蒙脱土和高岭土对吉非罗齐的吸附特征及影响因素研究

发布时间：2018-07-03 15:11

本文选题：粘土矿物 + 吉非罗齐　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：在再生水回灌过程中,其中所含的药物及个人护理用品(PPCPs)会产生地下水污染风险。因而研究这些污染物在土壤中的吸附特征将会为地下水污染风险评价提供重要的参考信息。本研究选择了水环境中频繁检测到的血脂调节药-吉非罗齐为PPCPs的代表,通过批实验方法,结合X射线衍射和傅里叶转换红外光谱表征手段,研究了土壤中广泛存在的两种粘土矿物蒙脱土和高岭土对吉非罗齐的吸附。主要得出以下结论:(1)蒙脱土和高岭土对吉非罗齐的吸附量均随溶液初始p H(3~11)的增大而减小,且在p H为3时达到最大,最大吸附量分别为0.111 mg/g和0.263 mg/g。溶液p H变化通过改变吉非罗齐的存在价态及粘土矿物的表面电荷特征来影响吸附。较高p H(4~11)条件下,两者之间存在较强的静电斥力而抑制吸附。(2)无机离子种类和强度会对粘土矿物吸附吉非罗齐产生影响,既包括促进作用,也包括抑制作用,这与溶液中离子引入引起的粘土矿物与吉非罗齐之间静电斥力减弱、盐析效应有关。较高离子强度(0.05 M~1 M)下,Ca2+与吉非罗齐竞争蒙脱土上吸附点位的能力强于Na+。与Na Cl相比,Ca Cl2作为背景溶液对粘土矿物吸附吉非罗齐的促进作用更强,表明阳离子键桥对吸附具有重要影响。(3)溶解性有机质(DOM)对粘土矿物吸附吉非罗齐的影响与其浓度及粘土矿物的类型有关。DOM对高岭土吸附吉非罗齐的影响程度比蒙脱土要小,这与其在高岭土表面有较高的亲和性,与吉非罗齐竞争表面吸附点位的能力更强有关。实验及X射线衍射和傅里叶转换红外光谱表征结果表明,DOM的引入,使得粘土矿物-DOM-吉非罗齐三者之间主要发生了共吸附作用。(4)蒙脱土和高岭土的吸附特征不同,同等条件下高岭土对吉非罗齐的吸附量普遍要比蒙脱土大,这与高岭土具有较小的表面电荷密度以及蒙脱土与吉非罗齐之间更强的静电斥力有关,从而使高岭土更能控制吉非罗齐迁移至地下水的污染风险。
[Abstract]:In the process of recharge of reclaimed water, the medicines and personal care products (PPCPs) may cause groundwater pollution risk. Therefore, studying the adsorption characteristics of these pollutants in soil will provide important reference information for groundwater pollution risk assessment. In this study, the frequently detected lipid regulator in water environment, Gifetozil, was chosen as the representative of PPCPs. The method of batch experiment combined with X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) was used to characterize PPCPs. The adsorption of two kinds of clay minerals, montmorillonite and kaolin, on Jifeilozi was studied. The main conclusions are as follows: (1) the adsorption capacity of montmorillonite and kaolinite for chiferozil decreases with the increase of initial pH _ (3N _ (11), and reaches the maximum at pH = 3, and the maximum adsorption capacity is 0.111 mg/g and 0.263 mg / g, respectively. The change of pH in solution affects adsorption by changing the valence state of giferozzi and the surface charge characteristics of clay minerals. At higher pH _ (4N _ (11), there is a strong electrostatic repulsive force between them to inhibit adsorption. (2) the type and strength of inorganic ions have an effect on the adsorption of chiferozil by clay minerals, including both promoting and inhibiting effects. This is related to the weakening of electrostatic repulsion between clay minerals and chiferozi caused by ion introduction in solution and salting out effect. The ability of Ca ~ (2 +) and Jifeilozi to compete for the adsorption sites on montmorillonite is stronger than that of Na at higher ionic strength (0.05 M ~ (-1 M). Compared with NaCl, CaCl _ 2 as the background solution can promote the adsorption of chiferozil by clay minerals. (3) the influence of dissolved organic matter (Dom) on the adsorption of chiferozil by clay minerals is related to its concentration and the type of clay minerals. Dom has less effect on the adsorption of chiferozil by kaolin than montmorillonite. This is related to its high affinity on the surface of kaolin and its stronger ability to adsorb on the competitive surface of Jifeilozi. The results of experiment, X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) show that the introduction of Dom leads to the coadsorption of clay mineral -DOM-Jifeilozzi. (4) the adsorption characteristics of montmorillonite and kaolin are different. Under the same conditions, the adsorption capacity of kaolin to jifeilozi is generally larger than that of montmorillonite, which is related to the lower surface charge density of kaolin and the stronger electrostatic repulsion between montmorillonite and giferozil. Thus, kaolin can better control the pollution risk of Jifeiloqi migration to groundwater.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

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