羟基磷灰石的粒径及其掺入牙膏后对镉离子吸附作用的研究

Effect of Hydroxyapatite and Dentifrice Containing Hydroxyapatite on Aqueous Cadmium Adsorption

研究不同粒径羟基磷灰石(hydroxyapatite,HA)及掺入牙膏后对水溶液中镉离子的吸附作用。将粒径为20 nm、60 nm、12μm的HA及按质量分数3%掺入牙膏后分别配制成一系列浓度的悬液,加入0.2 mg/L的镉离子溶液中,静置24 h后取上清液用电感藕合等离子发射光谱仪测定残余镉离子的量,计算HA及掺HA牙膏对镉离子的吸附率。3种粒径的HA对镉离子的吸附率均达70%以上,掺3种粒径的HA牙膏对镉离子的吸附率平均达50%以上,均以20 nm HA及掺20 nm HA牙膏的吸附率最高。纯HA及掺HA的牙膏对镉离子均有一定的吸附能力,以粒径最小的20 nm吸附率最好,掺HA牙膏吸附率有所下降。

The effect of hydroxyapatite（ HA） particles with various grain sizes and dentifrice containing hydroxyapatite on aqueous cadmium adsorption was studied. Three kinds of suspensions were prepared by adding dentifrice to HA suspensions containing 3% HA with grain sizes of 20 nm,60 nm and 12 μm with different concentrations. Cadmium ion solutions with initial concentration of 0. 2 mg / L were mixed with HA suspensions and dentifrice suspensions respectively,and then were kept still for 24 h. The residual cadmium ion concentration of the supernatant was measured by inductively coupled plasma emission spectrometer,and the sorption rate of cadmium ion was calculated. The sorption rates of cadmium ion of HA particle with 3 grain sizes were above 70%,and 20 nm HA was the best. The sorption rates of cadmium ion of dentifrice containing HA were over 50% by average,and dentifrice containing 20 nm HA was the highest. Pure HA and dentifrice containing HA could absorb cadmium ions. HA with size of 20 nm showed the best sorption property. The sorption property decreased by adding dentifrice.