Analysis of the Performance of Cover Soil in Attenuating the Physicochemical Parameters of Landfill Leachate by Soil Column Test

Abstract

Landfill leachate is of environmental concern due to its high levels of organic and inorganic pollutants. Leachate treatment using natural materials such as cover soil of sandy loam texture, laterites, and compost was performed through soil column experiment. This study aims to analyze the natural attenuation of physiochemical parameters such as pH, turbidity, electrical conductivity, biological oxygen demand, chemical oxygen demand (COD), ammonia, phosphate, heavy metals (Fe, Ni, and Pb) of leachate in the cover soil of the Sisdole landfill site (SLS) and enhanced cover soil, that is, a mixture of SLS soil, compost, and laterite (SCL). In addition, this study analyzes the response of the cover soil after infiltration of leachate in terms of physiochemical parameters. Two columns of specific heights and diameters were taken and leachate was fed manually into the soil columns to evaluate the attenuation of the physiochemical parameters of leachate by standard methods after passing through SLS and SCL soil. From the results, it was observed that the removal efficiency was the highest for the first three days (>70%), after which the capacity of the soil to attenuate leachate parameters decreased. Consistent and greater removal efficiency was seen for heavy metals and phosphate for the SLS soil column. Amendments such as laterite and compost were added to cover soil to enhance the performance of SLS soil. The results showed a consistent and greater removal percentage for COD and ammonia in SCL than in SLS soil column. It was observed that that studied soil (sandy loam) is capable of removing pollutants from leachate to a satisfactory level and adding materials with higher sorption capacity such as laterite and compost to sandy loam soil can improve removal ability for certain selected parameters.