Ion exchange properties of zirconyl phosphatess - PART II - Ion exchange equilibria on zirconyl phosphate

The tracer ion exchange equilibria ¹³⁴Cs-H⁺, ⁸⁶Rb-H⁺, ⁸⁹Sr-H⁺, ¹⁵²Eu-H⁺, ¹³⁴Cs-NH₄⁺, ⁸⁹Sr-Na⁺ and ⁸⁹Sr-NH₄⁺ on zirconyl phosphate have been studied in the concentration range 0.001-0.5 M; all obey the mass action law except the ⁸⁹Sr-Na⁺ equilibrium. The distribution coefficients indicate that a selective separation of ¹³⁷Cs from a 0.2 M HNO₃ fission product solution can be effected with a very high decontamination factor. Some macro-exchange systems have been studied in order to evaluate the interference of macro-quantitities of cations on zirconyl phosphate in the H⁺ form. The equilibrium constants of the systems Na⁺-H⁺, K⁺-H⁺, Ca²⁺-H⁺ and Sr²⁺-H⁺ are very low, but the difference between the constants of two neighbouring cations is relatively large. The adsorption affinity series of the ions in acid solution seems to differ slightly from the lyotropic series, NH₄⁺ and H⁺ ions displaying an uncommon behaviour.