A study of the distribution of lead, cadmium and copper between water and kaolin, bentonite and a river sediment

Experiments were carried out to monitor the equilibrium distribution of lea d, cadmium and copper between an aqueous phase modelling natural water and a solid phase modelling natural sediment, under varying conditions. The aqu eous phase was analysed using ETAAS and differential pulse anodic stripping voltammetry (DPASV), whereas XRD and FTIR were used to study the solid pha se. Sorption isotherms at constant pH were measured. Conditional distributi on constants were calculated as functions of the pH, the time of equilibrat ion and the amount of solid material. The results obtained stress the need for standardization of the approaches to the study of water-sediment intera ctions in order to be able to evaluate and compare the extensive data from field measurements and to predict these interactions.