Dielectric Barrier Discharge Coupled With Catalyzer For Chlorobenzene Degradation: Analysis Of PCDD/Fs And The Reaction Mechanism

Chlorobenzene is currently widely used in industrial production,and chlorobenzene pollution poses a serious threat to human health and the ecological environment.Compared with common volatile organic compounds,chlorobenzene has high biological toxicity and is difficult to biodegrade in the natural environment.At the same time,as a precursor of dioxin,chlorobenzene may produce highly toxic pollutant dioxin during the degradation process.Among them,the most widely used thermal catalytic technology to degrade chlorobenzene has been proved to produce dioxin,and the synthesis of dioxin The window temperature is 200-400℃.At present,a large number of studies have proved that DBD can also effectively degrade chlorobenzene,and DBD can obtain active particles at a lower temperature.The reaction temperature is below 200°C,which is not in the synthesis window temperature of dioxin,so the possibility of dioxin production is relatively high.Low.However,there is no research to prove whether DBD degrades chlorobenzene to produce dioxins,so this paper explores this issue in depth.（1）In this paper,the catalyst comparison experiment was carried out to study the degradation effect of Dielectric Barrier Discharge（DBD）combined with Fe,Co,Mn,Ce/γ-Al₂O₃ four catalysts on chlorobenzene,and the experimental results of catalyst characterization.It shows that the reduction and acidity of the catalyst have a significant effect on the degradation of chlorobenzene,while the structural properties of the catalyst have a limited effect on the degradation of chlorobenzene.The DBD combined catalyst significantly improved the chlorobenzene removal rate,mineralization rate,Cl selectivity and energy efficiency,and reduced the O₃concentration in the tail gas.Among them,Co/γ-Al₂O₃ has the best degradation effect.When the specific input energy is 510 J/L,the removal rate,mineralization rate,Cl selectivity and energy efficiency are 26.06%,25.52%,33.03%and 2.41g,respectively./k Wh.（2）In this paper,the effect of DBD operating parameters on the degradation of chlorobenzene was studied.The Response Surface Methodology（RSM）Center Composite Design（CCD）was used to study the applied voltage,flow rate,and initial chlorobenzene concentration.The effects of three DBD operating parameters on the degradation performance of chlorobenzene were verified,and the accuracy of the model was verified.The relative error between the measured value and the predicted value was less than 5%,indicating that the predicted value was in good agreement with the experimental value.（3）In this paper,high-resolution gas chromatography and high-resolution mass spectrometry analysis were used to demonstrate for the first time that dioxins were generated during the catalytic degradation of chlorobenzene by DBD.Taking Co/γ-Al₂O₃ as an example.Then,the organic intermediates generated during the degradation of chlorobenzene were detected by gas chromatography-mass spectrometry,and the possible degradation paths of chlorobenzene in the plasma catalytic system were reasonably speculated.In this paper,the influencing factors,influence rules and influence degree of DBD combined catalytic degradation of chlorobenzene were first explored,and then according to the production of organic by-products and dioxins,the degradation process of chlorobenzene and the mechanism of dioxin generation were inferred,so as to determine the mechanism of chlorobenzene degradation.Discuss the applicability and safety of plasma degradation of chlorobenzene,and analyze the inhibition methods of dioxins.