Steady state phenol degradation in a draft‐tube, gas‐liquid‐solid fluidized‐bed bioreactor

Experiments on phenol biodegradation by a mixed culture in a draft-tube, three-phase fluidized-bed biofilm reactor (DTFBR) at the steady state were performed. The characteristics of biofilms developed in the DTFBR were identified. A steady state biofilm model was proposed that considers the simultaneous diffusion and reaction of oxygen and phenol within the biofilm and the external mass transfer resistance between the biofilm and the completely mixed bulk liquid phase. The proposed model assumes a double-substrate limiting mechanism for microbial growth kinetics, and Haldane and Monod type expressions were used to characterize the dependence of microbial specific growth rate on phenol and oxygen, respectively. The experimental results were used to test the validity of the proposed model.