修复地下水氮污染的活性介质作用特性研究

发布时间：2018-01-08 22:23

本文关键词：修复地下水氮污染的活性介质作用特性研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：工业化过程中的大量污染物排放,以及农业生产过程中化肥、农药的大量使用,直接或间接导致土壤、地下水出现三氮(NH_4~+-N、NO_2~--N、NO_3~--N)污染问题,危害生态环境和人类的健康。目前关于地下水环境中氮污染的研究,主要集中在水、土环境监测、迁移转化机理以及地下水控制与修复技术研究,结合研究区,针对地下水中三氮降解菌及其附载材料效果研究甚少报道。本论文以国家十二五水专项项目为依托,针对东北某农作区地下水氮超标问题,在综合分析已有资料和科研成果基础上,进行研究区地下水环境调查和监测,分析研究区地下水环境特性(水化学类型、水化学要素、微生物种群等),在此基础上,富集筛选用于修复氮污染地下水的微生物活性介质材料——三氮降解菌,考察其降解特性;并结合课题组已研发的天然矿物材料——火山渣,制备吸附-降解型复合活性介质,分析主要影响因素和作用机制;开展氮污染地下水动态去除效果实验,利用现代分析技术,辅助揭示其动态作用特性。研究成果为氮污染地下水的控制与修复技术研发和应用提供重要科学依据。通过本论文研究,主要取得以下成果:1、基于宏基因组测序技术,揭示了地下水微生物菌群动态变化特征,分析微生物与环境因子之间的关系。地下水中微生物主要由Proteobacteria、Firmicutes、Cyanobacteria、Actinobacteria、Bacteroidetes、Verrucomicrobia、Acidobacteria、Planctomycetes等组成,占总序列96%以上;优势菌属与水环境要素Fe2+、Mn~(2+)、NH_4~+、NO_3~-、NO_2~-、DOC、pH值以及HCO_3~-含量具有相关性。2、筛选出了适用于低温、低氧、寡营养等实际地下水赋存环境特点的三氮土著降解菌,并揭示其作用特性。120h内去除率分别为90.83%、74.97%、73.35%;降解过程符合二级降解动力学方程;通过宏基因组测序测得菌种主要为Pseudomonas、Serratia、Enterobacter、Azomonas、Ewinglla、Paenibacillus、Janthinobacterium等菌属占总序列97.06%;通过扫描电子显微镜(Scanning Electron Microscope,简称SEM)观察到菌株主要为杆状,长约150nm,直径约50nm;通过Plackett-Burman(简称PB)实验和中心组合实验对菌种适宜的培养条件进行优化。优化结果为(g/L):K_2HPO_4·3H_2O4.0、NaCl0.1、MgSO_4·7H_2O0.0962、CaCl_20.4、MnSO_4 0.1、FeSO_4 0.1、CON_2H_4 1.936、C_6H_(12)O_65.0,另外pH值为7.22、DO含量为1.804mg/L。3、考察吸附-降解型复合活性介质对三氮的去除效果及影响因素研究。采用正交实验设计法对降解菌固定化火山渣条件进行优化,并对比火山渣与复合活性介质对三氮作用效果。结果表明:复合活性介质对三氮的去除率明显优于单一矿物火山渣,1h内复合活性介质对NH_4~+-N、NO_2~--N、NO_3~--N的去除率分别为96.05%、82.40%、83.16%,作用规律符合准二级动力学方程;复合活性介质去除三氮的最佳pH值为7,HCO_3~-、CO_3~(2-)对介质去除三氮具有抑制作用,Fe2+、Mn~(2+)、Ca~(2+)、Mg~(2+)对介质去除三氮基本具有低浓度促进高浓度抑制规律,SO_4~(2-)对介质去除NO_3~--N略有影响,对NH_4~+-N具有低浓度促进高浓度抑制的规律,对NO_2~--N具有低浓度促进高浓度抑制的规律。4、结合微型模拟柱揭示吸附-降解型复合活性介质对三氮的动态作用特性。不同流量、三氮初始浓度条件下,作用过程符合Thomas模型;不同填充高度条件下,作用过程符合Bohart-Adams模型。复合活性介质微型柱动态效果模拟实验,在2个月运行期内,三氮含量均低于饮用水标准,可以将复合活性介质应用于三氮超标地下水原位及异位处理技术中。5、利用现代分析技术,辅助揭示介质对三氮的作用特性。通过原子力显微镜(Atomic Force Microscope,简称AFM)观察固定化前后微观变化,固定化后比表面积较降解菌有较大的增加,有利于提高吸附材料的吸附效果;通过SEM从微观角度分析作用机理,对比作用前后,作用后介质表面孔隙被填充;通过宏基因组测序对复合活性介质表明降解菌进行动态监测,作用过程介质表面降解菌菌群结构组成动态变化较小,丰度差异性较大。
[Abstract]:A large number of pollutants in the process of industrialization, chemical fertilizer and agricultural production process, the extensive use of pesticides, directly or indirectly lead to soil, groundwater three nitrogen (NH_4~+-N, NO_2~--N, NO_3~--N) pollution, endanger the ecological environment and human health. Current research on the nitrogen pollution in the groundwater, mainly concentrated in the water. Soil environmental monitoring, migration and transformation mechanism and Study on groundwater control and remediation technology, combined with the study area, the underground water of three nitrogen degradation bacteria and its effect on carrier material seldom reported. In this paper, in 12th Five-Year the special water project, a farming region in the northeast of groundwater nitrogen exceed the standard problem, based on comprehensive analysis of existing data and research the results of the groundwater environmental monitoring and investigation, the study area, analysis of groundwater environment characteristics in the study area (water chemistry type, water chemical elements, microbial population etc. ), on this basis, the enrichment and screening for the repair of nitrogen pollution in groundwater by microbial activity in dielectric materials three nitrogen degrading bacteria, study its degradation characteristics; and combined with natural mineral materials research group has developed the volcano - slag, preparation of adsorption biodegradation composite active medium, analysis of main influence factors and mechanism of nitrogen pollution; carry out groundwater dynamic removal experiment, using modern analytical techniques, revealing its dynamic characteristics. The auxiliary research results provide an important scientific basis for groundwater nitrogen pollution control and remediation technology research and application. Through the research of this thesis, the main research achievements are as following: 1, metagenomic sequencing technology based on microbial flora reveals the groundwater dynamic changes the characteristics, analysis of the relationship between microbial and environmental factors. The microorganism in groundwater is mainly composed of Proteobacteria, Firmicutes, Cyanobacteria, Actinobacteria, Ba Cteroidetes, Verrucomicrobia, Acidobacteria, Planctomycetes etc., accounted for more than 96% series Fe2+ and water environmental factors; dominant genera, Mn~ (2+), NH_4~+, NO_3~-, NO_2~-, DOC, pH value and the content of HCO_3~- associated with.2, were screened for low temperature, hypoxia, three indigenous nitrogen degrading bacteria oligoltrophic etc. The actual occurrence of groundwater environmental characteristics, and reveals its role in the characteristics of.120h removal rate were 90.83%, 74.97%, 73.35%; the degradation process conforms to the level two degradation kinetic equation; through metagenomic sequencing the measured strains were mainly Pseudomonas, Serratia, Enterobacter, Azomonas, Ewinglla, Paenibacillus, Janthinobacterium and other bacteria accounted for by a sequence of 97.06%; scanning electron microscope (Scanning Electron Microscope, referred to as SEM) were observed for the main rod length of 150nm, diameter of about 50nm; the Plackett-Burman (PB) and experimental group The test of the strain suitable culture conditions were optimized. The optimized result is (g/L): K_2HPO_4, 3H_2O4.0, NaCl0.1, MgSO_4, 7H_2O0.0962, CaCl_20.4, MnSO_4 0.1, FeSO_4 0.1, CON_2H_4 1.936, C_6H_ (12) O_65.0, and the pH value is 7.22, the content of DO is 1.804mg/L.3, investigation of adsorption biodegradation composite active medium three of the nitrogen removal efficiency and influencing factors. The degradation of bacteria immobilized volcano slag conditions were optimized by orthogonal design method, and compared with the composite slag volcano active media on three nitrogen effect. The results show that the composite active medium of three nitrogen removal rate is higher than that of single mineral slag composite volcano, NO_2~--N activity medium 1h of the NH_4~+-N, and the removal rate of NO_3~--N was 96.05%, 82.40%, 83.16%, the role of law conforms to the two level dynamic equation; the best pH removal of three nitrogen compound active medium value is 7, HCO_3~-, CO_3~ (2-) on the media to In addition to the three nitrogen has inhibitory effect on Fe2+, Mn~ (2+), Ca~ (2+), Mg~ (2+) on the removal of basic nitrogen three medium with low concentration promoted high concentration inhibiting law, SO_4~ (2-) removal of NO_3~--N had slight influence on medium with low concentration promoted high concentration of inhibition of NH_4~+-N with low concentration to promote the high concentration of inhibition of.4 on NO_2~--N, combined with the micro simulation of dynamic characteristics of column adsorption and degradation of composite active medium of three nitrogen. Three different flow conditions, the initial concentration of nitrogen, process with the Thomas model; different filling height of a process, in accordance with the Bohart-Adams model. Simulation experiment of composite active medium micro column dynamic effect, in the 2 month operation period, three nitrogen levels were lower than the standard of drinking water, can be applied to the composite active medium three nitrogen exceed the standard of groundwater in situ and ectopic processing technology in.5, using modern analysis technology, auxiliary To reveal the role of three nitrogen. The characteristics of the medium by atomic force microscopy (Atomic Force Microscope, referred to as AFM) were observed before and after immobilization of microscopic changes after immobilization, the specific surface area is degrading bacteria was increased, can improve the adsorption effect of adsorption materials; analysis of the mechanism from the micro angle through the contrast effect before and after SEM. After the action, the surface of the medium pore is filled; through metagenomic sequencing of the composite active media shows that the dynamic monitoring of the degrading bacteria, process medium surface degradation bacteria structure dynamic variation abundance varied greatly.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X523

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