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Biosorption
characteristics of Aspergillus fumigatus in removal
of cadmium from an aqueous solution
Saleh M. Al-Garni*, Khaled M. Ghanem and Abdulaziz S.
Bahobail
Biological
Sciences Department, Faculty of Science, King Abdulaziz
University, Jeddah, Saudi Arabia.
*Corresponding author. E-mail:
salgarni@kau.edu.sa
Accepted 23
July, 2009 |
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Nineteen fungal species were isolated from soil contaminated
with industrial wastes of which Aspergillus species
were the most dominant. The growth of the isolates was
notice by Cd concentration in growth medium, thus about 20%
of the isolates can grow up to 50 mg Cd/100 ml medium and
only Aspergillus fumigatus and Penicillium
chrysogenum can grow at 100 mg Cd with growth decrease
of 88.2 and 99.4%, respectively. The results revealed that
the living biomass of the isolates were more efficient to
biosorb Cd than their dried powdered biomass by 15 - 44%.
The formulation of yeast peptone glucose (YPG) medium
fortified the isolates by ingredients favored the best
growth yields that have the highest Cd biosorption, compared
to yeast malt extract (YM) and sabourad (Sb) media. The
dried A. fumigatus biomass was the most efficient
than other tested fungi. The influence of different
treatments of dried A. fumigatus biomass on its Cd
biosorption activity, indicated that 0.5 N NaOH and
autoclaving was the most efficient treatment (3 fold
increase as compared to untreated). The biosorption of Cd by
treated A. fumigatus biomass was considerably
influenced by the pH value of the biosorption medium,
contact time, biomass levels and Cd concentration. Thus, 98%
of Cd was absorbed in biosorption medium containing 10 mg Cd
and 100 mg dried treated biomass/100ml bidistilled water at
pH 5 after 90 min of contact, nitric acid (0.05 N) was the
best Cd eluent (99.8%) as compared to the other eluents. The
desorbed A. fumigatus biomass was successfully reused
for 5 consecutive times for Cd biosorption with decrease
reached to 28% at the 5th reuse.
Key
words:
Biosorption, cadmium, Aspergillus fumigatus,
industrial wastes, biomass. |
