H. M Maina, J. N Egila.I Nkafa
Abstract
The elemental composition, distribution and some physicochemical aspects of soils in the vicinity of Ashaka cement factory were scrutinized. The pollution load and its impact on the environment were assessed using high-resolution energy dispersive X-ray fluorescence (EDXRF) spectrophotometer. The facility was integrated with computer system capable of determination of elemental composition of samples and some physiochemical aspects in form of their oxides. The major elemental components investigated in soil ranged as follows; CaO (1.13-14.17%), CaCO3 (2.02-23.40%), SiO2 (52.41-94.06%), Al2O3 (6.75-15.78%), Fe2O3 (1.52-3.97%), K2O (1.80-6.25%) and heavy metals Zn (47.47-76.23mgkg-1), Mn (515.01-960.00mgkg-1), Cu (68.83-103.30mgkg-1) and Pb (43.60-119.00mgkg-1). Physicochemical properties determined included lime saturation factor (LSF) (0.42-12.67), silica ratio (SR)3.33-10.92%, alumina ratio (AR) 2.47-7.38) and loss on ignition (LOI)(0.85-5.89%). The major components CaO and CaCO3 together with LSF were used as pollution tracers. These components along with the heavy metals show soil enrichment along the wind directions (northeast and southwest) with maximum pollution load at 5 and 7km distance. Similar patterns were observed with vertical distribution along the wind directions. Although levels of some elements were low in some areas, the mean concentration of most of the components were 2 – 10 folds greater in order of magnitudes than the levels expected in unpolluted soil.