Modelling the impact of inter-electrode spacing on nitrate removal using Response Surface Methodology (RSM)

Abstract

Nitrate contamination in water poses a significant concern for environmental engineers, as it has substantial and direct impacts on water quality, the economy, and public health. Consequently, managing nitrate levels in water sources ranks among the top priorities for water authorities. Currently, various treatment methods, including biological treatments and adsorption, are employed to eliminate nitrate from water or wastewater. A substantial body of literature exists focused on the application of electrocoagulation (EC) for nitrate removal from solutions. This method is favoured for its environmentally friendly attributes and ability to swiftly and cost-effectively remove pollutants. In this study, the EC method was employed to eliminate nitrate from water under varying inter-electrode spacing (I-ES) conditions ranging from 4 to 10 mm and different treatment durations (TD) spanning 5 to 55 minutes. The effects of I-ES and TD on nitrate removal were optimised using Response Surface Methodology (RSM). The study's results demonstrated that the most effective nitrate removal, reaching 91.3%, occurred at an I-ES of 4 mm and a TD of 50 minutes. The agreement between the experimentally observed and predicted removal rates was notably high, with an R² value of 0.973.