Adsorptive treatment of stabilized landfill leachate using activated palm oil fuel ash (POFA)

Abstract

Landfill leachate is a dangerous by-product of landfills which can lead to surface and ground water contamination if not properly managed. Landfill leachate must be treated to meet the Malaysia discharge standards before discharging to the environment. In this study, stabilized landfill leachate (SLL) collected from Sahom landfill was treated by adsorption using activated Palm Oil Fuel Ash (POFA). POFA was impregnated for activation purpose using nitric acid (HNO3) and potassium hydroxide (KOH) with different dosages i.e. 1 g: 0.1 g, 1 g: 0.3 g, 1 g: 0.5 g, 1 g: 1.0 g, and 1 g: 1.5 g. The best adsorption performance was obtained using 2 g of modified POFA (TPOFA.KOH) per 100 mL SLL, 2 hrs contact time and 250 rpm shaking speed. The optimum removal efficiencies of COD, colour and NH3-N were 59.19%, 25.00% and 17.18% respectively, can be yielded using TPOFA.KOH at an impregnation ratio 1 g:1 g of POFA to KOH. From the results of characterization of POFA, FTIR analysis showed that the diagnostic bands of TPOFA.KOH at 2367 cm-1 and 2345 cm-1 became more obvious as compared to POFA as there are more hydroxyl group (-OH) contributed by KOH whereas TGA showed that POFA has low moisture, volatile matter and fixed carbons contents which were 8.33 %, 6.06 % and 15.15 % respectively but high ash content 70.45 %.