Analysis of metal ions
The concentration of unadsorbed Cd (II) ions in the biosorption
medium was determined by using atomic absorption spectrophotometer
(AAS, Varian AA-220, Australia). The amount of Cd
sorption onto bacterial biomass was determined from the
difference between the Cd added to the solution and the Cd
remaining in the solution after 2 h. Blank samples (without
biomass) were also examined to ensure that no adsorption had
taken place on the walls of the apparatus used. Each experiment
was repeated three times to confirm the results.
The Cd uptake were calculated by using the following Eq