Analysis of leachate from solidified peat soil

¹ Faculty of Civil and Environmental Engineering  
² Universiti Tun Hussein Onn Malaysia (UTHM), Johor, 86400 Malaysia

Abstract

Peat soil is very compressible where this characteristic is lead to an excessive settlement. Solidification of peat soil is a method to improve engineering properties of peat soil. Currently, solidification of peat soil is increasing, wherefore it is a critical need to study the environmental effects from solidified peat soil leachate due to solidification peat mixtures usually used materials of generation wastes from coal-fired electric power. The effect of leachate from solidified peat to the environment is one of the most important criteria that should be investigated. This study aims to investigate the environmental impacts of leachate from solidified peat affected by rainwater. In this study, solidification of hemic peat soil was done by mixing hemic peat soil with ordinary Portland cement (OPC), fly ash (FA) and bottom ash (BA). Leachate is the liquid that has percolated through a soil column outlets. Therefore, this study was to analysis the leachate from solidified hemic peat when it is saturated by rainwater in two different conditions, which are a dry and wet season by using physical model (soil column). The leachate samples were analyzed by using Ionic Chromatography (IC) and Inductively Coupled Plasma Mass Spectrometry (IC-MS). The anions concentration of leachate from solidified peat has increased for Cl^-SO₄^2-in wet condition as result rainwater inflow was increased during the wet condition, and the chemical composition of rainwater contains Cl^-and SO₄^2-. The concentration of cations on the leachate from solidified peat has increased at Fe⁺² and Al⁺³ in wet condition, which proven solidified peat has an effect on the leachate In comparison with leachate of non-solidified peat. The concentration of anions for Cl^-and SO₄^2-the leachate still consider in the normal range of groundwater concentration that classified as freshwater, but in case FA, BA, and OPC are used excessively in the mixture for solidifying peat in a wetland, leachate from solidified peat will effect on elements concentration of groundwater and land properties.