Uranium sorption from saline lake brine by amidoximated silica

A series of silica sorbents with different content of amidoxime groups were prepared through co-condensation method and applied to extract uranium from saline lake brine. The optimum amidoxime group content was determined and effects of pH on uranium sorption were investigated. Sorption kinetic and isotherms were also investigated. XPS analysis indicated that the adsorption mechanism of uranium was attributed to the interaction between uranyl ion and N in the amidoxime. Amidoximated silica could efficiently absorb the naturally occurring uranium in the saline lake brine samples from Qinghai, China.