Continuous biodegradation of phenol in a spouted bed bioreactor (SBBR)

Experiments were carried out to evaluate the continuous biodegradation of phenol using Pseudomonas putida, immobilized in polyvinyl alcohol (PVA) gel matrices in a specially designed spouted bed bioreactor (SBBR) at different conditions. The plexiglas reactor had a total volume of 1.1 l and was equipped with a surrounding jacket for temperature control. The mean residence time in the SBBR was determined experimentally by tracking the concentration of a tracer compound in a continuous effluent stream. The effects of initial phenol concentration, air flow rate, liquid flow rate and PVA particle size, on the rate of phenol biodegradation, were investigated. It was found that the rate of continuous biodegradation increased with increasing the initial phenol concentration and decreased with increasing the liquid flow rate. Mass transfer and hence the accessibility of the biomass to phenol was enhanced by decreasing the PVA particle size and increasing the air flow rate, which had a positive effect on the rate of biodegradation.