New generation adsorbents for water treatment.

Of the variety of adsorbents available for the removal of heavy and toxic metals, activated carbon has been the most popular. A number of minerals, clays and waste materials have been regularly used for the removal of metallic pollutants from water and industrial effluents. Recently there has been emphasis on the application of nanoparticles and nanostructured materials as efficient and viable alternatives to activated carbon. Carbon nanotubes also have been proved effective alternatives for the removal of metallic pollutants from aqueous solutions. Because of their importance from an environmental viewpoint, special emphasis has been given to the removal of the metals Cr, Cd, Hg, Zn, As, and Cu. Separation of the used nanoparticles from aqueous solutions and the health aspects of the separated nanoparticles have also been discussed. A significant number of the latest articles have been critically scanned for the present review to give a vivid picture of these exotic materials for water remediation.

Nano‐adsorbents for the removal of metallic pollutants from water and wastewater

Remediating fluoride from water using hydrous zirconium oxide

Improvement of coke resistance of Ni/Al2O3 catalyst in CH4/CO2 reforming by ZrO2 addition

Adsorptive removal of noxious cadmium ions from aqueous medium using activated carbon/zirconium oxide composite: Isotherm and kinetic modelling

http://dspace.nitrkl.ac.in/dspace/bitstream/2080/339/1/sarkar2006.pdf

Synthesis and characterization of sol–gel derived ZrO2 doped Al2O3 nanopowder

Al2O3–ZrO2 composite gel powder was prepared by sol–gel route. The gel precursor compositions were preferred to achieve yield of 5–15 mol% zirconia after calcination of respective powders. The precursor gel was characterized by Differential Thermal Analysis (DTA)/Thermo Gravimetric (TG), IR and X-ray Diffraction study (XRD). The analysis reveal the gel contained pseudoboehmite and amorphous Zr(OH)4, which was decomposed in three and two stages respectively. The phase transformation of alumina during calcination followed the sequence of pseudoboehmite → bayerite → boehmite → γ-Al2O3 → θ-Al2O3 → α-Al2O3, while that of ZrO2 follows amorphous ZrO2 → t-ZrO2 → (t + m) ZrO2. Fourier Transform Infrared Spectroscopy (FTIR) studies showed that the number of M–OH and M–O bond increases with zirconia due to a change in the cationic charge of the composite powder. Transmission Electron Microscopy (TEM) photograph of calcined powder exhibited the presence of dispersed as well as agglomerated nano sized spherical particles. SEM and Electron Probe Microscope Analysis (EPMA) confirmed the near uniform distribution of zirconia particles in the alumina matrix.

Sambarta Ray

Papers

Synthesis and characterization of sol–gel derived ZrO2 doped Al2O3 nanopowder

Nanostructured Al2O3-ZrO2 composite synthesized by sol-gel technique: powder processing and microstructure