有机质及pH对卡马西平吸附及迁移影响研究

发布时间：2018-03-31 08:00

本文选题：卡马西平　切入点：腐殖酸　出处：《中国地质大学(北京)》2015年硕士论文

【摘要】：为研究有机质及p H对卡马西平在环境中迁移的影响,探索卡马西平在土壤地下水环境中的迁移机制,本研究通过制备不同有机碳含量及p H的高岭土-腐殖酸复合体开展了不同初始浓度的卡马西平的吸附实验,探讨了卡马西平在有机矿质复合体上的吸附行为特征,在此基础之上,通过控制不同溶解性有机质的含量及组分开展了卡马西平迁移模拟柱实验研究,分析了溶解性有机质对卡马西平迁移特征的影响,论文主要得出以下几个结论:(1)p H影响实验结果表明,p H是通过影响腐殖酸来影响高岭土-腐殖酸复合体对卡马西平吸附的,随有机质含量增大,p H对Kd增大趋势的影响表现为p H=7p H=4p H=10。这一现象的原因是随p H由4增到10,腐殖酸由沉聚态向自由迁移态转变,吸附点位逐渐增多;而腐殖酸及高岭土上活性基团随p H增高去质子化作用增强,导致对卡马西平的吸附减弱,两个因素共同影响导致此结果。(2)随复合体中有机碳含量的增加,腐殖酸在高岭土表面都呈三层叠加,不同p H条件下,三层腐殖酸在复合体中所占含量不同,而这会影响到复合体吸附性质。(3)柱实验结果表明,石英砂对卡马西平有一定的吸附作用,且DOM的加入增强了卡马西平在石英砂柱中的滞留,且浓度越高阻滞作用越强;浓度相同时,亲水组分比DOM对卡马西平的阻滞作用弱。原因是DOM的加入提供了吸附的中间媒介,石英砂表面的硅烷醇基团(Si-OH)作为主要的活性吸附位会和DOM形成了吸附从而间接提高了卡马西平的吸附量;而DOM亲水组分与石英砂吸附作用较强而在初期占据了大量吸附点位,导致实验前期卡马西平未被吸附,表现为阻滞因子与原DOM存在时相比较小。(4)在解吸实验中,各柱解吸率分别为54.09%,50.96%,26.42%和37.54%,此结果表明DOM浓度越高,解吸过程越难;且当DOM浓度相同时,与原DOM溶液相比,有亲水组分存在的石英砂柱解吸率较高。此结果表明卡马西平的解吸存在一定滞后性。这一原因是CBZ进入石英砂及DOM分子的微空隙,束缚其中不能被解吸。
[Abstract]:In order to study the effect of organic matter and pH on the migration of carbamazepine in the environment, the migration mechanism of carbamazepine in soil and groundwater was explored. In this study, the adsorption experiments of carbamazepine with different initial concentrations of carbamazepine were carried out by preparing kaolin humic acid complexes with different organic carbon contents and pH, and the adsorption behavior of carbamazepine on organic mineral complexes was discussed. On this basis, the effects of dissolved organic matter on the migration characteristics of carbamazepine were analyzed by controlling the contents and components of different dissolved organic matter. The main conclusions of this paper are as follows: the experimental results show that the influence of H on the adsorption of carbamazepine to carbamazepine is affected by the influence of humic acid on the adsorption of carbamazepine by the kaolin humic acid complex. With the increase of organic matter content, the effect of pH on KD increasing trend is as follows: (1) the reason of this phenomenon is that with pH increasing from 4 to 10, humic acid changes from precipitation state to free migration state, and adsorption sites increase gradually. However, the adsorption of carbamazepine on humic acid and kaolin increased with the increase of pH, which led to the decrease of carbamazepine adsorption. Three layers of humic acid were superimposed on the surface of kaolin. Under different pH conditions, the content of three layers of humic acid in the complex was different, which would affect the adsorption properties of the complex. The addition of DOM enhanced the retention of carbamazepine in quartz sand column, and the higher the concentration of carbamazepine was, the stronger the blocking effect was, and when the concentration was the same, the retention of carbamazepine in quartz sand column was increased with the addition of DOM. The effect of hydrophilic component on carbamazepine was weaker than that of DOM. The reason was that the addition of DOM provided the intermediate medium for adsorption. Si-OH) on the surface of quartz sand, as the main active adsorption site, forms adsorption with DOM, which indirectly increases the adsorption capacity of carbamazepine, while the hydrophilic component of DOM has strong adsorption with quartz sand and occupies a large number of adsorption sites in the initial stage. In the desorption experiment, the desorption rates of carbamazepine were 54.09% and 37.54%, respectively. The results showed that the higher the concentration of DOM, the more difficult the desorption process was. When the concentration of DOM was the same, the desorption rate of quartz sand column with hydrophilic component was higher than that of the original DOM solution. The results showed that the desorption of carbamazepine had some lag, which was due to the entry of CBZ into quartz sand and the microvoid of DOM molecule. The binding cannot be desorbed.
【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】：X50

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