Bioremediation of toxic metal ions using biomass of Aspergillus fumigatus from fermentative waste

Dried, nonliving, granulated biomass of Aspergillus fumigatus from fermentation industry was used for the removal of Cd super(2+), Co super(2+), Cu super(2+) and Ni super(2+) from solutions. Sorption studies showed sequestration (70-90%) of Cd super(2+) from solutions (0.1-4 mM). However, with increase in concentration, Cd super(2+) sorption efficiency decreased due to saturation of the biosorbent. Cu super(2+) binds most efficiently (72%) to the biosorbent followed by Cd super(2+) (61%), Co super(2+) (49%) and Ni super(2+) (37%). Metal removal from solutions containing a mixture of metal ions (Cd super(2+), Cu super(2+), Co super(2+), and Ni super(2+)), which reflects the features of the polluted wastewaters and industrial effluents, was also efficient (90%) at lower concentrations (0.1 mM each). At higher concentrations (5 mM to 25 mM), Cu super(2+) removal was predominant ( > 70%) over other ions. The biosorbent was reusuable up to 5 cycles with a 50% loss of initial Cd super(2+) binding capacity. However, a significant loss of Cd super(2+) binding capacity was observed when biosorbent was immobilized in polyvinyl foam. Infrared spectra of the biosorbent preparation showed the involvement of alcohol/amine (OH/NH sub(2)) and CH-OH functional groups in metal binding. The present studies suggest that fungal biomass, a waste from fermentative industry, has the potential for removal/recovery of toxic metal ions from aqueous solutions.