Amoxicillin electro-catalytic oxidation using Ti/RuO2 anode: Mechanism, oxidation products and degradation pathway

Present work investigates the application of electro-catalytic oxidation (EO) technique using dimensionally stable anode, titanium coated with ruthenium dioxide (Ti/RuO2), for abatement of amoxicillin trihydrate (AMT), a much commonly prescribed antibiotic detected in water and wastewater. AMT removal efficiency (%ARE) and TOC (Total organic carbon) removal efficiency (%TRE) were measured by varying process parameters such as initial pH, current density (i), initial AMT concentration (C-0) and supporting electrolyte (NaCl) concentration (S-0). Mineralization current efficiency (%MCE) and specific energy consumption (SEC) values were evaluated and compared for different values of i and S-0. Furthermore, decay kinetics of AMT was studied by varying i and C-0. Moreover, AMT degradation and mineralization mechanism was explored in detail. Additionally, a possible pathway of AMT degradation/mineralization was proposed by identifying the intermediates formed during EO reactions using UPLC-Q-TOF-MS. Besides, economic feasibility of EO treatment method was analysed by calculating the operating cost. The optimum current density and initial pH were found to be 5.88 mA cm(-2) and 7.0, at which, 60% ARE and 48% TRE were achieved in 60 and 240 min of electrolysis, respectively. Mineralization current efficiency was observed decreasing from 11.77% to 7.67% with increasing i value. (C) 2018 Elsevier Ltd. All rights reserved.