School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; Key Laboratory of Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai, 200444, PR China.
School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
Chemosphere. 2021 Jul;274:129713. doi: 10.1016/j.chemosphere.2021.129713. Epub 2021 Jan 26.
Due to their widespread use and harmful effects on aquatic environment, sulfonamide antibiotics (SAs) have become an emerging pollutant of great concern around the world. In this study, we investigated the degradation process and mechanism of sulfamerazine (SMR), sulfadiazine (SDZ), and sulfapyridine (SPD) by electron-beam irradiation (EBI). The results showed that the three SAs were well suited to the pseudo-first-order reaction kinetics, and they could be almost completely removed with high efficiency (5 kGy). Among the environmental factors, pH (3.0) and O atmosphere can further enhance the removal of the sulfonamides (SAs), while NO has the most pronounced degrading inhibitory effects among the many ions, these results illustrate that hydroxyl radicals play a dominant role. Compared with SMR and SDZ, the degree of mineralization of lower molecular weight SPD is obvious (45%). LC-MS and DFT calculations indicate that the concentrations of degradation products of the three SAs show a tendency to increase and then decrease, demonstrating that EBI can achieve efficient removal and further mineralization of SAs. Meanwhile, the results of the common product 4-Aminophenol produced during the degradation process further indicate that HO is the predominant reactive oxygen species (ROS). In addition, acute toxicity experiments with luminescent bacteria and predictions of ECOSAR procedures proved the toxic effects greatly decreased after the degradation. This study provides new ideas for achieving efficient and profound removal of emerging pollutants from the aquatic environment.
由于其广泛的应用和对水生环境的有害影响，磺胺类抗生素（SAs）已成为全球关注的一种新兴污染物。在本研究中，我们通过电子束辐照（EBI）研究了磺胺嘧啶（SMR）、磺胺二甲嘧啶（SDZ）和磺胺吡啶（SPD）的降解过程和机制。结果表明，这三种磺胺类药物非常适合准一级反应动力学，它们可以在高效率（5 kGy）下几乎完全去除。在环境因素中，pH（3.0）和 O 气氛可以进一步增强磺胺类药物的去除，而在众多离子中，NO 对其降解的抑制作用最为明显，这些结果表明羟基自由基起主导作用。与 SMR 和 SDZ 相比，低分子量 SPD 的矿化程度明显（45%）。LC-MS 和 DFT 计算表明，三种 SAs 的降解产物浓度呈现出先增加后减少的趋势，表明 EBI 可以实现磺胺类药物的高效去除和进一步矿化。同时，降解过程中产生的常见产物 4-氨基酚的结果进一步表明，HO 是主要的活性氧物种（ROS）。此外，发光细菌的急性毒性实验和 ECOSAR 程序的预测证明，降解后毒性大大降低。本研究为实现从水生环境中高效、深度去除新兴污染物提供了新的思路。
