Degradation of ethylparaben using photo-Fenton-like oxidation over BiFeO3

The degradation of ethylparaben using photo-Fenton-like oxidation was investigated in the presence of a BiFeO₃ catalyst. Firstly, the catalyst was synthesized using the sol-gel method and then, a parametric study was carried out in order to determine the optimum reaction conditions for the degradation of ethylparaben. In this context, the effects of catalyst loading, [H₂O₂]_o, pH, and temperature on the degradation were investigated. According to the results, the optimum reaction conditions were determined for a 5 ppm ethylparaben solution as 0.25 g/L catalyst loading, a pH of 3, and 2 mM [H₂O₂]_oand a 97.7% degradation of ethylparaben was accomplished. Iron leaching at the optimum conditions was evaluated as 1.53 ppm and it is lower than the E.U. iron concentration limitation (2 ppm) in the water. The kinetic study was carried out at the optimum reaction conditions at three different temperatures (25, 35, and 45 °C). The degradation of ethylparaben using photo-Fenton-like oxidation fitted the first order reaction kinetic model. The reaction rate constants were determined as 0.041, 0.050, and 0.069 min^-1 for 25, 35, and 45 °C, respectively. The activation energy was found as 20.4 kJ/mol.