【作者】 吕学谦；

【导师】 常玥；

【作者基本信息】 西北师范大学 ， 高分子化学与物理， 2009， 硕士

【摘要】 随着复合材料科学的不断发展,人们对经改性处理的无机复合材料的需求大幅增加。由于其储量丰富、价格低廉、物理化学性质稳定等优点,将粘土经过不同方法改性制备不同性能的复合材料引起人们的广泛关注。经有机改性后,粘土的内、外表面由亲水性转变为疏水性,使得粘土与有机物之间的亲和性增强,不但能够有效地去除废水中的有机物,还可以进一步扩大粘土的应用范围。本文在坡缕石性质、改性方法及应用的基础上,主要做了以下工作:1、采用微波辅助法和常规法制备了阴-阳离子表面活性剂改性坡缕石吸附剂,并且对其进行了元素分析、红外光谱和扫面电子显微镜的表征。2、研究了阴-阳离子表面活性剂改性坡缕石吸附剂对苯、对苯二酚、对硝基苯酚和甲基橙的吸附性能,考察了阳离子表面活性剂的种类、阴阳离子表面活性剂的配比、表面活性剂的用量、微波辐照时间吸附剂用量、pH值及温度等因素对废水中苯、对苯二酚、对硝基苯酚和甲基橙的去除效果的影响。通过和原土对比实验发现,阴-阳离子表面活性剂改性坡缕石对苯、对苯二酚、对硝基苯酚和甲基橙具有较好的吸附作用。3、吸附剂对苯的最大去除率为93.66%,最大吸附容量为1275.57mg·g-1。采用Langmuir方程和Freundlich方程对吸附等温线进行拟合,两种模型均可描述吸附过程,但Langmuir方程的拟合效果更好。热力学计算发现吸附过程为自发的吸热过程,吸附的焓变和熵变分别为61.05KJ·mol-1和223.73 J·mol-1·K-1,吸附自由能随着温度的升高而减小。4、改性坡缕石对对苯二酚的最大吸附容量为137.47 mg·g-1。等温吸附测量表明吸附过程可以用Langmuir方程进行较好拟合。热力学函数计算表明,阴-阳离子表面活性剂改性坡缕石对对苯二酚的吸附是自发的放热过程,吸附热和熵变分别为-93.58 KJ·mol-1和-299.32 J·mol-1·K-1,吸附自由能随温度的升高而增加。5、吸附剂对对硝基苯酚的最大吸附容量为137.74 mg·g-1。用Langmuir方程和Freundlich方程描述该吸附过程中,Langmuir方程的拟合效果更好。热力学计算发现吸附过程为为自发的吸热过程,吸附的焓变和熵变分别为59.16 KJ·mol-1和205.48 J·mol-1·K-1。吸附自由能随着温度的升高而减小,吸附过程为为拟二级动力学过程。6、吸附剂对甲基橙的最大吸附容量为127.60 mg·g-1,最大去除率可达98.80%。等温吸附测量结果表明,吸附过程可以用Langmuir等温吸附模型进行更好的模拟。热力学函数计算表明,自制吸附剂甲基橙的吸附是自发的放热过程,吸附热和熵变分别为-8.80 KJ·mol-1和-18.01 J·mol-1·K-1,吸附自由能随温度的升高而增加。更多还原

【Abstract】 With the development of the composite materials, the requirement of the modified inorganic composite materials was increased rapidly. Because of its advantages of abundant reserves、low prices and the stability of the physical and chemical properties, the different composite materials prepared from clays attracted extensive attention. After being modified by organic materials, the inner and outer sueface of the clay transfer from hydrophobic to hydrophilic, the affinity between the clay and the organic materials is increased, which can not only effectively remove the organic matter in wastewater, but also to further expand the scope of application of clay. Based on the review of the properties, modified methods and the applications of the palygorskite, the dissertation include following contents:1. The anion-cation surfactants modified palygorskite were preparaed by adopting microwave assistant and the convention methods, and there were characterized by element analysis, FTIR spectra and the SEM.2. The sorption property of modified palygorskite for benzene,hydroquinone, p-nitrophenol and methyl orange in water were studied. The effects of type of the cation surfactant, the ratio of anionic surfactant to cationic surfactant, amount of the surfactant, microwave irradiation time, the amount of the adsorbent, pH, temperature and sorption time on the removal of benzene, hydroquinone, p-nitrophenol and methyl orange were investigated. Comparing to natural palygorskite, the adsorption capacity of anion-cation modified palygorskite is higher in the treatment of benzene, hydroquinone, p-nitrophenol and methyl orange.3. The maximum removal rate of benzene was 93.66% and the maximum adsorption capacity for benzene was 1276.57mg.g-1. The adsorption isotherms were regression analyses with the Freundlich equations and Langmuir equations, but the Langmuir equation is better. Thermodynamic function calculation shows that the adsorption is a spontaneous and endothermic process. Enthalpy and entropy change of the sorption of benzene are 61.05 kJ·mol-1 and 223.73J·mol-1·K-1 , respectively. Free energy of the adsorption decreases with the increase of temperature.4. The maximum adsorption capacity for hydroquinone was 137.47mg·g-1. The adsorption equilibrium was in accordance with the Langmuir isothermal adsorption equations. The thermodynamic parameters were calculated, and the enthalpy(△H) and entropy (△S) of the adsorption were -93.58kJ·mol-1, -299.32J·mol-1·K-1, respectively, which showes that the adsorption is a spontaneous and exothermic process.5. The maximum adsorption capacity for p-nitrophenol is 137.74mg·g-1. The adsorption equilibrium is in accordance with the Langmuir isothermal adsorption equations, but the Langmuir equation is better. Thermodynamic function calculated shows that the adsorption is a spontaneous and exothermic process. The adsorption enthalpy and entropy change of p-nitrophenol are 59.16 kJ·mol-1 and 205.48J·mol-1·K-1, respectively. Free energy of the adsorption increases with increasing of the temperature. The adsorption of p-nitrophenol is a pseudo-second-order process.6. The maximum sorption capacity for methy orange was 121.77mg·g-1,the maximum removal rate of methyl orange was 98.80%. The sorption isotherms were regression analyses with Langmuir equations better. Thermodynamic function calculation shows that the adsorption is a spontaneous and exothermic process. Enthalpy and entropy change of the adsorption of methy orange are -8.80kJ·mol-1 and -18.01J·mol-1·K-1, Free energy of the adsorption increases with the increase of temperature.更多还原