Optimizing Ti/RuO2-IrO2 – electro activated persulfate oxidation processes for the degradation of ammonia-nitrogen and color from landfill leachate using Response Surface Methodology

Landfilling disposal method has raised many environmental concerns especially water pollution from the discharge of landfill leachate. This study is aimed at investigating degradation of ammonia and removal of color of landfill leachate by electro-persulfate activation using ruthenium-iridium coated titanium (Ti-RuO2/IrO2) electrode. Process variables such as reaction time, current density and persulfate dosage were optimized using central composite design via response surface methodology (RSM). RSM models show high coefficient of determination, R2 of 0.9182 and 0.9249 for ammonia-nitrogen (NH3-N) and color respectively. The maximum removal efficiency for NH3-N and color were recorded as 83.7% and 65.8% respectively. Persulfate can be used in oxidation processes as an activating agent to remove NH3-N and color from landfill leachate. © The Authors, published by EDP Sciences.