Use of an ultraviolet light-activated persulfate process to degrade humic substances: effects of wavelength and persulfate dose
Use of an ultraviolet light-activated persulfate process to degrade humic substances: effects of wavelength and persulfate dose
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DOI：
10.1007/s11356-021-15392-2
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发表时间：
2021-04
影响因子：
5.8
通讯作者：
Yiming Fang;H. Sakai
中科院分区：
文献类型：
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作者：
Yiming Fang;H. Sakai
天然有机物（NOM）常见于地表水和地下水，在饮用水中形成消毒副产物。通常，采用过氧化氢的高级氧化工艺（AOPs）来处理水；然而，硫酸盐自由基最近已被用于治疗顽固性有机物，因为它具有更高的氧化电位和比羟基自由基更有效的去除。因此，在本研究中，我们从降低腐殖质水平的角度来评估过硫酸盐的氧化效率，并研究了降解机制。结果表明，与过氧化氢和直接照射相比，紫外线活化过硫酸盐对腐殖质有较好的处理效果。治疗是剂量和波长相关的；较高的过硫酸盐浓度或较短的紫外波长对腐殖质更有效，因为产生了高浓度的硫酸盐自由基。降解机理与过氧化氢相似。芳香和发色团组分比低分子量组分更容易被降解，它们首先被分解为后者，降低了uv254的吸光度和SUVA254。低分子量材料最终降解为最终产品：NPOC水平下降。我们还用过硫酸盐处理了饮用水处理厂的流入，有效地去除了腐殖质物质。
Natural organic matter (NOM), commonly found in surface and ground waters, form disinfection by-products in drinking water. Generally, advanced oxidation processes (AOPs) featuring hydrogen peroxide are used to treat water; however, sulfate radical recently has been used to treat recalcitrant organics, because it is associated with a higher oxidation potential and more effective removal than hydroxyl radicals. Hence, in this research, we evaluated persulfate oxidation efficiency in terms of reductions in humic substance levels and investigated the degradation mechanism. The results showed that ultraviolet-activated persulfate effectively treated humic substances compared with hydrogen peroxide and direct irradiation. Treatment was dose and wavelength dependent; higher persulfate concentrations or shorter UV wavelengths were more effective for treating humic substances as high concentration sulfate radicals were created. The degradation mechanism was similar to that of hydrogen peroxide. Aromatic and chromophore components were more susceptible to degradation than were lower molecular weight components, being initially decomposed into the latter, reducing UV254absorbance and the SUVA254. Lower molecular weight materials were eventually degraded to end products: NPOC levels fell. And we also treated the inflow of a drinking water treatment plant with persulfate, and humic substances were effectively removed.