Biosorption of Uranium from Aqueous Solution by Reference and Indigenous Strains of Live Aspergillus.niger

The biosorption characteristics of uranium(VI) on reference and indigenous strains of live A.niger were evaluated. The influences of pH (3.0-7.0), biomass concentration (0.05-0.5 g dry biomass /100mL), initial uranium concentration (10-500mg/L), and contact time(30-1440 minutes) were investigated. In order to determine the residual concentration of metal, inductive coupled plasma spectrometry was used. The results indicate that the maximum biosorption of U on reference and indigenous biomass occur at pH=5 as 82.30% and 74.19%, respectively. The biosorption equilibrium was established in 60 and 120 minutes for reference and indigenous biomasses, respectively. The maximum biosorption was observed at a concentration 0.2 g dry biomass/100 mL for both biomasses. The maximum biosorption capacity of U was developed at an initial concentration of uranium 500mg/L as 105 and 143.5 mgU/g dry biomass for reference and indigenous biomasses, respectively. The adsorption process of reference and indigenous live A.niger could be well-defined by Langmuir isotherm with R2 values of 0.9972 and 0.9979, respectively. The obtained results indicated that the reference strain of live A.niger is more efficient for biosorption of U from aqueous solution in comparison with indigenous strain.