The biomass of
Penicillium cyclopium
was subjected to chemical treatment to study the role of the functional groups in the biosorption of heavy metal ions. The modifications of the functional groups were examined with infrared spectroscopy. Hydroxyl groups were identified as providing the major sites of heavy metal deposition, augmented by secondary binding by amides and carboxylates. Phosphate groups and the lipids fraction of the biomass did not play significant role in biosorption of the metal ions in the studied biomass. Biosorption of copper and cobalt ions displaced K
+, Mg
2+ and Ca
2+ present on the biosorbents indicating that biosorption took place as a result of an ion-exchange process.
