Photoassisted electrochemical degradation of organic pollutants on a DSA type oxide electrode: Process test for a phenol synthetic solution and its application for the E1 bleach kraft mill effluent

In this paper, the performance of a photoassisted electrolysis process, for the degradation of organic pollutants, is investigated. Results obtained i n this work have shown that the thermally prepared anode of titanium, coate d with 70TiO(2)/30RuO(2), exhibits photoactivity and may be used for the tr eatment of effluents. A synthetic phenol aqueous solution and a real paper mill industry effluent were treated. Kinetic analysis showed a synergetic e ffect of electrolysis and photocatalysis and degradation rates are an order of magnitude greater than the sum of the results reached by using both pro cesses individually. Using a 125 W mercury bulb and 20 mA cm(-2), the pheno l concentration decayed 85% in 90 min and 70% reduction of TOC was obtained . In the application of the treatment process for the degradation of the El bleach Kraft mill effluent, total phenols were practically eliminated in a short period of processing time, and color, usually resistant to biologica l treatment, was reduced to 10% from its initial value measured in terms of absorbance. Reductions of AOX, GOD, and BOD by 25%, 30%, and 35%, respecti vely, were also observed.