The Study Of Mechanism On Low Temperature Plasma For Degradation Of Nitenpyram Pesticide In Aqueous Solution

Plasma wastewater treatment is a new wastewater treatment technology combining high-energy electron irradiation, ozonation and ultraviolet decomposition. Recently, due to some outstanding advantages of degradation of pollution water using dielectric barrier discharge (DBD), DBD exhibits favorable application perspective. Currently, as a branch of plasma technology, the study of degradation of pollution water using DBD are widely and deeply exploring. As a newly developed technology, DBD has the advantage of high efficiency, good fidelity and could degrade nearly all sorts of organic pollutants without selectivity. Compared with the technology of conventional plasma discharge, the electromagnetism on DBD is comparatively low and also the equipment is much simple, cheaper and efficient. So the technology of DBD is more practical in on situ water treatment and has potential in being widely used industrialization. This subject studied the treatment of nitenpyram pesticide wastewater by low temperature plasma which produced by DBD.The reactor has a structure of the radial flow sedimentation tank that drenching the surrounding water. First, we studied the different discharge power of the dielectric barrier discharge and the effects of different external factors, such as Fe2+, pH, butanol (radical scavenger), Na2CO3, H2O2 and electricity conductivity on nitenpyram pesticide wastewater degradation. The results showed that when the discharge power was 200 W, the initial concentration of nitenpyram was 100 mg/L, and degradation of 180 min, the removal of nitenpyram reached 82.7%. When the addition of Fe2+, H2O2 to the solution was at a suitable amount, the number of OH in the solution increased, thus promoting the degradation of nitenpyram pesticides. While the addition of the n-butanol and Na2CO3 to the solution reduced the amount of·OH in solution, thus inhibiting nitenpyram pesticide degradation. The COD value has little change in the degradation of nitenpyram wastewater, and the TOC value decreased.According to analysis the products by HPLC-MS, the results showed that Acid substances produced during nitenpyram degradation, and this is the main reason that leads pH value to reduce. In addition, after measuring the·OH and H2O2 in the discharge process, we found that the concentrations of·OH and H2O2 in the electrohydraulic system of discharge process increased with the discharge time.The results showed that low temperature plasma produced by dielectric barrier discharge had a good effect on nitenpyram pesticide wastewater treatment, and it provide some technical guidance for low temperature plasma technology on industrial applications for pesticide wastewater treatment.