碳纤维阴极电化学还原氯霉素的效能与机理

Efficacy and Mechanism on Cathodic Reduction of Chloramphenicol by Carbon Fiber Electrode

摘要:

以CAP为对象，利用碳纤维阴极研究电化学还原氯霉素的效能与机制。重点探究电流密度、pH、CAP初始浓度、电解质浓度和种类对CAP降解效果、TOC去除率和脱氯效果等影响，研究表明电流密度和电解质种类对CAP的降解效果影响较大，阴极还原的最佳反应条件为：电流密度40 mA·cm^-2、CAP初始质量浓度10 mg·L^-1、Na₂SO₄浓度0.02 mol·L^-1。通过循环伏安法研究发现CAP在电极表面发生直接还原与间接还原，三维荧光测试结果表明反应后水中有机物含量仍较高。利用超高效液相-四极杆飞行时间质谱对中间产物进行检测并分析CAP在阴极降解的机理，还原后的产物主要为毒性较低的芳香胺物质。电化学处理CAP主要通过脱氯还原得到毒性较低的物质，从而降低了后续处理过程产生有毒物质的风险，研究结果为电化学还原去除水中抗生素的应用提供了相关探索和技术支撑。

Abstract:

Chloramphenicol （CAP） is a typical broad-spectrum antibiotic with stable physical and chemical properties. In this study， the efficacy and mechanism of electrochemical reduction of chloramphenicol were investigated using a carbon fiber cathode with CAP as the target. Focusing on the effects of current density， pH， initial concentration of CAP， electrolyte concentration and species on the degradation effect of CAP， TOC removal rate and dechlorination effect， the study showed that the current density and electrolyte species had a greater effect on the degradation effect of CAP， and the optimal reaction conditions for cathodic reduction were current density of 40 mA·cm^-2， initial concentration of CAP of 10 mg·L^-1， Na₂SO₄ CAP at an initial concentration of 10 mg·L^-1 and Na₂SO₄ at a concentration of 0.02 mol·L^-1. Direct and indirect reduction of CAP occurred on the electrode surface by cyclic voltammetry， and the results of three-dimensional fluorescence tests showed that the organic content in the water was still high after the reaction. The intermediate products were detected by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry （UPLC-TOF MS） and the mechanism of CAP degradation at the cathode was analyzed， and the reduced products were mainly aromatic amines with low toxicity. The electrochemical treatment of CAP mainly obtained less toxic substances through dechlorination and reduction， thus reducing the risk of toxic substances produced in the subsequent treatment process， and the results of the study provide relevant exploration and technical support for the application of electrochemical reduction in the removal of antibiotics in water.