Gao Ze-Chen, Lin Yi-Li, Xu Bin, Pan Yang, Xia Sheng-Ji, Gao Nai-Yun, Zhang Tian-Yang, Chen Ming
State Key Laboratory of Pollution Control and Resource Reuse, Institute of Disinfection By-product Control in Water Treatment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung 824, Taiwan, ROC.
Chemosphere. 2017 Nov;187:268-276. doi: 10.1016/j.chemosphere.2017.08.085. Epub 2017 Aug 19.
The degradation of acrylamide (AA) during UV/chlorine advanced oxidation process (AOP) was investigated in this study. The degradation of AA was negligible during UV irradiation alone. However, AA could be effectively degraded and mineralized during UV/chlorination due to the generation of hydroxyl radicals (OH). The degradation kinetics of AA during UV/chlorination fitted the pseudo-first order kinetics with the rate constant between AA and OH radicals being determined as 2.11 × 10 M s. The degradation rate and mineralization of AA during UV/chlorination were significantly promoted at acidic conditions as well as increasing chlorine dosage. The volatile degradation products of AA during UV/chlorination were identified using gas chromatography-mass spectrometry and the degradation pathways were then proposed accordingly. The formation of disinfection by-products (DBPs) in Milli-Q water and tap water during UV/chlorination of AA was also investigated. The DBPs included chloroform, dichloroacetonitrile, trichloroacetonitrile, 2,2-dichloroacetamide and 2,2,2-trichloroacetamide. Furthermore, the variations of AA degradation during UV/chlorination in different real water samples were evaluated.
本研究考察了紫外线/氯高级氧化工艺(AOP)中丙烯酰胺(AA)的降解情况。单独紫外线照射时,AA的降解可忽略不计。然而,由于羟基自由基(·OH)的产生,AA在紫外线/氯化过程中能够被有效降解和矿化。紫外线/氯化过程中AA的降解动力学符合准一级动力学,AA与·OH自由基之间的反应速率常数测定为2.11×10 M⁻¹ s⁻¹。在酸性条件以及增加氯投加量时,紫外线/氯化过程中AA的降解速率和矿化程度均显著提高。利用气相色谱 - 质谱联用仪鉴定了紫外线/氯化过程中AA的挥发性降解产物,并据此提出了降解途径。同时还研究了AA在紫外线/氯化过程中,超纯水和自来水中消毒副产物(DBPs)的生成情况。DBPs包括氯仿、二氯乙腈、三氯乙腈、2,2 - 二氯乙酰胺和2,2,2 - 三氯乙酰胺。此外,还评估了不同实际水样中紫外线/氯化过程中AA降解情况的变化。