Catalytic ozonation of basic yellow 87 with a reusable catalyst chip

Abstract

A porous copper fiber sintered sheet (PCFSS) with high porosity and large interfacial area, loaded with Cu/Zn/Al/Zr catalyst (i.e. CuO, ZnO, Al2O3 and ZrO2), was evaluated for catalytic ozonation of Basic Yellow 87 (BY 87) in water. We investigated the influences of temperature, ozone dosage, BY 87 concentration and ozone/BY 87 molar ratios on the kinetics of BY 87 degradation, and the removal efficiency of BY 87. Compared to the ozonation process, the presence of the catalyst chip significantly improved the degradation of BY 87 (two times and five times more effective in the removal efficiency of COD and TOC, respectively). Batch experiments results demonstrated that the catalyst chip could sustain a high removal efficiency of BY 87 (around 99%), COD (about 60%) and TOC (around 30%) under a wide range of temperatures (0.5-61 degrees C), BY 87 concentrations (216-1078 ppm) and O-3/BY 87 mole ratios (0.98-21.3) within 4 h of reaction time. The decomposition rate of BY 87 was enhanced with increasing O-3 and BY 87 concentrations under the constant molar ratio. However, a shift from zero-order to pseudo-first-order kinetics (regarding BY 87) was observed when increasing O-3/BY 87 mole ratio from 0.98 to a value higher than 2.44. This work also demonstrated that homogeneous and heterogeneous catalytic processes could be integrated together in the presence of the catalyst chip, which shortens the half-life of BY 87 degradation. After reuse of the catalyst chip for ten times, the degradation efficiency of BY 87 and COD remained 99.2% and 58.9%, respectively, indicating a stable activity of the catalyst chip. (C) 2013 Elsevier B.V. All rights reserved.