Liu Jingliang, Cao Jingjing, Hu Yaojuan, Han Yuxiang, Zhou Juan
School of Environmental Science, Nanjing Xiaozhuang University, Nanjing 211171, China E-mail:
School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China.
Water Sci Technol. 2017 Dec;76(11-12):2867-2875. doi: 10.2166/wst.2017.412.
Phosphate is generally considered to be one of the nutrients for plants which may cause eutrophication of the aquatic environment. In this study, a CeO-functionalized FeO@SiO core-shell magnetic nanomaterial (denoted as FeO@SiO-CeO) was prepared and used as the adsorbent to remove phosphate from water. The adsorbents were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and N adsorption/desorption isotherms. Characterization results show that the particle size is around 8.63 nm, Brunauer-Emmett-Teller (BET) surface area is 179.7 m · g and the pore volume is 0.39 cm · g for magnetite FeO@SiO-CeO. The adsorbents could be rapidly separated under an external magnetic field. Batch adsorption tests show that the FeO@SiO-CeO adsorbent exhibited high adsorption affinity for phosphate. Additionally, phosphate adsorption isotherms over the adsorbents could be well described by the Langmuir model, suggesting monolayer adsorption, and phosphate adsorption kinetics followed the pseudo-second-order kinetics. Moreover, increasing pH led to suppressed phosphate adsorption, and phosphate adsorption slightly increased with ionic strength.
磷酸盐通常被认为是可能导致水生环境富营养化的植物养分之一。在本研究中，制备了一种CeO功能化的FeO@SiO核壳磁性纳米材料（记为FeO@SiO-CeO）并用作吸附剂以去除水中的磷酸盐。通过X射线衍射、透射电子显微镜、X射线光电子能谱和N吸附/脱附等温线对吸附剂进行了表征。表征结果表明，磁铁矿FeO@SiO-CeO的粒径约为8.63 nm，比表面积（Brunauer-Emmett-Teller，BET）为179.7 m²·g，孔容为0.39 cm³·g。吸附剂在外加磁场作用下可快速分离。批量吸附试验表明，FeO@SiO-CeO吸附剂对磷酸盐表现出高吸附亲和力。此外，吸附剂上的磷酸盐吸附等温线可用Langmuir模型很好地描述，表明为单层吸附，且磷酸盐吸附动力学遵循准二级动力学。此外，pH升高导致磷酸盐吸附受到抑制，而磷酸盐吸附随离子强度略有增加。
