State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
Water Res. 2021 Feb 1;189:116625. doi: 10.1016/j.watres.2020.116625. Epub 2020 Nov 12.
UV/sulfite process in the absence of oxygen was previously applied as an advanced reduction process for the removal of many halogenated organics and inorganics in water and wastewater. Here, it was found that UV/sulfite process in the presence of oxygen could act as an advanced oxidation process. Specifically, the oxysulfur radicals (including sulfate radical (SO) and sulfite/peroxomonosulfate radicals (SO/SO)) played important roles on the degradation of iopamidol (IPM) as a typical iodinated contrast media (ICM). Furthermore, the contribution of SO on IPM removal gradually increased as pH increased from 5 to 7 and that of SO/SO decreased. Besides, all water quality parameters (i.e., chloride (Cl), iodide (I) and natural organic matter (NOM)) investigated here exhibited inhibitory effect on IPM removal. Three inorganic iodine species (i.e., I, reactive iodine species and iodate (IO)) were detected in UV/sulfite process in the presence of oxygen, while only I was detected in that without oxygen. During UV/sulfite/ethanol, UV photolysis and UV/peroxydisulfate (PDS)/tert-butyl alcohol (TBA) processes, thirteen transformation products including eleven deiodinated products of IPM were identified by ultra HPLC quadrupole time of flight-mass spectrometry (UPLC-Q-TOF-MS). Besides, these products generated by direct UV photolysis, SO and SO/SO were further distinguished. The acute toxicity assay of Vibrio fischeri indicated that transformation products by UV/sulfite under aerobic conditions were less toxic than that by direct UV photolysis.
在有氧存在的情况下，先前已经将 UV/亚硫酸盐工艺应用于水和废水中许多卤代有机物和无机物的高级还原过程。在这里，人们发现 UV/亚硫酸盐工艺在有氧存在的情况下可以作为一种高级氧化工艺。具体而言，氧硫自由基（包括硫酸根自由基（SO）和亚硫酸盐/过一硫酸盐自由基（SO/SO））在碘帕醇（IPM）的降解中发挥了重要作用，碘帕醇是一种典型的含碘对比剂（ICM）。此外，随着 pH 值从 5 增加到 7，SO 对 IPM 去除的贡献逐渐增加，而 SO/SO 的贡献则降低。此外，这里研究的所有水质参数（即氯（Cl）、碘（I）和天然有机物（NOM））都对 IPM 的去除表现出抑制作用。在有氧存在的 UV/亚硫酸盐工艺中检测到三种无机碘物种（即 I、反应性碘物种和碘酸根（IO）），而在无氧存在的 UV/亚硫酸盐工艺中仅检测到 I。在 UV/亚硫酸盐/乙醇、UV 光解和 UV/过二硫酸盐（PDS）/叔丁醇（TBA）过程中，通过超高效液相色谱四级杆飞行时间质谱（UPLC-Q-TOF-MS）鉴定出包括 IPM 的十一种脱碘产物在内的十三种转化产物。此外，还进一步区分了由直接 UV 光解、SO 和 SO/SO 生成的这些产物。发光菌的急性毒性试验表明，有氧条件下由 UV/亚硫酸盐生成的转化产物的毒性低于直接 UV 光解生成的产物。
