湿壁介质阻挡放电强化浮石载羟基氧化铁降解水中避蚊胺

Degradation of DEET in aqueous solution with Fe-coated pumice enhanced by wetted-wall dielectric barrier discharge plasma

以避蚊胺(DEET)为模型污染物,研究了湿壁介质阻挡放电(DBD)协同浮石载羟基氧化铁去除污染物的可行性。采用浸渍法制备了浮石载羟基氧化铁复合材料,并对其进行了SEM、XRF、XRD、FT-IR和BET表征。同时研究了放电电压、初始pH、催化剂投加量等参数对DEET的去除率的影响。结果表明:在DEET初始浓度为20 mg·L^(−1)、初始pH=7、放电电压为15 kV、催化剂添加量为0.45 g时,反应27 min后,DEET的去除率为90.52%,且经过4次循环使用后,材料对DEET仍然具有较高的去除率;相比于单一的湿壁介质阻挡放电,DEET去除率提高了13.22%,一级动力学反应速率提高了62.26%。最后讨论了DBD强化浮石载羟基氧化铁去除DEET的可能机制。以上研究结果可为DBD技术去除水中有机污染物的应用提供参考。

In this study,N,N-diethyl-m-toluamide(DEET)was used as the model pollutant to evaluate the feasibility of pollutants removal by wetted-wall dielectric barrier discharge(DBD)combined with Fe-coated pumice.Fe-coated pumice composites were prepared by impregnation method and characterized by SEM,XRF,XRD,FT-IR and BET.The effects of discharge voltage,initial pH value and catalyst dosage on DEET removal efficiency were also investigated in this system.The results showed that the removal efficiency of DEET was 90.52%when the initial DEET content was 20 mg·L^(−1),initial pH was 7,discharge voltage was 15 kV,and Fecoated pumice dosage was 0.45 g and the treatment duration was 27 min.And the catalyst still maintained high removal efficiency for DEET after four cycles.Compared with single wetted-wall dielectric barrier discharge plasma,the removal efficiency of DEET increased by 13.22%,and the first-order kinetic reaction rate increased by 62.26%.At the same time,the concentration of ozone in the system decreased in the presence of catalyst.Finally,the possible mechanism of DBD combined with Fe-coated pumice was discussed.This study can provide theoretical reference for the application of DBD technology in water organic pollutants control.