Effect of pretreatment on biosorption of uranium by brown alga in a continuous packed bed column

Biosorption is an emerging technique in heavy metals removal. In this research, biosorption of uranium (II) from aqueous solution by Cystoseira indica (type of brown alga) biomass and the effect of pretreatment were studied in a continuous packed bed column. The uptake capacity of uranium ions was investigated by natural biomass and different pretreatments. Solutions of HCl (0.1 M) and CaCl2 (0.1 M and pH=2.5, 4, 9.7) has been added to biomass as pretreatment. Also the biosorption mechanism was considered. Experiments were carried out with initial concentration of 0.5 mM, pH=4 and flow rate of 2.3 ml/min at 25 °C. Results show that uptake capacity of uranium ions with natural biomass was 284.06 mg/g. Addition of HCl (0.1 M) and CaCl2 (0.1 M and pH=2.5, 4, 9.7) solutions to biomass change the uptake capacity and uptake capacities were 182.95, 287.21, 371.39 and 359.70 mg/g, respectively. Considering the concentrations of cations proves that ion exchange is the main biosorption mechanisms.

Keywords:

Biosorption , Uranium , Sorption Column , Brown Alga , Ion Exchange