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 (Kd) of RuNO3+ for barium alginate (BaALG) tended to slightly decrease with increasing HNO3 concentration, while a relatively large Kd value of 52.0 cm3/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.