Study On The Electrochemical Degradation Thiamethoxam Wastewater By Home-made Gas Diffusion Electrode

Thiamethoxam market proportion is rising year by year as one kind of neonicotinoid insecticides. However the pesticide wastewater that generated in the production and use will cause adverse effects on the environment and human health. Conventional biochemical treatment process is limited on dealing with the class of refractory organics. Therefore we need to find an efficient technology to treat thiamethoxam pesticide wastewater.LaNiO3has been used widely in the field of electrochemistry as the only metal catalyst perovskite. Some researches show that B site doping can enhance the electro-catalytic properties of perovskite. The element Co will be doped at B site in the experiment. On the one hand the preparation method of nano-catalyst LaNi1-xCoxO3will be explored. On the other hand the electrochemical performance will be compared between LaNiO3and LaNi1-xCoxO3. The results shows that the oxygen reduction current density of nanometer perovskite catalyst increased above50%, and the electro catalytic performance improved significantly at the condition of La:Ni:Co=1:0.8:0.2,pH10,800％℃calcination.Acetylene black is a kind of electrode material with the advantages of larger surface area, excellent conductive properties, and great adsorption ability. It was be used in the gas diffusion electrode. The best ratio of Acetylene black, graphite, sodium sulfate, PTFE and catalyst had been analyzed with orthogonal method. The result showed that gas diffusion electrode had excellent electrochemical properties at the conditions of graphite5.4g, acetylene black0.6g, sodium1.0g, PTFE3.0g, catalyst0.6g. The influence of electrode material had been explored with CV. Sulfate as a pore-forming agent, PTFE as a binder and water repellent agent, acetylene black as a large specific surface area of the electrode material had more important effect on the creation of three-phase film and electrochemical properties.Thiamethoxam pesticide wastewater was degraded with improved gas diffusion electrode and ordinary graphite electrode. The optimal degradation conditions and degradation mechanism had been explored in the work. It would be reach the best degradation efficiency when the current density was3.1mA/cm2, pH3. The current density and pH meet the first order reaction kinetics equation in the process of thiamethoxam degradation. The degradation process was analyzed with LC-MS.An improved gas diffusion electrode was manufacture in the work. And the thiamethoxamin degradation was also invested. The degradation efficiency of refractory organics is improved with the method. Furthermore the study extends the application fields of electrochemical process.