Membrane bioreactors for treating waste streams

A review. Membrane bioreactors (MBRs) have a no. of advantages for treating wastewater contg. large quantities of BOD. This paper outlines the inherent advantages of an MBR, which include high potential biomass loadings, lower sludge yields, and retention of specialized organisms that may not settle well in clarifiers. A major problem in effluent treatment occurs when mixed inorg. and org. wastes occur with high concns. of pollutants. Inorgs. that might cause extremes of pH and/or salinity will inhibit microbial growth and only specialized organisms can survive under these conditions. Refractory orgs. are only biodegraded with difficulty by specialized organisms, which usually do not resist the extreme inorg. environments. The use of membrane bioreactors to help sep. the microorganisms from the inorg. compds., yet permit the orgs. to permeate, was developed in 2 different designs. The use of membrane contactors in a multimembrane stripping system to treat acidic chlorinated wastes is proposed and discussed. [on SciFinder (R)]