Electrocoagulation for nitrate removal from groundwater in Rabat-Kenitra, Morocco: Processing, modeling, optimization and cost estimation

Abstract

In this work, the electrocoagulation (EC) technique using aluminum electrodes was used to evaluate the process of nitrate-contaminated groundwater being denitrified to produce potable water. Two samples that were taken from the Rabat-Kenitra region were tested. An operating voltage of 30 Volts, an immersed surface area of 33 cm² per electrode plate, and an inter-electrode separation of 1.9 cm. The results demonstrated that nitrate removal efficiencies ranged from 88.48% to 94.1% after 120 minutes for the groundwater samples studied. Additionally, the findings indicated that sulfates were removed along with nitrates during the EC treatment, with removal efficiencies varying from 55% to 97.5%, based on the chloride concentration at the start. For most bacteria in the treated water, the EC process nearly completely removed the bacterial load. The sludge generated by the aluminum electrodes during the EC process was characterized using X-ray diffraction analysis. Finally, ANOVA is used to find the effects of the factors and how they interact with the responses to validate the model. The impact of voltage source value (VSV), Time, and nitrate concentration was evaluated using the Design of Experiments (DoE) approach and investigated by removing nitrate. Response Surface Methodology was used for further optimization.