COMETABOLIC DEGRADATION OF TRICHLOROETHYLENE IN A BUBBLE-COLUMN BIOSCRUBBER

A bubble column bioreactor was used as bioscrubber to carry out a feas ibility study for the cometabolic degradation of trichloroethylene (TC E). Phenol was used as cosubstrate and inducer. The bioreactor was ope rated like a conventional chemostat with regard to the cosubstrate and low dilution rates were used to minimize the liquid outflow, TCE degr adation measurements were carried out using superficial gas velocities between 0.47 and 4.07 cm s(-1) and TCE gas phase loads between 0.07 a nd 0.40 mg L(-1). Depending on the superficial gas velocity used, degr ees of conversion between 30% and 80% were obtained, A simplified reac tor model using plug flow for the gas phase, mixed flow for the liquid phase, and pseudo first order reaction kinetics for the conversion of TCE was established. The model is able to give a reasonable approxima tion of the experimental data. ICE degradation at the used experimenta l conditions is mainly limited by reaction rate rather than by mass tr ansfer rate. The model can be used to calculate the reactor volume and the biomass concentration for a required conversion. (C) 1995 John Wi ley and Sons, Inc.