羟基磷灰石及氟掺杂对UO2＋2的吸附性能研究

摘要

The hydroxyapatite(HA)and fluorine -substituted hydroxyapatite(FHA93,FHA200)were synthesized by the wet chemical precipitation method. The structures of these samples were analyzed by Fourier transform infrared spectroscopy,X-rays diffraction,Thermogravimetric analysis and X-ray pho-toelectron spectra. Meanwhile,we also explored the capacities for removal of uranyl( UO2+2 )from model wastewater. The effects of the different factors such as pH values,initial UO2+2 concentration,adsorption time and temperature on the adsorption of UO2+2 by hydroxyapatite and fluorine-substituted hydroxyapa-tite were examined. The results show that the maximum removal rate of HA,FHA93 and FHA200 is about 99. 5%. The equilibrium adsorption data is found to be well described by Langmuir model,and the pseu-do-second -order rate model fits the adsorption kinetic data. When the pH is ranged with 2 ~7, FHA200 exhibites excellent removal rate of UO2+2 . Furthermore,FHA93 reached the saturated adsorption capacity of 98% in 60 min. The thermogravimetric analysis and anti-acids tests also indicate that the FHA200 has the best thermal stability and acid resistance among these three materials. Accordingly,we found that the fluorine-substituted hydroxyapatite is more suitable for the treatment of UO2+2 -containing waste water.%采用湿化学沉淀法合成粉末状羟基磷灰石（ HA）和氟掺杂羟基磷灰石（ FHA93和FHA200），通过红外光谱、X射线衍射、热失重分析及X射线光电子能谱进行表征，研究了其对模拟废水中UO2＋2的吸附去除性能，考察了pH值、UO2＋2初始浓度、吸附时间和温度等条件对羟基磷灰石和氟掺杂羟基磷灰石去除UO2＋2的影响。结果表明：HA， FHA93和FHA2003种吸附剂对UO2＋2的最大去除率均在99.5%左右；吸附平衡数据符合Langmuir模型，吸附动力学数据与准二阶动力学方程较吻合；FHA200在pH值2~7范围内均有较高的UO2＋2去除率；FHA93在60 min内达到饱和吸附量的98%；热失重分析和耐酸性实验测试结果表明FHA200有更好的热稳定性和耐酸性。因此，氟掺杂羟基磷灰石比羟基磷灰石更适合应用于含UO2＋2废水处理。