AWWA MTC61209

The focus of this project was to determine if membranes operating at lower pressures can meet water quality requirements necessary for indirect potable reuse while meeting acceptable operational parameters such as feed pressure, permeate flux, and flux decline. For this purpose, a 19 gpm membrane pilot-skid was constructed and installed at the West Basin Water Recycling Plant (WBWRP) in El Segundo, California in order to test the performance of two candidate "lower pressure" membranes in treating non-nitrified and nitrified wastewater effluents for indirect potable water reuse applications. In order to select two candidate membranes for pilot-skid testing, a laboratory testing protocol was developed to investigate the viability of commercially available reverse osmosis (RO), ultra-low pressure reverse osmosis (ULPRO) and nanofiltration (NF) membranes for treating wastewater effluents during indirect potable reuse projects. Parameters relevant to indirect potable reuse projects were chosen as criteria for the evaluation and identification of membranes that could be used to efficiently treat wastewater effluents. The testing protocol evaluated membranes based on the rejection of relevant solutes and constituents present in wastewater effluents (total organic carbon, nutrients (NH₃ and NO₃ ^-), conductivity, and selected trace organics), as well as operational performance (specific flux, and flux decline due to fouling). Based on the results from the membrane testing, membranes were ranked in order of how well they performed and the highest ranking membrane was chosen for installation on the pilot-skid operated at the WBWRP. This paper presents the membrane testing protocol used to evaluate the candidate membranes and the selection criteria that were used to select membranes for installation on the pilot-skid operated at the WBWRP. Includes 8 references, tables, figures.