Adsorption of Uranium U(Ⅵ)from Salt Lake by Dunaliella tertiolecta and Dunaliella spp.
The vast uranium reserves in the salt lake brines of the Qaidam Basin make the exploration and development of salt lake uranium resources one of China's strategic priorities.The diatoms Dunaliella tertiolecta and Dunaliella spp.,purified from the salt lakes of the Qaidam Basin,were cultured,centrifuged,dried,and activated to produce algal powder.The effects of initial pH,adsorption time,adsorption temperature,initial U(Ⅵ)concentration,as well as different types and concentrations of salts,on the adsorption of U(Ⅵ)by the two types of algae were investigated.Both Dunaliella spp.and Dunaliella tertiolecta exhibited a single-molecule layer chemical adsorption process for U(Ⅵ),as evidenced by fitting to the Langmuir model,with maximum adsorption capacities reaching 276.57 mg·g-1 and 343.12 mg·g-1,respectively.The morphological characteristics and compositional changes of both algae types before and after adsorption were examined using SEM,EDS,FT-IR,XPS.Possible adsorption mechanisms were then proposed based on the observed results.Furthermore,investigation into the adsorption of U(Ⅵ)by the two algae in varying salt types and concentrations revealed that both exhibited effective adsorption capabilities at specific salinity levels.Dunaliella tertiolecta demonstrated superior adsorption performance compared to Dunaliella spp.under these conditions.
NETL
NSTL
万方数据
