Environmental Biotechnology
 

Biotechnology Industry

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 10 No. 3, Issue of July 15, 2007
© 2007 by Pontificia Universidad Católica de Valparaíso -- Chile Received September 29, 2006 / Accepted March 8, 2007
DOI: 10.2225/vol10-issue3-fulltext-12
RESEARCH ARTICLE

Heavy metal uptake by agro based waste materials

Suleman Qaiser*
Department of Chemical Engineering
University of Engineering and Technology
Post code 54890
Lahore, Pakistan
Tel: 92 42 6829488
Fax: 92 42 6822566
E-mail: engrsqaiser@yahoo.com

Anwar R. Saleemi
Department of Chemical Engineering
University of Engineering and Technology
Post code 54890
Lahore, Pakistan
Tel: 92 42 6829288
Fax: 92 42 6822566
E-mail: darsaleemi@yahoo.com

Muhammad Mahmood Ahmad
Department of Chemical Engineering
University of Engineering and Technology
Post code 54890
Lahore, Pakistan
Tel: 92 42 6829488
Fax: 92 42 6822566
E-mail: chemengguet@hotmail.com

*Corresponding author

Financial support: Merit scholarship for PhD to Suleman Qaiser by Higher Education Commission Pakistan.

Keywords: biosorption, ficus religiosa leaves, hexavalent chromium, kinetics, lead, wastewater.

Abbreviations:

FTIR: fourier transform infrared
M: molarity
Pb+2: lead cation
rpm: rotations per minute

Abstract   Full Text

Presence of heavy metals in the aquatic systems has become a serious problem. As a result, there has been a great deal of attention given to new technologies for removal of heavy metal ions from contaminated waters. Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from industrial wastewater. The aim of the present study was to utilize the locally available agricultural waste materials for heavy metal removal from industrial wastewater. The wastewater containing lead and hexavalent chromium was treated with biomass prepared from ficus religiosa leaves. It was fund that a time of one hr was sufficient for sorption to attain equilibrium. The equilibrium sorption capacity after one hr was 16.95 ± 0.75 mg g-1 and 5.66 ± 0.43 mg g-1 for lead and chromium respectively. The optimum pH was 4 for lead and 1 for chromium. Temperature has strong influence on biosorption process. The removal of lead decreased with increase in temperature. On the other hand chromium removal increased with increase in temperature up to 40ºC and then started decreasing. Ion exchange was the major removal mechanism along with physical sorption and precipitation. The biosorption data was well fitted to Langmuir adsorption model. The kinetics of biosorption process was well described by the pseudo 2nd order kinetics model. It was concluded that adsorbent prepared from ficus religiosa leaves can be utilized for the treatment of heavy metals in wastewater.

Supported by UNESCO / MIRCEN network