煤矸石制备多孔级ZSM-5分子筛及吸附性能研究

Preparation of Porous ZSM-5 Molecular Sieve from Coal Gangue and Study on Its Adsorption Performance

摘要: 本实验是以煤矸石为铝源和硅源，用硅溶胶为补充硅源，四丙基溴化铵(TPABr)为模板剂，按照SiO₂:Al₂O₃:TPABr:NaOH:H₂O = 50:1:2:4:1300的摩尔比配置的混合物，加入反应釜内在180℃反应72 h，将得到的产物离心洗涤至中性，过滤干燥并在550℃烧制5 h最后得到分子筛原样。并将烧制后的分子筛进行XRD、SEM和TEM表征分析。考察了分子筛在不同的情况下对亚甲基蓝的吸附效果。结果表明，当亚甲基蓝浓度为1 mg/L，投加分子筛的浓度为1.2 g/L，振荡时间为100 min，pH为10，温度为50℃时，亚甲基蓝的脱色率最高达到了95.3%。吸附等温线与吸附动力学实验研究后发现当利用Langmuir方程拟合时R²为0.418，而利用Freundlich方程时R²为0.908，所以分子筛对亚甲基蓝的吸附比较符合Freundlich方程，并且通过Lagergren动力学方程拟合后得出R²为0.95409，得出多级孔ZSM-5分子筛吸附属于物理吸附。

Abstract: In this experiment, coal gangue is used as the aluminum source and silicon source, silica sol is used as the supplementary silicon source, tetrapropyl Ammonium bromide (TPABr) is used as the template, and the mixture is prepared according to the molar ratio of SiO₂:Al₂O₃:TPABr:NaOH:H₂O = 50:1:2:4:1300. The mixture is added into the reactor to react at 180˚C for 72 h, the obtained product is centrifugally washed to neutral, filtered and dried, and fired at 550˚C for 5 h to finally obtain the original molecular sieve sample. And the calcined molecular sieves were characterized and analyzed by XRD, SEM, and TEM. The adsorption effects of molecular sieves on methylene blue under different conditions were investigated. The results show that when the concentration of methylene blue is 1 mg/L, the concentration of molecular sieve is 1.2 g/L, the shaking time is 100 min, the pH is 10, and the temperature is 50˚C, the maximum decolorization rate of methylene blue is 95.3%. After the experimental study of adsorption Contour line#Temperature and related subjects and adsorption kinetics, it was found that R² was 0.418 when using Langmuir equation to fit, while R² was 0.908 when using Freundlich equation, so the adsorption of methylene blue on molecular sieve was in line with Freundlich equation, and R² was 0.95409 after fitting through Lagergren kinetic equation, indicating that the adsorption of multistage pore ZSM-5 molecular sieve was physical adsorption.