Contaminants in soil-like material recovered by landfill mining from five old dumps in India

Soil-like material (SLM) was mined from five municipal solid waste (MSW) dumps to assess its potential for reuse in earthwork projects. The contamination levels of SLM (<4.75 mm) were determined based on organic content, total soluble solids, the release of colored leachate, and heavy metals. Organic content in SLM was found to be 4-24.5 % whereas in the local soils (nearby areas) it was found to be 1-1.2 %. Total soluble solids were found to be in the range of 4820-25220 mg/kg, several times higher than that of the local soils (500-1000 mg/kg). The intensity of yellow-brown color in the water extract from SLM was observed to be 205-925 PCU while in the water extract of local soils it was found to be 25-40 PCU, highlighting the potential for release of colored leachate from SLM. Heavy metals in the SLM including chromium, copper, nickel, zinc, cadmium, and lead were found to be moderately to strongly elevated. Though SLM appears to be an attractive option for reuse, the high levels of contaminants indicate SLM would require treatment before offsite reuse. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.