The Water Desalination Research & Development Program Newsletter - No. 12 - Winter 1998

PROGRAM AUTHORIZATION

The Water Desalination Research & Development (DesalR&D) Program was authorized by Congress under the Water Desalination Act of 1996, (Act) Public Law 104-298. The primary goal of the program is to develop more cost-effective, technologically efficient, and implementable means to desalinate water. The Act authorized program funding up to $5.0 million per year, beginning October 1997, for a six-year period. To initiate the program, funding was appropriated at $3.7 million for fiscal year 1998. For fiscal year 1999, which began October 1, 1998, funding was appropriated at $2.5 million.

This newsletter is a DesalR&D Technology Transfer effort and is provided to keep you informed of the latest activities and developments in the program. For more information about the DesalR&D program, contact Kevin Price, Program Manager, at 303-445-2260, or visit the DesalR&D web site at: http://www.usbr.gov/pmts/water/research/DWPR/.

NEW DESALR&D CONTRACTS

Following is a list of recently awarded contracts by task, including the name of the principal investigator, their company or academic affiliate, the contract amounts (total and Reclamation contribution, respectively), and a short project abstract:

TASK A - MEMBRANE PROCESS RESEARCH AND DEVELOPMENT STUDIES

Dr. Mark Wilf and Hydranautics will study Development of a New Ultrafiltration Capillary Membrane and Study of Fouling Parameters, Flux Restoration, and Pathogens Retention Using Membrane Sampling Device (total project: $261,957; Reclamation's contribution: $125,000). This study proposes to develop a new ultrafiltration (UF) capillary membrane element. The objective of this work is to investigate performance of the newly developed elements in field operation using heavily fouling surface and wastewater. Preliminary screening with respect to membrane fouling will be conducted using the novel test tool, the Membrane Sampling Device.

Dr. Anne Camper and Montana State University-Bozeman will study Design and Optimization of Biological Reactors for the Pretreatment of Reverse Osmosis Feed Water (total project: $133,933; Reclamation's contribution: $64,923). This study proposes to reduce membrane fouling by pretreating water using biological reactors to remove the organic nutrients that support formation of fouling biofilms. The technology will improve membrane productivity by complementing existing pretreatment processes while reducing dependence on use of disinfectants. The emphasis is on controlling biofouling in an engineered system rather than having it occur in undesirable locations.

Mr. Robert Lovo and Pacific Research Group will conduct a Cost Reduction Study for Seawater Desalination Membrane Processes (total project: $247,745; Reclamation's contribution: $122,300). A solution to the high cost associated with use of open ocean intake structures is to utilize the natural filtering properties and the low dissolved oxygen levels of the ocean seafloor. This can be done by locating an intake system within the porous strata of the seafloor. The objective of this project is to demonstrate a reduction of 20-30% in initial capital expenditures as well as a reduction of operation and maintenance (O&M) costs.

Dr. James Kilduff and Rensselaer Polytechnic Institute (RPI) will study Membrane Fouling: Influence of Natural Organic Matter Properties and Membrane Surface Treatment on Adhesion and Flux Decline (total project: $122,081; Reclamation's contribution: $122,081). The goal of this study is to understand how naturally occurring dissolved and colloidal organic matter (NOM) affect the adhesion of these foulant materials to membrane surfaces and to develop a procedure to modify commercially available membranes to reduce their tendency to foul by NOM. RPI expects to identify the properties of naturally occurring aquatic NOM that are most responsible for membrane fouling and how these properties vary among NOM sources.

Mr. Robert Riley and Separations Systems Technology, Inc., (SST) will study Polyamide Reverse Osmosis Membrane Fouling and Its Prevention (total project: $305,816; Reclamation's contribution: $123,814). Documented molecular modeling has shown that the bond angles of the ctct isomer of CPTC (cis, trans, cis, trans 1,2,3,4-cyclopentanetetracarboxylic acid chloride) are less strained than those of the five remaining isomers. Also, this material has been shown to demonstrate unusually good resistance to attack by chlorine. SST will continue work funded by others in development of a chlorine resistant polyamide membrane made using this acid chloride.

Dr. Christopher Bowman and University of Colorado (CU) will study Membrane Modification by Photografting for Reduction of Adhesion Fouling (total project: $129,665; Reclamation's contribution: $83,981). CU will continue an investigation that has been supported by Reclamation for several years. The main thrust is developing previously identified techniques of grafting onto polyethylene surfaces of moieties that will reduce adhesion of various foulants. The objective is to exploit the previously demonstrated advantages of rapid backpulsing in membrane filtration.

Dr. Amy Childress and University of Nevada-Reno will study Characterization of the Hydrophilicity of Polymeric Reverse Osmosis and Nanofiltration Membranes: Implications to Membrane Fouling (total project: $114,956; Reclamation's contribution: $79,983). Extensive research has been performed on contact angle characterization of UF membranes, but little work has been done on the characterization of reverse osmosis (RO) or nanofiltration (NF) membranes. In previous investigations, hydrophilicity has been approximated by contact angle measurements. This study proposes a method for determining actual hydrophilicity by performing a series of contact angle measurements using polar and apolar liquids. The goal is to characterize the hydrophilicity of several membranes and to relate hydrophilicity to the fouling potential of the membranes.

TASK B - THERMAL PROCESS RESEARCH AND DEVELOPMENT STUDIES

Dr. John Walton and University of Texas at El Paso (UTEP) will study Solar and Waste Heat Desalination by Membrane Distillation (total project: $139,500; Reclamation's contribution: $124,873). This study will test and evaluate the performance and O&M procedures of a commercially available distillation unit built by SCARAB using low grade thermal energy (40-100øC) supplied by a salinity-gradient solar pond. The research will include measuring the flux and separation of ions over a range of feedwaters and temperatures and obtaining data on membrane fouling.

Dr. John Walton and UTEP will study Thermal Desalination Using MEMS and Salinity-Gradient Solar Pond Technology (total project: $139,616; Reclamation's contribution: $124,989). This study will test and evaluate the performance and O&M procedures of a Licon multi-effect, multi-stage (MEMS) thermal flash distillation unit when driven by thermal energy supplied by a salinity-gradient solar pond. The research will provide useful data and information for improving the overall thermal efficiency and economics of a solar pond coupled to MEMS desalination.

TASK C - NON-TRADITIONAL AND ALTERNATIVE DESALINATION RESEARCH AND STUDIES

Dr. James Beckman and Arizona State University (ASU) will study Innovative Atmospheric Pressure Desalination (total project: $73,042; Reclamation's contribution: $53,122). This study will investigate a heat driven tower process known as Continuous Contacting Dewvaporation Process (CCDP). The tower uses air as a carrier-gas to evaporate water from saline feeds at atmospheric pressure. The heat source can be low temperature solar, waste heat, or combustible fuels. This research will focus on the enhancement of the heat and mass transfer coefficients in the linear flow regime which will reduce the cost of the technology. This research will also include investigation of the scaling potential, mathematical modeling, and development and testing of a prototype with brackish water and seawater.

Dr. Robert Amme and University of Denver will study Application of Electret Technology to Low Cost Desalination (total project: $123,247; Reclamation's contribution: $99,447). This study will conduct research on a novel ion separation process that employs electrostatic fields produced by electrets (permanently polarized or charged dielectric materials). This technology has been patented (U.S. Patent 4,948,514 and 5,061,376) and preliminary testing has been conducted. This research will involve an extensive investigation to optimize the design, which will include selection of electret material and ion-transfer membranes. A prototype will be constructed and tested, and an economic analysis and modeling will be performed.

TASK D - WATER RECYCLING AND REUSE

Dr. Peter Fox and ASU will study Evaluation of Flow Fields in Wetlands (total project: $126,898; Reclamation's contribution: $73,184). This project involves both lab models and site tests of wetlands for treatment of wastewater effluents. Flow, depth, vegetation, and other parameters will be varied to study the performance of wetlands for treating wastewater.

Dr. Paul Anderson and Illinois Institute of Technology will study Innovative Photocatalytic Process for Silver Recovery and Wash Water Reuse (total project: $60,844; Reclamation's contribution: $60,844). This project involves fabrication of a titanium dioxide photocatalyst to remove silver from the wastewater from photo processing industries. A major benefit to this industry would be realized if this technology is successful.

Dr. Michael Johnson and New Mexico State University will study Improvement of the Treatment Facility at the Leadville Mine Tunnel (total project: $90,760; Reclamation's contribution: $75,000). This project involves forming magnetite for magnetic separation of heavy metals in cold waters such as the drainage from the Leadville Mine Drainage Tunnel. Los Alamos National Laboratory will be used to develop and test the magnetic separator.

Dr. Chin-Pao Huang and University of Delaware will study Treatment of Wastewaters for Water Reuse by a Catalytic Sonochemical Process (total project: $123,996; Reclamation's contribution: $74,990). Previous research has shown that the use of hydrogen peroxide and ultrasound destroys organic material and is effective in destroying pathogens. This work will focus on tests aimed at reducing total trihalomethanes (TTHM) and killing cryptosporidium and giardia in the effluent of four wastewater treatment plants (WWTP) along the east coast.

Mr. William Bart Hines and the City of McAllen, Texas, will continue the study of microfiltration (MF) and RO treatment of McAllen's WWTP effluent (total project: $350,800; Reclamation's contribution: $40,000). McAllen is presently finalizing agreements with other financial contributors. This 3,600 hours of work will demonstrate that ZENON's Zenogem process can produce effluent which meets secondary WWTP standards (10 mg/L TSS, 15 mg/L BOD₅, and <3 mg/L NH₃-N). A comparison will be made between the conventional WWTP MF/RO process and the Zenogem/RO process, including initial capital expenditures as well as O&M costs.

TASK F - CONCENTRATE ISSUES

Dr. Mike Mickley and Mickley & Associates will study Membrane Concentrate Disposal: Practices and Regulation (total project: $200,968; Reclamation's contribution: $97,268). The purpose of the study is to provide the desalination industry with a valuable reference source focusing on characterizing and documenting concentrate disposal practices and regulations on a state-by-state basis. The two main thrusts of the study are: (1) a survey of water treatment plants (WTP) and WWTPs that generate a concentrate stream (for both membrane and thermal desalination) to catalog their disposal practices; and (2) a state-by-state documentation of the regulations covering the various concentrate disposal options.

TASK G - TESTING OF LABORATORY SCALE AND PILOT SYSTEMS

Mr. Paul Gagliardo and the City of San Diego, California, will study Membrane Bioreactors for Water Purification-Phase II (total project: $1,102,500; Reclamation's two-year contribution: $270,000). San Diego will conduct a side-by-side comparison of three pilot-scale membrane bioreactors (MBR) from different manufacturers (ZENON Municipal Systems, Mitsubishi Rayon Corporation, and Lyonnaise des Eaux/Infilco Degremont). The investigation, to be conducted at the San Diego's Aqua 2000 Research Center in Escondido, California, will determine the ability of the MBRs to treat primary effluent to RO feed water requirements. If successful, MBR technology could be incorporated into San Diego's water purification program to augment local water supplies.

Dr. Ali Dabiri and Science Applications International Corporation (SAIC) will study VARI-RO^TM Desalting Pilot Plant Advancement Project (total project: $684,667; Reclamation's two-year contribution: $270,000). SAIC will design, build, and test a 10 HP direct drive engine (DDE) system that will be coupled to their existing VARI-RO pump and energy recovery pilot system. This engine will be based on the closed-loop Brayton cycle. The result will be an integrated pump and engine system, which will offer the potential of reducing the total cost of RO desalted water in two ways: (1) by lowering total energy consumption compared to conventional centrifugal pump and turbine energy recovery systems; and (2) by using lower cost energy sources as compared to electric power rates.

TECHNOLOGY TRANSFER

The following cooperative agreements or in-house research projects, which emphasize the DesalR&D program requirement to provide for technology transfer (TT), represent a few of the TT efforts that were initiated or completed during fiscal year 1998:

WATER TREATMENT PRIMER FOR COMMUNITIES IN NEED

The Water Treatment Primer for Communities in Need (primer), an on-going, in-house research project, was recently updated with the following new contaminant fact sheets: alkalinity, arsenic, fluoride, radionuclides, and zinc. Additionally, the primer was recently placed on the Internet at www.usbr.gov/water/primer.html. Fiscal year 1999 funding was approved for continued update of the primer. Work this year will focus on updating the cost curves with more recent construction and O&M costs, preparation of several new fact sheets for the remaining primary drinking water contaminants, and updates regarding the DesalR&D program.

DESALTING HANDBOOK FOR PLANNERS

The Desalting Handbook for Planners (handbook) was originally prepared by the Office of Saline Water (OSW) in 1972. A second edition was prepared in 1979 by Catalytic, Inc., for OSW's successor agency, the Office of Water Research and Technology (OWRT). The purpose of the handbook was for use in preliminary planning of desalting facilities and as a source of information on various desalting processes requirements, applicability of these desalting processes, and economic planning. Special problems such as feed water availability, concentrate disposal, and environmental effects were also discussed. The handbook was not meant as a substitute for a thorough engineering analysis that would precede a decision to build a desalting plant. Because of the age of the handbook, many of the current technologies and methodologies are not included and most other sections are very out of date. As a result, O. J. Morin and Ian Watson of the firm of AEPI/RosTek, Inc., were awarded $64,250 to update the handbook. The principal tasks required to update the handbook include: (1) scan a hard copy of the original document and then edit the scanned file as necessary to provide an exact electronic duplicate of the original document; (2) use the scanned duplicate to revise and update the handbook as specified by Reclamation in the contract; (3) provide final drafts of both the original and revised documents to Reclamation for review; (4) incorporate Reclamation's final comments; and (5) provide Reclamation with electronic and hard copies of the original and revised documents as specified. The project is scheduled for completion by April 30, 1999.

AUTOMATED COST ESTIMATOR FOR MEMBRANE SYSTEMS

Over the past decade or so, hundreds of membrane systems have been successfully implemented at higher efficiencies, improved reliabilities, and lower costs than ever before. These installations represent important information on current membrane system costs as well as the factors contributing to these costs. Although the cost drivers associated with membrane systems may be understood qualitatively, quantitative information from existing installation remains uncompiled, inaccessible, and unused. As a result, Dr. Miriam Heller of the University of Houston was awarded $20,000 to render usable the economic membrane systems data from existing installations. The American Desalting Association (ADA) is collaborating with Dr. Heller and Reclamation on this cost model. Preparation of the cost model will entail developing: (1) normalized cost estimates for membrane systems as well as adjustment factors to account for differential costs according to geography, demography, influent water characteristics, etc.; and (2) a user-friendly automated system to build a cost estimate for a membrane system based on user input about a particular system, the expected normalized costs of that system, and appropriate adjustment factors. The project is scheduled for completion by August, 1999.

U.S. DESALTING PLANT INTERNET DATABASE - DEMONSTRATION

This project will prototype the use of the Internet as a way to provide useful information on U.S. desalting plants. It is expected that the plant owner, designer, equipment supplier, builder, and water user will benefit by making this information freely available. This could be a very practical way to advertise the substantial successes of desalting technologies in the U.S. to communities that may need to consider desalination in the future. Preparation of a demonstration inventory of selected desalting plants will provide a method and format for developing a complete inventory and provide for a "trial use" period of the demonstration inventory to help determine the need for a complete inventory. As a result, Prof. Eremitus Nabil El-Ramly and Dr. Richard Peterson, of the University of Hawaii, and Dr. Linda Volonino, of Canisius College, were awarded $5,000, $2,500, and $2,500, respectively, to complete a demonstration inventory. Prof. El-Ramly will inventory a minimum of 10 desalting plant in the U.S. A minimum of 1 distillation, 1 electrodialysis (ED) or ED reversal, 1 RO, 1 NF, 1 UF/MF plant will be included in the demonstration inventory. Dr. Volonino will complete the programming and create a searchable database containing the information obtained by Prof. El-Ramly. Dr. Peterson will complete the programming and create the .html files of the searchable database for placement of the database on the Internet. Hyperlinks from the database to the inventoried desalting plants will be provided, if available. The project is scheduled for completion by April 30, 1999.