钇/羟基磷灰石的制备及对含磷废水的净化

以氢氧化钙和磷酸二氢钠为原料制备羟基磷灰石，通过化学沉淀法制备钇/羟基磷灰石复合材料，利用SEM-EDS（扫描电子显微镜）、XRD（X射线衍射）、FTIR（傅里叶变换红外光谱）等表征其晶体结构与形貌，并采用静态吸附实验考察吸附剂的负载比例、pH、吸附时间和初始浓度对磷酸盐的吸附性能的影响。结果显示：羟基磷灰石为分散均匀的稻米状颗粒，XRD图谱显示为典型的羟基磷灰石，钇/羟基磷灰石颗粒发生团聚且粒径变大，特征峰峰强减弱，但未出现新的强特征峰。吸附研究表明：钙与钇的摩尔比为2∶1时吸附效率最高，复合材料的吸附容量随初始浓度的增加而增大，最大吸附量为116.38mg/g，吸附过程符合准二级动力学模型、双室一级动力学模型和Freundlich等温吸附模型，吸附过程由化学吸附主导，随pH在3~9的范围增加，复合材料的吸附效率先增后减，在pH为5~6时达到最大值。

Preparation of yttrium/hydroxyapatite and purification of wastewater containing phosphorus

Nano hydroxyapatite were prepared from calcium hydroxide and sodium dihydrogen phosphate. The yttrium/hydroxyapatite composite were prepared by chemical precipitation method. The composite materials were characterized by numerous techniques including SEM-EDS, XRD and FTIR. The effects of loading ratio, pH, adsorption time and initial concentration on the adsorption performance of phosphate were investigated by static adsorption experiment. The results showed that the nano-hydroxyapatite was uniformly dispersed rice-like particles, and the XRD pattern showed that the nano-hydroxyapatite was typical. Yttrium/hydroxyapatite particles agglomerate and become larger. The intensity of characteristic peaks decreased, but no new strong characteristic peaks appeared. Adsorption studies showed that when molar mass of calcium and yttrium was 2∶1, the adsorption efficiency was the highest. The adsorption capacity of the composite increases with the increase of the initial concentration, and the maximum adsorption capacity was 116.38mg/g. The adsorption process was in accordance with the quasi-second-order kinetic model, the two-chamber first-order kinetic model and the Freundlich isothermal adsorption model. With the increase of pH in the range of 3—9, the adsorption efficiency of composites increases first and then decreases, and then reaches the maximum when pH was 5—6.