Risk Assessment of Chlorinated Effluents from Pulp and Paper Industry and Their treatment by Advanced Oxidation Process

Abstract

This study presents performance of wet air oxidation in degradation of pulp and paper black liquor, optimization of operating parameters and process kinetics. The pH, contact time and catalysts dosage were found optimized at 11, 180 min and 4 mg/L, respectively. The percentage of COD degradation was in the range of 27 to 47 without catalyst, 35 to 58 with catalyst CuSO₄ and 46 to 65 with catalyst TiO₂, respectively for the pH optimization, in the range of 18 to 61 without catalyst, 20 to 66 with catalyst CuSO₄ and 30 to 71 with catalyst TiO₂, respectively for the contact time optimization and in the range of 63 to 69 with catalyst CuSO₄ and 68 to 74 with catalyst TiO₂, respectively for the catalyst dosage optimization. Rate of reaction on colour removal and COD degradation were behaved in first order with kinetic rate constant was 0.004. Performance of COD degradation was achieved better with catalyst TiO₂.