Heavy metal biosorption by dried powdered mycelium of Fusarium flocciferum

The biosorption capacity of dead biomass of Fusarium flocciferum for copper (Cu), cadmium (Cd), and nickel (Ni) was studied with the aim of developing the basis for an industrial effluent treatment. It was verified that a Langmuir isotherm describes well the biosorption of cadmium and nickel, whereas copper showed a more irregular behavior. Estimated maximum uptake, Q(max), expressed as mg metal/100 mg biosorbent, was 19.2 for cadmium and 5.2 for nickel. Maximum reproducible values for copper biosorption were between 4 and 6 mg/100 mg. Ln this case, it was verified that process efficiency depends on the balance between biosorbent and metal initial concentrations. Studies with different contact times showed that the process was completed within a few minutes. No difference in biosorbent metal affinity was found for cell incubation periods ranging from 24 hours to 4 days, but the biosorbent obtained from older cultures showed a decrease in metal removal capacity. This biosorbent is prepared from a fast-growing fungus with low nutritional and physical requirements. It can be used to remove metals from very dilute solutions at neutral pH values, as in the final steps of heavy metal removal from industrial wastewaters.