THE APPLICATION OF MEMBRANE BIOLOGICAL REACTORS FOR THE TREATMENT OF WASTEWATERS

Combining membrane technology with biological reactors for the treatme nt of municipal and industrial wastewaters has led to the development of three generic membrane processes within bioreactors: for separation and recycle of solids; for bubbleless aeration of the bioreactor; and for extraction of priority organic pollutants from hostile industrial wastewaters. Commercial aerobic and anaerobic membrane separation bio reactors already provide a small footprint alternative to conventional biological treatment methods, producing a high-quality effluent at hi gh organic loading rates. Both the bubbleless aeration and extractive membrane bioreactors are in the development stages. The former uses ga s-permeable membranes to improve the mass transfer of oxygen to the bi oreactor by providing bubbleless oxygen. By using a silicone membrane process, extractive membrane bioreactors transfer organic pollutants f rom chemically hostile wastewaters to a nutrient medium for subsequent biodegradation. All three membrane bioreactor (MBR) processes are com paratively and critically reviewed. (C) 1996 John Wiley & Sons, Inc.