Electrochemical degradation of ethidium bromide using boron-doped diamond electrode

Ethidium bromide (EtBr), a DNA intercalating pollutant, is widely disposed in aqueous solutions by most biomedical laboratories. The release of EtBr in the ecosystem may cause serious environmental problems like water pollution, eutrophication and perturbation in aquatic life. In this study, the degradation behavior of EtBr on boron-doped diamond (BDD) electrode was investigated under galvanostatic conditions. The electro-oxidation behavior of EtBr at BDD electrode was firstly examined by means of cyclic voltammetric technique. Such operating parameters as applied current density, types of electrolyte, temperature and initial concentration of EtBr were then varied in order to determine their effects on this oxidation process. The degradation of EtBr was mainly monitored by UV-vis spectrophotometer. The experimental results revealed the suitability of electrochemical processes employing BDD electrode for removing EtBr completely from the solution. The kinetics for EtBr degradation followed a pesudo-first order reaction in most cases, indicating the process was under mass transport control. Moreover, the better performance of BDD anode was proved on a comparative study with PbO2 anode under similar experimental conditions. As a result, the BDD technology could be considered as a nice solution to the treatment of EtBr-polluted wastewater. (C) 2013 Elsevier B.V. All rights reserved.