β-FeOOH的合成及其对阴离子染料酸性橙Ⅱ的吸附特性

SYNTHESIS OF β-FeOOH AND ADSORPTION MECHANISM OF ANIONIC DYES ACIDIC ORANGE Ⅱ

采用简单的水热法合成棒状β-FeOOH,用于去除水中阴离子染料酸性橙Ⅱ(AOⅡ)。利用扫描电镜(FE-SEM)、X射线衍射仪(XRD)、粒径和比表面积(BET)对产物进行表征,研究了吸附动力学和等温线模型,考察了pH值、初始浓度和吸附剂载量对吸附效果的影响。结果表明:吸附剂对AOⅡ在15,35,55℃条件下最大吸附量分别为284. 90,283. 29,277. 78 mg/g;吸附过程符合准二级动力学模型和Langmuir模型,吸附过程主要是单分子层吸附;在酸性和中性条件下有利于吸附;当AOⅡ初始浓度在200～500 mg/L时,吸附量随着初始浓度的增大而增加;当β-FeOOH载量为0. 015 g时,吸附效率最高。

Rodlike β-FeOOH adsorbents were fabricated via a hydrothermal process, to be used for the removal of anionic dye acid orange Ⅱ(AOⅡ) in aqueous solutions.The adsorbent was characterized by scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD) and particle size and specific surface area (BET), the adsorption kinetics and isotherm model were studied, and the adsorption performance by pH, initial concentration of AOⅡ and dosage of composite adsorbents was investigated.The results indicated that the maximum adsorption capacity of the adsorbent to AOⅡ was 284.90, 283.29, 277.78 mg/g at 15, 35, 55 ℃, respectively;the adsorption process conformed to quasi second-order kinetic model as well as Langmuir model, and the adsorption process was mainly monolayer adsorption;it was favorable for adsorption under acidic and neutral conditions;when the initial concentration of AOⅡ was 200~500 mg/L, the adsorption amount increased with increase of the initial concentration;when the β-FeOOH load was 0.015 g, the adsorption efficiency was the highest.