Fig. 18. (A) K_d of individual and competitive Cs⁺ and Sr²⁺ ion exchange vs. molar concentration of Na⁺ (initial concentrations were 7.4 and 6.9 ppm for Cs⁺ and Sr²⁺ respectively, V m^–1 ratio was 1000 mL g^–1, and pH ∼ 7). (B) K_d for UO₂²⁺ ion exchange vs. molar concentration of Na⁺ (initial concentration of UO₂²⁺ was 1 ppm, V m^–1 ratio was 1000 mL g^–1, and pH ∼ 7).