Volume 2, No. 2, 2008
Received: 2008/08/27, Accepted:
Authors:
H. Allaboun; F. A. Abu Al-Rub;
Abstract:
Adsorption of heavy metals on biological sorbents, activated carbon and synthetic resin particles is a common
separation technique. In this study, the biosorption of nickel ions from aqueous solution by palm tree leaves was
investigated as a function of shaking time, nickel ions concentration and equilibrium pH. Competitive adsorption
of nickel on palm tree leaves with EDTA and citric acid was also investigated.
Batch adsorption experiments revealed that the biosorption of nickel on palm tree leaves was strongly pH
dependent, and maximum nickel sorption was found to occur at equilibrium pH of 6.0. Dynamics studies showed
that: the initial uptake of nickel on palm tree leaves was rapid, equilibrium was established within 30 minutes,
and the data followed the pseudo-second order reaction. The equilibrium sorption data of nickel on palm tree
leaves at solution pH 6.0 were described by two-parameter isotherm models such as the Langmuir, Freundlich,
and D-R models and three-parameter models such as Redlich-Peterson and Sips isotherm models. Ion-exchange,
adsorption-complexation and intraparticle diffusion mechanisms were found to be involved in the biosorption
process.
The Effect of ions interference on the biosorption of nickel on palm tree leaves showed that the sorption of
nickel on palm tree leaves was adversely affected by the presence of chelating agents such as EDTA and citric
acid.
Keywords:
Biosorption, Nickel, Palm tree leaves, Isotherms.