Nanotech to the rescue in treating textile effluents
Dr. S. Ramaprabhu
Wastewater containing dyes presents a serious environmental problem due to its high toxicity which leads to ground water and surface water pollution. Further, the discharge of colored effluents into water bodies affects the sunlight penetration which in turn decreases the photosynthetic activity. Therefore the removal of the high stable dyes from the textile effluents is of prime importance.
The solution to the above problem can be obtained by using nanomaterials. Notable for their extremely small size, nanomaterials have the potential for wide-ranging industrial, energy, biomedical, and electronic applications. In nanomaterials, the small size ensures that many atoms or molecules will be near interfaces which lead to very high surface area. Surface properties such as energy levels, electronic structure and reactivity can be quite different from interior states and give rise to quite different material properties.
In carbon based nanomaterials, selective functional groups can be attached to the surfaces of these different dimensional nanomaterials and these functional groups can be used to adsorb the dye molecules. The adsorbing capacity is enhanced due to the use of nanomaterials having large surface area.
The present invention, filed as patent by IITM, shows the ability of a novel nanocomposite adsorbent to adsorb dye molecules from basic dyes (Tolune blue, Evan's blue, Trypan blue, Eosin yellow, Coomassie Brilliant Blue), VAT dye, AZO dye, and industrial waste-waters. The nanocomposite adsorbent is made up of nano-metal/nano-metal oxide dispersed on support material which is a combination of one dimensional, two dimensional and three dimensional nanomaterial.
The large surface area and the attachment of proper functional groups on the surface of the nanocomposite adsorbent result in the dye adsorbing capacity and the complete removal of the dye molecules. Ultra violet-visible spectra were studied to ensure the complete color adsorbance. This nanocomposite adsorbent also removes the odor by trapping the gas molecules on the functional groups.
Optimum conditions for the removal of all dyes were obtained with varied adsorbent dosage. The dye adsorbed nanocomposite adsorbent is shown not to give out any of the dye molecules when allowed to react with water and can be re-activated by suitable fluid treatment and reused.
The work is progress to optimize the nanocomposite adsorbent for the complete removal of contamination from leather industrial waste-waters.
Professor S. Ramaprabhu, Alternative Energy and Nanotechnology Laboratory and Nano Functional Materials Technology Centre (NFMTC), Department of physics, is leading a research group on the processing of different types of nanomaterials and the surface area applications of nanomaterials. The research group is involved in state of the art research in Nanotechnology, Carbon nanotubes, Graphene, Hydrogen Energy and Fuel cell.
Fibre2fashion News Desk - India