Abstract

Assessment of pollution potential of soil and groundwater by MSW landfill leachate in an industrial city of the eastern India has been carried out through physico-chemical characterization of soil and groundwater, identification of priority contaminants, batch adsorption and isotherm studies of priority contaminants. The study region used to receive wastes for 8-10 years in an area of 1000m × 500m before it was abandoned 3 years ago. Cr⁶⁺ has been taken as priority contaminant in the leachate because of its presence in the MSW dump site soil as seven times higher (10.16 mg/Kg) than the CCME standard. Hydrogeologically the dump area underlies potential unconfined aquifer with easterly flow direction of the groundwater. Depth of water table (0.91-5.92 m) suggests a thin zone of aeration which increases the possibility of the contaminant to reach groundwater. Batch equilibrium study revealed that the intermediate soil zone possess good resilience with respect to Cr⁶⁺ transport in the subsurface. Freundlich isotherm model provided the best fit (<em>R</em>²=0.9837, RMSE=0.89) to Cr⁶⁺ batch adsorption results. Multiple binding of Cr⁶⁺ was facilitated by the presence of higher concentration iron in the in-situ soil.