Zhang Lingfan, Zhu Tianyi, Liu Xin, Zhang Wenqing
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China; Research Center of Analysis and Test, East China University of Science and Technology, Shanghai 200237, PR China.
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
J Hazard Mater. 2016 May 5;308:1-10. doi: 10.1016/j.jhazmat.2016.01.015. Epub 2016 Jan 12.
Since most existing arsenic removal adsorbents are difficult to effectively remove arsenite (As(III)), an urgent need is to develop an efficient adsorbent for removing As(III) from contaminated water. In this study, a novel ultrafine nanobiosorbent of cerium modified chitosan (Ce-CNB) with simultaneous oxidation and adsorption As(III) performance has been successfully developed. The resulting Ce-CNB with or without As(III) adsorption was characterized by FTIR, XRD, SEM, EDS, TEM, EMI and XPS analysis. Batch of adsorption experiments were performed to investigate the effects of various conditions on the As(III) adsorption. The adsorption behaviors were well described by the Langmuir isotherm and the pseudo-second-order kinetic model, with the maximum adsorption capacities of 57.5 mg g(-1). The adsorption mechanisms for As(III) were (i) formed monodentate and bidentate complexes between hydroxyl groups and arsenite; and (ii) partial As(III) oxidized to As(V) followed by simultaneously adsorbed on the surface of Ce-CNB. This novel nanocomposite can be reused while maintaining a high removal efficiency and can be applied to treat 5.8L of As(III)-polluted water with the effluent concentration lower than the World Health Organization standard, which suggests its great potential to remove As(III) from contaminated water.
由于大多数现有的除砷吸附剂难以有效去除亚砷酸盐（As(III)），因此迫切需要开发一种高效吸附剂用于去除受污染水中的As(III)。在本研究中，成功开发了一种具有同步氧化和吸附As(III)性能的新型铈改性壳聚糖超细纳米生物吸附剂（Ce-CNB）。采用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、能谱分析（EDS）、透射电子显微镜（TEM）、电子顺磁共振（EMI）和X射线光电子能谱（XPS）分析对吸附或未吸附As(III)的Ce-CNB进行了表征。进行了一系列吸附实验以研究各种条件对As(III)吸附的影响。吸附行为可用朗缪尔等温线和伪二级动力学模型很好地描述，最大吸附容量为57.5 mg g(-1)。As(III)的吸附机制为：（i）羟基与亚砷酸盐之间形成单齿和双齿配合物；（ii）部分As(III)氧化为As(V)，随后同时吸附在Ce-CNB表面。这种新型纳米复合材料可重复使用并保持高去除效率，可用于处理5.8L As(III)污染水，出水浓度低于世界卫生组织标准，这表明其在去除受污染水中As(III)方面具有巨大潜力。
