Application Of Electrochemical Oxidizing Method To Domestic Wastewater Reuse

In modern environmental science, it is important to develop new techniques for the treatment of organic wastewater. Among them the electrocatalytic oxidizing method is being widely used in recent years. But limited by the electrode materials, this method shows lower current efficiency and higher energy consumption.In this paper, a new high efficient electrochemical oxidizing method, which used oxide modified electrodes, was established for organic wastewater degradation. The anodes' physical and electrochemical properties, their electro-oxidation degradation effects for the treatment of organic wastewater were studied. The correlations between the electrochemical parameters and oxidizing current efficiency are correlated, which can provide theoretical guidance for the optimization of high efficient anode materials were indicated. Furthermore, the anode's electro-oxidization mechanisms and its kinetic processes were also studied, which can provide theoretical and applicable background for the electrocatalytical oxidization researches on the organic wastewater.The six electrodes were prepared by pyrolytic depositing a thin film of multi-valence noble metal oxide, which are traditionally considered with high chemical catalytic characteristics(Sn02,Sb203),on a titanium substrate. It shows that the modified oxide films are with the structures and properties of the semiconductors.The SnO2-Sb2O3 /Ti anode, which was prepared at temperature 500~600℃ and the doped molar content of Sb/Sn9~11%,is with high catalytic and good conductive properties. The results show that oxygen evolution potential and the transmission coefficient B are tow important elements for the evaluation the anode whether it can be efficiently used to dispose the organic wastewater. The essential condition for the material that can be used as the anode is that it must possess with emanation potential, which enhance the direct oxidizing probability of the organic materials on the anode. Whereas, it must also possess with large transmission coefficient, which gives the electrocatalytic capability of the anode.With the increment of the electrolysis current density, both the COD and organic removalrate are increased, but the current efficiency is decreased, thus causing more energy consumption. The suitable electrolysis current density is in the range of 10-30 mA/cm2.