Hydrogen-polarized vacuum ultraviolet photolysis system for enhanced destruction of perfluoroalkyl substances
Hydrogen-polarized vacuum ultraviolet photolysis system for enhanced destruction of perfluoroalkyl substances
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DOI：
10.1016/j.hazl.2022.100072
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发表时间：
2022-11
影响因子：
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通讯作者：
Gongde Chen;Sitao Liu;Qingyang Shi;Jay Gan;Bosen Jin;Y. Men;Haizhou Liu
中科院分区：
文献类型：
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作者：
Gongde Chen;Sitao Liu;Qingyang Shi;Jay Gan;Bosen Jin;Y. Men;Haizhou Liu
使用水合电子（e aq−）的还原水处理是一种有前途的破坏全氟烷基物质的技术;然而，它面临着反应动力学缓慢，不希望的化学添加和高能耗的挑战。在此，我们开发了一个氢（H2）极化的水光解系统，利用185 nm的真空紫外（VUV）光对全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）进行还原性降解。185 nm的光子直接将H2 O和OH-光解为HO·、H·和e aq−。H2通过消除溶解氧的清除作用并将羟基自由基（HO·/O·-）转化为e aq−，使未调谐真空紫外系统中e aq−的准稳态浓度提高了18倍。H2的极化效应使PFOA的降解率从10%提高到95%，使PFOS的脱附率从17%提高到94%，使PFOS的脱附率达到87%. pH影响H2 O和OH-之间的真空紫外光子吸附，并移动H·和e aq−之间的平衡，这导致PFOA破坏的最佳pH为10.3。氯化物和硫酸盐的存在增强了e aq−的产生，并促进了PFOA的破坏。H2极化真空紫外光解水系统产生高水平的e aq−从清洁的水成分和显着降低能源消耗PFAS处理在温和的碱性条件下。
Reductive water treatment using hydrated electrons (e aq−) is a promising technology to destruct perfluoroalkyl substances; however, it faces challenges of slow reaction kinetics, undesirable chemical addition, and high energy consumption. Herein, we developed a hydrogen (H 2)-polarized water photolysis system using vacuum UV (VUV) light at 185 nm for reductive destruction of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The 185-nm photons directly photolyzed H 2 O and OH-into HO·, H·, and e aq−. H 2 elevated the quasi steady-state concentration of e aq− 18 times in untuned VUV systems through eliminating the scavenging effect of dissolved oxygen and converting hydroxyl radicals (HO·/O·-) into e aq−. The polarization effect of H 2 increased the degradation of PFOA from 10% to 95% and the defluorination from 17% to 94% and led to 87% of defluorination for PFOS. The pH impacted VUV photon adsorption between H 2 O and OH-and shifted the equilibrium between H· and e aq−, which led to an optimal pH of 10.3 for PFOA destruction. The presence of chloride and sulfate enhanced the production of e aq− and promoted PFOA destruction. H 2-polarized VUV water photolysis systems produced high levels of e aq− from clean water constituents and significantly reduced energy consumption for PFAS treatment under mild alkaline conditions.