The Removal of Hexavalent Chromium from Aqueous Solutions Using Modified Holly Sawdust: Equilibrium and Kinetics Studies

The removal of hexavalent chromium from aqueous solutions onto modified holly sawdust was studied at varying initial hexavalent chromium concentrations, adsorbent doses, pHs and contact times. The removal of hexavalent chromium from aqueous solutions increased with increasing adsorbent dosage and contact time. The percentage of hexavalent chromium removed from the aqueous solutions decreased with increasing hexavalent chromium concentration and pH of the solution. The kinetics of the adsorption of hexavalent chromium onto modified holly sawdust was analyzed using pseudo first-order and pseudo second-order models. The pseu do second-order model described the kinetics of adsorption of hexavalent chromium. The Langmuir and Freundlich isotherm models were used for modeling of the adsorption equilibrium data. The Langmuir isotherm model well described the equilibrium data for the removal of hexavalent chromium by modified holly sawdust. The obtained maximum adsorption capacity was 18.86 mg/g at pH 7. The results showed that modified holly sawdust can be used as a low cost adsorbent for the treatment of aqueous solutions containing chromium.

[1]  S. Azizian.  Kinetic models of sorption: a theoretical analysis. , 2004, Journal of colloid and interface science.

[2]  Y. Sharma.  Cr(VI) removal from industrial effluents by adsorption on an indigenous low-cost material , 2003 .

[3]  J. Gardea-Torresdey,et al.  Characterization of Cr(VI) binding and reduction to Cr(III) by the agricultural byproducts of Avena monida (oat) biomass. , 2000, Journal of hazardous materials.

[4]  Xiaoyuan Wang,et al.  Removing copper, zinc, and lead ion by granular activated carbon in pretreated fixed-bed columns , 2000 .

[5]  V. Gupta,et al.  Biosorption of chromium(VI) from aqueous solutions by green algae Spirogyra species. , 2001, Water research.

[6]  Mohammed M. Farid,et al.  Adsorption kinetics for the removal of chromium(VI) from aqueous solution by adsorbents derived from used tyres and sawdust , 2001 .

[7]  C. Huang,et al.  The removal of Cu(II) from dilute aqueous solutions by Saccharomyces cerevisiae , 1990 .

[8]  C. Forster,et al.  A preliminary examination into the adsorption of hexavalent chromium using low-cost adsorbents , 1994 .

[9]  A. G. Bhole,et al.  Removal of Cr6 + and Ni2+ from aqueous solution using bagasse and fly ash. , 2002, Waste management.

[10]  R. Saravanane,et al.  Efficiency of chemically modified low cost adsorbents for the removal of heavy metals from waste water: a comparative study. , 2002, Indian journal of environmental health.

[11]  B. Babu,et al.  Removal of toxic metal Cr(VI) from aqueous solutions using sawdust as adsorbent: Equilibrium, kinetics and regeneration studies , 2009 .

[12]  Mustafa Karatas,et al.  Heavy metal adsorption by modified oak sawdust: thermodynamics and kinetics. , 2007, Journal of hazardous materials.

[13]  T. Anirudhan,et al.  Chromium(VI) adsorption by sawdust carbon : Kinetics and equilibrium , 1997 .

[14]  K. Ranganathan.  Chromium removal by activated carbons prepared from Casurina equisetifolia leaves , 2000 .

[15]  K. Kadirvelu,et al.  Removal of Cr(VI) from aqueous solution by adsorption onto activated carbon. , 2001, Bioresource technology.

[16]  J. F. Porter,et al.  Sorption of acid dyes from effluents using activated carbon , 1999 .

[17]  C. Forster,et al.  Column studies into the adsorption of chromium (VI) using sphagnum moss peat , 1995 .