Removal Of Heavy Metals Through Adsorption Using Sand

Abstract

 Water contaminants include a large number of chemicals ranging from aromatic hydrocarbons, organic solvents, pesticides and metals. Heavy metal contamination is commonly found in areas where industrial effluents are discharged into natural waters. The harmful effects of such metals on living being are well known. Chromium exists in as  and  in water. These are biologically critical species (Sawyer, 1994; Dara, 1997);  is carcinogenic in nature whereas long-term exposure to  can cause allergic skin reactions leading to cancer. Similarly, copper is extremely toxic to aquatic biota (U. S. EPA, 1985). Lead (Manahan, 1991) and zinc (Diamond, 1993; Murray, 1994; Evangelou, 1998) have also been classified as water pollutants. Consequently, removal of heavy metals from wastewater and industrial wastes has become a very important environmental issue. The process of adsorption is considered one of the most suitable methods of the removal of contaminants from water and a number of low cost adsorbents have been reported for the removal of heavy metals (ions) from aqueous solutions.