pH值对纳米羟基磷灰石吸附水体中稀土离子影响的研究

[目的]研究pH值对纳米羟基磷灰石吸附水体中稀土离子的影响。[方法]用热分解法合成羟基磷灰石(HAP),并研究合成样品的组成、粒径和形状,进行HAP的溶解和修复试验。[结果]结果表明,样品为纯相HAP,形状为球形,粒径为60~80 nm。当溶液pH≤3时,HAP可迅速溶解,且在60 min内将REEs3+全部转化为沉淀;当溶液pH≥4时,HAP的溶解速度和REEs的去除率均明显下降。HAP修复受到稀土离子污染水体的产物主要是稀土磷酸盐,溶液pH值为4、P/REEs为15/5是最佳修复条件。[结论]HAP对水溶液中稀土离子的去除受诸多因素影响。

Study on the Influence of pH Value on Nano-hydroxyapatitev Adsorption of Rare-earth Ions in Polluted Water

[Objective] The aim of this paper was to study the effect of pH value on nano-hydroxyapatitev adsorption rare-earth ions in polluted water.[Method] Hydroxyapatite(HAP) was prepared by the pyrolysis method.The fourier transform infrared spectroscopy(FTIR),X-ray diffractometry(XRD) and transmission electron microscopy(TEM) was used to confirm the compostion and shape of syntheticed HAP.The experiment of dissolution and rehab of HAP was carried on.[Result]The results indicated that the HAP abtained was purity-phased and the diameters was about 60-80 nm with a spherical shape.The HAP remediation of contaminated waters by REEs experiments showed under pH-constant system at 3 and below,the dissolution rate of HAP was rapid,and complete conversion of REEs3 to precipitation within 60 min.The dissolution rate of HAP decreased with increasing pH value,and the transformation was incomplete at pH value of 4 and above.In the constant pH systems XRD analysis indicated that rareearthapatite was the primary reaction product,the optimal conditions of rehab was pH value of 4 and P/REEs of 15/5.[Conclusion] HAP to the removal of rare-earth ions in water solution is affected by many factors.