Minimisation of biomass in an extractive membrane bioreactor

Abstract

Many traditional biological methods for the treatment of wastewater cope poorly with toxic, volatile organic compounds. The extractive membrane bioreactor is a novel process for the treatment of industrial wastewaters containing such compounds which combines extraction across a silicone rubber membrane with biodegradation. Previous work has shown that there is a problem in this system with excess biofilm growth on the membrane surface, resulting in reduced flux of organic substrate across the membrane. The work presented here shows that addition of sodium chloride to the biomedium increases the maintenance energy requirement of the degradative microorganisms and results, in a carbon-limited situation, in a reduction in biofilm growth. Flux of organic substrate was shown to remain high under reduced biofilm growth conditions.