气-液两相复合放电等离子体激活过硫酸盐降解难矿化VOCs及其产物气溶胶的效能和机理

Aimed at dealing with the emerging smog pollution induced by photochemical smog and PM2.5, etc., a novel method of producing sulfate radicals from activated persulfate by gas phase/liquid phase discharge plasma (GLDP) is put forward for degrading VOCs according to the high efficacy of sulfate radical in the process of degrading organic contaminants. Waste gas containing VOCs is purified in sequence by a gas phase discharge and a strong oxidative system of sulfate radical/hydroxyl radical to highly mineralize VOCs and derived aerosol products, therefore, the problem of high energy cost and production of harmful aerosols in the degradation process of recalcitrant VOCs by gas phase discharge can be solved. The design method of gas discharge chambers containing a DBD radiation light source is studied as well as the formation of hybrid gas phase/liquid phase discharge by coordinating the gas discharge chamber with liquid phase discharge chamber are investigated, in which the DBD radiation light source is used for promoting the activation of aqueous persulfate into sulfate radicals and then enhancing the removal of VOCs and aerosols. The physic-chemical effect and its correlation with the activation efficiency of persulfate are diagnosed to reveal the activation pathways of persulfate. The evolution of organic compounds and its correlation with the reactive species in gas/liquid phases are also diagnosed to illuminate the degradation pathways of VOCs by combining the calculation of reaction pathways. This study can be referenced for purification of complex VOCs waste gas from industries.

面向细粒子及光化学烟雾等引发的雾霾污染问题，基于硫酸根自由基降解有机污染物的高效性，提出气-液两相复合放电激活过硫酸盐、生成硫酸根自由基降解VOCs的方法。有机废气依次被气相放电、气-液两相放电等离子体激活过硫酸盐形成的双强氧化自由基（硫酸根自由基/•OH）体系处理，VOCs及其降解生成的气溶胶被深度矿化，解决气相放电处理成分复杂、含难矿化VOCs废气时的能耗高及生成有害气溶胶问题。研究具有准分子辐射光源功能的气相介质阻挡放电与液相放电形成复合放电、协同激活液相过硫酸盐的方法，高效生成硫酸根自由基，提高气-液两相放电等离子体去除VOCs及气溶胶的效能；诊断气-液两相复合放电生成的物化效应与过硫酸盐激活效能的关系，气/液相体系中有机物的演化过程及其与反应活性物质的关系、结合化学反应途径计算，阐明过硫酸盐的激活途径及VOCs的降解机理。本申请可为复杂工业有机废气的净化研究提供参考。

面向细粒子及光化学烟雾等引发的雾霾污染问题，基于硫酸根自由基降解有机污染物的高效性，提出气-液两相复合放电激活过硫酸盐、生成硫酸根自由基降解VOCs的方法。本研究给出了气-液两相放电装置的的设计方法，包括放电装置的高压电极供电方法和电极结构设计方法；测试了气-液两相复合放电等离子体特性和活性物质；计算了正脉冲电源供电的气-液两相放电装置的气相放电空间的电场分布及等离子体分布；给出了气-液两相放电激活液相过硫酸盐的方法和机理，包括放电等离子体激活过硫酸盐的影响因素、效能及机理，强化过硫酸盐激活效率的方法；研究了气-液两相复合放电激活液相过硫酸盐降解VOCs 的效能和机理，给出了苯降解的物化过程和机理。结果表明：优化研究后的气-液两相放电等离子体可以高效激活过硫酸盐，放电等离子体与低浓度铁离子在激活过硫酸盐过程中存在协同效应，可以提高液相污染物的降解率达到30-60%(酸性橙)和20-46%（对硝基苯酚）、提高气相苯降解达到10%以上，且气相氮氧化物、有机气溶胶的排放得到了有效控制；等离子体激活过硫酸盐的效应包括液相电子和氢原子、过氧化氢、等离子体通道的局部高温等。本研究对于难降解液相污染物、惰性挥发性气态有机物的高效降解方法研究具有一定参考价值，该方法应用后将有助于控制上述污染物导致的环境污染问题。