NO3 -and SO4 2-are abundant in many U mining effluents , so their effects on PEC methods were examined. The results show that slightly higher U extraction rates were obtained by replacing the 20 mM NaCl with 20 mM NaNO3 or Na2SO4 in the synthetic U-containing water (Figure ). The speciation of aqueous U(VI) could be different in the presence of different anions, because of the different complexation abilities of different anions with U(VI).