Comparative analysis of soil contamination caused by existing municipal solid waste management facilities

Abstract

This study investigates soil contamination around existing municipal solid waste (MSW) management facilities specifically, composting, and active landfill sites in Bangalore, India. The physicochemical parameters considered are pH, electrical conductivity (EC), sodium adsorption ratio (SAR), and concentration of heavy metals namely copper (Cu), chromium (Cr), nickel (Ni), and zinc (Zn). Soil samples collected from MSW sites and natural soil, are chemically analysed in laboratory. A comparison of parameters was done by designing and testing 28 statistical hypotheses.

This empirical study revealed that the concentration order of heavy metals was Zn > Cr > Cu > Ni for landfill site samples and Zn > Cu > Cr > Ni for composting site samples. The mean values of pH, SAR, Cu, Cr, Zn, Ni, and EC in landfill site samples were higher than that control samples by 21 %, 60 %, 152 %, 4 %, 131 %, 114 %, and 555 % respectively. Similarly, for composting site samples, the mean values of pH, SAR, Cu, Cr, Zn, Ni, and EC were higher than that control samples by 13.61 %, 108 %, 1088 %, 5 %, 374 %, 236 %, and 2144 % respectively. Heavy metals concentrations, EC, and SAR in composting site samples exceeded control and landfill site samples. However, pH of landfill site samples was higher than that in both composting site and control samples. While the Cr concentrations among the three sites was not statistically significant, it was highest in composting site samples. The study recommends measures to obviate soil contamination from existing MSW management facilities.