| 三维网状HZO@SGH对水中氟离子的吸附作用和机制 |
| 摘要点击 1823 全文点击 709 投稿时间：2017-05-30 修订日期：2017-08-22 |
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| 中文关键词 水合氧化锆 石墨烯水凝胶 氟离子 吸附 拟二级动力学模型 D-R吸附等温模型 |
| 英文关键词 hydrous zirconium oxide graphene hydrogels fluoride adsorption pseudo-second-order kinetic model Dubinin-Radushkevich isotherm model |
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| 中文摘要 |
| 本研究采用均相沉淀法制备得到具有独特三维网状结构的水合氧化锆包覆的石墨烯水凝胶（HZO@SGH）.利用X射线衍射（XRD）、扫描电子显微镜（SEM）、傅里叶红外光谱分析仪（FTIR）和X射线光电子能谱分析仪（XPS）对HZO@SGH进行表征，分析其形貌结构和除氟机制.通过批量吸附实验考察HZO@SGH对水中氟离子的吸附性能.结果表明，HZO@SGH对溶液中氟离子的吸附容量明显高于HZO和SGH.拟二级动力学模型能很好地拟合HZO@SGH对氟离子的吸附动力学数据，说明吸附速率主要由化学吸附控制；吸附氟离子过程可由D-R吸附等温模型描述，最大吸附量达31.79mg·g-1，高于部分已报道的含锆复合材料的吸附量.HZO@SGH在较低pH（3~6.5）和含有NO3-、Cl-、低浓度SO42-（≤ 10 mg·L-1）的氟离子溶液中能保持优异的吸附性能.吸附剂制备过程简单环保，易于从溶液中分离而不产生二次污染，是一种潜在的氟离子吸附剂. |
| 英文摘要 |
| Three-dimensional porous composites based on hydrous zirconium oxide and self-assembled graphene hydrogels (HZO@SGH) were successfully synthesized via homogeneous precipitation. HZO@SGH was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) to investigate the morphology and the defluoridation mechanism. The adsorption performance and mechanism of HZO@SGH for fluoride was investigated via batch adsorption experiments. The results revealed that the adsorption capacity of HZO@SGH for fluoride was obviously higher than that of HZO or SGH singly. The adsorption data for fluoride onto HZO@SGH complied with the pseudo-second-order kinetic model, indicating that the adsorption rate was mainly controlled by chemical adsorption. The adsorption process could be described well with the Dubinin-Radushkevich isotherm model, as the maximum adsorption capacity was approximately 31.79 mg·g-1, which is higher than that of some zirconium-containing adsorbents, as previously reported. HZO@SGH showed excellent adsorption properties in the fluoride solution contained NO3-, Cl-, and a low concentration of SO42- (≤ 10 mg·L-1) at low pH (3-6.5). The preparation of HZO@SGH was convenient and environmentally friendly, as it was easily separated from the fluoride solution and did not cause secondary pollution. Hence, the prospect of HZO@SGH in practice was brilliant. |
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