Ozonation of aqueous solution containing bisphenol A: Effect of operational parameters

Abstract

The degradation of bisphenol A (BPA) in aqueous solution by ozonation was studied. The study was conducted experimentally in a semi-batch reactor under different operational conditions, i.e., varying influent ozone gas concentration, initial BPA concentration, pH, and bicarbonate ion concentration. The results of the study indicated that ozonation could be used to effectively remove BPA from contaminated water. Keeping other operational parameters constant, the rate of BPA degradation linearly increased with ozone dosage. At pH value of 7.0, the second-order rate constants for the reaction of BPA with aqueous ozone were determined as 1.22 × 10 5, 1.71 × 10 5, and 2.59 × 10 5 M −1 s −1 for ozone gas dosages of 1.4, 2.2, and 5.1 mg L −1, respectively. Bicarbonate ion in the range of 1.0–8.0 mM (61–488 ppm) showed no significant effect on BPA degradation for concentrations of BPA used in the study (23.0–57.0 μM). It was also observed that the rate of BPA degradation increased with pH up to 7.0, resulting in rate constants of 0.48 × 10 5, 0.94 × 10 5, and 1.71 × 10 5 M −1 s −1 at pH values of 2.0, 5.0, and 7.0, respectively; and the rate constant decreased to 1.16 × 10 5 M −1 s −1 at pH of 10.0.