Characterisation of soil-like material restored from landfill mining activities in Indian cities

This paper demonstrates the characteristics of soil-like material extracted from the landfill mining activity at the Ariyamangalam dump yard, located in Tiruchirappalli city of southern India. The landfill mining waste was collected and characterised for contaminant potential, thereby its suitability for reuse applications offsite. Soil-like materials of size fractions finer than 2 mm have been assessed for their physico-chemical characteristics and compared the acceptability criterion with the drinking standard IS 10500: 2012. Total soluble solids and closely associated parameters have been determined in the water extract from soil-like materials and local soils and compared with the international regulatory standards for reuse acceptability. From the total heavy metal concentration of soil-like material and local soil, three different pollution indices, namely contamination ratio, geo-accumulation index, and enrichment factor, have been identified and categorised soil-like material as low contaminated for lead; low to moderately contaminated for chromium, nickel, and iron; moderately contaminated for manganese; and moderately to strongly contaminated for copper and zinc. The organic and moisture content of soil-like material was reported as 22 and 19.6%, whereas the local soil showed 2.4 and 1.5%, respectively. Due to its enormous organic content, soil-like materials pose as less efficient in utilising offsite applications without primary treatment.