Oxidative Phenol Degradation Using Non-Noble Metal Based Catalysts

Phenol laden waste streams are not considered suitable for conventional biological treatment if phenol is present in amounts higher than 70 mg/L. Catalytic wet air oxidation (CWAO) is one of the potential methods for treating waste streams containing such compounds. The present work investigated the degradation of synthetic wastewater contaminated with phenol (1 g/L) using a CWAO process in the presence of homogenous (CuSO(4)) and heterogeneous (LaCoO(3), CuX and CuO-ZnO/CeO(2)) catalysts. The reaction was conducted at low temperature (90 degrees C) and atmospheric pressure, and at moderate operating conditions (T >= 160 degrees C and total pressure <= 0.8 MPa), Among all the tested catalysts, CuSO(4), LaCoO(3) and CuX were used for WAO reactions performed at atmospheric pressure conditions, whereas the performance of CuO-ZnO/CeO(2) catalyst was tested in above atmospheric pressure studies. At atmospheric conditions, homogeneous CuSO(4) was found to be the best showing ca. 90% phenol degradation and ca. 83% chemical oxygen demand (COD) reduction after a 24 h reaction period. The above atmospheric studies with catalyst showed ca. 82% phenol reduction and 54% COD removal within 3 h reaction time. The effect of pH, catalyst concentration, pressure and temperature are also reported. Finally, the major results are summarized and the recommendations for future work are given