Pretreatment of pharmaceutical wastewater by catalytic wet air oxidation(CWAO)

Abstract

Pharmaceutical industrial wastewater contains highly concentrated and toxic organic compounds which can not be removed by conventional treatment methods. The present study explores a possible method for the effective removal of organic compounds by wet air oxidation (WAO) and catalytic wet air oxidation (CWAO).The results show that 36% of chemical oxygen demand (COD) removal was achieved after 1 hour reaction at 300°C by the WAO method. Homogenous copper nitrate catalyst exhibites better performance than WAO even at a lower temperature of 220°C. Mn-Ce catalyst prepare in our laboratory is used in the CWAO of the wastewater and 94% of the COD is removed after 80 minutes of oxidation. Moreover, this catalyst also indicates a good stability of activity in CWAO of pharmaceutical industrial wastewater. The color variation and the pH profiles are also analyzed for catalytic oxidation over Mn-Ce catalyst.