solutionsF a l l 2 0 1 1

America’s Authority in Membrane Treatment

Improving America’s Waters Through Membrane Filtration and Desalting

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AbstractUltrafiltration (UF) is a membrane process that separates suspended solids from water streams, similar to conventional media filters; however, unlike media filtration, UF is capable of efficiently removing particles much smaller than UF’s conventional filter counterpart. Membrane filtration has gained acceptance by the drinking water community for use in treating surface water supplies for the production of drinking water, and increasingly is installed in lieu of conventional filters downstream of conventional coagulation, flocculation, and sedimentation processes. Although UF and conventional filters require backwash cycles as a part of normal operating protocols, UF often requires chemical enhanced backwashes (CEBs) to maintain productivity. As a result, the integration of UF into conventional surface water treatment facilities may cause an unintended disruption of the coagulation process when spent filter backwash water is recycled back to the headworks due to the presence of residual chemicals specifically used for maintenance of UF membranes. Results of jar tests designed to simulate conventional water treatment plant recycle of spent citric acid (CA) backwash upstream of alum and ferric coagulation basins indicated that there exists a recycle threshold, as defined by acid to coagulant molar ratios (MR), beyond which significant deterioration in coagulation basin settled water turbidity occurs. This work documents, for the first time, the occurrence of coagulation interference thresholds at CA/coagulant MRs of approximately 0.15 for alum coagulation and approximately 0.11 for ferric chloride coagulation beyond which settled water turbidity values exceed 2.0 NTU.

IntroductionThe use of size-exclusion membrane technologies such as UF has increased dramatically over the recent years (Belfort et al. 1994) and MF/UF membranes

Integrating Ultrafiltration within Conventional Coagulation Facilities and the Unintended Consequence of Membrane Maintenance Chemicals Entering Conventional Recycle StreamsSteven J. Duranceau, PhD., P.E.; University of Central Florida, Orlando, FLChristopher C. Boyd, EI; University of Central Florida, Orlando, FL

are now commonplace in drinking water treatment (Duranceau and Taylor 2010). UF presents a physical barrier to the suspended particles in the feed stream, whereby particles larger than the pore are retained on the feed side of the membrane. The retained particles, however, accumulate on the surface of the membrane and increase the resistance to water flow across the membrane. As a result, UF membranes must be periodically backwashed by reversing the direction of flow through the membrane to remove the deposited particles. However, backwashing typically recovers only a portion of productivity lost through operation, which results in membrane fouling (i.e. irreversible productivity loss).

CEBs are commonly used to maintain UF membranes and limit the decline in performance caused by fouling. Successful membrane maintenance depends often on foulant type, chemical type, contact time, flow rate, concentration, backwash chemical and solution temperature (Zondervan and Roffel, 2007). The selection of chemicals for membrane maintenance is claimed to be a trial and error process (Strugholtz et al., 2005), and further research is desired on this topic. Common CEB chemicals include citric acid, sulfuric acid, sodium hypochlorite and sodium hydroxide. Citric acid is a chelating agent frequently used in membrane CEBs, because it is well suited to remove organo-metallic foulants. Some membrane manufacturers’ may require the use of citric acid in enhanced backwashes as part of warranty or other agreements (Lyons and Sangines 2010).

In 2001, the Environmental Protection Agency (EPA) released a rule governing the process of recycling waste water generated by the backwashing of drinking water filters. Spent filter backwash water can contain microbial contaminants, often in very high concentrations. Recycling these streams can reintroduce microbes and other contaminants to the

President’s Message

PublicATion Schedule

Winter Pretreatment

SpringNew Facilities

SummerWater Quality

FallMembrane Residuals

AMTA Solutions is published quarterly for the members of AMTA. AMTA Solutions is mailed to AMTA members and published on the AMTA website.

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Current Executive CommitteePresidentPeter Waldron

First Vice PresidentMehul Patel, P.E.Orange County Water District

Second Vice PresidentLynne GuliziaToray Membrane USA, Inc.

TreasurerSteve MalloyIrvine Ranch Water District

SecretaryKaren LindseyAvista Technologies, Inc.

Immediate Past PresidentSteve Duranceau, Ph.D., P.E. University of Central Florida

AMTA StaffExecutive DirectorIan C. Watson, P.E.

Administrative DirectorJanet L. Jaworski, CMP

American Membrane Technology Association2409 SE Dixie Hwy.Stuart, FL 34996772-463-0820772-463-0860 (fax)admin@amtaorg.comwww.amtaorg.com

EditorsTom Seacord, P.E. and Winnie Shih, Ph.D., Carollo Engineers, P.C.

Peter M. Waldron

Dear AMTA Members,

Welcome to our Fall 2011 edition of AMTA’s Solutions newsletter. It’s hard to believe that by the time this newsletter comes to print, we will be more than two months removed from our conference in Miami Beach. Despite the difficult economic times, we managed to attract over 600 attendees and exhibitors from all over the world. Combined with our unmatched technical content, we view this as a very successful event. AMTA’s 2011 Annual Conference was the event of the year for membrane technology in North America. Thanks to all who made this a success!

Speaking of our Annual Conference, Miami Beach marked the last of our Conferences to be held in July. Starting in 2012, we will combine our event with the AWWA’s Membrane Technology Conference. While it is with mixed emotions that our Annual summer event ends, we look forward to having two of the leading water authorities combining forces to create the premiere event for anyone involved in membrane technologies. preparation is underway for this conference as it moves to the last week of February in glendale, AZ.

In the meantime, as fall unfolds, we have two upcoming workshops. The first workshop will be in Sacramento, CA in September to be held jointly with our west coast affiliate SWMOA. The second workshop will be in Kansas City during the first week of November. Brochures for both have been mailed to our members and can also be found on our website. Check out the calendar on the back cover for specific dates. We have also begun working on our 2012 program and dates will be announced soon. If you have suggestions or want to be involved in helping plan a workshop, please feel free to contact any of our Board members.

The Fall edition of Solutions focuses on membrane residuals. There are two articles featured in this issue. The first article is on recycling spent UF backwash and the impact it has on the upstream coagulation process. The second is on using electrodialysis metathesis to remove scaling salts in a high recovery RO system. These two articles bring to our attention the importance of maximizing water recovery and minimizing waste discharge. For inland communities as well as those not connected to a brine line, maximum efficiency of a treatment process is critical in getting a discharge permit. As I have often mentioned, before designing a new plant, look to other communities with similar issues and see what they have done. In addition, AMTA’s Conferences and Tech Transfer Workshops give individuals the chance to talk to other operators and vendors working to solve similar problems. Networking is a key benefit of having an organization dedicated to helping solve water issues around the world.

On behalf of the Board of Directors, thank you for being part of this dynamic organization. We encourage your participation and feedback to make this the only organization to turn when considering a membrane-based solution.

I look forward to seeing you all at an upcoming event.

peter M. Waldron president – American Membrane Technology Association

Ben’s O&M Tip CornerBy: Ben Mohlenhoff

If you have a tip or a suggestion for a future O&M article, please contact Ben Mohlenhoff (772) 546-6292 bmohlenhoff@aerexindustries.com

Membrane ResidualsIn this industry we spend a lot of time figuring out how to improve water quality and efficiency of the membrane systems that we design and work on. Frequently we get so focused on improving the characteristics of the permeate stream that we sometimes loose track of the residuals in our concentrate stream.

In most instances the initial design of the plant has carefully taken into consideration both streams in the permitting process. Unfortunately one of the biggest potential for problems with residuals comes as the plant ages and we decide to modify the system design to improve operating efficiency. We must be very careful not to lose sight of the quantity and make-up of the residuals that will eventually end up in the concentrate stream.

Review the Discharge PermitDepending on what method of disposal is involved, the permit may be very specific about total gallons per day or maximum allowable levels for some specific constituents (residuals) in the concentrate stream.

It is not uncommon to take advantage of new membrane technology when retrofitting an existing system. However if you modify the recovery rate to accommodate a rise in the chlorides found in the supply wells you may find that you have exceeded the average GPD of the Discharge Permit. This then becomes a very unpleasant situation for the Owner with the local regulatory agency.

The use of high rejection membranes in an effort to increase recovery or the percentage of blend can also run into problems. If the discharge is to a waste

water plant the improved efficiency of the membrane system may prove a disaster to the WWTP. The new higher chloride levels may stress the bugs and create other problems. It is extremely important we understand what will end up in our concentrate stream so we can plan to dispose of it correctly.

EducationIn my opinion, we at AMTA need to continue to increase our efforts to influence those committees and agencies that have the power to modify and reinterpret the regulations and laws that effect the disposal of our concentrate streams. We must continue to protect the environment and operate membrane facilities while working to increase public awareness.

From the Editors

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By: Tom Seacord, P.E. and Winnie Shih, Ph.D.

SubMiTYouR

ARTicleTodAY!

AMTA Solutions continually

solicits technical articles for

future issues. We are currently

collecting articles in a variety

of water treatment subject

areas such as pretreatment,

Water Quality, New Facilities and

Membrane Residuals. Contact

AMTA for additional information.

Welcome to the fall edition of AMTA Solutions. This edition focuses on membrane residuals and we have two great articles to share with you. Our first article, by Dr. Steve Duranceau, won the Best Paper Award at the AMTA 2011 Annual Conference, and discusses recycling spent UF backwash stream to the upstream coagulation basins and its effect on the coagulation process. His research indicated that there is a threshold for acid to coagulant ratio, and exceeding that threshold will lead to turbidity problems in the settled water. The second is a technical paper

by Brad Biagini from Veolia, where we get to learn about the electrodialysis metathesis process which removes calcium salts that cause scaling in high recovery RO.

We look forward to the next edition and – with that in mind – we urge each of our readers to consider submitting an article for this publication. Submissions and inquiries can be sent to either (tseacord@carollo.com) or Winnie Shih (wshih@carollo.com). Thank you and we look forward to your feed back on this issue of Solutions.

Integrating Ultrafiltrationcontinued from page 1

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treatment system. Additionally, large volume recycle streams may upset treatment processes, allowing contaminants to pass through the system. To minimize these risks, the FBRR requires that recycle streams pass through the processes of a system’s existing conventional or direct filtration system (as defined in 40 CFR 141.2) that the EPA has recognized as capable of achieving 2-log (99 percent) Cryptosporidium removal (unless an alternative location is approved). However, the FBRR did not foresee or anticipate the conflicts that water purveyors replacing existing conventional filtration infrastructure, or constructing newly integrated coagulation-UF facilities, can experience if spent UF CEB residuals are not compatible with the coagulation process. Although this understanding has been learned by some within water community’s operations sector, much of this institutional knowledge has neither been fully vetted, nor adequately published within the literature.

Methods and ProceduresThe jar testing experiment was designed to simulate a full scale coagulation-flocculation-sedimentation basin. In this way, jar testing results can be used to identify potential water quality impacts from the recycle of UF backwash water containing citric acid. The Lake Manatee WTP was selected as the model for these experiments, and raw water from the Lake Manatee Reservoir was used in jar testing to collect the data presented herein. The Lake Manatee WTP practices alum coagulation with an organic polymer flocculant aid and lime addition for pH adjustment. Jar testing with Lake Manatee Reservoir water involved the addition of a coagulant, caustic for pH adjustment and an organic polymer. The organic polymer served as a flocculant aid and is used at the Lake Manatee WTP to improve floc formation.

Temperature, pH, and turbidity were collected during jar testing. Temperature and pH were measured during the slow mix phase of jar testing as it was an experimental goal to maintain relatively constant pH and temperature within the jars for each coagulant tested. The ferric chloride dose was determined through jar testing by evaluating different coagulant dose and pH combinations and comparing the settled water turbidity values. A ferric chloride dose of 75 mg/L with a target coagulation pH of 5.0 was selected based on the jar tests. An alum dose of 100 mg/L and target coagulation pH of 5.5 were selected based on the actual operating conditions of the Lake Manatee WTP at the time of jar testing.

The jar testing apparatus consisted of six 2-liter square jars commonly referred to as “gator” jars. The water used for testing was brought to room temperature and mixed before use. Jars were first spiked with the appropriate concentration of citric acid prior to the addition of the coagulant, sodium hydroxide and polymer. Coagulant and sodium hydroxide doses were added (either by vial or septa) just prior to the start of rapid mix. Jar mixing times and speeds were provided by the Lake Manatee WTP. An organic polymer dose of 0.18 mg/L was added during the slow mix sequence to facilitate the agglomeration of flocs. Temperature and pH measurements

were also taken during the slow mix sequence. To facilitate sampling, a uniform settling time of 15 minutes was selected based upon the guidelines in ASTM D 2035 – 80 prior to the collection of settled water samples for turbidity testing.

Results and DiscussionThe USEPA has recommended individual sedimentation basin performance goals for surface water treatment facilities. For facilities with average annual raw water turbidity values greater than 10 NTU, the settled water turbidity goal is less than 2 NTU 95% of the time (USEPA, 1998). This study defines the coagulation interference threshold as the acid to coagulant molar ratio (MR) beyond which settled water turbidity values exceed 2 NTU. Table 1 presents the citric acid dose ranges used for evaluating impacts on alum and ferric chloride coagulants. In order to maintain a relatively constant pH during coagulation, titrations were conducted to determine the required sodium hydroxide dose for each sample.

Table 1 citric Acid dose Ranges for Jar Testing

Water Source coagulant coagulant dose (mg/)

citric Acid Range (mg/l)

Lake Manatee, FL Aluminum Sulfate 100 0.25 - 70

Lake Manatee, FL Ferric Chloride 75 0.25 - 70

Figures 1 and 2 present the settled water turbidity results for alum and ferric chloride coagulation in the presence of citric acid. For both coagulants, settled water turbidity was observed to spike once an interference threshold was reached. Alum turbidity values increased significantly from 1.4 to 13.8 NTU beyond a CA/alum MR of 0.15, which corresponds to a citric acid concentration of 5 mg/L at an alum dose of 100 mg/L. Settled water turbidity values for ferric chloride jars increased from 1.07 to 28.9 NTU beyond a CA/ferric chloride MR of 0.11, which corresponds to a citric acid concentration of 10 mg/L at a ferric chloride dose of 75 mg/L.

Preliminary FindingsThis study has demonstrated that coagulation and settling interferences can occur when spent citric acid backwash recycle flows enter either alum or ferric chloride coagulation basins depending upon the CA concentration. Results of jar tests designed to simulate conventional water treatment plant recycle of spent CA backwash streams indicated that a recycle threshold exists, as defined by acid to coagulant molar ratios, beyond which significant deterioration in settled water turbidity occurs. This work documents, for the first time, the occurrence of coagulation interference thresholds at CA/coagulant MRs of approximately 0.15 for alum coagulation and approximately 0.11 for ferric chloride coagulation beyond which settled water turbidity values exceed 2.0 NTU. If the CA/coagulant MR is such that pin floc formation occurs in the coagulation basin, then mass loading on downstream filters may greatly increase. The work presented herein represents preliminary results and additional research remains ongoing with respect to the subject matter of citric acid interferences.

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AcknowledgementsThe research reported herein was funded by UCF project agreement number 16208085. A special thank you is offered to the Manatee County Utilities Department (17915 Waterline Road, Bradenton, FL 34212) who provided support, access to facilities and bulk source water supplies required for UCF’s testing. This project would not have been possible without the support of Manatee County Utilities staff, namely Bruce MacLeod, Bill Kuederle, Mark Simpson, in addition to many others who remain unnamed. The support of Alameda County Water District (Fremont, CA), Horizon Industries, Inc. (Las Vegas, NV), Toyobo Industries Co, Inc. (Osaka, Japan), and Harn R/O Systems, Inc. (Venice, FL) are acknowledged and were greatly appreciated. The contents of this paper do not necessarily reflect the views and policies of the sponsors, nor does the mention of trade names or commercial products constitute endorsement or recommendation. The comments and opinions expressed herein may not necessarily reflect the views of the officers, directors, affiliates or agents of the participants of this research project. The assistance and outstanding efforts of UCF graduate students Jayapregasham Tharamapalan, Andrea Cumming, Nancy Holt and Yuming Fang are noted and appreciated. n

ReferencesBelfort, G. (1981) “Fluid Mechanics in Membrane Filtration Recent Developments,” Journal of Membrane Science, Vol.40, pp. 123-147.

Boyd, C. C. (2011). Effect of Acetic or Citric Acid Ultrafiltration Recycle Streams on Coagulation Processes. Masters Thesis, University of Central Florida.

Duranceau, S.J and J.S Taylor. (2010). “Chapter 11 Membrane Processes” in Water Quality and Treatment, 6th Edition. Ed. J. K. Edzwald. New York: McGraw-Hill; pages 11-1 to 11-106.

Lovins, W.A.; S.J. Duranceau, R.M. Gonzalez and J.S. Taylor (2003). “Optimized Coagulation Assessment for a Highly Organic Surface Water Supply.” Journal AWWA. 95(10): 99-108.

Lyons, A. and L. Sangines. (2011). Troubleshooting and Optimization of a Surface Water Membrane Plant. Proceedings of the AMTA Annual Conference and Exposition, San Diego, CA; July 12-15, 2010.

Matilainen, A., Vepsalainen, M., & Sillanpaa, M. (2010). Natural Organic Matter Removal by Coagulation During Drinking Water Treatment: A Review. Advances in Colloid and Interface Science, Vol. 159, 189-197.

Strugholtz, S., Panglisch, S. S., Lerch, A., Brugger, A., & Gimbel, R. (2005). Evaluation of the Performance of Different Chemicals for Cleaning Capillary Membranes. Desalination, Vol. 179, 191-202.

USEPA. (1998). Optimizing Water Treatment Plant Performance Using the Composite Correction Program. EPA Handbook.

Zondervan, E. and Roffel, B. (2007). Evaluation of different cleaning agents used for cleaning ultrafiltration membranes fouled by surface water. Journal of Membrane Science, Vol. 304, 40-49

Dr. Steven J. Duranceau is Associate Professor of Environmental Engineering at the University of Central Florida (UCF) in Orlando, Florida. Dr. Duranceau’s research focuses on advanced water treatment process cost and performance, mass transfer, , and operation-related topics. He is also interested in distribution system water quality and corrosion control research, with more recent emphasis on water treatment nanotechnology applications. Dr. Duranceau is an Associate Editor of Desalination and Water Treatment. He previously served on the editorial advisory board of the Journal AWWA from 2001 to 2008 and Desalination from 2001-2011. Since 2006 he has been a member of the Research Advisory Board of the National Water Research Institute. Dr. Duranceau is a licensed professional engineer in Florida.

Figure 1citric Acid/Alum Molar Ratio versus Turbidity.

Figure 2citric Acid/Ferric chloride Molar Ratio versus Turbidity.

Ben’s Design Tip CornerBy: Ben Movahed, PE, BCEE

If you have a tip or a suggestion for a future design article, please contact Ben at: Ben Movahed: 301-933-9690 movahed@watek.com

Ben Movahed

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The primary residuals of low pressure membrane (MF and UF) filtration plants consist of Clean In-Place (CIP) and backwash water wastes.

The CIP solution is usually neutralized and disposed to the sanitary sewer. Due to the low volume and high concentration of CIP chemicals and contaminants, typically there is no incentive to recycle this stream.

Backwash water primarily consists of the naturally occurring feed water solids retained by the membranes. It also contains coagulants, oxidants, adsorbents and any other chemical used as pretreatment. The volume of waste depends on the system recovery, which is dictated by the feed water characteristics and

system design. Typical backwash waste volume for municipal applications varies from 4 to12% of the filtrate water produced. This could be a significant volume for large systems and therefore a candidate for recycle, reuse or at least safe discharge back to the surface waters.

The majority of the membrane filtration plants discharge the backwash to either surface waters or sanitary sewers. Before discharging to surface waters, backwash waste is typically processed for turbidity removal through settling ponds, decant systems or another solid removal mechanism. A 2000 survey of MF/UF plants in the US showed about 50% discharged to sewers and 40% to surface water. As low pressure membrane plants get larger and larger, a significant increase in surface

Low pressure membrane filtration residual recycling

Westminster WtP Process FloW Diagram

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...for wastewater treatment.

www.outokumpu.com/stainless/na

water discharges is anticipated. The National Pollutant Discharge Elimination System (NPDES) sets the minimum treatment standards for surface water dischargers and also establishes the framework for setting additional discharge standards under section 402 of the Clean Water Act. These regulations are typically enforced by all states and compliance is mandatory.

Some plants utilize a secondary membrane system to concentrate the backwash from the primary treatment system and return the filtrate of the secondary system to either the head works or to finished water tank. It is critical to evaluate the risk of re-introducing increased concentrations of pathogenic contaminants such as Cryptosporidium and Giardia to the drinking water supplies. USEPA Long Term Enhanced Surface Water treatment and Filter Backwash Rule also require self-assessment concerning the impacts of recycling the recovered waste streams.

For example, when the new 5 MGD membrane plant was built in the City of Westminster, Maryland, we utilized portions of the old sand filters to recover the MF backwash, as shown in the process flow diagram. The City has very limited water supply sources and overall recovery of the plant was a major design factor. With this recycle approach, the plant has been successfully operating with a total recovery of over 98% for the last 2.5 years. Obviously this is a unique situation where we had the luxury of keeping the old sand filters since there was no need or plans to demolish them.

In summary, the potential of recovering low pressure membrane backwash water should be carefully evaluated, especially for larger plants and systems with limited water supplies. n

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ZDD Technology DescriptionIn the ZDD technology, the calcium salts that cause scaling in a high recovery RO process are removed by an electrodialysis metathesis (EDM) process that is a variant of electrodialysis. A four-compartment electrodialysis metathesis stack is used to produce an EDM product, or diluate stream, plus two separate streams of highly soluble salts of the ions that are problematic in RO. The EDM stack is comprised of ion exchange membranes (alternating cation and anion) and thin solution compartments. A direct electric potential is applied to the ends of the stack, resulting in a direct current (DC) that is carried by ions migrating through the membranes and solution compartments. The DC potential draws ions through membranes from a dilute solution to one that is more concentrated. The major salts in the two depleting streams essentially change partners, forming concentrated solutions of highly soluble salts of the ions that are problematic in RO (see Figure 1). The two highly concentrated streams can then be mixed to precipitate a byproduct such as gypsum (calcium sulfate) or apatite (calcium phosphate).

Additionally, because only ionized constituents are able to permeate the EDM membranes, un-ionized silica passes directly to the EDM product, or diluate stream. By eliminating a cyclic concentration of silica within the treatment system and by maintaining silica just below its saturation point, higher overall recoveries can be achieved.

Zero Discharge Desalination (ZDD) Technology Yields High Recovery of Irrigation Water for ReuseBrad Biagini, N.A. Water Systems, Moon Township, PABernie Mack, Veolia Water Solutions & Technologies, Waltham, MAJohn Campbell and David Crawmer, Hilmar Cheese Company, Hilmar, CA

Hilmar Cheese Dairy Manufacturing PlantHilmar Cheese operates one of the largest cheese production plants in the world and has a comprehensive water reclamation plant that is designed to reuse water. The major existing treatment steps at Hilmar Cheese include Two-Stage Equalization, Physical-Chemical Dissolved Air Flotation (DAF), Anaerobic Digestion, Activated Sludge, Ultrafiltration, Two-Stage Reverse Osmosis, and Solids Dewatering and Concentrate Processing prior to deep

well injection. The dairy production plant reuses approximately 50-60% of the site water, and the water reclamation plant processes a flow normally in the range of 2.3 million gallons per day (MGD). The advanced secondary treated water that is processed by ultrafiltration and reverse osmosis contains elevated concentrations of calcium, phosphate, silica, and bicarbonate at alkaline pH. As these constituents are concentrated in an RO process, they reach solubility limits that can be detrimental to the life of

Figure 1electrodialysis Metathesis Process

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an injection well unless post-treatment is provided. RO permeate from the existing plant is reused for internal and agronomic purposes. Historical RO operation required up to daily cleaning with chemicals, use of anti-scalants, and pH adjustment to reduce calcium phosphate and carbonate precipitation.

Recently, Hilmar has been challenged by new surface discharge limits on electrical conductivity (EC) and TDS. As a result, Hilmar decided to evaluate several technologies, including ZDD, downstream of biological treatment for the purpose of achieving the EC/TDS permit limitations and possibly supplanting the RO operation, or improving its reliability and performance.

Zero Discharge Desalination (ZDD) technology was evaluated by Hilmar Cheese Company in 2010 as a potential solution to meet its water reclamation plant treatment needs. The goals of the evaluation were to determine if ZDD technology could successfully meet irrigation water reuse standards and reduce the quantity of brine directed to Hilmar’s injection wells. The primary goals of the pilot were to assess the performance of the ZDD process to:

• Maximize the overall system recovery in order to minimize the volume of the liquid stream requiring deep well disposal.

• Concentrate the waste streams and thus help to protect the deep well formation.

• Reduce the quantity of silica in the deep well injected waste stream to reduce scaling.

• Achieve irrigation water quality (< 900 μS/cm conductivity, < 85 mg/l chlorides), while increasing the overall yield of irrigation water and reducing the concomitant disposal.

Phase 1 Feasibility TestingTwo phases of ZDD piloting were conducted from January – April 2010 at the Hilmar Cheese site. Phase 1 Feasibility Testing was first conducted with a 0.5-gpm trailer-mounted pilot system that was provided by the University of Texas at El Paso (UTEP). The pilot system was operated by N.A. Water Systems with the support of Hilmar Cheese personnel, and consisted of an RO system and an EDM stack. During this phase, four different source waters were fed to the ZDD pilot system: 1) Ultrafiltration Permeate (Un-

Softened); 2) Ultrafiltration Permeate (Softened); 3) RO Concentrate; and 4) Well Water.

The water was fed to an RO system that operated at approximately 60% recovery. The RO concentrate was fed to the EDM stack, where the majority of the salts were removed into one of the two highly soluble mixed salt streams. The EDM product water (diluate) flow was split, with a portion being recycled to the RO feed and the remainder directly blended with the RO permeate to mitigate the risk of silica scaling within the system. A process flow diagram of the ZDD treatment line that was utilized during this phase of testing is shown in Figure 2.

Phase 1 testing successfully demonstrated an increase in overall system recovery, from 80 – 90% (based on RO operation) to 96 – 98% of the water, producing an effluent that was suitable for reuse in irrigation. The two EDM concentrate

Figure 2Zdd Process Flow diagram

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Zero Discharge DesalinationContinues from page 9

Parameter Ro Feed Ro concentrate Ro Permeate

edM Feed edM diluate

Mixed Sodium Salts

Mixed chloride

Salts

TeST 1 - ulTRAFilTRATion PeRMeATe (un-SoFTened) FeedConductivity, µS/cm 4,963 7,901 609 4,874 4,504 95,305 115,903

Calcium, mg/l 35.0 60.4 2.4 31.7 29.4 75.0 1,239

Sodium, mg/l 966 1,659 82 1,024 932 37,892 30,683

potassium, mg/l 277 405 88 189 185 680 6,988

phosphate, mg/l 202 90 2.3 60.6 57.8 1,410 63.7

Chloride, mg/l 649 1,146 130 694 597 27,910 53,615

Bicarbonate Alkalinity, mg/l as CaCO3

1,512 2,356 55 1,419 1,391 35,427 774

Silica, mg/l 17.7 31.6 1.9 33.4 32.6 18.3 15

TeST 2 - ulTRAFilTRATion PeRMeATe (SoFTened) FeedConductivity, µS/cm 6,253 9,025 215 4,593 4,350 98,886 194,868

Calcium, mg/l 7.1 10.9 0.5 4.6 4.5 19.1 504

Sodium, mg/l 1,251 1,992 23 959 1,519 30,112 48,817

potassium, mg/l 194 301 12 111 120 720 8,378

phosphate, mg/l 50 119 1.3 51 66 1,442 61

Chloride, mg/l 712 1,119 24 453 434 17,071 73,029

Bicarbonate Alkalinity, mg/l as CaCO3

1,940 2,644 34 1,530 1,268 47,259 583

Silica, mg/l 20.4 33.4 0.4 33.6 31.5 18.3 13.8

TeST 3 – Ro concenTRATe FeedConductivity, µS/cm

N/A

12,862 11,867 78,447 180,353

Calcium, mg/l 18.1 16.2 23.0 433

Sodium, mg/l 3,096 2,731 23,365 54,191

potassium, mg/l 438 357 730 10,630

phosphate, mg/l 247 231 631 13

Chloride, mg/l 1,469 1,241 14,977 85,200

Bicarbonate Alkalinity, mg/l as CaCO3

4,616 3,929 24,503 665

Silica, mg/l 74.0 72.3 38.2 18.2

TeST 4 – Well WATeR FeedConductivity, µS/cm 1,553 1,922 184 1,674 1,802 89,560 102,422

Calcium, mg/l 45.8 59.5 0.8 47.4 43.3 5,716 11,180

Sodium, mg/l 196 266 29.9 219 240 43,986 45,546

potassium, mg/l 11.4 10.5 1.6 8.6 8.1 910 1,432

phosphate, mg/l 15.3 20.9 1.2 17.3 21 435 241

Chloride, mg/l 349 800 9.4 374 377 84,154 134,433

Bicarbonate Alkalinity, mg/l as CaCO3

198 246 103 207 242 17,251 134

Silica, mg/l 118 157 0.7 123 161 134 42.8

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streams that comprised the remaining 2 -4% were: 1) a mixed sodium salts stream with a concentration of approximately 16% TDS, which contained the majority of the phosphate ions; and 2) a mixed chloride salts stream with a concentration of approximately 13% TDS, which had the potential to be suitable as a regenerant for Hilmar’s ion exchange softening process. The ability of the EDM process to pass silica directly into the irrigation water provided a distinct advantage over other technologies (such as RO and evaporation) that would be limited by the concentrations of silica within the system. The results achieved from treatment of each of the four feed waters are summarized on the proceeding page.

One of the most significant benefits demonstrated by the technology during this phase of testing was the ability to treat feed water with high silica concentrations and pass the majority of the silica into the product water. Because silica is present in the EDM stack as an un-ionized species, most of the silica does not migrate through the membranes. Only a small quantity of silica is present in the mixed salt streams due to the water of hydration that migrates through the membranes along with the charged species. The majority of the silica passes into the EDM diluate stream. This proved to be advantageous in reducing the silica scaling potential of the waste streams being sent to the deep well.

The primary limitation of system recovery that was identified during Phase 1 was the temperature-dependence of sodium bicarbonate solubility. At a temperature of approximately 60°F, crystallization of sodium bicarbonate in the mixed sodium salts stream was significant, preventing flow and resulting in a system shutdown. Due to high alkalinity in the feed water, a significant concentration of sodium bicarbonate was being generated in the mixed sodium salts stream, which was primarily comprised of sodium bicarbonate and sodium chloride. When the feed water contains a mixture of chloride and bicarbonate, as in this case, the interaction of sodium chloride on the solubility of sodium bicarbonate has to be taken into account. As illustrated in Figure 3, the solubility of sodium bicarbonate decreases at lower temperatures as well as at increasing concentrations of sodium chloride. While the salts are readily soluble in a dilute solution and can be re-dissolved very easily by dilution, the crystallization of sodium bicarbonate in a sodium chloride solution limits the possibility of increasing the water recovery in waters that contain substantial quantities of chloride and bicarbonate.

The concentrations of the EDM mixed salt streams are managed during operation by controlling the system at a conductivity setpoint. Therefore, after the sodium bicarbonate crystallization scaling was

Figure 3Solubility of Sodium bicarbonate as a Function of Temperature and Sodium chloride

Parameter Ro concentrate edM Feed edM diluate Mixed Sodium Salts

Mixed chloride Salts

Conductivity, mS/cm 38,984 18,421 16,192 132,753 178,841

Calcium, mg/l 214 56.4 38.7 82.5 2,122

Sodium, mg/l 7,353 3,728 3,282 40,756 44,695

potassium, mg/l 1,560 588 483 1,123 9,205

phosphate, mg/l 337 209 193 1,142 77.3

Chloride, mg/l 3,888 2,193 1,809 24,691 78,743

Bicarbonate Alkalinity, mg/l as CaCO3

5,528 2,616 2,791 17,404 1,047

Silica, mg/l 93 97 97 50.7 27.2

continued on page 12

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observed, the conductivity setpoint of the mixed sodium salts stream was lowered to manage this effect.

Phase 2 Validation TestingPhase 2 of the pilot project involved validation of ZDD technology on a larger scale in order to develop a full-scale system design. N.A. Water Systems constructed and mobilized a commercial EDM system to complete this testing. During this phase of testing, Hilmar provided an RO concentrate stream from its existing system to feed the EDM stack. Data were collected on the pilot unit for approximately three weeks from April 6 to April 29, 2010. For the first week, Hilmar’s RO system was operated as a single stage at approximately 80% recovery. During the second and third weeks, a second-stage RO was included in Hilmar’s treatment scheme to treat the concentrate from the first-stage RO. This second-stage RO operated at approximately 50%, increasing the overall RO recovery to 90%. The analytical results (average values) from this phase of testing are shown on the proceeding page.

Phase 2 testing validated that the treatment goals of Hilmar Cheese could be achieved with ZDD technology by maximizing the concentrations of the mixed salt waste streams for deep well injection and minimizing the

concentration of silica in those water streams. The average EC of the mixed salt streams achieved during the Phase 2 test was about 133,000 µS/cm mixed sodium salts and 179,000 µS/cm mixed chloride salts. The mixed chloride stream was composed primarily of sodium chloride, which potentially could be used as a regenerant in Hilmar’s ion exchange softening process. The majority of the silica was passed into the EDM diluate, with less than 51 mg/l in either of the mixed salt streams, eliminating any silica scaling potential.

Figure 4 shows a relatively linear relation between stack amperage and mixed salt conductivities, as would be expected. The reduction in conductivity across the stack (i.e., EDM diluate conductivity) was dependant on the stack voltage. At an applied voltage of 100 V, the average conductivity reduction was 80%, whereas at an applied voltage of 50 V, the average conductivity reduction was 35%. Therefore, when designing an EDM system, the correlation between power consumption and required diluate quality must be evaluated to determine the optimum design.

ConclusionDuring two pilot testing phases, ZDD technology successfully achieved the water treatment goals at Hilmar Cheese. By combining RO and EDM technologies, the scaling concerns prevalent with a conventional

Figure 4edM Stack conductivities as a Function of Applied Voltage and Amperage

RO treatment approach (calcium phosphate, calcium carbonate, silica) were eliminated. Because only ionized constituents are able to permeate the EDM membranes, un-ionized silica passes directly to the EDM product, or diluate stream, eliminating the potential for silica scaling in the waste streams that would be deep-well injected. By using ZDD technology, a 96 – 98% water yield was achieved with quality suitable for irrigation. The desired product water conductivity (< 900 μS/cm) was also achieved during the pilot testing. As an added value, the mixed chloride stream was composed primarily of sodium chloride and potentially could be reused as a regenerant in Hilmar’s ion exchange softening process. n

References1. Faust, S.D. and O.M. Aly, Chemistry of Water Treatment, 2nd Edition, 1998.

2. Meller, F., Electrodialysis – Electrodialysis Reversal Technology, Ionics, Incorporated, 1984.

Brad Biagini is a Product Manager with N.A. Water Systems, a Veolia Water Solutions & Technologies Company. He has a total of 10 years of experience in process design and optimization efforts, which includes 4

years of experience in the Water Treatment field. He holds a bachelor’s degree in Chemical Engineering from The Pennsylvania State University and a master’s degree in Materials Science and Engineering from North Carolina State University. Mr. Biagini’s areas of expertise includes unique high-recovery membrane-based technologies that consist of ultrafiltration, reverse osmosis, and electrodialysis. He has executed both pilot projects and full-scale commissioning and startup operations.

Zero Discharge DesalinationContinues from page 11

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Christine A. Owen

Legislative Affairs & Regulatory Programs Committee Chair

Regulatory Update

Department of Homeland Security Chemical Security Analysis Center (CSAC) of DHS is developing a Chemical Terrorist Risk Assessment (CTRA) in order to evaluate chemical security risks. The CTRA considers a number of threat scenarios; of interest to the drinking water industry is contamination via drinking water distribution systems. The Department has hired Battelle to work with distribution system data from at least 15 municipal water systems. The data and subsequent analysis will be classified “For Official Use Only”.

Participation in this effort is voluntary. DHS cannot require utilities to provide such data as the Department does not have regulatory authority over the water sector.

Next Regulatory Determinations for EPA Will Use 2005 Cancer Guidelines EPA intends to apply age dependent adjustment factors for early life exposure to mutagenic carcinogens. EPA indicated it is considering nitrosamines as one of the first groups for this approach. Nitrosamines have been identified as a potential group for regulation. To determine the carcinogenicity for contaminants under consideration, EPA will adjust the cancer slope factor based on the 2005 agency document, Cancer Guidelines and Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens (www.epa.gov/moaframework). In addition to nitrosamines, there are at least a dozen other contaminants being considered for regulatory decision in this round. The agency plans to publish preliminary determinations for comment in late 2012 and final determinations in 2013. Proposed regulations from Reg-Det 3 are expected in 2015.

EPA NOAA Partnership To Encourage Sustainable Coastal CommunitiesNOAA and EPA announced a joint effort aimed at strengthening coordination and communication between the two agencies to assist territories, regional governments, states, tribes and local governments to become sustainable and resilient coastal communities. The Memorandum of Agreement (http://tinyurl.com/3fd7xm2) highlights the importance of protecting healthy coastal ecosystems, restoring ecosystems and adapting to climate change. The partnership will strive to “maximize skills, knowledge and effectiveness on targeted projects and activities.” NOAA has similar agreements memorandums with the U.S. Army Corps of Engineers and U.S. Geological Survey to work more closely together to address the nation’s water resources challenges.

Community-Based Water Resiliency Electronic Tool Available for DownloadEPA has released the Community-Based Water Resiliency (CBWE) electronic tool which is designed to help utilities assess their present state of resiliency to water service interruptions. The tool was developed in collaboration with community stakeholders and includes more than 350 resources.

Alternative Testing Methods For Drinking Water ContaminantsEPA has approved 11 analytical methods for determining contaminant concentrations in samples collected under the Safe Drinking Water Act (http://tinyurl.com/2011/AlternativeMethods). The new methods do not replace previously approved

methods, but are in addition. The Safe Drinking Water Act authorizes EPA to approve alternative methods through an expedited process of publication in the Federal Register. A new method can be considered for approval using the expedited process, if it has performance characteristics that fall within the range of performance characteristics obtained by the methods listed in regulation for the same contaminant. The final rule was effective immediately upon its publication.

RTCRThe Revised Total Coliform Rule (RTCR) is scheduled to be finalized in 2012. Work underway on the RTCR includes updates to supporting documents (i.e., Economic Analysis, Cost and Technology Document) which are required prior to final Office of Management and Budget review. Because the RTCR is based on an Agreement in Principle developed as part of the Federal Advisory Committee process, little change is expected from the proposed version to the final version of the rule.

Perchlorate and Carcinogenic VOC’s Two drinking water regulations on the regulatory horizon include perchlorate and carcinogenic volatile organic compounds (VOCs) with scheduled proposal dates in 2013. Work on these contaminants is in the early stages of development as EPA reviews the science and data on occurrence, health effects and feasible treatment technologies that will form the basis of the rulemaking efforts. A Small Business Advocacy Review Panel is currently being assembled to give small entity stakeholders a chance to provide input to the perchlorate rule process. Additional stakeholder outreach is expected in late 2011.

HOT TOPICS

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Cr-VI California’s Office of Environmental Health Hazard Assessment (OEHHA) has adopted the nation’s first public health goal for Cr-VI. California set the public health goal at 0.02 ppb, which is lower than the 0.06 ppb goal originally proposed in 2009 by the State. The lower 0.02 ppb public health does have an impact on future state rules since any enforceable standard, by state law, must be set as close as possible to the public health goal as technological and cost constraints allow. The adoption of the California public health goal puts additional pressure on EPA to consider a federal Cr-VI drinking water standard.

Bisphenol A (BPA) EPA published an Advance Notice of Proposed Rulemaking (ANPRM) to “solicit public input on the necessity for and best approach to obtain environmental effects, exposure and pathway information relevant to determining whether Bisphenol A (BPA) presents an unreasonable risk of injury to the environment.” The ANPRM was issued under the Toxic Substances Control Act and would require manufacturers and processers of BPA to conduct toxicity and environmental testing to fill existing environmental data gaps. Additional testing related to human health effects is not being considered under the ANPRM at this time

Quality Of State Drinking Water Violation DataIn July, the General Accountability Office (GAO) released a report, “Unreliable State Data Limit EPA’s Ability to Target Enforcement Priorities and Communicate Water Systems’ Performance,” which is highly critical of the quality of states’ drinking water violation data. The assessment is based in part on 2009 EPA audit data for 14 states showing that 26 percent (778) of health-based violations and 84 percent (54,600) of monitoring violations were reported incorrectly or omitted. These

data are required to be reported under the Safe Drinking Water Act. Although in line with previous year estimates, the state of data reporting is seen as an impediment to efficient enforcement. Inadequate staffing, training, guidance and associated funding deficits are cited as major reasons for the data quality issues. EPA has acknowledged the findings but stresses that it has been aware of the issues and has several ongoing efforts to address them. Efforts include a major update to the Safe Drinking Water Information System (SDWIS) which will allow EPA direct access to state enforcement and monitoring violation reporting. The GAO report is available at www.gao.gov/products/GAO-11-381.

Proposed and Pending Rules.Bisphenol A (BPA)Notice: Advance Notice of Proposed Rulemaking (ANPRM)

Proposal: TBD

Description/Status: EPA requested comments on its ANPRM for environmental testing, testing of drinking water and its sources

Carcinogenic Volatile Organic Compounds (VOCs)Notice: National primary drinking water regulation (NPDWR) for up to 16 VOCs

Proposal: October 2013

Final: April 2015

Description/Status: EPA conducting evaluations and developing supporting materials

Lead and Copper Rule: Regulatory RevisionsProposal: May 2012

Description/Status: EPA conducting evaluations and developing supporting materials

NPDES Pesticides General PermitProposal: June 4, 2010

Final: October 31, 2011

Description/Status: The U.S. Court of Appeals for the Sixth Circuit granted a stay of its April 9 deadline for pesticide users to obtain an NPDES permit for aquatic pesticide use until October 31.

PerchlorateNotice: Regulatory determination

Proposal: February 2013

Final: August 2014

Description/Status: EPA conducting evaluations and developing supporting materials

Radon RuleProposal: November 2, 1999

Description/Status: Regulatory Agenda lists the final action for this rule as “to be determined.”

Revised Total Coliform Rule (RTCR)Proposal: June 17, 2010

Final: November 2012

Six-Year ReviewNotice: March 29, 2010

Final: TBD

Description/Status: Awaiting EPA decisions on possible regulatory determinations

Unregulated Contaminant Monitoring Rule 3 (UCMR 3)Proposal: March 3, 2011

Final: December 2012

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p A g e 1 6

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p i p i n g • s y s t e m • s o l u t i o n s

Ian C. Watson, P.E. Executive Director

Message from the Executive Director

Dear AMTA Members:

After the exciting but somewhat warm week in Miami Beach at our 2011 joint AMTA/SEDA Conference and Exposition, the rest of this year will not slow down! Coming up in September and late October, we will have two more workshops to round out the year. SEDA will have its Fall meeting in Clearwater, and SCMA has concluded their annual meeting in August in San Antonio. We are working on the 2012 joint AMTA/SWMOA/AWWA joint conference in Glendale AZ next February, a slate of workshops for 2012 is starting to move forward, and soon we will be starting work on the 2013 joint conference in San Antonio. Never a dull moment!

There will be new look to AMTA’s website within a few weeks. Our contractor has started to develop some concepts, and when the new web site is rolled out, your new interactive map will also be launched.

This year in Miami, I continued with the interviews we call “Chats with the Pioneers”. This year I interviewed representatives from Envirogenics Systems Company, or ESCO, which started life as a division of Aerojet General. ESCO was a big player in the Middle East in 70’s and 80’s, and built one

of the first RO plants in Florida, at Greater Pine Island water Association near Cape Coral in 1974. The second interview was with Basic Technologies. This was the first Florida based OEM, and was very successful for many years. As you will know from the earlier history of membrane softening, Paul Culler, who founded Basic, was the inventor of membrane softening. Truly a pioneer. When we get these interviews edited, and clipped, we will post the clips on the website, so that all the members can listen to what these folks had to say about the beginnings of our industry.

AMTA continues to flourish, even in these tough economic times. We had a great turnout in Miami Beach, and our membership is holding its own. But, you can still do you part, and recruit new members. As I have said before, if you are in this business you must join AMTA. It is the only sensible thing to do! An association is only as good as its membership, and you are the best. We need more like you.

Best Regards

Ian C. Watson, P.E., Executive Director American Membrane Technology Association

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Lynne Gulizia Steve Malloy Membership Co-Chairs

Membership Update

Since our last newsletter we have welcomed 36 new members!Salem Alzahrani National University of Malaysialila Arcaya Patrick Armstrong National Oilwell VarcoRon Aube JMAR, LLCKelly bertrand National Oilwell VarcoMatthew bryce National Oilwell VarcoRobert “bruce” chalmers CDMeric coe Garney ConstructionRon davis CalDesaldouglas de Freitas don deMichele Carollo Engineers, Inc.Frank deStefano Purolite CompanyMark eyers Ph.d.Thermphos

Steve Fischer JMAR, LLCTony Gedeon Sulzer Pumps (Canada) Inc.Greg Gilles Ruben Gonzalez Rodrigo J. Gonzalez Michael J. halbur Garney ConstructionMike hart National Oilwell VarcoTri Q. huynh bSchemeToray Membrane USA, Inc.holly R. Johnson Veolia Water Solutions & TechnologiesJohn R. Jones Ahmad Y. Kalender edward b. labelle P.e.Jacques lamy Jack Manns Tina Masters-odum P.e.Duraflow, LLCPaul Matz

Masato Mikawa Alex nunn Synder FiltrationMike l. Price MWH Americas, Inc.Mark Said Enceladus Water Group, LLCorren Schneider Kirk Shelton National Oilwell Varcoeben J. Williams Flotech, Inc.

Members!It was so nice to see many of you during the annual conference in Miami in July. The conference was a great success, and I hope by attending you continued to find value in your membership. The conference offered topics of interest to all attendees including engineers and operators from water utilities, consulting engineers, membrane industry manufactures, college professors and students, and several international representatives. Everything from the quality of the papers and exhibit booths to the food and the social activities was top notch. We were able to thank you for your membership by giving away a number of prizes at a packed Membership Meeting, including 2 Kindles and an iPad!

The value of our association and our sole emphasis on membrane technologies is evident by our partnership with AWWA and the joint conference we will be bringing to you in March 2012 in Glendale, Arizona. The conference will combine the strengths of both organizations to bring you what we are

sure will be the largest conference ever dedicated to membrane technology. Be sure to keep your membership current so you can take advantage of the member rates to attend the conference. Because the conference will be earlier than our traditional summer dates, be sure to mark your calendars now to ensure you won’t miss a thing.

Thanks again for your continued support and enthusiasm. Ideas and suggestions for membership activities are always welcome.

Hope to see you in Sacramento, Kansas City or Glendale, Arizona in the near future.

Lynne M. Gulizia Membership Chair Steve Malloy Membership Chair

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transitionGordon Leitner, 1922–2011Gordon F. Leitner died on 25 August in Mystic, Connecticut, from cancer. He was 89.

Gordon was born in Chicago, Illinois and received a mechanical engineering degree from the University of Illinois. After serving in the US Army during World War II, he returned home to his first ‘real job’ designing boilers for Babcock & Wilcox.

Earlier this year, he was still a bit wistful when describing the drive home from that job interview: “I was so enamored with the position that I had been offered that I drove right through a red light. A cop

stopped me and when he came to my car, I asked him if he was looking for someone. He said, ‘Yes, you. You just went through a red light.’ I was still thinking about that great job opportunity; I’ve always loved steam.”

In 1951, he went to work for Cleaver-Brooks, the Wisconsin-based boiler company that developed the Aqua-Chem line of vapor compression desal units for the US Army. In the mid-1950s, he and Richard Goeldner designed and patented the long-tube, brine recirculation MSF evaporator, and in the late 1950s, he co-invented the Spray-Film multiple effect evaporator, a process which he described to WDR as follows:

“During a 1958 visit to Kuwait with Fred Loebel, Ken Cotterill proudly showed us a converted three-effect falling film evaporator. Before the conversion, the carryover of salt droplets in the distillate was unmanageable. To correct the problem, the water level was dropped below the tube bundle, a circulating pump and spray nozzles were added, and it worked! We were so impressed that we ordered our R&D department to build a pilot model, which we branded Spray Film. Not only did we get high quality distillate, but a much improved heat transfer coefficient. All of which confirms the old adage that unexpected benefits of development sometimes outweigh the original objective.”

When Coca Cola bought Aqua-Chem in 1971, Gordon resigned as president and started Water Services of America (WSA), continuing his involvement with steam-based systems. However, WSA gradually embraced membrane systems, eventually designing and building the US’s first commercial SWRO system in Key West, Florida in 1980.

Later, he started Leitner & Associates to provide independent consulting services. In 1992, he compiled the first comprehensive report on the capital and operating costs of desalination for NWSIA, AMTA’s predecessor. Gordon and his daughter Faith served as co-editors of the Desalination and Water Reuse Quarterly from 1994 to 2000, and he was elected to AMTA’s Hall of Fame in 1996.

He continued to follow the desal industry closely, and was completing a book on its history at the time of his death. The book will now be published by his daughters.

Gordon was a desal pioneer and one of the shrinking number of desalters who are equally comfortable with thermal and membrane processes. Although he always loved steam, his appreciation for membranes never stopped growing.

He is survived by Jessie, his wife of 65 years, daughters Wendy, Penelope and Faith, and three granddaughters.

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Calendar of Events

contact the following organizations for more information regarding their listed events:AMTA – 772-463-0820, admin@amtaorg.com, www.amtaorg.comAWWA – 303-794-7711, awwamktg@awwa.org, www.awwa.orgCaribDA – 772-781-8507, admin@carbida.com, www.caribda.comIDA – 978-887-0410, paburke@idadesal.org, www.idadesal.orgSCMA – 512-236-8500, info@scmembrane.org, www.scmembrane.orgSeDA – 772-781-7698, admin@southeastdesalting.com, www.southeastdesalting.comSWMOA – 888-463-0830, admin@swmoa.org, www.swmoa.org

newsletter Advertisement is Available.

Janet L. Jaworski American Membrane Technology Association2409 SE Dixie Hwy. • Stuart, FL 34996772-463-0820 • 772-463-0860 (fax)admin@amtaorg.comA form is available on the website at www.amtaorg.com/publications.html

Please Contact AMTA for rates and availability.

2011 events

Oct. 23-25, 2011 SeDA Fall Symposium, Clearwater Beach, FL

Oct. 31-Nov. 2, 2011 AMTA Technology Transfer Workshop, Kansas City, MO

Nov. 14-18, 2011 SeDA MOC Short School, palm Coast, FL

Nov. 16, 2011 SWMOA Workshop, San Diego, CA

Dec. 7, 2011 SeDA Operation & Maintenance of Degasifiers & Scrubber Systems Workshop,

Hollywood, FL

2012 events

Jan. 30-Feb. 2, 2012 SWMOA Annual Conference, Redondo Beach, CA

Feb. 27-Mar. 1, 2012 AWWA/AMTA Membrane Technology Conference & expo, glendale, AZ

May 21-23, 2012 AMTA Technology Transfer Workshop, Seattle, WA

June 17-20, 2012 SeDA Spring Symposium, Bonita Springs, FL

June 19-22, 2012 CaribDA 2012 Conference & expo, Aruba

Oct. 23-25, 2012 AMTA/SeDA Joint Technology Transfer Workshop, Key Largo, FL

Non profit Org.U.S. postage

p A I DWest palm Beach, FL

permit #20852409 Se Dixie Hwy.Stuart, FL 34996