稻壳灰制备介孔分子筛的改性及其吸附性能研究

摘要以稻壳灰为硅源提取二氧化硅合成介孔材料MCM-41，并用三甲基氯硅烷对其进行改性。将改性前后的材料通过X-射线粉末衍射分析（XRD）、N2吸附-脱附、扫描电镜（SEM）和傅里叶变换红外光谱（FTIR）进行表征，并用于吸附模拟废水中的2,4-DNT。结果显示，改性前后的材料均具有长程有序的751方介孔结构和较高的有序度。Freundlich和Langmuir等温吸附模型均能较好地拟合两种材料的吸附等温线。二者的吸附动力学均可以用伪二级动力学方程拟合。溶液中2,4-DNT的去除率与两种材料的投加量均呈正相关关系。改性前材料的吸附效果随pH的升高而降低，而改性后材料的吸附效果在pH=7时最佳。经热力学和动力学分析认为改性后材料的吸附过程既存在物理吸附又存在化学吸附。6019
关键词稻壳灰 MCM-41 改性吸附
毕业设计说明书（论文）外文摘要
Title The modification of mesoporous molecular MCM-41 synthetized from rice husk ash as it’s silica source and their application to adsorption of 2,4-Dinitrotoluene
Abstract
Mesoporous MCM-41 was synthesized using rice husk ash (RHA) as the silica source and then it was modified by reacting with trimethylchlorosilane. These two kinds of material were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), N2 adsorption-desorption and Fourier transform infrared spectroscopy (FTIR). Then they were used to adsorb 2,4-Dinitrotoluene from aqueous solution. Both Freundlich isotherm and Langmuir isotherm could be fitted well with the two kinds of material’s adsorption isotherms. Both the adsorption kinetics could be fitted with pseudo-second kinetic equation well. There was a positive correlation between the removal efficiency and the dosage of both kind of material. For MCM-41, the adsorption capacity was reduced with the increase of pH. But for modified MCM-41, the adsorption capacity was best at pH=7. Analysts believed that both physical adsorption and chemical adsorption exist in the adsorption process of the modified materials.
Keywords RHA MCM-41 modification adsorption
目录

1   引言   1
1.1   2,4-DNT概述   1
1.2   MCM-41概述   1
1.2.1   MCM-41的特点   1
1.2.2   MCM-41的合成   1
1.2.3   MCM-41在吸附方面的应用   2
1.3   稻壳提取SiO2   3
1.3.1   稻壳的组成   3
1.3.2   稻壳制备SiO2的研究进展   4
1.4   本文的工作   5
2   实验部分   6
2.1   仪器设备   6
2.2   实验试剂   6
2.3   检测方法   6
2.4   材料的制备   6
2.4.1   RHMCM-41的合成   6
2.4.2   CH3-MCM-41的制备   7
2.5   材料的表征   7
2.5.1   X-射线粉末衍射分析   7
2.5.2   低温N2吸附-脱附   7
2.5.3   红外光谱分析   7
2.5.4   扫描电镜分析   8
2.6   吸附实验   8
2.6.1   吸附动力学   8
2.6.2   吸附等温线   8
2.6.3   pH的影响   8
2.6.4   投加量的影响   8 稻壳灰制备介孔分子筛的改性及其吸附性能研究:http://www.751com.cn/shengwu/lunwen_3336.html