Assessment of Heavy Metal Contamination in Soil of Waste Disposal Site in Bangladesh: Implication of Spatial, Seasonal Variation and Indices

This study illustrates the extent of contamination for presence of heavy metal in soil of a selected waste disposal site at Rajbandh, Khulna, Bangladesh. Thus, this research was executed to assess the vulnerability associated with heavy metals in soil using integrated indices containing potential contamination (Cp), contamination factor (CF), pollution load index (PLI), modified contamination degree (mCD), numerical integrated contamination factor (NICF), enrichment factor (EF), geo-accumulation index (I_geo) and potential ecological risk index (PERI). To these endeavours, soil samples were collected from 60 selected locations of the disposal site in two different seasons; dry season (April, 2016) as well as rainy season (June, 2016). The relevant concentrations of Al, Fe, Mn, Cr, Cu, Pb, Zn, Ni, Cd, As, Co and Sc were measured in the laboratory through the standards method by atomic absorption spectrophotometer (AAS). The results of study can be concluded as most of the indices, i.e. CF, mCd, I_geo and PERI, indicated that the soil was polluted by heavy metals of Cd and Sb as well as Pb and As which is detrimental for the surrounding area. Pearson correlation analysis was performed to estimate the degree of association among the variable metals present in soil. Finally, the outcomes of this study will provide some useful insights for making appropriate management strategies to prevent or decrease soil pollution by metals around waste disposal site.