Treatability and Kinetic Analysis of BPA-containing Wastewater by Catalytic Ozone Processes Using ZnSO₄ and ZnO Catalysts

ABSTRACT

BPA (Bisphenol-A) is an organic colorless crystalline synthetic compound with the chemical formula of (CH₃)–C–(C₆H₄-OH)₂. The chemical structure of BPA consists of two methyl functional groups which are connected by a bridge to the phenol rings. The purpose of this study is to investigate the treatability of containing BPA wastewater using by homogeneous (ZnSO₄ catalyst) and heterogeneous (ZnO catalyst) catalytic ozone processes (COPs). The BPA removals of ZnO catalyst COP method and ZnSO₄ catalyst COP methods were compared and using the ZnO catalyst COP process gave better results than the ZnSO₄ catalyst COP process. For the BPA removals, the experimental parameters including pH, catalysts dose, ozone dose, and reaction time parameters were optimized by changing one parameter at a time. As a result of 12.5 min of ZnSO₄ oxidation, 94.16% of BPA removal was achieved under the optimum conditions (pH 6.32, 1 mg/L ZnSO₄ dose, 2400 mg/L O₃ dose). However, under optimum conditions (pH 6.32, 50 mg/L ZnO dose, 2400 mg/L O₃ doze, 20 min reaction time), the BPA removals have been obtained as 98.52%. The second-order kinetic model has been found to be the most suitable model for both processes and the regression coefficients (R²) have been found as 0.999 and 0.9979 for ZnSO₄ and ZnO catalysts COPs, respectively. The reaction rate constants (k) have also been calculated as 0.0939 L.mg⁻¹.min⁻¹ and 0.0509 L.mg⁻¹.min⁻¹ for BPA in homogeneous and heterogeneous COPs, respectively.

KEYWORDS:

• BPA
• catalytic ozone process
• ZnSO₄
• ZnO
• kinetic modeling