Preparation Of Gas Diffusion Electrode And Application On Nitenpyram-Containing Wastewater Treatment

Wastewater with agricultural chemical is bound to be discharged in the progress of nitenpyram production and application, which would seriously contamin the nature environment. Nitenpyram is one kind refractory organic pollutants, which is difficult to be degradated with traditional treatment methods, making it urgent to find a new way to treat the agricultural chenical wastewater effectually. In this paper, electrolyse method was emploied as the pretreatment of the nitenpyram-containing wastewater, to removal the toxic and hazardous radical and enhance the biodegradability of the waste water, creating the conditions for the further biological treatment.CCD-RSM (Central Composite Design-Response Surface Methodology) was applied for the optimization of the catalyst preparation, the gas diffusion electrodes (GDEs) preparation and the nitenpyram-containing wastewater degradation. As a result, the optimal conditions for the catalyst preparation were determined as follows: the mol ratio of citric acid with metal ions 1.54:1, pH 9.94 and the calcination temperature 824.39℃, when the theory color removal rate was 91.996%. The optimal conditions for the GDEs preparation were determined as follows:the catalyst content 1.50 g, pore-forming agent content 0.73 g, PTFE content 3.98 g, the calcination temperature 255.96℃, when the theory color removal rate was 101.476%. The optimal conditions for the nitenpyram-containing wastewater degradation were determined as follows:the current intensity 0.35 A, and pH 3.34, when the theory nitenpyram removal rate was 100.088%. The mechanisms of the catalyst preparation, the GDEs preparation and the nitenpyram-containing wastewater degradation were discussed too, which would furnish some theoretical basis for the application of GDEs on the treatment of pesticide wastewater.Variety of detection and analysis methods, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), potentiodynamic polarization measuremeng and so no, were emploied for the characterization and analysis of catalyst and GDEs. Results indicated that:①The catalyst prepared had a pure crystalling phase, a high deffraction peak intensity and an integrity and stable perovskite structure;②The GDEs prepared had a rich-pore structure, a good gas diffusion property, a great polarization resistance and an excellent electro-catalytic capability.In this paper, the theory of GDEs preparation was enriched, and a new treatment method of POPs was provided.