【摘要】 为了解在惰气环境Pu(OH)4(am)与碳酸盐溶液中HCO3-,CO23-的配位行为,考察了放置时间对Pu总浓度的影响;同时也考察了pH值、碳酸根总浓度变化对碳酸盐溶液中Pu的主要存在形态及溶解总浓度的影响。实验结果表明,HCO3-离子与Pu(OH)4(am)生成[Pu(OH)4(HCO3)2]2-(lgK=-2.61±0.18,lgβ=54.25±0.18)或[Pu(OH)2(CO3)2]2-(lgK=-2.61±0.18,lgβ=46.91±0.18);CO23-离子与Pu(OH)4(am)生成[Pu(OH)4(CO3)2]4-(lgK=-3.52±0.11,lgβ=53.33±0.11)。可能的配位反应方程式为:Pu(OH)4(am)+2 HCO3-[Pu(OH)4(HCO3)2]2-,Pu(OH)4(am)+2 HCO3-[Pu(OH)2(CO3)2]2-+2 H2O,Pu(OH)4(am)+2CO32-[Pu(OH)4(CO3)2]4-。更多还原

【Abstract】 The complex formation of Pu（OH）_4（am） with carbonate is studied with the variation of pH（8.92¹3.08）,and the total carbonate concentration range of 10^-410^-2 mol/L.The effect of pH value and total carbonate concentration on the dissolved total concentration of Pu（OH）_4（am） and species of Pu in solution are discussed.All experiments were performed in a anaerobic glove box which contained high purity Ar（99.99%）,with an oxygen content of less than 5×10^-6mol/mol.The experimental results show that 1∶2 complex of(Pu（OH）_4（am）) with（bicarbonate） is obtained and the complex formation constants determined in the experiments.Pu（OH）_4（am）+2HCO^-₃[Pu（OH）₄（HCO₃）₂]^2-,K=10^{（-2.61±0.18）}Pu（OH）_4（am）+2HCO^-₃[Pu（OH）₂（CO₃）₂]^2-+2H₂O,K=10^{（-2.61±0.18）}At high pHs（10.28¹3.08） where carbonate ion is dominant,1∶2 complex of(Pu（OH）_4（am）) with carbonate ion is obtained:Pu（OH）_4（am）+2CO^2-₃[Pu（OH）₄（CO₃）₂]^4-,K=10^{（-3.52±0.11）}.更多还原