Nano‐adsorbents for the removal of metallic pollutants from water and wastewater

Abstract

Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbon has been the most popular. A number of minerals, clays and waste materials have been regularly used for the removal of metallic pollutants from water and industrial effluents. Recently there has been emphasis on the application of nanoparticles and nanostructured materials as efficient and viable alternatives to activated carbon. Carbon nanotubes also have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions. Because of their importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu. Separation of the used nanoparticles from aqueous solutions and the health aspects of the separated nanoparticles have also been discussed. A significant number of the latest articles have been critically scanned for the present review to give a vivid picture of these exotic materials for water remediation.

Removal of heavy metals and pollutants by membrane adsorption techniques

“…Carbon nanotubes have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions (Sharma et al 2009). Due to its importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu.…”

The role of nanomaterials as effective adsorbents and their applications in wastewater treatment

“…An ideal adsorbent for wastewater treatment purposes should satisfy the following criteria [26]: (1) should be environmentally benign; (2) should demonstrate a high sorption capacity and high selectivity especially to the pollutants occurring in water at low concentration; (3) the adsorbed pollutants can be easily removed from its surface, and (4) should be recyclable. In recent years, many studies have proved that the nanomaterials can satisfy most of these requirements [38][39][40].…”

Nanomembrane Materials Based on Polymer Blends

“…Other formation processes are inert gas condensation, spray pyrolysis, laser pyrolysis, flame spray pyrolysis, pulsed laser ablation, spark discharge generation, ion sputtering, photothermal synthesis, thermal plasma synthesis, flame synthesis, low temperature reactive synthesis, mechanical alloying/milling, mechanochemical synthesis, and electro-deposition [43,128]. Li et al [130] recently reported the first mixed-matrix composite membrane made of commercially available poly (amide-b-ethylene oxide) mixed with the nano-sized zeolitic imidazole framework ZIF-7.…”

“…The applications of nanoparticles for membranes are usually prepared through the sol-gel process, which yields high-purity samples and allows the control of nanoparticle size, composition, and surface chemistry [128,129]. Other formation processes are inert gas condensation, spray pyrolysis, laser pyrolysis, flame spray pyrolysis, pulsed laser ablation, spark discharge generation, ion sputtering, photothermal synthesis, thermal plasma synthesis, flame synthesis, low temperature reactive synthesis, mechanical alloying/milling, mechanochemical synthesis, and electro-deposition [43,128].…”