【作者】 俞建波；

【导师】 王东田；

【作者基本信息】 苏州科技学院 ， 应用化学， 2011， 硕士

【摘要】 膨润土在自然界储量丰富,其主要成分为蒙脱石。由于蒙脱石自身独特的层状铝硅酸盐结构而具有巨大的吸附潜能。采用适当的方法进行改性,使膨润土中蒙脱石的比表面积得到极大的提高,从而显著地改善其吸附性能。本论文以提高膨润土中蒙脱石的吸附性能并用于去除水中重金属离子为主要研究内容,研究蒙脱石的表面性质与吸附性能的相关性。在传统外源柱撑的基础上,重新分析合成过程,提出内源柱撑的合成新方法。并研究了蒙脱石柱撑后的层间距、比表面积和孔径分布等物理参数。本论文主要研究内容及结论如下:以市售膨润土为原材料,采用内源柱撑的改性法制备柱撑蒙脱石,采用BET方程分析和计算比表面积、孔容、孔径分布等。研究了浆固含量、反应时间、pH和反应温度等因素对蒙脱石比表面积和孔容孔径的影响。研究结果表明:pH和反应温度是影响柱撑蒙脱石比表面积和孔结构参数的主要因素。通过优化柱撑条件,制备出了比表面积和平均孔容分别高达223.12 m²/g和0.4981cm³/g的内源柱撑蒙脱石。与膨润土原土和传统方法制得的柱撑土相比,内源柱撑土吸附性能优异。对汞离子和铅离子溶液,内源柱撑土对其的最佳吸附pH分别为7和6,最佳吸附时间分别为90 min和60 min。在相应的最佳吸附条件下,250 mg内源柱撑土对100 mL浓度都为10 mg/L的汞和铅溶液分别能接近百分之百去除,传统方法制得的柱撑土需300 mg、原土需800 mg才能分别对其几乎完全吸附。即内源柱撑土的吸附能力分别是传统方法制得的柱撑土和原土的1.2倍和3.2倍。准二级动力学方程和Elovich方程能很好地描述内源柱撑土和外源柱撑土对Hg²⁺、Pb²⁺的吸附过程,化学吸附控制了吸附过程的速度。且平衡吸附量qeq与平衡浓度C_eq之间的关系符合Freundlich等温方程。更多还原

【Abstract】 Bentonite is a montmorillonite clay for major compositions and is abundant in nature. Montmorillonite has the huge adsorption potential because of its own unique layered aluminosilicate structure. If we use different methods through the varying modification, the surface area of montmorillonite will be greatly improved, thus its adsorption properties will be significantly improved.This topic’s goal is to improve the adsorption performance of montmorillonite and it will be applied to the removal of metal ions in waste water. The relevance between the surface properties of montmorillonite and its adsorption performance was studied.Based on the external-intercalation which is the traditional method of intercalation , the synthesis process was analyzed and a new method of inner-intercalation was put forward.The interlayer distance of post-pillared montmorillonite,surface area, distribution of pore size and other physical parameters were studied,too. The paper made the following aspects:Bentonite as raw material from commercial, was modified by the inner- intercalation to prepare pillared montmorillonite and according to the nitrogen adsorption - desorption isotherms of pillared samples in 77K , the BET equation was used to analyze and calculate the surface area , pore volume and distribution of pore size. The effect on the surface area and pore size of montmorillonite of slurry solid content, reaction time, pH and reaction temperature during the preparation of pillared montmorillonite, was deeply discussed. The results showed: pH and reaction temperature were the main elements affecting the surface area and pore structure parameters of montmorillonite. Pillared by the optimum conditions, the pillared montmorillonite was prepared with the specific surface area and the average pore volume being as high as 223.12 m² / g and 0.4 981 cm³ /g, respectively.Compared with original soil and pillared montmorillonite by the traditional methods,montmorillonite pillared by method of inner-intercalation obtained high adsorption performance. For the solution of mercury and lead, inner-intercalated bentonite get the best adsorption on pH of 7 and 6, respectively, and best adsorption time of 90 min and 60 min, respectively. Under the best adsorption conditions, 100 mL concentration for 10 mg/L mercury and lead solution can be completely adsorbed by 250 mg inner-intercalated bentonite,while traditional external-intercalation bentonite and the original soil were 300 mg and 800 mg respectively, namely the capability of adsorption of montmorillonite pillared by method of inner-intercalation was 1.2 times and 3.2 times,respectively,more than montmorillonite obtained by traditional methods of external-intercalation and original soil.The adsorption dynamics follows the laws of pseudo second-order kinetics and Elovich equation,and the chemical adsorption control the speed of the adsorption processes. The relationship between adsorption capacity(q_eq) and equilibrium mass concerntration(C_eq) is in accord with the isothermal adsorption equation of Langmuir.更多还原