Water Desalination and Soluble Organic Carbon (SOC) Removal Using Low-Pressure Reverse Osmosis

1. Purpose and Objectives: The proposed research will demonstrate the feasibility of using low pressure reverse osmosis and/or nanofiltration for reclaiming wastewater and for treating high salinity, high Soluble Organic Carbon (SOC) surface water, SOC produces a brown color in water that can be caused by decaying organic matter. Dissolve solids (salt), hardness and SOC will be removed using a 10 liter per minute flow rate, trailer mounted, self-contained, low pressure reverse osmosis pilot system that will be designed and constructed with the assistance of the Fluid Process Systems, Inc. and operated at 1) El Paso Ubenhauer-Robertson Water Treatmetn Plant on Canal Street which treats Rio Grande/Rio Bravo surface water and at 2) El Paso’s Northwest Wastewater Treatment Plant to reclaim treated wastewater.

2. Funding: $72,561

3. Partners: SCERP

4. Description and Methodology: The El Paso Water Utility is switching from primary dependence on groundwater to Rio Grande water which is renewable. Surface water, however, is more difficult to treat than groundwater. The EPA is currently developing regulations on the removal of SOC from surface water in order to greatly reduce the formation of cancer-producing compounds called disinfection by-products (DBPs). DBPs are formed when the water is disinfected with strong oxidants such as chlorine that kill potential disease-causing organisms. Membrane processes are very effective in removing SOC but have not been widely used for this purpose due to high operating costs and membrane fouling. Recent technological advancements in membranes have reduced the operating cost. The proposed trailer mounted system will have the flexibility for testing the latest in membrane technology and will protect the membranes from both biological and mechanical (solids) fouling.

5. Status: The research design and proposed operation of the system are being closely coordinated with the El Paso Water Utility (EPWU). The EPWU is playing a key role in the development of this research project and has shown their interest and commitment to this project and membrane technology. Membrane technology could be used to treat as much as 50,000,000 gallons per day of water within 10 years and will also enable EPWU to recycle a large portion of its wastewater. The study continues and no results have been published.

6. U.S. Contacts: Charles D. Turner, UTEP, (915) 747-6908, e-mail turner@mickey2.ce.utep.edu; Ernest Rebuck, EPWU, (915) 594-5562