Electro-oxidation of amoxicillin trihydrate in continuous reactor by Ti/RuO2 anode

Abstract

Electro-oxidation (EO) of synthetic wastewater containing amoxicillin (AMT) antibiotic as a model pollutant was performed using dimensionally stable Ti/RuO2 electrodes in a continuous reactor set-up. Response surface methodology (RSM) was used for optimization of continuous EO process. Individual and interactive effects of initial pH of synthetic wastewater (2−10), applied current, I (0.25–1.25 A), elapsed time, t (20–180 min) and retention time, RT (15–195 min) on AMT removal, total organic carbon (TOC) removal and specific energy consumption (SEC, kWh (g TOC removed)−1) were investigated. At optimum conditions (pH = 7.53, I = 0.7 A, RT = 175.6 min, t = 128.89 min), 51.64% and 37.82% AMT and TOC removal was achieved, with SEC value of 0.408 kWh (g TOC removed)−1. AMT and TOC removal at optimum conditions was found to follow pseudo-first order kinetics. Mineralization current efficiency for optimum run of continuous EO came out to be 9.81%. Furthermore, 8 transformation products/reaction intermediates of AMT (ARIs) were determined by UPLC-Q-TOF-MS analysis, and subsequently, a plausible degradation scheme of AMT by anodic oxidation and cathodic reduction using Ti/RuO2 electrodes was proposed.