Rapid decontamination of tetracycline hydrolysis product using electrochemical CNT filter: Mechanism, impacting factors and pathways.

Abstract

In this study, electrooxidation of the tetracycline hydrolysis products was investigated using a carbon nanotube (CNT) electrochemical filter and 4-epianhydrochlortetracycline (EACTC) as a model compound. Electrochemical filtration of 10μmolL-1 EACTC at a voltage of 2.5V and a flow rate of 1.5mLmin-1 (hydraulic residence time <3s) provided an oxidation flux of 1251±28μmolh-1 m-2. Replacement of the Ti cathode with a CNT filter cathode increased the EACTC oxidative flux by 1.3 fold at a voltage of 2.5V. The electrochemical filtration process is effective for the degradation of EACTC and the reduction of the antimicrobial activity based on liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) analysis and luminescent bacteria test. The high oxidation flux within 300min (1212-1263μmolh-1 m-2) and affordable cost (0.25kWh m-3) at a voltage of 2.5V show the potential application of the electrochemical filtration system as a promising unit for EACTC degradation. These findings provided new insights into the rational design principles of novel continuous-flow filtration system aimed to efficiently remove hydrolysis products of the antibiotic tetracycline.