KINETICS AND REACTION-ENGINEERING ASPECTS OF THE BIODEGRADATION OF DICHLOROMETHANE AND DICHLOROETHANE

This paper presents some new results on the aerobic degradation of dic hloromethane (DCM) and 1,2-dichloroethane (DCA) in a fluidized bed rea ctor without direct oxygenation. Oxygen was supplied by diffusion thro ugh a synthetic membrane. High bacteria concentrations and high degrad ation rates were obtained. DCM degradation reached 1400 mg (1 h)(-1) a nd DCA degradation up to 600 mg (1 h)(-1). Yields for oxygen consumpti on and biomass production could be established. Haldane kinetics were suitable to describe the influence of DCA and oxygen concentration on the degradation rate of DCA. The DCM degradation rate is only influenc ed by the substrate concentration. Kinetic parameters for the Haldane model were reached in batch and extended-culture experiments. Extended -culture experiments keep the substrate concentration in the reactor c onstant and allow a determination of the growth rate by evaluation of the reaction volume. Copyright (C) 1996 Elsevier Science Ltd.