人工合成羟基磷灰石对水溶液中Pb~(2+)、Cd~(2+)离子的固定作用

以硝酸钙和磷酸氢二铵为反应物,采用均匀沉淀法制备羟基磷灰石粉体。羟基磷灰石能有效的固定溶液中重金属离子,并讨论了pH值、羟基磷灰石的用量、作用时间、离子的初始浓度及离子间的相互影响。试验结果表明：当羟基磷灰石的浓度为5g/L时,溶液中铅离子浓度和镉离子浓度分别为500 mg/L和30mg/L,常温搅拌30min后。在弱酸性或中性废水中,铅离子去除率可达99．6％以上,镉离子去除率可达到99．9％以上,溶液中残留镉离子浓度低于O．004．mg/L。

Action on immobilization of artificial synthesized HAP on Pb2+ , Cd2+ in solution

Hydroxyapatite(HAP)is prepared by liquid homogeneous precipitation method from Ca(NO_3)_2·4H_2O and (NH_4)_2HPO_4. Aqueous heavy metal ion could be immobilized effectively by HAP. The effect factors on the immobilization, such as pH value, the amount of sample, reaction time, initial concentration of ion and mutual effect of different ion were discussed. The experimental result shows that, when the concentration of HAP is 5 g/L, the concentration of Pb~(2+) and Cd~(2+) are 500 mg/L, 30 mg/L respectively, stirring 30 min at normal temperature, the removing rate of Pb~(2+) and Cd~(2+) are over 99.6% ,99.9% respectively in waste water, the residual concentration of Cd~(2+) is lower than 0.004mg/L.