Mobility and transport behavior of lead in agricultural soils

The description of contaminant transport behavior in porous media is essential to optimally manage soils and subsurface aquifers, and to deal with chemical pollution in these resources. This study was conducted to examine the transport behavior of Pb through soil columns at different concentrations of Pb. Soil columns were collected from three different agricultural fields, namely, close canopy cocoa (CCC), open canopy cocoa (OCC) and an arable field grown with maize. The soils from all the three fields had a loamy sand texture. Soil from the CCC field had the best structure as evinced by the high total porosity (f), macroporosity (fm), soil organic carbon (SOC), and saturated hydraulic conductivity (Ks), and low bulk density (BD). The results indicated that high concentrations of applied Pb resulted in high concentrations of Pb in the effluents. In addition, the transport of Pb through the soil columns were found to be significantly affected by SOC, f, fm, Ks, and BD. The highest rates of Pb leaching at all application concentrations were observed in the CCC soil, and the least in the arable field.