The Effectiveness of Silica Sand in Semi-Aerobic Stabilized Landfill Leachate Treatment

Ezlina Othman,Yung-Tse Hung,Mohd Suffian Yusoff,Hamidi Abdul Aziz,Mohammed J K Bashir,Mohd Nordin Adlan

doi:10.3390/w2040904

Ezlina Othman, Yung-Tse Hung + Show 4 more

Open Access

https://doi.org/10.3390/w2040904

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Journal: Water	Publication Date: Dec 6, 2010
Citations: 44	License type: CC BY 3.0

Affiliation: Universiti Sains Malaysia, Cleveland State University

Abstract

This study examines the suitability of natural silica sand as a low-cost adsorbent for the removal of ammoniacal nitrogen and heavy metals, particularly iron and zinc, from semi-aerobic stabilized landfill leachate. Leachate samples were collected from the Pulau Burung landfill site (PBLS) in Penang, Malaysia. The above-mentioned contaminants are highlighted in this study because of their unsafe concentrations at PBLS. The effects of shaking time, settling time, and silica sand dosage on the study parameter removal efficiencies were investigated to predict the performance of the process. The adsorptions of ammoniacal nitrogen, iron, and zinc were judiciously described by Langmuir and Freundlich isotherm models. The optimum removal efficiencies of ammoniacal nitrogen, iron, and zinc obtained were 51%, 44.4%, and 39.2%, respectively, with a shaking time of 90 min, a settling time of 60 min, and with a dosage of 60 g (0.5 kg/L) of silica sand. Based on the coefficient of determination (R2) values obtained from Langmuir and Freundlich isotherm models, ammoniacal nitrogen, iron, and zinc adsorption were better fitted to the Freundlich model.

Highlights

Landfill is the technique employed most worldwide for the disposal of municipal solid waste (MSW) in developing countries such as Malaysia [1,2,3]
The present study focuses on the leachate generated from the Pulau Burung landfill site (PBLS)
The high concentrations of color and Chemical oxygen demand (COD) are mainly contributed by dissolved organic substances; the presence of high amounts of NH3-N are attributed to the degradation of nitrogenous compounds present in the dumped solid wastes

Summary

Introduction

Landfill is the technique employed most worldwide for the disposal of municipal solid waste (MSW) in developing countries such as Malaysia [1,2,3]. After being placed in landfills, solid waste habitually decomposes through a series of combined physicochemical and biological processes. The decomposition of waste in combination with percolating precipitation results in the creation of an extremely polluted liquid called landfill leachate. The generation of landfill leachate creates the potential for long-term impact on the surrounding environment. The potentiality of leachate to eventually find its way into ground/surface water creates serious hazards to public health and ecosystems. The leachate composition from different sanitary landfills, as mentioned by Renou et al [9], displays wide variation.

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