高压脉冲介质阻挡放电降解土壤中芘的研究

Study on treating soil contained pyrene by high voltage pulsed dielectric barrier discharge

针对我国土壤多环芳烃的污染问题,通过自研的介质阻挡脉冲反应器处理土壤中的芘,研究了放电电压、放电频率、土壤湿度、土壤厚度、空气流速和土壤pH等条件对降解效果的影响。结果表明,随着放电电压和放电频率增加,芘的降解率提高,空气流速和土壤湿度在适宜的范围内,有利于芘的降解,增加土壤厚度和降低pH会降低芘的降解率。最适降解条件为:放电电压12.6 kV、放电频率1.0 kHz、土壤湿度3.0%、土壤厚度1 mm、空气流速2 L/min、土壤pH≥7,芘的降解率为97.04%。通过HPLC-MS和FT-IR分析,间接证明放电产生的活性物质O_(3)、·OH、NO_(x)等导致了芘的降解,提出了芘可能的降解途径。

Aiming at the pollution of the polycyclic aromatic hydrocarbons(PAHs) in soil in China, the selfdeveloped dielectric barrier pulse reactor was used to treat pyrene in soil, and the effects of discharge voltage,discharge frequency, soil moisture, soil thickness, air velocity and soil pH on the degradation effect were studied.The results showed that the degradation rate of pyrene increased with the increase of discharge voltage and discharge frequency, and the air flow rate and soil moisture were favorable for the degradation of pyrene. The degradation rate of pyrene decreased with the increase of soil thickness and the decrease of pH. The optimal degradation conditions are as follows: discharge voltage 12.6 kV, discharge frequency 1.0 kHz, soil moisture 3.0%,soil thickness 1 mm, air flow rate 2 L/min, pH≥7. The degradation rate was 97.04%. According to the analysis of HPLC-MS and FT-IR, it was indirectly proved that the active substances such as O_(3), ·OH, NO_(x) produced by the discharge were beneficial to the degradation of pyrene, and the possible degradation pathway of pyrene is proposed.