Treatment of Tropical stabilized landfill leachate by Adsorption using Powdered Activated Carbon: Isothermal and Kinetic Studies

Abstract

This study investigates the adsorption removal capacity of chemical oxygen demand (COD), color, and ammoniacal nitrogen (NH3-N) from Sahom stabilized landfill in Kampar, Malaysia by powdered activated carbon (PAC). The effects of shaking speed, contact time, dosage of activated carbon and pH level on the adsorption performance were tested in a batch equilibrium study. Equilibrium data was favorably descried by Langmuir isotherm model. The maximum monolayer adsorption capacity for COD, color and NH3-N were 27.7 mg/g, 172.4 PtCo/g and 4.76 mg/g, respectively and achieved at the optimum conditions of: shaking speed 250 rpm, contact time 4 hours, PAC dosage 4 g/100 ml leachate, and at pH = 9. Effluent's average removal efficiency was found to be 66.00, 87.63 and 25.89% for COD, color, and NH3-N, respectively. Based on the kinetic data, the adsorption process was controlled by chemisorption as it agreed satisfactorily with the Pseudo-second order model. The regeneration of activated carbon was done thermally via microwave heating. The recovery efficiency for COD, color and NH3-N were found to be 85.47%, 92.65% and 59.53%, respectively. The results revealed the feasibility of PAC adsorbent for the adsorptive treatment of landfill leachate.