Electrochemical degradation of bisphenol A using a flow reactor with a boron-doped diamond anode

Constant current electrolyses are performed in a filter-press reactor using a boron-doped diamond (Nb/BDD) anode to investigate the effect of volumetric flow rate, temperature, pH, current density, and NaCl addition on the chemical oxygen demand (COD) abatement of a 150 mg L-1 bisphenol A (BPA) solution. Only the volumetric flow rate, temperature, and current density significantly affect the COD abatement. However, at 25 degrees C, NaCl addition significantly increases the COD abatement rate at 30 mA cm(-2), but no effect is observed at 6.5 mA cm(-2); under optimized hydrodynamic conditions, the best condition in terms of current efficiency and energy consumption occurs at 6.5 mA cm(-2) and 7.0 L min(-1), in the absence of NaCl, when only 1.7 A h L-1 is needed to attain a 90% COD abatement. When comparative electrolyses are carried out at 25 degrees C and 30 mA cm(-2) using Nb/BDD. Ti-Pt/beta-PbO2, and TiO2-RuO2 anodes, the Nb/BDD anode always presents the best performance, in the absence or presence of NaCl. The oxidation performance attained with the Nb/BDD anode using the filter-press reactor is significantly better than those previously reported in the literature for the degradation of BPA using conventional electrochemical cells. (C) 2012 Elsevier B.V. All rights reserved.