College of Chemical Engineering and Material, Zhejiang University of Technology , Hangzhou 310014, China.
Environ Sci Technol. 2013 Jul 16;47(14):7934-9. doi: 10.1021/es400786p. Epub 2013 Jul 5.
The technology of packed bed dielectric barrier discharge (DBD) plasma followed by a chemical absorption has been developed and was found to be an efficient way for decomposition treatment of sulfuryl fluoride (SO2F2) in simulated residual fumigant. The effects of energy density, initial SO2F2 concentration, and residence time on the removal efficiency of SO2F2 for the DBD plasma treatment alone were investigated. It was found that the SO2F2 could be removed completely when initial volume concentration, energy density, and residence time were 0.5%, 33.9 kJ/L, and 5.1 s, respectively. The removal mechanism of SO2F2 in the packed bed DBD reactor was discussed. Based on the detailed analysis of SO2F2 molecular stability and its exhaust products in the DBD plasma reactor, it was concluded that the energetic electrons generated in the packed bed DBD reactor played a key role on the removal of SO2F2, and the major decomposition products of SO2F2 detected were SO2, SiF4, and S (Sulfur). Among these products, SiF4 was formed by the F atom reacted with the filler-quartz glass beads (SiO2) in the packed bed DBD reactor. Aqueous NaOH solution was used as the chemical absorbent for the gaseous products of SO2F2 after plasma pretreatment. It was found that the gaseous products in the plasma exhaust could be absorbed and fixed by the subsequent aqueous NaOH solution.
填充床介电阻挡放电（DBD）等离子体后化学吸收技术已被开发出来，并被发现是一种有效处理模拟残留熏蒸剂中硫酰氟（SO2F2）的方法。研究了能量密度、初始 SO2F2 浓度和停留时间对单独使用 DBD 等离子体处理去除 SO2F2 的效率的影响。结果发现，当初始体积浓度、能量密度和停留时间分别为 0.5%、33.9 kJ/L 和 5.1 s 时，SO2F2 可完全去除。讨论了填充床 DBD 反应器中 SO2F2 的去除机制。基于对 DBD 等离子体反应器中 SO2F2 分子稳定性及其排放产物的详细分析，得出结论：填充床 DBD 反应器中产生的高能电子在去除 SO2F2 方面发挥了关键作用，检测到的 SO2F2 的主要分解产物为 SO2、SiF4 和 S（硫）。在这些产物中，SiF4 是由填充床 DBD 反应器中的 F 原子与填充剂-石英玻璃珠（SiO2）反应生成的。NaOH 水溶液用作等离子体预处理后 SO2F2 气态产物的化学吸收剂。结果发现，等离子体尾气中的气态产物可以被后续的 NaOH 水溶液吸收和固定。
