高比表面积介孔α-FeOOH的制备及其Sb(Ⅴ)吸附性能

Preparation of mesoporous α-FeOOH with high specific surface area and its adsorption capability to Sb(Ⅴ)

采用水热合成的方法制备了高比表面积介孔α-FeOOH吸附剂,并探究其对水中Sb(Ⅴ)的去除效果。采用XRD、SEM、ATR-FTIR等方法对吸附剂进行了表征。考察了吸附剂投加量、溶液pH对Sb(Ⅴ)去除效果的影响,以及Sb(Ⅴ)吸附过程的动力学和热力学特性。表征结果显示:介孔α-FeOOH具有棒状结构,长度大约为50~100nm,最可几孔径为20nm,比表面积为137.6m2/g。实验结果表明,当初始Sb(Ⅴ)质量浓度为10mg/L、pH为7、介孔α-FeOOH投加量为0.25g/L、吸附时间为2h、吸附温度为25℃时,Sb(Ⅴ)去除率可达100%;pH为4~7时,Sb(Ⅴ)去除率受pH的影响较弱;Sb(Ⅴ)吸附过程符合拟二级动力学模型及Langmuir吸附模型。

An adsorbent mesoporousα-FeOOH with high specific surface area was prepared by hydrothermal method and its removal capability to Sb(Ⅴ)in water was investigated.The adsorbent was characterized by XRD,SEM,ATR-FTIR and so on.The effects ofα-FeOOH dosage and solution pH on Sb(Ⅴ)removal,and the kinetics and thermodynamic characteristics of Sb(Ⅴ)adsorption process were studied.The characterization results indicate that the mesoporousα-FeOOH has a rod-like structure with about 50~100 nm of length,20 nm of most probable pore size and 137.6 m2/g of specific surface area.The experimental results show that theremoval rate of Sb(Ⅴ)can reach 100%when the initial Sb(Ⅴ)mass concentration is 10 mg/L,the pH is 7,theα-FeOOH dosage is 0.25 g/L,the adsorption time is 2 h and the adsorption temperature is 25℃;In the range of pH 4-7,the removal rate of Sb(Ⅴ)is weakly affected by pH;The Sb(Ⅴ)adsorption process conforms to the pseudo second-order kinetic model and the Langmuir adsorption model.