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

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.