Soil Quality as Affected by Municipal Solid Waste Dumping

Abstract

This paper presents soil quality as affected by dumped municipal solid waste. Landfill leachate was collected from a hole dug 10 m away from the waste dump site for laboratory analysis. Soil samples were also collected from four trial pits in the dumpsites at the depth of 0.3, 0.6 and 0.9 m and at a distance of 10, 20, 30 m and the control 100 m away from the dumping site. The collected soil samples were subjected to physiochemical and geotechnical analysis. This includes particle size distribution, pH, EC, total organic carbon, total organic matter, extractable micronutrients and heavy metals (Zn, Cu, Mn, Fe, Pb, Cd, Cr, Cl and Ni), Attterberg limits, specific gravity and hydraulic conductivity. The physicochemical concentration was then compared with the maximum allowable concentrations of chemical constituents in uncontaminated soil. The Laboratory analysis shows high value of pH (8.51) DO (0.17 mg/l), COD (68mg/l), BOD5 (324 mg/l), Pb (0.31 mg/l) and Cd (0.06 mg/l) in the leachate sample. The physical properties of the soil near the dumpsite indicated that the soil belongs to sandy loam in texture. pH (6.3-8.32), Electrical conductivity (241-2018 s/cm), total organic carbon (0.24-2.16 ) and total organic matter (0.41-3.73%) were higher near the vicinity of the dumpsite and decreased with increase in the depth and distance. Extractable micro nutrient and heavy metal concentration (Zn, Cu, Mn, Fe, Pb, Cd, Cr, Cl and Ni) were also found to be high near the dumpsite and decreased along the soil depth and distance from the dumping site. The variance in the geotechnical properties of soil revealed by the test results was impacted by the dumped municipal solid waste. These effects decrease with increase in depth. These findings will help in facilitating the invention and introduction of site specific technologies.