A study on the potential use of waste foundry sand in multi layer cover system of landfills

Abstract

With the rapid growth of urbanization and industrialization, significant amounts of waste in newlinevarious forms are being produced. Despite efforts to reduce, recycle and reuse wastes are taken, newlinethe need for storage or disposal remains, with landfills serving as a key solution. This research newlineexplores the feasibility of using Waste Foundry Sand (WFS), a byproduct of metal casting newlineindustries, for constructing the hydraulic barrier layer of a Multi-Layer Cover System (MLCS) newlinein landfills. WFS alone does not meet the required regulatory standards for hydraulic barrier newlinelayers due to its high hydraulic conductivity and low plasticity. Therefore, amendments with newlinebentonite and marine clay were proposed to modify its Geotechnical properties. Laboratory newlineexperiments were conducted to determine the effects of these amendments on hydraulic newlineconductivity, plasticity, compaction characteristics, volumetric shrinkage, and crack newlinedevelopment. The performance of bentonite- and marine clay-amended WFS was compared newlinewith that of bentonite-amended red earth, a commonly used hydraulic barrier soil in Kerala. newlineThe study found that WFS + 10% bentonite, WFS + 15% bentonite, WFS + 33% marine clay, newlineand WFS + 50% marine clay met the regulatory requirements. While marine clay-amended newlineWFS exhibited lower shrinkage than bentonite-amended WFS, it was found to be slightly newlinevulnerable to loss of cohesion and increased hydraulic conductivity under cyclic wetting and newlinedrying conditions.Wetting-drying cycle studies demonstrated that bentonite-amended WFS maintained its newlinehydraulic properties and structural integrity more effectively than marine clay-amended WFS. newlineAlthough bentonite-amended WFS is more resilient for long-term landfill applications, marine newlineclay-amended WFS may be recommended for construction of hydraulic barrier layer as the soil newlinemix satisfy the regulatory norms. newline