Structural determination of Pb binding sites in Penicillium chrysogenum cell walls by EXAFS spectroscopy and solution chemistry

Abstract

Fungal cell walls possess strong complexing properties, which make them valuable biosorbents to remove heavy metals from wastewaters. The binding mechanism of Pb to Penicillium chrysogenum cell walls was studied by the combination of solution chemistry and EXAFS spectroscopy as a function of the complexation rate, the metal concentration range investigated including two orders of magnitude. The corroborating macroscopic and microscopic results allowed us to identify two different Pb-binding functional groups, carboxyl and phosphoryl groups. The former were the strongest and minor (about 5%) complexing groups, whereas the latter were the weakest and predominant (about 95%) groups.