A membrane bioreactor with novel modules for effective biodegradation of toluene

Two novel membrane modules, tubular and spiral type with numerous hollow fibers of silicone rubber were incorporated into a bioreactor system for effective degradation of volatile organic chemicals (VOC) in wastewater. Biodegradation and transfer of toluene as a model VOC were studied in the membrane bioreactors using Pesudmonas putida mt-2 as the degrader. The overall mass-transfer coefficient of toluene across the membranes was estimated to be 4.8x10(-7) m/s for the tubular type module and 4.6x10(-7) m/s for the spiral one. Both bacterial growth and toluene degradation in the two types of membrane bioreactors were the same as those obtained from the culture under an ideal condition. The mass transfer of toluene across the membranes was not a rate-limiting factor for the bacterial degradation of toluene. (C) 2000 Elsevier Science S.A. All rights reserved.