Novel Nonporous Fouling-Resistant Composite Nanofiltration Membrane and Membrane Separation systems for Wastewater Treatment Important for CPSON5/ PPSON1: Minimization of Oily and Non-Oily Wastewater.

摘要

Navy ships generate large volumes of wastewater (about 20-70 gal/day of water per crew member) which, to meet new regulations, require treatment prior to overboard discharge. In the past, all wastewater was simply discharged overboard. More recently, regulating bodies such as MARPOL, the EPA, the U.S. Coast Guard, and some states have enacted restrictions on the location and extent of such discharges. Polymeric nanofiltration/ultrafiltration membranes able to produce dischargeable water have already been considered for shipboard wastewater treatment. The problem with this approach is fouling of the membrane by a layer of colloidal and particulate material that forms a secondary barrier to flow through the membrane. To overcome the problems of membrane fouling and the need for periodic cleaning, NC State University (NCSU) and Membrane Technology and Research, Inc. (MTR) have developed a new type of composite membrane in which a thin, highly water-permeable polymer coating layer is used to completely eliminate internal membrane fouling and significantly reduce the effect of surface fouling.