复合吸附材料TLA的制备及其砷氟共除性能的研究

以硫酸钛、硝酸镧和活性炭为原料,制备了新型的TLA复合吸附剂.比较了TLA和活性氧化铝除砷除氟吸附等温线、吸附动力学和pH对除砷除氟效果的影响;通过X射线衍射仪(XRD)和扫描电镜(SEM)对吸附剂进行了表征,并对吸附机理进行了探讨.结果表明,TLA对砷氟的吸附容量显著优于活性氧化铝.在pH为7,砷氟单独存在时,TLA对砷和氟的Langmuir吸附容量分别是30.3mg.g-1和27.8mg.g-1;当砷氟共存时,TLA对砷和氟的Langmuir吸附容量分别是25.1mg.g-1和17.0mg.g-1.TLA对砷、氟的吸附符合拟二级动力学方程.溶液pH值显著影响砷、氟去除效果.电荷分布多位络合模型(Charge-distribution multisite complexation model,CDMUSIC)能准确模拟砷、氟的吸附行为.

Preparation of a titanium-lanthanum-activated carbon adsorbent and its adsorption of coexisting arsenate and fluoride

An effective adsorbent for simultaneous arsenate and fluoride removal from drinking water was prepared by loading titanium and lanthanum on activated carbon (TLA). The adsorption isotherm, kinetics, pH effect were investigated and compared with that of activated alumina (AA). X-ray diffraction and scanning electron microscopy were employed to characterize TLA. The results show that TLA has a significantly higher adsorption capacity than AA. The adsorption capacity of TLA determined using Langmuir isotherm at neutral pH was 30.3 mg·g-1and 27.8 mg·g-1 for As(V) and F, respectively. The adsorption capacity was reduced to 25.1 mg·g-1 and 17.0 mg·g-1 for As(V) and F, when the anions coexisted. The adsorption follows pseudo-second order kinetics. The charge-distribution multisite complexation model can be used to precisely describe the As(V) and F adsorption behavior.