载锆蒙脱石对蔗糖溶液中没食子酸的吸附特性分析

该研究以氧氯化锆和蒙脱石为原料，通过共沉淀法制备载锆蒙脱石。通过扫描电镜（SEM）、傅里叶红外光谱（FT-IR）、X射线衍射（XRD）、X射线光电子能谱（XPS）和比表面积分析（BET）研究改性和吸附对载锆蒙脱石表观结构和表面基团的影响，并考察了载锆蒙脱石对蔗糖溶液的吸附特性。表征结果显示，载锆蒙脱石相较于蒙脱石表面更加粗糙，比表面积达到了204.47 m2/g，是改性前的3.39倍；表面有纳米小颗粒堆积，FT-IR和XPS结果证明氧化锆成功负载到蒙脱石表面，载锆蒙脱石等电点为7.39。吸附试验表明载锆蒙脱石吸附量相较于蒙脱石吸附量提高了102.54%，载锆蒙脱石对蔗糖溶液中没食子酸吸附的最佳pH为7.0，时间为300 min时达到平衡。吸附过程可以准二级吸附动力学模型和Langmuir等温吸附模型准确描述，饱和吸附量达到129.87 mg/g；热力学研究表明吸附过程为吸热过程，能自发进行。经过5次再生后，载锆蒙脱石可以保持初次吸附量的80%以上。吸附过程主要通过静电引力和氧化锆的配位离子交换吸附没食子酸。综上所述，载锆蒙脱石对蔗糖溶液中没食子酸具有良好的吸附性能，是一种有前景的糖用吸附剂。

Analysis of Adsorption Characteristics of Zirconium-loaded Montmorillonite on Gallic Acid in Sucrose Solution

In this study, zirconium chloride and montmorillonite were used as raw materials to prepare zirconium-loaded montmorillonite by coprecipitation. The effects of modification and adsorption on the surface structure and surface group of zircalmontmorillonite were studied by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and specific surface area analysis (BET). The adsorption properties of the montmorillonite on sucrose solution were investigated. The results showed that the surface of zirconium loaded montmorillonite was coarser than that of montmorillonite, with a specific surface area of 204.47 m2/g, which was 3.39 times of the former; nano particles accumulation was observed on the surface. FT-IR and XPS results showed that zirconia was successfully loaded on the surface of montmorillonite, and the isoelectric point of zirconia loaded montmorillonite was 7.39. The adsorption test showed that the adsorption capacity of zircalmontmorillonite was 102.54% higher than that of montmorillonite, and the optimum pH and equilibrium time of adsorption on gallic acid from sucrose solution were 7.0 and 300 min, respectively. The adsorption process could be described accurately by the quasi second-stage adsorption kinetic model and Langmuir isotherm adsorption model, and the saturated adsorption capacity reached 129.87 mg/g; the thermodynamic research showed that the adsorption process was endothermic and can proceed spontaneously. After 5 times of regeneration, zirconium loaded montmorillonite can maintain more than 80% of the initial adsorption capacity. Gallic acid was mainly adsorbed by electrostatic attraction and coordination ion exchange of zirconia. In conclusion, zircalmontmorillonite exhibited good adsorption performance for gallic acid in sucrose solution, and it may be a promising adsorbent for sugar engineering.