Radiochemical Investigation of the Partition and Sorption of Lead in Groundwater/Sediment Systems

Abstract

Lead / 210 Pb / Sorption / Sediments / Suspended particles / Colloids SummaryIn three different groundwater/sediment systems the partition of 210 Pb on the molecular fraction, the fine (colloid) particles and the coarse particles suspended in the groundwaters and the sorption ratios without filtration, after 0.45 μπι filtration and after ultrafiltration were determined as function of time. The methods of equilibration (smooth equilibration and equilibration by shaking), the volume to mass ratio V/m of groundwater and sediment, the concentration of Pb and the pH were varied.In general, relatively high sorption ratios are found after separation of groundwaters and sediments by filtration or ultrafiltration. The changes in the partition of Pb on the molecular fraction, the fine (colloid) and the coarse particles suspended in the groundwaters and the spectrum of sorption ratios obtained are discussed on the basis of the properties of the groundwaters and their components and the influences of the various parameters (method of equilibration, method of separation of groundwater and sediment, time, Vjm ratio, concentration of Pb, pH). As already observed for other elements, the sorption ratios are increasing strongly with the V/m ratio, indicating the influence of suspended fine (colloid) particles carrying Pb.