ADSORPTION OF HEAVY METALS ON RIVER SEDIMENT

Abstract

Adsorption is one of the most important processes in water quality control; it may determine the fate and transport of pollutants in the aquatic environment. Heavy metals today have a great significance due to their toxicity and adsorption behavior. The adsorption-characteristics of-the bed sediments collected from river Hindon near village Sishki have been studied for the uptake of lead and zinc ions. The parameters controlling the uptake viz. initial metal ion concentration, the solution pH, sediment dose & contact time have been evaluated. The adsorption of metal ions increases with increasing initial metal ion concentration. The optimum contact time in which equilibrium is attained was found to be 45 min for both the metal ions. It is observed that the extent of adsorption increases with the increase of pH of the solution but on the other hand, metal ion concentration decreases with increased in pH value. The adsorption of metal ions on the bed sediments follows three distinct phases viz. i) instantaneous extremely fast uptake, ii) transition phase and iii) extremely slow uptake. Further, the adsorption of metal ion increases with increasing adsorbent doses. The adsorption data of the two metal ions by sediments of river Hindon has also been analyzed with the help of Langmiur and Freundlich models to evaluate the mechanistic parameters associated with the adsorption process. Some parameter viz., monolayer capacity and sorption intensity have been evaluated for the system.