Distribution and Speciation of Heavy Metals in Crude Oil Contaminated Soils from Niger Delta, Nigeria

摘要: Soil samp les at depths of 0-15cm and 15-30cm were collected with an auger around abandoned crude oil well a history spillage fro m control sites Abara Ozuzu during the rainy dry seasons. The speciation (exchangeable, carbonate, Fe-Mn o xide, organic residual fract ions) metals was determined using sequential extraction methods. exchangeable ion had highest concentrations fraction lowest concentrations. In season 22.27% Pb, 25.41% Cu, 37.78% Cd, 22.24% Cr, 24.84% Ni, 21.43% Mn 22.43% Zn bound to fraction. heavy in area potentially bioavailable since soils are acidic (pH 4.70 - 6.70), have low silt clay contents higher metal associated non fractions. contaminated but do not pose serious adverse effect humans environment for now as generally within or belo w permissible limits recommended by Rivers State Ministry Environ ment. Regular mon itoring recommended. re-distribution other contaminants reduced their spilled site.