The Study On The Degradation Of Dinotefuran By Dielectric Barrier Discharge Non-thermal Plasma In Aqueous Water

The steady rise of the food economy has led to the rapid development of modern agriculture,bringing unprecedented economic benefits to mankind,and the accompanying pesticide economy has brought great burden to the natural ecological environment.The production process of pesticide industry and the large-scale use of pesticide products can producewastewater and wastes,these substanceshave caused irreversible damage for natural environment,recently,pesticide wastewaterhas become the focus point.Dinotefuran is a new generation of nicotine pesticide,due to its good insecticidal effect,dinotefuran is used extensively.Pesticide wastewater treatment problems are very serious,some traditional processing techniquesare difficult to achieve treatment purpose,so advanced oxidation technologies came into being by experts and scholars highly favored.According to the treatment problem of pesticide wastewate by traditional wastewater treatment process,dinotefuran was used as the target pollutant,and the modified titanium dioxide photocatalyst was introduced into the dielectric barrier discharge non-thermal plasma reaction system.The synergistic effect of two advanced oxidation techniques on dinotefuran wastewater was studied by using the self-designed radial flow reactor.The lanthanum modified(0%,2%,5%,10%,15%)titanium dioxide catalysts were prepared by gel-sol method,whose properties were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray(EDX)and diffuse reflectance spectroscopy(DRS).And we have analysed the crystal form of the sample,the surface distribution,the presence of elements,the response of the sample to visible light and calculated the bandgap energy.The modified titanium dioxide was used to introduceinto the dielectric barrier discharge non-thermal plasma reaction system..The lanthanum modified titanium dioxide catalyst was screened out according to the treatment conditions and the results of the characterization.The effects of various conditions on the degradation of dinotefuran were investigated in the presence of the best catalyst.The conditions included:initial concentration,input power,initial pH,initial conductivity,catalytic ion,hydrogen peroxide and alcohol inhibitors.The results showed that the optimum initial concentration and input power were 100 mg/L and 150 W,respectively.The alkaline environment was beneficial to the degradation reaction of dinotefuran,and the degradation efficiency was 96.8%when pH was 10.5.Low concentration of Fe2+ is 50 mg/L,which could greatly improve the degradation efficiency(99.0%),and the catalytic effect of Cu2+ is not as good as that of Fe2+.Appropriate amount of hydrogen peroxide could increase the concentration of hydroxyl radical in the reaction environment and promotethe degradation of dinotefuran.The addition of isopropanol reduced the degradation efficiency of dinotefuran and confirmed the important role of hydroxyl radicals in the reaction process.The process of treatment is acidification process,the pH of the solution was gradually decreased and finally stabilized.The conductivity of the solution was always in the rising state,which was related to the decomposition of dinotefuran.The degradation products of dinotefuran were detected by high performance liquid chromatography-mass spectrometry(HPLC-MS).The structures of the products were deduced based on the relative molecular mass and related references.It was further speculated that dwarfazapine Blocking the possible degradation pathways in dielectric barrier discharge non-thermal plasma.The experimental results showed that the degradation efficiencies of dinotefuran by dielectric barrier discharge non-thermal plasma combinedmodified titanium dioxide were better than that of single dielectric barrier discharge.The study could provide some references for pesticide wastewater treatment in plasma field.