Fouling-Resistant Ultrafiltration Membranes for Treatment of Oily Bilge WaterEPA Contract Number: 68D02015
Title: Fouling-Resistant Ultrafiltration Membranes for Treatment of Oily Bilge Water
Investigators: Nemser, Stuart
Small Business: Compact Membrane Systems Inc.
EPA Contact: Richards, April
Project Period: April 1, 2002 through September 1, 2002
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2002) RFA Text | Recipients Lists
Research Category: Watersheds , SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
There is a recognized need for more effective and economical treatment processes for oily bilge waters. Direct filtration through currently available ultrafiltration (UF) membranes is a mechanically simple process that can provide excellent effluent quality. A limitation to more extensive use of this technology is the tendency of the hydrophilic membranes currently used to foul in the presence of oils, with a resultant drop in permeation capacity.
Compact Membrane Systems, Inc. (CMS) has developed proprietary, inherently nonfouling UF membranes. In tests with simulated naval graywater, a CMS membrane delivered two to three times the steady-state permeate flow of a conventional hydrophilic UF membrane at process conditions typical of commercial installations. With the CMS membrane, the operating time between cleaning was more than three times longer. The goal of this project is to demonstrate that similar increases in permeate flux and operating time between cleanings can be achieved in the treatment of oily bilge waters. The low free surface energy of the CMS UF membrane should minimize adsorption of both oily substances and those bilge water constituents that foul hydrophilic membranes. During Phase I, CMS will vary water quality conditions by varying oil percentage and those additives (e.g., surfactants) that enhance fouling. By broadly evaluating performance, the range of applicability of the concept should be demonstrated. Rigorous analysis of various contact angles (e.g., oil/air/solid, water/air/solid, and water/oil/solid) will be used to explain results. This is a resubmittal of a previous request strengthened by revisions recommended by peer reviews.
Ultrafiltration membranes with dramatically improved resistance to fouling will allow for highly efficient, relatively low-cost shipboard treatment of oily bilge waters. This combination of previously unavailable properties will encourage the treatment of bilge water discharges from both merchant and naval vessels. The recognized need for such treatment will aid commercialization of the technology as these new membranes are made available to existing vendors of wastewater treatment filtration systems. Much wider applications in oily water treatment should become apparent, in part because of the success of this application.