Nanotechnology for Remediation of Wastewaters containing Heavy Metals
Clean Technology 2008

Nanotechnology for Remediation of Wastewaters containing Heavy Metals

M. Singh, M. Bansal, D. Singh
National Institute of Technology, Kurukshetra, IN

nanotechnology, heavy metals, adsorption, nanomaterials, carbon nanotubes, zeolites, nanoparticles, sorbents

Widespread concern over the cumulative toxicity and environmental impact of heavy metals has led to extensive research into developing effective alternative technologies for the removal of these potentially damaging substances from effluents and industrial wastewaters. The major driving force for this research is increasingly stringent environmental legislation and the powers of the authoritative bodies established to enforce these regulations, Sources of heavy metals include metal extraction, metal fabrication, metal finishing, electroplating, painting, dyeing, surface treatment industry and printed circuit board manufacture. Conventional heavy metal removals are either expensive or ineffective, especially when the metal concentrations are very low in the solution. Adsorption is a promising alternative due to its cost effectiveness. Many kinds of adsorbents for metal ions removal have been commercialized or are being developed in the search of more effective one. Recent advances in nanotechnology suggest that nanomaterials can be helpful in solving the problems of heavy metal pollution. Nanomaterials have much larger surface areas than bulk materials and exhibit novel properties due to their small size. Unique properties of nanomaterials are being exploited by the researchers for developing more effective sorbents and improving the existing ones for metal ions removal and recovery from effluents. In recent years, carbon nanotubes, zeolites, carbon nanobeads, nanoparticles of TiO2, Fe2O3, ZrO2, NiO and their derivatives have been investigated for their removal and recovery of metal ions. Encouraging results have been obtained from these studies and it was observed by most researchers that the capacity and efficiency of sorbents increases more than expected when the materials are reduced to nanoscale. This paper gives a brief overview of potential of nanomaterials for removal of heavy metals from wastewater.