Research On Dielectric Barrier Discharge Combined With Solution Absorption And Removal Of VOCs

Volatile organics（VOCs）with complex components and widely distributed pollution sources are important precursors of secondary fine particulate matter(PM_2.5),which mainly come from chemical plants,paint plants,petroleum refineries,rubber plants,pesticide plants,etc.Long-term exposure to VOCs causes people to suffer from anemia and leukemia,resulting in respiratory and nervous system diseases,which have a significant impact on the human healthy and the environment.In this study,VOCs were removed by DBD cooperative solution absorption reactor combined with the low-temperature plasma and solution absorption,and the degradation effects on toluene of the DBD reactor and the DBD cooperative solution absorption reactor were analyzed and tested.The degradation efficiency,absolute removal amount and main products of toluene in this two reactors were analyzed,and the factors affecting the degradation effect of toluene were also tested,including discharge voltage,discharge frequency,initial concentration and gas flow.Finally,the energy consumption impact of this two reactors was analyzed.The study found that the DBD synergistic solution absorption reactor had a better removal effect on toluene than the single DBD reactor when the initial concentration of VOCs was 1000 mg/m3,the gas flow rate was 700 ml/min,the discharge voltage was 5-10 k V,and the discharge frequency was 5-9 k Hz.The degradation efficiency and absolute removal of toluene gradually increased when the voltage increased from 5 k V to 10 k V,and the degradation efficiency of toluene decreased with the increase of gas flow and initial concentration,but the absolute removal increased.The degradation efficiency and absolute removal of toluene first increased and then decreased when the frequency was increased from 5 k Hz to 9 k Hz,and both the removal efficiency and the absolute removal reach the peak value when the frequency was 7 k Hz,which was the same under different voltages,gas flow rates and initial concentrations.The research results showed that the power of the DBD synergistic solution absorption reactor was greater than that of the single DBD reactor under the same conditions,which was also consistent with the removal rate of toluene.Energy efficiency decreased with the increase of voltage,first decreased and then increased with the increase of frequency,and increased with the increase of gas flow rate and initial concentration.However,the increase in energy efficiency came at the expense of degradation rate,and the increase in degradation rate would inevitably lead to a rapid decrease in energy efficiency.The analysis showed that the DBD synergistic reactor stabilized the removal efficiency while also improved energy efficiency,and the ozone and carbon dioxide produced by the system further verified that the DBD synergistic solution absorption reactor had better toluene removal effect than the separate DBD reactor.The classical kinetic model was used to analyze the system,and it is found that the experimental results were consistent with the primary kinetic model.And the changes of the kinetic constant（k）under different voltages were also analyzed,it is found that k increased with the increase of voltage.