Investigating the Adsorption Properties of Soil Additive Mixtures Using Microstructural Characterization Techniques for Liner Applications

This study evaluated the potential of readily available Indian soils, red soil (Bengaluru) and black cotton soil (Belgaum), as sustainable and cost-effective alternatives to synthetic landfill liners for heavy metal containment. Utilizing Scanning Electron Microscopy (SEM) and Energy-Dispersive Spectroscopy (EDS), we characterized the soil's microstructural properties and elemental composition to assess their adsorption capabilities. To enhance metal capture, soils were amended with lime, cement, and fly ash. Batch leaching experiments, simulating landfill conditions with copper and chromium contamination, quantified adsorption efficiency. Microscopic analysis of leached samples using SEM and EDS corroborated macroscopic findings, revealing key adsorption mechanisms such as particle aggregation and the formation of binding compounds. Black cotton soil, particularly when amended, exhibited superior adsorption, likely due to its higher organic matter content. This integrated approach, linking microscopic observations to macroscopic performance, demonstrates the viability of these local soils, especially with additives, for effective and sustainable landfill liner applications.