Research Group of Water Pollution Control and Water Reclamation, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China.
Shanxi Jinhuankeyuan Environmental Resources Technology Co., Ltd, Taiyuan, Shanxi, 030024, PR China.
Chemosphere. 2020 Jul;250:126163. doi: 10.1016/j.chemosphere.2020.126163. Epub 2020 Feb 11.
Due to the potential threatening of antibiotics in aqueous environment, a novel electro-oxidation (EO) - electro-Fenton (EF) -persulfate (PS) system with the addition of peroxydisulfate and Fe was installed for the degradation of cefotaxime. Ti/CNT/SnO-Sb-Er with an ultra-high oxygen evolution potential (2.15 V) and enhanced electrocatalytic surface area was adopted as anode. The OH production and electrode stability test demonstrated great improvement in the electrochemical performances. Ni@NCNT cathode was tested with higher HO generation by the presence of nitrogen functionalities due to the acceleration of electron transfer of O reduction. Experiment results indicated CNT and ErO modification increased the molecular and TOC removal of cefotaxime. Coupling processes of EO-EF and EO-PS both resulted in shorter electrolysis time for complete cefotaxime removal, however, the mineralization ability of EO-PS process was lower than EO-EF, which might result from the immediate vanishing of PS. Thus, a further improved treatment EO-EF-PS system achieved an 81.6% TOC removal towards 50 mg L cefotaxime after 4 h electrolysis, under the optimal working condition Fe = PS = 1 mM. The influence of current density and initial concentration on the performance of all processes was assessed. Methanol and tert-butanol were added in the system as OH and SO scavengers, which illustrating the mechanism of EO-EF-PS oxidizing process was the result of the two free radicals. Major intermediates were deduced and the degradation pathway of cefotaxime was analyzed. This research provides a potential coupling process with high antibiotic removal efficiency and effective materials for practical uses.
由于抗生素在水环境中具有潜在的威胁，因此安装了一种新型的电氧化 (EO) - 电芬顿 (EF) - 过硫酸盐 (PS) 系统，该系统添加了过一硫酸盐和 Fe，用于降解头孢噻肟。采用具有超高析氧电位 (2.15 V) 和增强的电催化表面积的 Ti/CNT/SnO-Sb-Er 作为阳极。OH 生成和电极稳定性测试表明电化学性能有了很大的提高。由于氮官能团加速了 O 还原的电子转移，因此具有氮官能团的 Ni@NCNT 阴极可以产生更高的 HO。实验结果表明，CNT 和 ErO 的修饰提高了头孢噻肟的分子和 TOC 去除率。EO-EF 和 EO-PS 的耦合过程都导致了较短的电解时间以完全去除头孢噻肟，但是 EO-PS 过程的矿化能力低于 EO-EF，这可能是由于 PS 的立即消失。因此，在优化工作条件下（Fe = PS = 1 mM），进一步改进的处理 EO-EF-PS 系统在 4 h 电解后可实现 50 mg/L 头孢噻肟的 81.6% TOC 去除率。评估了电流密度和初始浓度对所有过程性能的影响。在系统中添加甲醇和叔丁醇作为 OH 和 SO 清除剂，说明了 EO-EF-PS 氧化过程的机制是两种自由基的结果。推导出主要中间体并分析了头孢噻肟的降解途径。这项研究为抗生素去除效率高且具有实际应用潜力的耦合工艺提供了高效的材料。
