Nanomaterials for the Removal of Heavy Metals from Wastewater

Abstract

Removal of contaminants in wastewater, such as heavy metals, has become a severe problem in the world. Numerous technologies have been developed to deal with this problem. As an emerging technology, nanotechnology has been gaining increasing interest and many nanomaterials have been developed to remove heavy metals from polluted water, due to their excellent features resulting from the nanometer effect. In this work, novel nanomaterials, including carbon-based nanomaterials, zero-valent metal, metal-oxide based nanomaterials, and nanocomposites, and their applications for the removal of heavy metal ions from wastewater were systematically reviewed. Their efficiency, limitations, and advantages were compared and discussed. Furthermore, the promising perspective of nanomaterials in environmental applications was also discussed and potential directions for future work were suggested.

Metal Ion Sensing and Electrochemical Behavior of MOF Derived ZnCo2O4

“…Consequently, detection and removal of such undesirable metal ions from water or wastewater are highly important and a challenging issue. Several methods proposed to perform the task starting from chemical precipitation, adsorption to electrochemical treatment can be found in the recent reviews . In this concern, the nanosized metal oxides attract special attention for being the promising candidate to remove heavy metal ions from aqueous medium.…”

“…In this concern, the nanosized metal oxides attract special attention for being the promising candidate to remove heavy metal ions from aqueous medium. [18b], The peculiar feature of nanosized metal oxides is related to the large surface areas and size effect. The oxides of iron, manganese, aluminum and titanium are extensively studied to remove heavy metals from aqueous solution through adsorption.…”

“…The oxides of iron, manganese, aluminum and titanium are extensively studied to remove heavy metals from aqueous solution through adsorption. [18b]…”

“…It has been reported that adsorption of heavy metal ions on metal oxide nanoparticles is mainly electrostatic in nature and sensitive to the pH of the medium. [18a], The hydrated ionic radii of metal ions have significant role on adsorption to the metal oxide surfaces. The cations with smaller hydrated ionic radii show preferential absorption onto the oxide surface.…”

“…The cations with smaller hydrated ionic radii show preferential absorption onto the oxide surface. [18a], Different operating factors including nature of metal oxide surface, temperature, pH as well as several thermodynamic parameters results in differential adsorption and sensitivities of metal ions towards a particular metal oxide surface. This can be exemplified by the altered affinity of heavy metals towards γ‐Fe 2 O 3 (Cu II > Cr VI > Mn II > Ni II > Cd II ) and α‐ Fe 2 O 3 (Pb II > Zn II > Cd II > Cu II ).…”