Uptake and recovery of ruthenium by alginate gel polymers

The uptake and recovery of ruthenium ions were investigated by using alginate gel polymers. The uptake of RuNO³⁺ attained equilibrium within 2 d and the uptake percentage was above 90%. The distribution coefficient (K_d) of RuNO³⁺ for barium alginate (BaALG) tended to slightly decrease with increasing HNO₃ concentration, while a relatively large K_d value of 52.0cm³/g was obtained even in the presence of 6.7 M HNO₃, indicating a high affinity of BaALG for RuNO³⁺ ions. The separation factor of RuNO³⁺ and Rh³⁺ was 16.0 in the presence of 2.5 M HNO₃. The Ru ions were uniformly dispersed throughout the gel particle and the maximum uptake capacity was estimated to be 1.30 mmol/g. The RuNO³⁺ ions were effectively adsorbed on the packed column of BaALG and eluted with concentrated HNO₃ solution.