Chemical speciation of Zn, Pb, Fe and Mn in soil samples from the vicinity of a kaolin milling plant in Alkaleri, Bauchi state Nigeria

Abstract

This work is aimed at speciatiating some heavy metals in soil samples from the vicinity of a Kaolin milling plant. Soil samples analyzed in this research work were collected from twelve sampling sites from the vicinity of a Kaolin milling plants. Sample speciation analysis was carried out using method proposed by Tessier et al. as adopted by Omuku et al. with some modification. Elemental determination of manganese, iron, zinc and lead in the various speciation fractions were carried out using atomic absorption spectrometry (AAS) at various wavelengths. The result showed the distributions of heavy metals in various fractions as follows: Mn (F4,F2<F3<F5<F1) with concentration range in mg/kg between 1.00 – 5.50 and percentage range between 7.8 – 42.9%. Fe (F2<F1<F4<F3<F5) with concentration range in mg/kg between 11.7 – 110.8 and percentage range between 6.0 – 56.8%.Zn (F1<F4<F5<F3<F2) with concentration range in mg/kg between 0.0 – 2.5 and percentage range between 0 – 48.4%. Pb (F4<F5<F3<F1<F2) with concentration range in mg/kg between 4.00 – 14.67 and percentage range between 8.8 – 32.2%.Mn, Zn and Pb were seen to be highly mobile since they were mostly found in the fractions characterized by high mobility while Fe predominantly existed at the residual fraction.

Keywords: Speciation, Heavy metals, AAS, Soil, Kaolin, milling plant