State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China.
State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China.
Chemosphere. 2021 Jul;274:129726. doi: 10.1016/j.chemosphere.2021.129726. Epub 2021 Jan 25.
In this study, UV-driven advanced oxidation with peracetic acid (PAA) was adopted to enhance the removal of oxytetracycline (OTC) as well as to lower the formation potential of N-nitrosodimethylamine (NDMA). Results implied that the combination of UV and PAA had a synergetic effect on both the removal and mineralization of OTC. OTC (≤5 mg L) could be completely removed in 45 min in the UV/PAA system under the conditions of an initial pH of 7.10 and a PAA dose of 5 mg L; additionally, 50.9% of mineralization rate of OTC was obtained. Electron paramagnetic resonance analysis and quenching experiments indicated that ·OH was the main oxidizer for the removal of OTC, while UV, PAA and carbon-centered radicals (R-C·) also participated in its removal. During the degradation of OTC, 31 kinds of degradation intermediates were traced, and 20 kinds of them were first detected in the UV/PAA system. OTC was removed through five pathways, and the hydroxylation pathway was involved in nearly the entire degradation period. The NDMA formation potential decreased by 65.8% after the reaction, and residual dimethylamine accounted for 15.1% of its total composition. The proposed UV/PAA process is a promising method not only for the removal of refractory antibiotics but also for controlling the formation of NDMA.
在本研究中，采用紫外光驱动过氧乙酸（PAA）高级氧化法来增强土霉素（OTC）的去除效果，并降低 N-亚硝基二甲胺（NDMA）的生成潜能。结果表明，紫外光和过氧乙酸的结合对 OTC 的去除和矿化具有协同作用。在初始 pH 值为 7.10 和过氧乙酸剂量为 5 mg/L 的条件下，紫外光/PAA 体系中 OTC（≤5 mg/L）在 45 min 内可完全去除，此外，OTC 的矿化率达到 50.9%。电子顺磁共振分析和猝灭实验表明，·OH 是去除 OTC 的主要氧化剂，而紫外光、过氧乙酸和碳中心自由基（R-C·）也参与了其去除过程。在 OTC 的降解过程中，追踪到 31 种降解中间产物，其中 20 种是在紫外光/PAA 体系中首次检测到的。OTC 通过 5 种途径去除，羟基化途径几乎贯穿整个降解过程。反应后 NDMA 的生成潜能降低了 65.8%，残留的二甲胺占其总组成的 15.1%。所提出的紫外光/PAA 工艺不仅是去除难降解抗生素的一种很有前途的方法，而且也是控制 NDMA 形成的一种方法。
