Sorption Kinetics of Hg(II) onto Potamogeton natans Biomass

C. Lacher^a and R.W. Smith^b*

^a Forschungszentrum Karlsruhe, Technik und Umwelt, Institute for Technical Chemistry, Section Water and Geotechnology, Germany
^b Metallurgical and Materials Engineering, University of Nevada, Reno, USA

Received 17 April 2002; accepted 10 October 2002



ABSTRACT

The kinetics of sorption of Hg(II) from aqueous solution onto the dead biomass of the aquaphyte Potamogeton natans was studied. Chemical and instrumental analyses including atomic absorption, electron microscopy and X-ray energy dispersion analyses were used to elucidate sorption mechanisms. It was found that, although sorption of Hg(II) took place over the entire biomass surface, there were spots on the surface where apparent multilayer sorption of Hg(II) occurred. Kinetic studies and the construction of various adsorption isotherms confirmed multilayer sorption at least on parts of the biomass. The maximum uptake of Hg(II) by P. natans biomass is about 180 mg/g biomass. The minimum concentration of Hg(II) in solution that can be achieved appears to be limited to about 4-5 mg/l. An attempt was made to determine whether or not the Hg(II) sorbed onto the biomass could be removed by elution with an acid or a base.


Keywords: Potamogeton natans; Biosorption; Mercury; Kinetics



* Corresponding author
   E-mail : smithrw@scs.unr.edu