Kinetic and statistical analysis of Bisphenol A in wastewaters by ozonation and electrooxidation-ozonation processes

Abstract

The purpose of this study is to investigate the treatability of synthetic Bisphenol A (BPA) solution by electrooxidation-ozone (EO+O-3) and ozone (O-3) processes. The BPA removal efficiencies of both combined method and O-3 methods were compared and the combined process gave better results than the O-3 process. For the BPA removal efficiencies, the experimental parameters including pH, current density, ozone dose, and reaction time parameters were optimized by changing the one parameter at a time. The BPA removal efficiencies have been obtained for EO+O-3 as 90.68%, and for O-3 as 83.92% under the optimum conditions (pH 7, 1.5 g/L h ozone dose, 4.57 mA/cm(2) current density, and 25 min reaction time) by using the Ti/RuO2(0,70)-IrO2(0,30) anode electrode. The experimental data, obtained from EO+O-3 and O-3 process has been evaluated by applying three different kinetic theories, that is, first, second, and pseudo-second-order. The second-order-kinetic model has been found to be the most suitable model for both processes and the regression coefficients (R-2) has been found as 0.94 and 0.92 for EO+O-3 and O-3, respectively. The reaction rate constants (k) have been also calculated as 1.8 x 10(-2) and 9 x 10(-3) L/mg min for EO+O-3 and O-3, respectively. The obtained results showed that the BPA removal efficiency of EO+O-3 process has superiority over 0 3 process. The detailed investigation revealed that no by-product has been observed during the BPA removal.