Sequential Electrochemical/Biological Treatment for The Removal of 2,6-Dichlorophenol From Synthetic Wastewater

摘要

The paper examines the effect of chloride on the oxidation of 2,6-dichlorophenol (DCP) performed at TiO_2/RuO_2 DSR anodes, which are specific catalysts for chlorine evolution. The results indicate that chloine/hypochlorite originating from chloride oxidation in certain favourable conditions reacts with the orgaic substrate at the diffusion layer near the anode, accelating the mass transfer of the reactant towards the electrode surface. When the bulk concentration of orgaic substrate has become very low, the oxidising species can accumulate in the bulk solution where the accomplishment of the oxidation of residual reactant and of its intermedaites takes place. Solutions which also contained glucose were electrolysed in order to verify the high level of selectivity of DCP oxidatoin with respect to a biodegrabadle substrate: glucose was found to be unchanged up to nearly complete elimination of DCP. The toxicity of the solution was sufficiently reduced to reach values compatible with the subsequent biological treatment.