| 巯基改性海泡石吸附水中的Hg(Ⅱ) |
| 摘要点击 2670 全文点击 1796 投稿时间：2015-09-23 修订日期：2016-01-08 |
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| 中文关键词 海泡石 巯基改性 汞 吸附动力学 吸附热力学 |
| 英文关键词 sepiolite sulfydryl modification mercury adsorption thermodynamics adsorption kinetics |
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| 中文摘要 |
| 为发展高效低廉的重金属废水处理技术、促进海泡石的资源化利用,利用巯基乙酸改性天然海泡石,并对改性材料进行扫描电镜、X-射线衍射、比表面、Zeta电位和红外光谱分析;采用静态吸附实验,研究了改性海泡石对水中Hg(Ⅱ)的吸附动力学和热力学特征.结果表明,通过有机改性向海泡石中引入了巯基,改性海泡石的表面变得更加光滑,空隙增多,且带有更多的负电荷,有利于提高其对Hg(Ⅱ)的吸附能力.改性海泡石吸附水中Hg(Ⅱ)的最佳pH为6, 30℃时可在60 min内达到吸附平衡,吸附过程符合假二级动力学方程,初始吸附速率常数为0.063 mg·(g·min)-1;吸附热力学特征可以用Langmuir等温吸附模型很好地描述,改性海泡石对Hg(Ⅱ)的最大吸附量为3.256 mg·g-1;该吸附过程为自发进行的吸热过程,是物理吸附和化学吸附共同作用的结果,但以物理吸附为主. |
| 英文摘要 |
| In order to develop highly efficient and low-cost treatment technique for heavy metal wastewater and promote the resource utilization of sepiolite, natural sepiolite was modified by using thioglycollic acid and characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), specific surface, Zeta potential and infrared spectrum (IR) analysis, and the adsorption kinetic and thermodynamic characteristics of the modified sepiolite to Hg(Ⅱ) in water were studied by static adsorption experiments. The results showed that sulfydryl groups were grafted onto sepiolite, and the surface of the modified sepiolite became smoother with more gaps and negative charges to improve the adsorption ability for Hg(Ⅱ). The optimal pH for Hg(Ⅱ) adsorption on the modified sepiolite was 6, and the adsorption process reached equilibrium in 60 min at 30℃. This process could be described by the pseudo second-order kinetic equation, and the initial adsorption rate constant was 0.063 mg·(g·min)-1. The adsorption thermodynamic characteristics could be well described by Langmuir isothermal adsorption model, and the maximum adsorption capacity was 3.256 mg·g-1. The investigation revealed that the adsorption process was a spontaneous endothermic process, resulting in physical adsorption and chemical adsorption, which was dominated by physical adsorption. |
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