220
240
%RSD
0.0
0.0
Iron (mg/L)
Date
Raw Water
Feed Water
Filtrate
9/13/04
9/22/04
10/05/04
Rep 1
1.1
0.90
0.99
Rep 2
0.91
0.84
0.99
%RSD
13
4.9
0.0
Rep 1
1.9
1.8
2.1
Rep 2
2.6
1.8
2.2
%RSD
22
0.0
3.3
Rep 1
0.02
0.02
0.02
Rep 2
0.02
0.02
0.02
%RSD
0.0
0.0
0.0
Other Parameters (10/05/04)
Parameter
Raw Water
Feed Water
Filtrate
Chloride (mg/L)
Sulfate (mg/L)
Barium (ug/L)
Calcium (mg/L)
Magnesium (mg/L)
Manganese (ug/L)
Fluoride (mg/L)
TOC (mg/L)
Rep 1
21
14
160
69
20
26
0.6
0.7
Rep 2
18
14
160
69
20
26
0.6
0.7
%RSD
11
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Rep 1
20
21
160
69
21
32
0.6
0.6
Rep 2
24
22
160
69
21
32
0.6
0.6
%RSD
13
3.3
0.0
0.0
0.0
0.0
0.0
0.0
Rep 1
24
14
170
68
21
21
0.5
0.6
Rep 2
20
15
150
70
20
21
0.6
0.6
%RSD
13
4.9
8.8
2.0
3.4
0.0
13
0.0
4.7.3.4 Field Blanks and Method Blanks
Field blanks were collected once per week for water quality parameters collected daily or three
times per week, and were collected twice during the verification test for water quality parameters
being tested on a weekly basis. The field blanks were prepared in the field using distilled water.
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The blank samples used the same bottles and preservatives as the regular samples. These field
blanks provide data to show that the contamination was not being introduced during the sample
collection, handling, and transportation or in the laboratory analysis.
Results for the field blank analyses are shown in Table 4-20. These results show that for most
parameters the results were below the laboratory reporting limits. The TOC blanks showed
positive results near the detection limit of 0.1 mg/L and the turbidity blanks showed steady
readings at 0.1 NTU, again near the lowest limit that can be detected with the bench-top
turbidimeter. The field blank results demonstrated that the sampling, handling, and analyses
procedures were in control and did not introduce any contaminants to the samples.
Table 4-20. Field Blank Results
Date
Parameter Units 9/10/04 9/13/04 9/20/04 9/27/04 10/02/04
Chloride
Sulfate
Total Arsenic
Soluble Arsenic
Arsenic (III)
Barium
Calcium
Iron
Magnesium
Manganese
Alkalinity
TOC
Fluoride
Turbidity
Free Chlorine
Total Chlorine
Color
TSS
mg/L
mg/L
ug/L
ug/L
ug/L
ug/L
mg/L
mg/L
mg/L
ug/L
mg/L
mg/L
mg/L
NTU
mg/L
mg/L
C.U.
mg/L
<0.5
<0.5
<2
<2
<2
<1
<0.02
<0.02
<0.02
<1
<5.0
0.1
<0.1
0.10
<0.05
<0.05
5
<2
<2
<0.02
5.9
0.10
<0.05
<0.05
0
<0.5
<0.5
<2
<2
<2
<10
<0.02
<0.02
<0.02
<1
<5.0
0.1
<0.1
0.10
<0.05
<0.05
0
<2
<1
<0.02
<0.02
<0.02
<1
<5.0
0.10
<0.05
<0.05
0
<2
<0.02
<5.0
0.10
<0.05
<0.05
0
The laboratory analyses, and where appropriate, the field analyses, included method blanks as
part of the standard analysis procedures. Methods blanks were analyzed in accordance with the
approved methods. The NSF QA department reviewed the laboratory data and found the method
blanks to be acceptable. No data were flagged as having been impacted by method blank results.
4.7.3.5 Completeness
Completeness is defined as the following (Equation 4-4) for all measurements:
%C = (V/T)X100 (4-4)
where: %C = percent completeness
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V = number of measurements judged valid
T = total number of measurements
Completeness refers to the amount of valid, acceptable data collected from a measurement
process compared to the amount expected to be obtained.
The completeness objective for data generated during this verification test was based on the
number of samples collected and analyzed for each parameter and/or method. A completeness
objective of 90% applied to: total arsenic, iron, pH, daily bench-top turbidity, residual chlorine,
and TSS. Completeness criteria also applied to the following operating parameters: filtrate flow
rate, pressure differential across the membrane, amount of chemicals added to the water, and
volume and flow rate measurements for backwash water. Samples for all of the critical
parameters, total arsenic, iron, pH, daily bench-top turbidity, residual chlorine for raw, feed, and
filtrate water, and backwash water TSS were collected and analyzed at the frequency specified
for the verification test. All data were usable except for one suspect iron result, one total residual
chlorine value, and four free residual chlorine values. Table 4-21 provides a summary of the
completeness results for the verification test.
Table 4-21. Completeness Results
Parameter
Percent
Completeness
Comment
Filtrate Flow Rate
TMP
Chemicals Added
Volume and Rate of
Backwash
Total Arsenic
Iron
PH
Bench-top Turbidity
Total Residual Chlorine
Free Residual Chlorine
Backwash TSS
100 All required daily measurements recorded.
100 All required daily measurements recorded.
100 Total amount of chemicals used recorded.
100 All required daily measurements recorded.
100 All scheduled samples and analyses completed.
100 All scheduled samples and analyses completed.
100 All required daily measurements recorded.
100 All required daily measurements recorded.
99 All required daily measurements recorded. One
value out of 90 samples flagged.
96 All required daily measurements recorded. Four
values out of 90 samples flagged.
100 All scheduled samples and analyses completed.
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Chapter 5
References
EPA/NSF ETV Protocol for Equipment Verification Testing for Arsenic Removal. U.S. EPA/NSF
International. September 2003.
Hack Water Analysis Handbook. Hach Company, Loveland, Colorado. 1992.
Product Specific Test Plan for the Pall Microza Microfiltraiton System for Arsenic Removal from
Drinking Water. Scherger Associates and NSF International. August 2004.
Standard Methods for the Examination of Water and Wastewater. 20th edition. APHA, AWWA,
and WEF, Washington D.C. 1999.
U.S. EPA Drinking Water Methods for Chemical Parameters. EPA Office of Ground Water and
Drinking Water. EPA Methods are available from the National Technical Information Service
(NTIS).
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Chapter 6
Vendor Comments
Pall Corporation submitted the following comments concerning the ETV test and report;
supporting documentation from Pall Corporation can be found in Appendix H. These statements
were not validated in the verification test and are the opinion of Pall Corporation:
"The U.S. EPA's new Arsenic Rule became effective on February 22, 2002 and reduced the
Maximum Contaminant Level (MCL) for arsenic in drinking water from 50 (j,g/ L to 10 |j,g/ L.
The date by which systems must comply with this new MCL is January 23, 2006.
Pall Corporation conducted a NSF/EPA Environmental Technology Verification (ETV) pilot
study to verify the coagulation/microfiltration (C/MF) process for arsenic removal. The C/MF
process effectively removed naturally occurring arsenic in ground water to undetectable levels.
Based upon the results of the pilot trials, the Pall C/MF system can be designed with the
following parameters:
1. Flux of 120 GFD (ambient temperature) with a recovery of 98.0%,
2. Undetectable levels of arsenic in filtrate, and
3. Greater than 30-day Clean In Place (CIP) interval.
The process consists of adding an iron-based coagulant, such as ferric chloride, to water
contaminated with arsenic followed by microfiltration. The ferric chloride will hydrolyze in
water to form ferric hydroxide particles, which have a net positive surface charge at pH values
less than 8. Arsenate ions are negatively charged and will absorb onto the positively charged
ferric hydroxide particles. The particles are then removed with microfiltration. Naturally
occurring dissolved iron in the water can be oxidized to form ferric hydroxide particles as well.
Pall is a $1.8 billion corporation with manufacturing, sales, marketing, engineering, and
technical support located throughout the world. We have over 50 years of experience in
thousands of successful installations using state-of-the-art filters to remove contaminants from
liquid and gas streams. As the world's largest supplier of filters, filter systems and fluid
purification equipment we focus our strengths on advancing the state of the art in separation
technology in thousands of diverse applications. We owe our success to developing products
that offer our customers optimal value and economy of use."
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