Treatment of wastewater by mixed bacterial consortium in continuous reactors packed with solid waste

Phenol is one of the priority pollutants as declared by EPA (USA). Very few comparative studies have been carried out with continuous packed bed reactors (PBR) for bacterial degradation of phenol and applying the result in real time situation. The present study compared the performance of a co-current and a counter-current continuous PBR in degrading phenol by a mixed consortium of bacteria isolated from the East Calcutta Wetlands based on both rate of phenol degradation and phenol removal efficiency. Different process parameters like air flow rate, hydraulic retention time and temperature were varied for both the systems. Performance of the co-current continuous PBR was found to be more efficient. To validate the performance of this system in actual application in industry a real time phenolic industrial effluent was fed to this system. Phenol degradation rate was 1.43 mg/l min and the phenol removal efficiency of this co-current continuous PBR was 72.85%.