Decontamination of heavy metal ions from water by composites prepared from waste
Nityananda Agasti
Abstract
Due to high toxicity, heavy metal ions in water pose great risk to the biological system. Therefore decontamination of water polluted by heavy metal ions attracts significant interest of researchers. Adsorption by solid adsorbents has been widely used technique for removal of heavy metal ions from water. Solid wastes generated from industry or anthropogenic activities, and biomass, have been utilized as adsorbents but these wastes modified by nanomaterials have shown improvement in their performance. Therefore, modification of wastes by nanomaterials to form composites and application of those composite materials as adsorbent for removal of heavy metal ions is a potential approach for decontamination of water. Further, this is a twin strategy for reuse of waste and decontamination of water. This paper provides an account of recent advances in applications of composites prepared from modification of wastes by nanomaterials. This covers two types of wastes; (i) Industrial/anthropogenic waste, (ii) biomass waste. The component derived from waste, its role in the formation of the composite and the role it is playing in adsorption of heavy metal ions have been discussed along with role of the nanoparticle component in the composite. The mechanisms of adsorption, regeneration and reuse of composites have also been discussed. This review may pave the way for the design of new composites by modifying wastes for decontamination of heavy metal ions from water.