Sertraline degradation by electrochemical oxidation process using a low- cost electrochemical cell

Abstract

Sertraline (SRT) has been found in different concentrations in surface and wastewater systems worldwide, for its toxic and adverse environmental impacts, different methods need to be investigated to remove it from water bodies. A highly efficient and cost-effective approach for eliminating emerging contaminants is Electrochemical Advanced Oxidation Processes (EAOPs), these processes have proven to be effective in degrading organic pollutants (as SRT), converting them into simple compounds such as carbon dioxide and water for its stabilization. This method boasts high current efficiency and can be implemented on-site with minimal requirements to be carried out as stainless-steel electrodes and an electrical power supply. Additionally, the required electrical energy can be generated from renewable sources such as solar or wind power. Degradation of SRT in surface water (SW) was conducted with a stainless-steel electrodes cell in four different pH of 3, 5, 7 and 9, with direct current densities (CD) of 9.0 mA/cm² (6V), 17.9 mA/cm² (12V) and 36.0 mA/cm (24V). For all current densities applied, SRT degradation was observed by high-performance liquid chromatography with diode-array detection (HPLC-DAD) at 220 nm. Faster degradation was observed at the higher current density with the lowest pH. In comparison with the other pH and current densities, above 99% of SRT was oxidized in 30 seconds at 36.0 mA/cm² at pH3, while in the lowest current density and highest pH the degradation had a reaction time above 30 minutes. There were not oxidation products observed by HPLC at 220 nm. For all current densities the faster degradation process occurred in pH 3. Results found in this research show a practical and low-cost application for remotion of SRT since its investment cost goes to $13.42 US dollars per liter treatment and energy consumption does not surpass 100 kWh, that can be potentially supplied by renewable energies.