Removal of heavy metal ions from wastewater by carbon nanotubes (CNTs)

Abstract

Advent of nanotechnol. has introduced us with new generation of adsorbents such as carbon nanotubes (CNTs) which have aroused widespread attention due to their outstanding ability for the removal of various inorg. and org. pollutants from large vols. of water. This article reviews the practical feasibility of various kinds of raw and surface modified carbon nanotubes for adsorption of heavy metal ions from wastewater. Further, properties of CNTs (adsorption sites), characterization of CNTs (pore vol., BET surface area, surface total acidity, surface total basicity) and soln. properties (ionic strength, effect of pH) are explained very well. The adsorption mechanisms are mainly attributable to chem. interactions between metal ions and surface functional groups of the CNTs. The adsorption capacity increases to greater extend after functionalization i.e. surface oxidn. of CNTs. Future work on developing cost effective ways of prodn. of CNTs and analyzing its toxicity are recommended. [on SciFinder(R)]