脉冲介质阻挡放电降解三氯乙烯的研究

研究了不同操作条件下脉冲介质阻挡放电等离子体对三氯乙烯的降解效果,通过红外分析探讨了降解的反应历程.结果表明:当载气为N2时,脉冲介质通过阻挡放电等离子体可实现三氯乙烯的有效降解,降解率随放电参数及气体流量的变化而变化,在保证体系能量效率最大的基础上可获得三氯乙烯降解的最佳处理条件,即输入电压25 V、脉冲频率500 Hz、脉冲占空比50％、放电间隙5 mm、气体流量300 mL/min;当载气中含O2时,三氯乙烯的降解率随输入电压的变化而变化,即输入电压小于25 V时,三氯乙烯降解率随O2的增加而提高,输入电压大于25 V时,三氯乙烯降解率随O2的增加而下降.三氯乙烯降解过程中会产生CHCl2 COCl、CCl3-CN或ClCH2CH2NH2,终产物中除含有HCl、CO2和CO外,还含有COCl2.

Degradation of Trichloroethylene in a Rod-in-Tube Pulsed Dielectric Barrier Discharge Reactor

The performance of a laboratory-scale pulsed dielectric barrier discharge(DBD) reactor for trichloroethylene(TCE) degradation was studied.The reaction process of degradation was discussed by the infrared spectroscopy analysis.The experimental results show that when the background gas was pure N2,the pulsed DBD could effectively destroy TCE molecules,and the removal efficiency clearly depended on the discharge parameters and gas flux.From the maximum efficiency of energy utilization of the whole system,the process parameters for optimum removal of TCE were obtained,i.e.,25 V in the input voltage,500 Hz in the pulse frequency,50% in the pulse duty ratio,300 mL/min in the gas flux,and 5 mm in the discharge gap width.When the carrier gas included O2,the removal efficiency of TCE increased with an increase in the O2 content at low input voltage(<25 V) but decreased with an increase in the O2 content at high input voltage(>25 V).CHCl2COCl,CCl3—CN or ClCH2CH2NH2 were produced during the degradation of TCE,and the final products contained COCl2 as well as HCl,CO2 and CO.