TR(BR)-10/97-98 : Adsorption of cadmium bed sediments

Abstract

The report presents original study range of cadmium adsorption according to the experimental data. The effect of operating variables, viz., solution pH, sediment dose, contact time, and particle size, have been studied on the adsorption of cadmium ions on bed sediments of the highly polluted river in western Uttar Pradesh, India. The role of the coarser sediment fraction has been compared to those of the clay and silt fractions. The optimum contact time needed to reach equilibrium is of the order of 30 and 60 minutes for 0-60 and 210-250 Am size of the sediment respectively. The extent of adsorption increases with an increase of pH. Furthermore the adsorption of cadmium increases with increasing adsorbent doses and decreases with adsorbent particle size. The important geochemical phases, iron and manganese oxide, act as the active support material for the adsorption of cadmium. The competitive experiments conducted in the presence of lead and zinc ions indicate that both the ions suppresses the ability of cadmium to adsorb onto sediments.