Effect of Influent Concentration on Biodegradation of Phenol Using Packed Bed Reactor

There is a general perception that the phenols being toxic are not amenable to biological degradation. Continuous biodegradation of phenol in synthetic wastewater is carried out in a packed bed bioreactor using immobilized Nocardia hydrocarbonoxydans. Glass beads were used as the carrier particles for cell immobilization. The effect of influent phenol concentration on packed bed bioreactor for phenol biodegradation during start up and at steady state were studied. Almost 99.6% degradation of 200 ppm phenol could be achieved. Percentage degradation of phenol decreased with the increase in influent concentration. The combined effect of higher phenol concentration and volumetric phenol loading might have resulted in lower degradation. Only 58.4% degradation of 1000 ppm phenol could be achieved with the packed bed bioreactor containing 6400 glass beads. Toxic effects of phenol were found to play a role at 1000 ppm influent concentration. With increase in dilution rate, the percentage degradation was decreased.