Mechanism of biosorption of heavy metals by Mucor rouxii

Fungi such as Aspergillus niger and Mucor rouxii are capable of removing heavy metals from aqueous solutions. The role various functional groups play ill the cell wall of M. rouxii in metal biosorption of lead, cadmium, nickel and zinc Was investigated in this paper. The biomass was chemically treated to modify the functional carboxyl, amino and phosphate groups. These modifications were examined by means of infrared spectroscopy. It was found that ail esterification of the carboxyl groups and phosphate and a methylation of the amine groups significantly decreased the biosorption of the heavy metals studied. Thus, the carboxylate, amine and phosphate groups were recognized as important in the biosorption of metal ions by M. rouxii biomass. The role the lipids fraction play was not significant. The study showed that Na, K, Ca and Mg ions were released from the biomass after biosorption of Pb, Cd, Ni and Zn, indicating that ion exchange was a key mechanism in the biosorption of metal tons by M. rouxii biomass.