Novel Membrane-Based System for Shipboard Treatment of GrayWater and Oily Waste Water

Navy ships generate large valumes of graywater and oily wastewaters but most have minimal capacities for storing these wastes. The goal of this program is to develop a membrane-based shipboard graywater-treatment system (GTS) that allows recovery of more than 95% of the wastewater, reducing the volume of wastewater that must be stored by a factor of at least 20. Key to this system is development of a fouling-resistant tube-side-feed module that contains a new type of robust hollow-fiber nanofiltration (NF) membrane. This module will combine the fouling-resistant characteristics of ultrafiltration modules and the high selectivity of NF membranes. In Phase I, feasibility will be demonstrated by 1) developing an NF membrane specifically for graywater treatment, 2) demonstrating the fouling resistance of the module, and 3) demonstrating the effectiveness of backflushing and other operating techniques to minimize fouling. An NF module will be operated on actual graywater generated on ships. In Phase IIF, development of the GTS will be completed and a prototype system will be delivered to the Navy for evaluation.