Journal of Applied Phycology

, Volume 11, Issue 1, pp 79–87

Modelling complexation and electrostatic attraction in heavy metal biosorption by Sargassum biomass

  • Silke Schiewer

DOI: 10.1023/A:1008025411634

Cite this article as:
Schiewer, S. Journal of Applied Phycology (1999) 11: 79. doi:10.1023/A:1008025411634


Biosorption, the passive accumulation of metal ions by biomass, can be used for purifying metal bearing wastewater. Seaweeds represent a readily available source of biosorbent material that possesses a high metal binding capacity. For example, Sargassum can accumulate 2 mequiv of Cd per gram of biomass i.e. 10% of its dry weight. Binding of Cd and Cu by Sargassum is an ion exchange process involving both covalent and ionic bonds. The amount of cations bound covalently or by complexation can be predicted using multi-component sorption isotherms involving 2 types of binding sites, carboxyl and sulphate. A Donnan model was used to account for the effect of ionic strength and electrostatic attraction. The use of a multi-component isotherm that included one term for Na binding was less appropriate than the Donnan model for modelling ionic strength effects. It was possible to predict metal and proton binding as a function of the pH value, metal concentration and ionic strength of the solution.

biosorption seaweeds ion exchange pH ionic strength heavy metals 

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Silke Schiewer
    • 1
  1. 1.Department of BiologyHong Kong Baptist UniversityHong Kong (phone

Personalised recommendations