Oxidation of bisphenol A by permanganate: Reaction kinetics and removal of estrogenic activity

The kinetics for reaction between bisphenol A (BPA) and permanganate was examined over pH range of 5.0-9.9 and the estrogenic activity of aqueous BPA solution after oxidation was assessed by yeast two-hybrid assay. Reaction kinetics follows the second-order rate law, with the apparent second-order rate constant of 15.1 ±1.1 M^-1 s^-1 at pH 6.0 and 25°C and the activation energy of 48.7 kJ/mol. The kinetics exhibits pH dependency and the specific rate constants related to speciation of BPA are 50 ± 28 M^-1s^-1, 9.6 (±0.6)103M ^-1s^-1 and 1.4 (±0.1)10⁴M ^-1s^-1 for BPA, BPA^- and BPA^2-, respectively. The results of the estrogenic/antiestrogenic activity test show that there is a hysteresis for the removal of estrogenic activity of aqueous BPA solution at pH 7.3. Removal of BPA is completed in 10 min, but complete removal of estrogenic activity requires a further 20 min.