Biodegradability enhancement of industrial organic raffinate containing pyridine and its derivatives by CWAO using ceria promoted MnOx/Al2O3 catalyst at atmospheric pressure

The catalytic wet air oxidation (CWAO) of non-biodegradable industrial organic raffinate containing pyridine and its derivatives (β-picoline, 3-cyanopyridine) was carried out using MnOx/Al2O3 catalyst at atmospheric pressure. The catalyst was prepared using impregnation method and characterized using various techniques. The effect of metal loading, catalyst dosage, reaction temperature and operating pressure on degradation of industrial organic raffinate was studied and the results were interpreted in terms of COD removal. Experiments were conducted using spent catalyst to explore the reusability of catalyst. The metal leaching from the catalyst was studied by determining the metal content in the CWAO effluent. The effect of ceria as a promoter on biodegradability enhancement, catalyst recycling and metal leaching was studied. The biodegradability and toxicity tests confirmed the biodegradability enhancement and complete removal of toxicity of the CWAO effluent. The biological aerobic treatment of the CWAO effluent resulted in 98.36% COD removal.