A Review on Removal of Heavy Metals from Water by Adsorption

Abstract

Substantial contamination of heavy metals in drinking water has been an issue to consumers since long. The persisting contamination level has been monitored by various agencies and researchers, which direct towards constant deterioration of water quality. The quality of water is degrading exponentially from rural to urban areas in a significant manner. Industrial effluents, sewage and agricultural waste are the prime sources of contamination of water resources. Various heavy metals such as nickel, chromium, lead, arsenic, cadmium, mercury and copper may be present in industrial effluents. Though different methods such as chemical precipitation, ion exchange, membrane filtration, coagulation – flocculation and electro dialysis are known, amongst which adsorption being the most versatile and economically viable has been extensively adopted by various researchers for trace level of concentrations. In this review, several low cost adsorbents are reported in the literature have been studied at length. Different types of adsorbents like nanosorbent, biosorbents, carbonaceous material and metal based adsorbents have been considered for the review paper. The review paper evaluates the possibilities of utilizing various adsorbents for efficient removal of different heavy metals from water. Study reflected towards remarkable adsorption capacity, efficiency and cost effectiveness of adsorbents utilized by researchers. The boundless use of low cost adsorbents for treatment of wastewater are strongly recommended due to their availability,