邻苯二甲酸二丁酯在土壤微生物—矿物界面的吸附行为及机制

发布时间：2018-01-19 01:10

本文关键词： 邻苯二甲酸二丁酯吸附微生物矿物 DMPP　出处：《湖南农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：邻苯二甲酸二丁酯(DBP)作为邻苯二甲酸酯类的一种,是环境中较为常见的环境激素类有机污染物。本文从DBP染毒后的土壤污染样品中筛选出一株对DBP有较高耐受性的微生物伯克霍尔德菌(Burkholderia),研究其对土壤中DBP的吸附行为和机制,及其与三种矿物(针铁矿、高岭土、蒙脱石)组成的复合体系对DBP的吸附行为和机制。在研究Burkholderia对DBP的吸附行为时,从吸附动力学、吸附等温模型拟合、解吸等方面进行分析,并考察了pH值、不同浓度的3,4-二甲基吡唑磷酸盐(DMPP)等因素对菌体吸附DBP的影响,结合傅立叶转换红外光谱(FTIR)对Burkholderia吸附DBP前后的表面基团的变化进行了分析；在研究细菌-矿物复合体系吸附DBP时,考察了复合体系的吸附量(率)和解吸量(率),及细菌矿物之间不同比例、不同DMPP浓度的影响。结合扫描电子显微镜(Scanning Electron Microscope, SEM)观察Burkholderia与三种矿物复合后的表面形貌；同时通过三种复合体系疏水性实测值与预估值之间的对比,进一步阐明了复合体系的吸附机理。通过以上大量实验初步探明了DBP在Burkholderia和三种矿物界面的吸附行为及机制。本文的研究结论有如下几点：(1) Burkholderia吸附DBP的过程符合Freundlich吸附等温模型,相关性R2=0.94,吸附等温式为：qe=2A6×Ce1/1.02。(2)解吸实验发现,Burkholderia对DBP的吸附有物理吸附和化学吸附,其中主要是化学吸附。(3)红外光谱分析结果表明,细菌对DBP的吸附主要是通过C-H的伸缩振动而相互作用在一起的。同时,细菌表面的活性基团和细胞壁也参与了吸附行为。(4)在1：1的混合比例下,复合体对DBP吸附的实测值与理论值之间的差异最大,对DBP吸附的影响较大。细菌-针铁矿和细菌-蒙脱石的实际吸附量比理论值分别提高了1.10 mg/g和1.83 mg/g,而细菌-高岭土则下降了1.16 mg/g。(5)通过扫描电镜观察发现,微生物与三种矿物结合形态不同,与针铁矿和蒙脱石结合紧密,与高岭土结合松散。(6)不同浓度的DMPP加入对细菌的生长、DBP的吸附和复合体系吸附DBP均有影响,且2 mmol/L的DMPP可以较大提高细菌-蒙脱石复合体系对DBP的吸附。
[Abstract]:Dibutyl phthalate (DBP) is a kind of phthalate ester. It is a common environmental hormone organic pollutant in the environment. In this paper, a microorganism with high tolerance to DBP was isolated from soil contaminated samples exposed to DBP. Burkholderia. The adsorption behavior and mechanism of DBP in soil and its relationship with three minerals (goethite and kaolin) were studied. The adsorption behavior and mechanism of DBP in montmorillonite (MMT) composite system. The adsorption kinetics and isotherm model of DBP adsorption by Burkholderia were fitted. The effects of pH value and different concentration of 3o 4- dimethylpyrazole phosphate on the adsorption of DBP were investigated. The changes of surface groups before and after Burkholderia adsorption on DBP were analyzed by Fourier transform infrared spectroscopy (FTIR). In the study of the adsorption of DBP by bacteria-mineral complex system, the adsorption capacity (rate) and desorption capacity (ratio) of the composite system were investigated, as well as the different ratios between bacteria and minerals. Combined with scanning electron microscope (SEM), scanning Electron Microscope. The surface morphology of Burkholderia combined with three minerals was observed. At the same time, the hydrophobicity of the three composite systems was compared with the estimated values. The adsorption mechanism of the composite system was further elucidated. The adsorption behavior and mechanism of DBP at the interface of Burkholderia and the three minerals were preliminarily proved by a large number of experiments mentioned above. The conclusion of this paper is as follows:. The following points:. (. 1) the process of DBP adsorption by Burkholderia accords with the isotherm model of Freundlich adsorption. The desorption experiment showed that the adsorption isotherm equation was: 1: QE 2A6 脳 ce 1 / 1.02.2.2. The adsorption of DBP by Burkholderia includes physical adsorption and chemisorption, mainly chemisorption. The adsorption of DBP by bacteria is mainly through C-H stretching vibration and interaction. At the same time. The active group and cell wall on the surface of bacteria also participated in the adsorption behavior. 4) under the mixed ratio of 1: 1, the difference between the measured values and the theoretical values of DBP adsorption by the complex was the largest. The adsorption capacity of bacteria-goethite and bacteria-montmorillonite was 1.10 mg/g and 1.83 mg/g higher than the theoretical values, respectively. On the other hand, bacteria-kaolin decreased by 1.16 mg / g 路L ~ (5). By scanning electron microscope, it was found that the microorganism binds closely with goethite and montmorillonite in different forms with the three minerals. The addition of different concentrations of DMPP to kaolinite could affect the adsorption of DBP on the growth of bacteria and the adsorption of DBP in the composite system. The adsorption of DBP on the bacteria-montmorillonite composite system could be greatly improved by 2 mmol/L DMPP.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592;X172

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