Simultaneous removal of nitrate and phosphate using cross-flow micellar-enhanced ultrafiltration (MEUF)
Kim, B.K.; Baek, K.; Yang, J.W.
Water Science and Technology a Journal of the International Association on Water Pollution Research 50(6): 227-234
2004
ISSN/ISBN: 0273-1223 PMID: 15537011 Document Number: 569195
The feasibility of cross-flow micellar-enhanced ultrafiltration (MEUF) was investigated to remove nitrate and phosphate simultaneously. At the above critical micelle concentration (CMC), a cationic surfactant added in wastewater forms micelles, which have positive charge on their surface. Anionic contaminants such as nitrate and phosphate can be bound on the micelles by electrostatic interaction, and the micelle-pollutants complex is removed effectively by ultrafiltration. In this study, a cross-flow MEUF system was designed and investigated the feasibility of MEUF for field application. A cationic surfactant, cetylpyridinium chloride (CPC), was used, and the synthetic wastewater was treated by the polyacrylonitrile membranes with molecular weight cut-off (MWCO) of 30,000 Da and 10,000 Da. With the molar ratio of CPC to total pollutants of >3, >86% of nitrate and >91% of phosphate were removed, respectively, and >97% of CPC was also rejected. The flux was maintained 20-30% of the flux of distilled water. Therefore, it is feasible to remove nitrate and phosphate simultaneously using the cross-flow MEUF system.