Adsorption Studies of COD and Fe2+from Stabilized Landfill Leachate on Activated Carbon and Calcite Containing Alginate

In this study, composite adsorbent was produced from the combination of activated carbon (AC) and calcite by four (4) different mixing ratios (AC:Calcite) of 9:1, 7:3, 1:1, 3:7, 1:9. The mixture was mixed with alginate as the binder. The composite adsorbent was tested in batch of experimental study to observe the effectiveness of removing COD and Fe2+ from sample of leachate collected from semi-aerobic sanitary landfill at Pulau Burung, Penang, Malaysia. The effect on contact time was conducted to observe its impact on the adsorption of COD and Fe2+. Besides, the adsorption kinetic model was also conducted to study the mechanism of adsorption process by applying pseudo-first order and pseudo-second-order rate equations. Based on experimental results, optimum removal of COD and Fe2+ was obtained at mixing ratio of 7: 3 with optimum removal of 54.6% for COD and 68.06% for Fe2+. This result indicates that high amount of AC in mixing ratio of adsorbent contributed to the highest removal of both COD and Fe2+. In addition, the study also proves that a combination of AC and calcite has improved the adsorption efficiency. The results of adsorption kinetic model indicate that both COD and Fe2+ followed the pseudo-second order kinetic model which means that the chemisorptions is the favorable mechanism of adsorption process.