用于地下水除氟的羟基磷灰石制备及其除氟效能

针对地下水中氟离子的去除分别合成了粉状和球状两种羟基磷灰石,利用红外光谱扫描、电镜扫描、X射线衍射仪、X射线能谱小试实验分析其基本特征,并进一步利用小试实验确定其对水中氟离子的去除效能.结果表明,制备的粉状羟基磷灰石具有较高的纯度,但结晶度相对较低;而球状羟基磷灰石则较为规则、带孔隙的球形颗粒,粒径约为1mm左右.粉状羟基磷灰石对徐州地下水中氟离子的去除容量约为15.2mg/g,且其去除速度较快,主要集中在30min以内;球状羟基磷灰石对地下水中氟离子的去除容量约为7.5mg/g,但其去除过程持续时间较长.利用粉状和球状羟基磷灰石组合的工艺可将地下水中的氟离子浓度降低至0.8~0.9mg/L,且去除效果稳定.综上所述,粉状和球状羟基磷灰石的组合工艺可用于地下中氟离子的去除.

Preparation of the hydroxyapatite to remove fluorine from groundwater and its removal performance

Powdered and spherical hydroxyapatite were prepared in the lab for the removal of fluorine from groundwater, in addition, character and removal effect were determined using infrared spectrometer, scanning electron microscopy instrument, X ray diffraction, X-ray photoelectron spectrometer and batch scale experiment. The results show that, powdered hydroxyapatite prepared in lab had high purity but relatively low crystallinity, while the prepared spherical hydroxyapatite is relatively regular, porous spherical particles with particle size about 1mm. Removal capacity of powdered hydroxyapatite and spherical hydroxyapatite to fluoride from groundwater were about 15.2mg/g and 7.5mg/g respectively, however, the removal process had great difference. Powdered hydroxyapatite could remove most fluorine in 30min, while the process of spherical hydroxyapatite to remove fluorine lasted longer time and needed an interval of more than 8h. The combined process of powdered and spherical hydroxyapatite could decrease the concentration of fluorine in groundwater to 0.8~0.9mg/L stably. In all, the combined process could be used to remove fluorine from groundwater.