Heavy Metal Pollution of Soil and Its Physicochemical Properties at Adama City Solid Waste Disposal Site

Abstract

The uncontrolled disposal of solid waste causes different adverse environmental impact. One of the serious problem is the leaching or migration of heavy metals to the nearest environment compartment. The aim of this study to analysis the heavy metal contents, extent of pollution and physicochemical properties of soil nearby solid waste disposal site. The sampling location was selected by transect from nearby disposal site toward gully erosion. The depth-specific soil samples were taken at the depth of 5-20cm and 20-30cm. Stainless steel materials were used to collect soil sample. The air dried soil samples sieved to pass 2mm and subsample of <2mm were used for pH, EC, CEC, soil porosity and heavy metals concentration analysis. The pH of soil near Qobbo Luxo and Jogo Dedo disposal site had slightly basic and basic respectively. In both disposal sites low CEC and EC were alayzed. Vertical distribution of indicate that Cd, Cr and Pb are increase but Cd and Pb are not in fixed pattern in Qobbo Luxo disposal site. Regarding to Jogo Dedo disposal site Cr and Pb are increases but Cd is in decreasing pattern. The soil is unpolluted to moderately polluted for all three heavy metals in Qobbo Luxo site based on geo accumulation indices classes but Jogo Dedo site shows unpolluted to moderately polluted by Cr and Pb but moderately polluted to Cd. Generally, soil nearby disposal sites indicates contamination of soil by heavy metal. This result alarm for the environmental risk of having heavy metals through food chain and possibly leaching to water sources. The possible recommendation remedial action should take place and installation of leachate collection as well as establishing of buffer zone necessary.