Optimization of Nitrate Removal by Electro-Reduction Using a Ti/RuO 2 + IrO 2 Electrode: Process Modeling by Response Surface Methodology

Abstract

Agricultural activities and the excessive use of fertilizers significantly contribute to nitrate contamination in the environment. These ions can cause a serious threat to both human health and ecosystems through the contamination of surface water and groundwater. It is therefore necessary to reduce their concentration before consumption. The general objective of this work is to propose new electrochemical treatment methods based on the Design of Experiments Methodology. Indeed, this approach allows to reduce the need for costly and lengtly experimental trials. Various parameters that could improve the efficiency of the process were studied, including initial concentration, pH, electrolysis time, and current intensity, in order to determine the optimal operating conditions. The results show that the process is effective at a reduction current intensity of ?603 mA, a NaNO 3 concentration of 100 mg-N/L, and an electrolysis time of 10 min at a slightly basic pH, allowing a nitrate removal efficiency of 91%. The results highlight the importance of statistical modeling in improving and controlling electrochemical processes.