Adsorption of metal ions on bed sediments

Abstract
The adsorption of lead and zinc ions on bed sediments of the River Kali in western Uttar Pradesh, India, has been studied. The role of the coarser sediment fraction (210–250 μm) in controlling metal pollution has been elucidated and compared to those of the clay and silt fractions. The parameters controlling metal uptake, viz., solution pH, sediment dose, contact time, and particle size have been evaluated. The optimum contact time needed to reach equilibrium is of the order of 45 min for both the metal ions. The extent of adsorption increases with an increase of pH. Furthermore, the adsorption of the metal ions increases with increasing adsorbent doses and decreases with adsorbent particle size. The two geochemical phases of iron and manganese oxide act as the active support material for the adsorption of the metal ions.