Preparation Of Electro-catalytic Oxidation Anodes And Their Applications In Organic Waste Water Treatment

Ti/PbO₂,Ti/SnO₂,Ti/SnO₂+Sb₂O₃/PbO₂ anodes are prepared by brush coating with high temperature oxidation and electro-deposition method. Methodology for the electrochemical decomposition of cyclohexanone, adipic acid, imazethapyr using Ti/PbO₂,Ti/SnO₂,Ti/SnO₂-Sb₂O₅/PbO₂ anodes are suggested in the paper.The results of an experimental study on the destruction of imazethapyr by electrochemical oxidation in NaCl medium are compared with the data obtained by electrochemical oxidation in Na₂SO₄ medium. The UV-VIS spectra obtained by process monitoring indicated that the reaction mechanism is different from each other when using different electrolyte. Imazethapyr was mineralized directly when using Na₂SO₄ as the electrolyte, while a kind of intermediate product was formed rapidly and then mineralized fast when using NaCl as the electrolyte. NaCl was selected as the electrolyte for electrochemical oxidation of imazethapyr and the conditions of electrolysis reaction were optimized. The process of electrochemical decomposition was primarily monitored by ultra-violet spectrophotometric method. The electrochemical decomposition mechanism of imazethapyr was studied by UV-VIS spectrophotometry and the comparative aerobic biological water treatment test. The effectiveness of the electrochemical pretreatment was proved by the comparative aerobic biological treatment based on the activated sludge process.The results of an experimental study on the destruction of cyclohexanone, adipic acid by electrochemical oxidation in Na₂SO₄ medium, and studied the effection of Na₂SO₄ medium concentration, pH value, space between the electrodes, electric current, Optimizing the electrolytic response condition. The optimized electrochemical decomposition conditions as following, electric current is 40mA/cm², Na₂SO₄ concentration is 2.4g/L, pH is 6, distance between electrodes is 10mm.The electrochemical decomposition mechanism of cyclohexanone and adipic acid was studied primarily by UV-VIS spectrophotometry. The electro-decomposition process ofcyclohexanone on the surface of Ti/PbO2> Ti/SnO2+Sb2O3/PbO2 is similar. A kind of intermediate product was formed, and the organic compound was mineralized gradually. While the compound was electrochemical combustion on the surface of Ti/SnO2 anode, it was mineralized directly.The electro-decomposition process of adipic acid on the surface of Ti/PbC>2^ Ti/SnC>2> Ti/SnO2+Sb2O3/PbO2 anodes was similar. A series of intermediate product was formed, and the organic compound was mineralized gradually.Chemical oxygen demand (COD) of waste water was monitored by potassium dichromate method, and COD removal achieved at 50% when the sample was electrolyte 270 minutes.