Content of Pb and Zn in Soils Collected in the Vicinity of Selected Automobile Workshops in Kaduna, Nigeria

Abstract

To assess the availability of metals in soil for absorption, the chemical forms must be determined. In this regard, a modified  sequential extraction technique was used to determine the geochemical partitioning of Pb and Zn concentration of the soil sample obtained from these workshops were determined using flame Atomic Absorption Spectrometry (FAAS). The soil samples were digested and extracted using different digestion and extraction media. The results revealed that the concentrations of Pb and Zn in the samples varied from one automobile workshop to another and similarly the Pb concentration bound to the residual phase (HNO₃: H₂O₂ (2:1)) was highest in all locations followed by that bound to magnesium chloride, EDTA and Oxalic acid. Thus HNO₃/H₂O₂ >MgCl₂>EDTA>Oxalic acid. While the Zn concentration bound to the oxide phase (Oxalic acid) was highest in all the sampling locations followed by that bound to magnesium chloride, EDTA and nitric acid/ hydrogen perioxide. Hence, oxalic acid>MgCl₂>EDTA>HNO₃/H₂O₂.

Keywords: Bioavailability, metal content, soil, Automobile workshop.