粉煤灰基NaA/NaX双晶型沸石分子筛构建及其协同吸附氨氮性能
Construction of fly ash-based NaA/NaX double crystal zeolite and its synergistic adsorption of ammonia nitrogen
蔡元韬 1王坤 1郭欣辰 1卢莹怡 1张慧琦 1韩熠垚 1谢云龙 2叶向荣2
作者信息
- 1. 浙江师范大学行知学院,化学与材料科学学院,金华 321004
- 2. 浙江师范大学行知学院,化学与材料科学学院,金华 321004;浙江光电子研究院,金华 321004
- 折叠
摘要
以粉煤灰为原料,采用"联合改性三步合成法"——超声辅助碱熔微波晶化法联合废旧玻璃/13X晶种/NaH2PO4浸渍三阶段改性合成沸石分子筛(GFS);作为对比,采用传统碱熔水热法合成沸石分子筛(FS);采用"三步合成法"——超声辅助碱熔微波晶化法合成沸石分子筛(WFS).并采用X射线衍射(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱(FTIR)、能量色散光谱(EDS)、N2吸附-脱附等方法对材料的组成、形貌和结构进行了表征.结果表明,WFS和GFS较FS具有更高的比表面积和发达的介孔、微孔,且沸石分子筛晶型从NaA单晶型转为NaA/NaX双晶型.氨氮吸附实验结果表明,GFS(56.01 mg·g-1)较WFS(49.17 mg·g-1)和FS(39.75 mg·g-1)吸附性能更优,吸附动力学和热力学数据符合二级动力学模型和Langmuir模型,氨氮吸附过程为以离子交换为主的吸附,且为自发放热过程,低温促进氨氮吸附.
Abstract
The synthesis of zeolite molecular sieves(referred to as GFS)using fly ash as a raw material was carried out in three stages.The method employed for this synthesis was called"combined modification three-step synthe-sis",which involved ultrasonic-assisted alkali fusion microwave crystallization combined with waste glass/13X seed/NaH2PO4 impregnation.To compare the results,traditional alkali fusion hydrothermal synthesis was used to synthe-size zeolite molecular sieves(referred to as FS).In addition,zeolite molecular sieves(referred to as WFS)were syn-thesized using the"three-step synthesis"method of ultrasonic-assisted alkali fusion microwave crystallization.The materials were characterized using various techniques including X-ray diffraction(XRD),scanning electron micros-copy(SEM),Fourier-transform infrared spectroscopy(FTIR),energy-dispersive spectroscopy(EDS),and N2 adsorp-tion-desorption analysis to determine their composition,morphology,and structure.The results indicated that WFS and GFS exhibited higher specific surface areas and well-developed mesopores and micropores compared to FS.Additionally,the crystal type of zeolite molecular sieves shifted from NaA single crystal to NaA/NaX twin crystal.Ammonia nitrogen adsorption experiments revealed that GFS(56.01 mg·g-1)showed better adsorption performance than WFS(49.17 mg·g-1)and FS(39.75 mg·g-1).The adsorption of ammonia nitrogen follows the second-order kinet-ics model and the Langmuir model,as indicated by kinetic and thermodynamic data.This process primarily relies on ion exchange and is both spontaneous and exothermic.Lower temperatures enhance the adsorption of ammonia nitrogen.
关键词
联合改性三步合成法/粉煤灰/NaA/NaX双晶型/吸附氨氮Key words
combined modification three-step synthesis/fly ash/NaA/NaX double crystal zeolite/ammonia nitrogen adsorption引用本文复制引用
基金项目
浙江省"尖兵"研发攻关计划(2022C01030)
金华市重点科学技术研究计划(2021-1-020)
出版年
2024
NETL
NSTL
维普
万方数据