Original Articles
J Derayat, M Pirsaheb, A Hasan
Abstract
In the present study, the treatment of raw landfill leachate with emphasis on the COD, NH4+-N, total suspended solid (TSS), Cr, Cd and Ni removal efficiency was carried out by electrochemical (EC) method using aluminium electrodes. Central composite design (CCD) with three factors, namely current density, reaction time (t) and anionic polyelectrolyte concentration, with each factor at five levels, was applied to optimise the factors for higher landfill leachate treatment. The region of assessment for the process was chosen as the area enclosed by current density (0.5-1 A/cm2), electrolysis times (20-100 min) and anionic polyelectrolyte concentrations (0-15 ppm) boundaries. The optimum current density, reaction time and polyelectrolyte concentration at which the removal efficiency of COD (89.5%) and TSS (99.7%) reached the maximum values were found to be 0.88 A/cm2, 100 min and 15 mg/l, respectively. For the current density of 1 A/cm2, N-NH4, Ni, Cr and Cd removal efficiencies were 64.5, 92.5, 99.6 and 83.4%, respectively.