Synthesis, characterization of nanostructured sulfated Zirconia@silica catalyst using green chemistry and its catalytic application in one pot isomerization of n-alkane

Nano structured sulfated zirconium-sillicon binary oxides were synthesized in different mole-ratios of Zr4±:Si4±, 2:1 (SZS-1), 1:1 (SZS-2) and 1:2 (SZS-3), by a simple precipitation chemical method using green chemistry. The preparation of the catalysts from rice husk that is a waste product is highly exclusive and unique. Evaluation of these catalysts was carried out in a batch reaction system at normal temperature and pressure as well as at high temperature –flow-reactor during the isomerization of n-hexane, n-heptane and n-octane to their corresponding branched isomers. The best performing catalyst (SZS-2) was characterized by TEM, SEM, AFM, FTIR, TG-DTA, BET and small angle XRD. The super acidity of the catalyst was measured by performing ammonia-TPD. From this end, the SZS-2 contains nano particles of ~ 20 nm, presenting an amorphous nature and having no definite surface morphology.  Catalyst evaluation and characterization allowed proposing a reaction mechanism, elucidating a probable role of Bronsted and Lewis acid sites on the studied reaction-catalyst. This catalyst can be effectively used in future to enhance the efficiency of petroleum

Cadmium(II), Lead(II) and Copper(II) biosorption on Baker’s yeast (Saccharomyces cerevesiae)

© 2015 American Society of Civil Engineers. The biosorption properties of ethylenediaminetetraacetate (EDTA)-treated biomass of baker's yeast (Saccharomyces cerevisiae) are studied for the removal of Cadmium(Cd), Lead(Pb), and Copper(Cu) from artificially prepared industrial wastewater. The metal ions are chosen for biosorption studies with regard to their availability in industry and potential pollution impact. The optimum biosorption capacity of these metal ions on the biomass is obtained at pH 5. It is observed that the sorption capacity of EDTA-treated biomass increases when the initial concentration of the metal ions is increased. Both Langmuir and Freundlich isotherm models are used to fit experimental biosorption equilibrium data. The maximum biosorption capacity as determined via the Langmuir isotherm is 32.26, 200.0, and 17.24 mg/g for Cd(II), Pb(II), and Cu(II) ions, respectively. The kinetics of biosorption is studied using both pseudo first order and pseudo second order models. Based on a linear regression correlation coefficient, pseudo second order metal uptake rate kinetics is found to give the best fit.status: publishe