Degradation of Thiamethoxam in Wastewater by Low Temperature Plasma

In this paper, different dielectric barrier discharge powers and the effects of various external factors on the degradation of thiamethoxam were investigated. TiO2 catalyst was added to improve the degradation efficiency, and the effects of different forms of catalysts (powdered TiO2 and TiO2 loaded on ceramic) were compared. The results showed that the removal rate of thiamethoxam could reach 85.9% after 160-min degradation with a discharge power of 150 W. The degradation process was inhibited with the increase of initial electrical conductivity and initial pH, or the addition of n-butyl alcohol, whereas Fe2+ and Cu2+ could promote the degradation. The catalytic efficiency of TiO2 loaded on ceramic was slightly higher than that of powdered TiO2. According to the analysis results of the degradation products by high performance liquid chromatography-mass spectrometry low temperature dielectric barrier discharge plasma could effectively degrade the thiamethoxam in water. In conclusion, the dielectric barrier discharge plasma can facilitate the degradation of thiamethoxam in water, which lays a solid foundation for wastewater treatment in the field of pesticide.