Application of common nano-materials for removal of selected metallic species from water and wastewaters: A critical review

Wastewater treatment and water purification have always posed challenges to mankind and this problem has become severe with escalating population and industrialization. This topic has attracted the global scientific community. Activated carbon adsorption became popular choice for water purification but its high cost prompted scientific workers to search for its alternates. In that series, several materials including minerals, waste materials, cellulosic materials, etc. were also applied as adsorbents. Recently, especially after advent of nano technology, there was a shift toward application of nano materials as 'adsorbents' and the term was coined as 'nano adsorbents'. Present review has been focussed on the application of common nano materials for the removal of metallic species which are found in aqueous environment. The 'most common' metallic species are As, Cd, Cr, Cu, Pb, Hg, and Ni. Sb, Pd, Pt, U and Th are the other miscellaneous metallic species where nano particles are applied for their removal from aqueous solutions and water. We have critically discussed the articles published recently on this topic.