Indirect electrochemical oxidation of reverse osmosis membrane concentrates at boron-doped diamond electrodes

The treatment or disposal of concentrates generated from the filtrative treatment of water is rapidly becoming a factor of major environmental concern. This preliminary study discusses a novel approach in the abatement of reverse osmosis membrane retentate i.e. electrochemical oxidation. The recalcitrant organic constituents as well as the ammonia nitrogen in the retentate could be readily oxidised using boron-doped diamond electrodes. From the model fitted to these data, a constant removal rate and current efficiency was calculated. Analysis of the inorganic chlorinated species revealed that the oxidation mechanism was mainly due to the indirect oxidative action of electrogenerated hypochlorite. (C) 2002 Elsevier Science B.V. All rights reserved.