Electrochemical Treatment Of Bactericide Wastewater

Ti/SnO₂+Sb₂O₃/PbO₂ electrode was prepared by method of coating and electro-deposition method. The structure and property of electrode were also analyzed by SEM, XRD and steady state polarization curve. Indigo carmine solution was used to study the electrochemical oxidation mechanisms of Ti/SnO₂+Sb₂O₃/PbO₂ anode. And the mechanisms include direct electro-oxidation and indirect electro-oxidation. The main one is direct electro-oxidation, while the secondary one is indirect electro-oxidation. In this study, electrochemical oxidation experiment using a Ti/SnO₂+Sb₂O₃/PbO₂ anode was applied to treat an isothiazolin-ketone solution. The kinetics of isothiazolin-ketone degradation and chemical oxygen demand (COD_cr) destruction was investigated, while the operating parameters affecting the mechanism were also studied. Not only the model of the relationship of reaction velocity constant and initial concentration is established, but also the model of the relationship of reaction velocity constant and current density is established. The parameters investigated included current density, electrochemical oxidation time and pH. 98% isothiazolin-ketone and 43% COD_cr was removed at a current density of 15 mA/cm², initial isothiazolin-ketone of 200 mg/L and oxidationt time of 180min. The intermediates of electrochemical oxidation were analyzed by UV spectrum. The chlorine atom was removed from isothiazolin-ketone firstly. Then the chemical bond of S-N was disconnected. So the heterocycle of the isothiazolin-ketone was disconnected and oxidized into amine products, and the sulfur atom was removed.Then the amine products were oxidated into CO₂ and H₂O. In this study, we also use the micro-electrolysis and electro-oxidation to treat the bactericide wastewater. The bactericide wastewater includes the isothiazolin-ketone and sulfide (organic and inorganic) which were harmful to microorganism. So it is very important to remove the isothiazolin-ketone and sulfide (organic and inorganic) by micro-electrolysis and electro-oxidation firstly. Base on the experiment, the bactericide wastewater was treated by electro-oxidation and micro-electrolysis firstly, then was treated by biological treatment include anaerobic hydrolysis-acidification, biological contact oxidation and membrane bioreactor in the bactericide wastewater treatment project. Now the bactericide wastewater treatment project runs very well, the drainage water quality attains the national standard. So the bactericide wastewater treatment scheme is reasonable to treat the bactericide wastewater. Base on the experiment and bactericide wastewater treatment, the method of micro-electrolysis and electro-oxidation suit for the treatment of waste water with high toxicity and high organic...