All experiments on the kinetics of BPA oxidation by KMnO4
were conducted in brown glass bottles with stopples at pH
7.0 ± 0.1 and 20 ± 1 C unless otherwise specified. The headspace
of the glass bottles to aqueous phase ratio was 1:10 by volume.
In a typical experiment, brown glass bottles containing 200 mL of
BPA and 30 mM NaCl (as background electrolyte) were put in
water bath for at least 30 min to ensure the temperature of the
reactant was 20 C. The experiments were initiated after addition
of an aliquot of the permanganate stock solution into the reactor
while stirring, and the reaction lasted 20 min. At fixed time intervals
10 mL of sample was rapidly transferred with a syringe to a
small beaker containing 100 lL of Na2S2O3 (0.1 M) to terminate
the reaction immediately, and filtrated with a membrane filter
(pore size, 0.22 lm). The concentration of residual BPA was analyzed
directly by HPLC. No buffer was used at pH 4.0–7.0 and borate
buffer was used at pH 8.0–9.0. The pH values changed very
little (