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

Siboni, M. Shirzad; Samarghandi, M. R.; Azizian, S.; Kim, W. G.; Lee, S. M.

doi:2011.16.2.55

Environmental Engineering Research 2011;16(2): 55-60. DOI: https://doi.org/10.4491/eer.2011.16.2.55

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

M. Shirzad Siboni¹, M. R. Samarghandi², S. Azizian³, W. G. Kim⁴, and S. M. Lee⁴^†

¹Environmental Health Research Center, Kurdistan University of Medical Science, Sanandaj, Iran
²Department of Environmental Health, School of Public Health, Hamadan University of Medical Science, Hamadan, Iran
³Department of Physical-Chemistry, Hamadan University of Bu-Ali Sinna, Hamadan, Iran
⁴Department of Environmental Engineering, Kwandong University, Gangneung 210-701, Korea

Corresponding Author: S. M. Lee ,Tel: +82-33-649-7535, Fax: +82-33-642-7635, Email: leesm@kd.ac.kr

Received: June 3, 2010; Accepted: March 11, 2011.

ABSTRACT

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 pseudo 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.

Keywords: Adsorption | Cr(VI) | Isotherm | Kinetic models | Sawdust