Journal of Environment and Earth Science www.iiste.org ISSN 2224-3216 (Paper) ISSN 2225-0948 (Online) Vol.7, No.3, 2017 98 The Speciation and Potential Bioavailability of Zinc, Manganese, and Lead in Soils of Automobile Workshops in Sapele, Nigeria Augustine. A. Chokor Department of chemistry, Federal University Otuoke, Nigeria Abstract This paper presents the result of speciation of three heavy metals (Zn, Mn, & Pb) in soils from ten automobile workshops in Sapele, Nigeria. Soil samples were taken from depth 0 – 60cm and heavy metal concentration were determined. Higher concentrations of these metals were found in soils in the vicinity of the automobile mechanics workshops compared to that of the control. On speciating, 20 to 28% Zn, 23 to 39% Mn, and 15 to 23% Pb, were potentially mobile and bio-available. Keywords: soils, heavy metals, automobile workshops, speciation, bio-available. 1. Introduction Total amount of heavy metal provide a useful index of the degree and the extent of contaminations but furnish little or no information on bioavailability and mobility of heavy metals (Chukuma, 1993; Lo and Yang, 1998). The bioavailability and mobility of heavy metal in a contaminated soil is governed by the chemical forms in which the metals exist and are distributed in the soil fractions (Tessier et al., 1979; Lo and Yang, 1998). Metal fractionation (speciation) in soils has been carried out with sequential extraction procedure to determine the metal binding forms (Tessier et al., 1979; Van-Valin and Morse, 1982; Lake et al., 1984; Shuman, 1985, 1991; Berti and Jacobs, 1996). It is indeed a process of separating soils, sediments and soil component into operationally defined fractions in the assessment of contamination (Asagba et al; 2007). Such separation has been widely used in various environmental studies (Kennedy et al., 1997; Ahumada et al., 1999; Christensen and Huang, 1999; Narwal et al., 1999; Kabala and Singh, 2001; Oviasogie and Ndiokwere, 2008). The study of the speciation of contaminants in the environment is necessary to: assess the ultimate impacts of contaminants on human health; understand the mechanism of chemical and microbial transformation; develop predictive models, effective remediation and waste management strategies and risks assessment. The soils surrounding the automobile workshops are being exposed to contamination. Automobile used (waste) oil contain oxidation products, sediments water and metallic particles resulting from machinery wears organic and inorganic chemicals used in oil additives and metals that are present in fuel and transferred to the crankcase during combustion ( EEA, 2007). These wastes including also wastes oils used for cleaning during servicing, metal scraps, used batteries e.t.c, indiscriminately discarded on the soil by artisans, contaminates the soil. Percolation of leachates from these materials poses threat to underground water and creates concern for the normal functioning of the ecosystem. The investigations on the metal forms, particularly using sequential extraction mainly concern surface soil (0-15cm) (Iyengar et al., 1981; He and Singh, 1995; Ma and Rao, 1997; Chlopecka et al., 1998; Ahumada et al., 1999), studies of contaminated areas however; require that the whole soil profile including subsurface horizon be considered. This study was therefore, undertaken to: • investigate the distribution and chemical fractions of Zn, Mn, and Pb, in the soil profile (depths: 0 – 60cm). • asses the mobility and bioavailability of the metals and the degree of contamination in the different soils. • determine the physiochemical properties of the soil and investigate the relationship between soil properties and the chemical fractions of the heavy metals. brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by International Institute for Science, Technology and Education (IISTE): E-Journals