Development of a high performance electrochemical wastewater treatment system

In order to construct a high performance electrochemical system for practical use in industrial and municipal wastewater treatment, laboratory scale electrochemical experiments were performed to select anode materials by applying pulse voltage. Based on the results obtained from laboratory experiments, a pilot plant of electrochemical treatment system (0.3 m(3) h(-1)) was successfully developed, in which electrocoagulation and electrooxidation processes were used. The performance of the treatment system was evaluated by treating domestic wastewater, pond water containing algae and wastewater from hog raising. As a result, production of hydroxyl radicals detected with p-nitrosodimethylaniline (RNO) at Ti/RuO2-TiO2 anode was larger than with a platinum anode, and hydroxyl radicals were not detected at Ti anode. Moreover, a significant difference in electro-catalytic properties for ammonia oxidation between platinum and Ti/RuO2-TiO2 electrodes was not observed from the cyclic voltammogram. The removal of T-N, T-P, NH4-N and COD from domestic wastewater and pond water containing algae was approximately 90%, while the removal of chlorophyll-a (chl-a) of algae was approximately 100%. Although the electrochemical treatment system was effective on biologically treated wastewater from hog raising, the treatment of raw wastewater was not remarkable. Therefore, the electrochemical treatment system requires pretreatment when used with wastewater containing high concentrations of suspended solids. (C) 2003 Elsevier B.V. All rights reserved.