Effect of heavy metal contamination on soil physicochemical propertiesin selected areas of central rift valley of eastern shoa zone, Oromia region, Ethiopia

Abstract

This study was conducted to determine the effect of heavy metals (Pb, Cr, Cd, Fe, Cu, Zn, and Mn) contamination on soil physic-chemical properties around Mojo, Meki and Ziway. The air dried soil was digested, using wet digestion method for heavy metals and physico-chemical properties of soil such as pH, electrical conductivity, cation exchange capacity, organic carbon, organic matter and particle size were determined. The levels of the heavy metals were determined using flame atomic absorption spectrometer. Applying statistical packages, analysis of variances and correlation between heavy metals levels and soil physic-chemical properties were evaluated. The pH values of the soil samples range from 8.09 - 8.34 which shows the soils of Mojo, Meki and Ziway are moderately alkaline (8.4–7.9).The result show that pH is positively correlated with OC, CEC, Clay and Cd but negatively correlated with Cr, Cu, Zn, Pb, Mn, silt, sand and Fe.