(279e) Evaluation of the Applicability of Polyelectrolyte-Based Membranes to Treating Real Wastewater Effluents

This study aims at evaluating the possibility of using polyelectrolyte multilayer (PEM) membranes to treating a real wastewater effluent, which in this case is an electrocoagulation-treated, anaerobic digestion (AD) effluent.  A number of researchers have shown PEM membranes as highly  permeable membranes with equivalent or higher salt rejection than some commercial nanofiltration (NF)/reverse osmosis (RO) membranes. However, the lab-based simple ion-containing solutions that are used to test these membranes fail to emulate the complexities involved in real effluents. Our study thereby focused on two typical polyelectrolyte-based systems and comparison of their performance (both flux and COD removal) with some commercial NF/RO membranes. It was found that irrespective of the pH of the effluent, the membranes showed higher permeability than commercial brackish water RO membranes with equivalent COD reduction. One major concern related to such wastewater effluents is the presence of natural organic matters (NOM) which tend to foul the membrane surfaces and lead to a decline in flux over a period of time. In our study, the PEM membranes demonstrated better anti-fouling properties than their commercial counterparts. In an effort to further reduce the fouling propensity of PEM membranes, some known anti-fouling polymers like poly ethylene glycol (PEG) or polydopamine were coated on their surfaces to prevent the flux decay over time. On being coated with these fouling resistant polymers using appropriate deposition conditions, the PEM membranes present a viable option for treating a wide variety of effluents.