Kinetics for aerobic biological treatment of o-cresol containing wastewaters in a slurry bioreactor: biodegradation by utilizing waste activated sludge

A toxic volatile organic compound (VOC), o-cresol, was biologically degraded by utilizing waste activated sludge in a gas-liquid-solid three-phase slurry bioreactor. The biodegradation kinetics of o-cresol was examined in batch experiments at varying initial o-cresol concentrations (from 30 to 600 mg/L), waste activated sludge concentrations (from 1000 to 11,500 mg/L) and aeration rates (from 0.05 to 1.0 L/min). The kinetic parameters of o-cresol aerobic biodegradation were estimated using Haldane substrate inhibition equation with the correlation factors of approximately 0.95. The oxygen consumption during the biodegradation process was also examined. The oxygen consumption rate was adequately described by the Haldane type model with the correlation factor of 0.965. The biodegradation of o-cresol by waste activated sludge and the change of dissolved oxygen concentration in the slurry bioreactor were successfully simulated.