Cu^(2+)-H_2O系羟合配离子配位平衡研究

Study on Equilibrium of Hydroxyl Complex Ions in Cu^(2+)-H_2O System

根据配位化学热力学平衡原理,绘制了Cu2+-H2O系配合离子浓度pc-pH图、铜羟合配离子分率αn-pH图及Cu(OH)2条件溶度积pPS-pH图。pc-pH图描述了Cu(OH)2(固)溶解平衡时,铜的总离子平衡浓度与pH值关系,pH值为7.32~10.68时Cu(OH)2的溶解度最小;αn-pH图指出了各种羟合配离子分率与pH值关系,每种羟合配离子都有其最佳的存在pH值范围;Cu(OH)2(固)的条件溶度积pPS-pH图表明pH在7.0~9.0范围内Cu(OH)2(固)的条件溶度积最小。研究结果可为中和水解法从含重金属废水中除铜等技术提供理论依据。

Based on thermodynamic equilibrium of coordination chemistry,diagrams for the concentration of complex ions pc-pH,the ratio of copper hydroxy complex ions αn-pH,conditional solubility product of Cu(OH)2 to pH in Cu2+-H2O system,were drawn respectively.The relationship between the equilibrium concentration of total copper ions and pH was shown in Cu2+-H2O system,when dissolution of Cu(OH)2 is in equilibrium.The solubility of Cu(OH)2 is the least when pH=7.32~10.68.The diagram for αn-pH shows that each hydroxy complex ion existed in the system is dependent upon an optimized pH value.The diagram for the conditional solubility product pPS-pH indicates that the pPS reaches minimum when pH=7.0~9.0.The results can provide a theoretical basis for the technology on removal of copper ion from the wastewater by neutralized hydroxylation method.