A review of polymeric membranes and processes for potable water reuse

tConventional water resources in many regions are insufficient to meet the water needs of growing popu-lations, thus reuse is gaining acceptance as a method of water supply augmentation. Recent advancementsin membrane technology have allowed for the reclamation of municipal wastewater for the production ofdrinking water, i.e., potable reuse. Although public perception can be a challenge, potable reuse is often theleast energy-intensive method of providing additional drinking water to water stressed regions. A vari-ety of membranes have been developed that can remove water contaminants ranging from particles andpathogens to dissolved organic compounds and salts. Typically, potable reuse treatment plants use poly-meric membranes for microfiltration or ultrafiltration in conjunction with reverse osmosis and, in somecases, nanofiltration. Membrane properties, including pore size, wettability, surface charge, roughness,thermal resistance, chemical stability, permeability, thickness and mechanical strength, vary betweenmembranes and applications. Advancements in membrane technology including new membrane mate-rials, coatings, and manufacturing methods, as well as emerging membrane processes such as membranebioreactors, electrodialysis, and forward osmosis have been developed to improve selectivity, energy con-sumption, fouling resistance, and/or capital cost. The purpose of this review is to provide a comprehensivesummary of the role of polymeric membranes and process components in the treatment of wastewa-ter to potable water quality and to highlight recent advancements and needs in separation processes.Beyond membranes themselves, this review covers the background and history of potable reuse, andcommonly used potable reuse process chains, pretreatment steps, and advanced oxidation processes.Key trends in membrane technology include novel configurations, materials, and fouling preventiontechniques. Challenges still facing membrane-based potable reuse applications, including chemical andbiological contaminant removal, membrane fouling, and public perception, are highlighted as areas inneed of further research and development.