The Preparation And Characterization And Adsorption Performance Of Polyhydroxy Cation Pillared Montmorillonite

Montmorillonite is a clay mineral with expandable layer structure. Mesoporous pillared montmorillonite can be prepare by introducing simple metal cation ions, hydroxyed inorganic metal cations, organic ions, organic molecule, organic polymer. Thus formed pillared montmorillonites have improved capabilities, such as specific surface area, strong surface activity, large aperture, excellent adsorptivity, high thermal stability. It can be used widely as catalysts carriers, selective adsorbents potentially, as well as in the fields of nanocomposite materials.In this dissertation, it studies the preparation and characterization of Fe-Zn pillared montmorillonite and Fe-Zn-Al pillared montmorillonite. Fe-Zn pillared montmorillonite and Fe-Zn-Al pillared montmorillonite are used to adsorb copper ion to study suitable conditions for adsorption property. Fe-Zn pillared montmorillonite and Fe-Zn-Al pillared montmorillonite can be recycled, and they are potential substance for adsorption of environmental pollutants.In the paper, Ca-montmorillonite is used as material, after modifying it with sodium compounds. The main physical property of Ca-montmorillonite and Na-montmorillonite is tested, including the cation exchange capacity (CEC), the expanded volume etc. The result shows that the physical property of Na-montmorillonite is more enhenced than Ca-montmorillonite.Fe-Zn pillared montmorillonite is prepared by ultrasound method using montmorillonite as raw material. The preparation temperature of Fe-Zn pillaring solution, the radio of OH^-/Fe³⁺, the radio of Zn²⁺/Fe³⁺, the radio of Fe³⁺/ montmorillonite are changed during the process of the preparation. According to the analysis of XRD, the optimal conditions are as follows: the preparation temperature of the pillaring solution is 40℃, the radio of OH^-/Fe³⁺ is 2.4, the aging time is 96 h, the radio of Zn²⁺/Fe³⁺ is 0.10, the ratio of Fe⁺ and montmorillonite is 10 and the intercalation temperature is 80℃, respectively. The Fe-Zn-MMT prepared under the optimal conditions has large basal interlayer spacing.Fe-Zn-Al pillared montmorillonite is prepared by ultrasound method using Na-montmorillonite as raw material. The conditions of Fe-Zn-Al-MMT pillaring solution, the intercalation temperature, the quality of Fe-Zn-Al-MMT are changed during the process of the preparation. According to the analysis of XRD,the optimal conditions are as follows: the preparation temperature of the pillaring solution is 40℃, the radio of OH^-/A1³⁺ is 2.6, the aging time is 96 h, the radio of (Fe³⁺+Zn²⁺)/Al³⁺ is 0.10, the ratio of Al³⁺ and montmorillonite is 10 , the intercacation temperature is 80℃, respectively. The Fe-Zn-Al-MMT prepared under the optimal conditions has large basal interlayer spacing.The X-ray diffraction (XRD)analysis, Fourier transform infrared (FTIR) spectra, differential scanning calorimetry (DSC) analysis, differential thermal analysis (DTA), scanning electron microscope (SEM) and Transmission electron microscopy (TEM) analysis indicates that the ion and zinc, Al₁₃ enter into the interlayer of montmorillonite but do not destroy the crystal structure of montmorillonite.The performance of montmorillonite interlayer compounds is compared in treating wastewater containing copper ion. The results show as follows: Fe-Zn-Al-MMT has better treatment effects than Fe-Zn-MMT; the copper ion removal rate reaches the best in the case of stirring time 30min, feeding amount 0.5g; the Fe-Zn-MMT and Fe-Zn-Al-MMT can be recycled and have well adsorption in treating wastewater containing copper ion, and they are potential substance for adsorption of environmental pollutants.