DUAL PURPOSE ELECTROCHEMICAL TREATMENT OF WASTEWATER

Industrial wastewater containing toxic waste compound and metal ions pose manyproblems of disposal. The most generally used method of removing metalcontaminants is lime treatment to precipitate metals as hydroxides. The metalis not normally recovered resulting in the need for sludge disposal. The costof sludge disposal plus fewer available disposal sites makes that methodincreasing less attractive. Alternative methods of metal ion removal (e.g. ionexchange and reverse osmosis) have several drawbacks including high equipmentcosts. Oxidation of organic compounds in wastewater and simultaneouselectrowinning of metals as described in this proposal are of great economic andenvironmental significance. This proposal describes research to demonstrate thefeasibility of using a three dimensional packed bed electrode as the anode forthe oxidation of organic compounds and another packed bed electrode as thecathode for metal ion deposition. The two packed beds are separated from eachother by a porous separator and operated as the anode and cathode of a singleelectrochemical reactor. The proposed method utilizes electrocatalyticconducting particles as the anode bed material for oxidation of organicsprimarily to carbon dioxide and nitrogen. The metal deposited on the particlesforming the cathode bed can be dissolved anodically to form a concentratedsolution of metal ions which can then be used for further processing to recovermetals.