Synergistic degradation of antibiotic sulfadiazine in a heterogeneous ultrasound-enhanced Fe0/persulfate Fenton-like system
Synergistic degradation of antibiotic sulfadiazine in a heterogeneous ultrasound-enhanced Fe0/persulfate Fenton-like system
复制标题
DOI：
10.1016/j.cej.2014.07.048
复制
发表时间：
2014-12
影响因子：
15.1
通讯作者：
Xiaoli Zou;Tao Zhou;Juan Mao;Xiaohui Wu
中科院分区：
文献类型：
--
作者：
Xiaoli Zou;Tao Zhou;Juan Mao;Xiaohui Wu
在这项研究中，开发了一种新型超声增强异质 Fe0/过硫酸盐 (US/Fe0/PS) 系统，并研究了抗生素磺胺嘧啶 (SD) 的降解。结果表明，与相应的对比系统相比，US/Fe0/PS 系统可以在 SD 降解效率方面实现显着的协同作用。 US/Fe0/PS 系统中的 SD 降解可以通过 akobs(SD) 值为 3.4 ± 0.20 h−1 的伪一级动力学来应用。进一步研究了初始pH、[Fe0]:[PS]用量比、US输入功率和反应温度等影响因素。在 3-7 的广泛 pH 范围内，使用相对较低的 PS 剂量即可有效降解 SD。在反应过程中，在三个对比体系（US/Fe0、Fe0/PS 和 US/Fe0/PS）中评估了可溶性铁物质和 PS 的同时演化。可以得出结论，US在US/Fe0/PS体系中的促进作用是双重的，即增强非均相铁腐蚀反应和加速本体自由基反应。降解中间体的鉴定表明硫酸根（SO4自由基点−）氧化是SD的主要降解途径。第一步是攻击苯环中的胺基，然后断裂杂环中的 C-N 键。另一种降解途径，即 S-N 键的直接断裂也应该存在。
In this study, a novel ultrasound-enhanced heterogeneous Fe0/persulfate (US/Fe0/PS) system was developed and investigated for the degradation of an antibiotic sulfadiazine (SD). It was demonstrated that the US/Fe0/PS system could achieve a significant synergy in the degradation efficiency of SD, as compared to its corresponding comparative systems. The SD degradation in the US/Fe0/PS system could be applied by the pseudo-first-order kinetic with akobs(SD) value of 3.4 ± 0.20 h−1. Affecting factors such as initial pH, dosage ratio of [Fe0]:[PS], US input power and reaction temperature were further studied. SD could be effectively degraded with a relatively low PS dosage at a broad pH range of 3–7. Simultaneous evolution of soluble iron species and PS was evaluated in three comparative systems (US/Fe0, Fe0/PS and US/Fe0/PS) during the reaction. It could be concluded that the promotional role of US would be dual in the US/Fe0/PS system, i.e. enhancement in the heterogeneous iron corrosion reactions and acceleration in the bulk radical reactions. Identification of the degradation intermediates indicated that sulfate radical (SO4radical dot−) oxidation was the main SD degradation pathway. Attacking of the amine group in the benzene ring would be its first step, followed by cleavage of C–N bonds in the heterocyclic ring. Another degradation pathway, i.e. direct cleavage of the S–N bond should be also present.