Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing, 100084, People's Republic of China.
Beijing Key Laboratory of Radioactive Waste Treatment, Tsinghua University, Beijing, 100084, People's Republic of China.
Environ Sci Pollut Res Int. 2019 Sep;26(27):27712-27725. doi: 10.1007/s11356-019-05925-1. Epub 2019 Jul 23.
Antibiotics are becoming ubiquitous emerging contaminants in the aquatic environments due to their large amount of production and extensive application, which have received increasing public concern. In this paper, the degradation and mineralization of sulfamethoxazole (SMX) by ionizing radiation in the presence of FeO as Fenton-like catalyst were evaluated, the influencing factors, such as the initial SMX concentration, initial pH, water matrix, and radical scavenger, etc. were examined. The results demonstrated that SMX could be efficiently degraded. The addition of FeO could improve the degradation efficiency of SMX and increased the dose constant at various SMX initial concentrations. More than 98% of SMX was degraded in FeO/gamma radiation system at a wide range of pH (about 3.0-11.0). The mineralization of SMX in the presence of FeO was increased by 200%. Adding free radical scavenger (tert-butyl alcohol) inhibited the degradation of SMX. The addition of FeO enhanced the dose constant of ·OH, indicating that FeO promoted the formation of hydroxyl radicals (·OH) and then improved SMX degradation and mineralization. The degradation efficiency of SMX in secondary effluent of WWTP decreased from 100 to 84% in secondary effluent compared with that in deionized water. The intermediate products during the degradation of SMX by ionizing radiation were identified by high-performance liquid chromatography, and a possible pathway of SMX degradation in such a system was tentatively proposed. Graphical abstract Schema illustration of SMX degradation by irradiation in the presence of FeO.
由于抗生素的大量生产和广泛应用，它们在水环境中成为普遍存在的新兴污染物，引起了公众越来越多的关注。本文研究了 FeO 作为类 Fenton 催化剂存在时，离子辐射对磺胺甲恶唑（SMX）的降解和矿化作用，考察了初始 SMX 浓度、初始 pH 值、水基质和自由基清除剂等影响因素。结果表明，SMX 可以被高效降解。添加 FeO 可以提高 SMX 的降解效率，并增加不同初始 SMX 浓度下的剂量常数。在广泛的 pH 值范围（约 3.0-11.0）下，FeO/γ 辐射体系中 SMX 的去除率超过 98%。在 FeO 的存在下，SMX 的矿化程度提高了 200%。添加自由基清除剂（叔丁醇）会抑制 SMX 的降解。FeO 的添加增强了·OH 的剂量常数，表明 FeO 促进了羟基自由基（·OH）的形成，从而提高了 SMX 的降解和矿化效率。与去离子水相比，在二级污水处理厂的二级出水中，SMX 的降解效率从 100%下降到 84%。通过高效液相色谱鉴定了 SMX 在离子辐射下降解过程中的中间产物，并初步提出了该体系中 SMX 降解的可能途径。
