苯胺降解菌在含水层中的迁移机制及污染修复效能研究

发布时间：2018-03-09 10:17

本文选题：地下水污染　切入点：生物强化　出处：《吉林大学》2017年博士论文　论文类型：学位论文

【摘要】：随着城市化和社会经济的高速发展,污染物的泄漏导致地下水的严重污染,特别是有机污染普遍存在,对人类饮用水安全构成了严重的威胁。苯胺是现代农业、医药和化工产品的常用原料,应用范围非常广泛,对地下水的污染比较普遍。由于苯胺对人体具有毒性、致癌、致突变性和在环境中的持久性,苯胺污染地下水的防治受到了人们的普遍关注。在苯胺污染地下水修复方法中,物理修复技术能耗及处理成本高,化学修复技术则易对环境造成二次污染,而原位生物修复技术由于其相对经济、有效和环境友好且易和多种修复手段联合应用等特点,具有明显优势。其中,生物强化可通过向地下环境中注入外源降解菌,达到缩短修复时间、提高修复效率的目的。但是,实际修复中往往由于外源降解菌在投加到场地后活性和数量大幅度降低,导致生物强化失败。所以,外源降解菌在地下环境中的存活和迁移对生物强化至关重要。本论文通过研究含水层中的降解菌存活、降解菌迁移和生物强化修复效率三者之间的关系,为实际生物强化原位修复苯胺污染地下水提供理论基础。通过之前的研究表明,Pseudomonas migulae AN-1是一株适冷、高效的苯胺降解菌,其在低温下的降解性能已经清楚,降解条件也被优化,但AN-1在地下环境中的存活、迁移和对苯胺污染含水层的修复效能尚未明确。本论文研究了AN-1在含水层中存活和迁移的相关性能;构建了一种新的绿色荧光蛋白(Green fluorescent protein,GFP)标记结合光投射技术的方法体系,直观并实时监测了降解菌在模拟含水层中的迁移,首次实现了无扰动同时捕捉游离菌和附着菌的迁移动态,揭示了降解菌在含水层中的迁移机制,对明确修复范围及强化调控生物修复具有重要的指导意义;运用皂素对降解菌在含水层中的迁移进行强化,通过研究AN-1—液体—固体介质三者的表面热力学性质、界面表面能、吉布斯自由能和DLVO相互作用能,进一步阐明了皂素强化迁移的机理,为强化生物修复和缓解生物堵塞在理论和技术上奠定了基础;考察并验证了AN-1在模拟苯胺污染含水层中的存活、迁移和修复效能,建立了一套较为完整的原位生物修复苯胺污染地下水技术体系,对实际修复具有重要参考价值。通过上述研究,本论文主要得出以下结论:⑴AN-1在含水层中存活和迁移的相关特性AN-1可适应苯胺浓度的变化,自动调节自身的细胞膜通透性、疏水性和自聚集性。AN-1具有附着成膜能力,且AN-1形成的生物膜也具有较好的苯胺降解及抗苯胺冲击性能。地下水中的Ca2+和SO42-(≥5 m M)对AN-1成膜有促进作用,Fe2+有抑制作用。⑵AN-1在含水层中的迁移机制采用GFP标记结合光透射技术,无扰动同时捕捉了模拟含水层中游离菌和附着菌的迁移动态,直观并定量的揭示了AN-1在含水层中的迁移机制,即降解菌在含水层中的迁移受自身生物特性和地下水对流、弥散的共同作用,为生物因素和水文地质因素共同影响。(1)降解菌迁移速度:AN-1迁移速度比地下水流速快,且含水层介质粒径越小,对AN-1迁移速度促进越大,AN-1迁移越快。(2)降解菌迁移能力:含水层介质粒径越大、地下水流速越快、地下水中离子强度越小、溶解性有机质越多,AN-1在饱和多孔介质中的质量回收率就越大,沉积速率系数越小,越易在含水层中迁移。其中,相同离子强度、相同阴离子,二价阳离子比一价阳离子对AN-1迁移的抑制作用大;相同离子强度、相同阳离子,二价阴离子比一价阴离子对AN-1迁移的抑制作用小。(3)降解菌迁移动态:对于菌羽的初始形状,菌羽在中砂中沿注入井形成一条窄带,在粗砂中于注入井下半部形成一个椭球;对于菌羽的面积,与时间呈线性关系,而且在相同降解菌注入量、相同时间内、相同地下水流速条件下,中砂中的面积大于粗砂;对于菌羽的范围,从注入井至降解菌羽锋面,可形成连续的微生物带,包括游离菌羽区域和后方的附着菌区域,对明确修复范围及强化调控生物修复具有重要的指导意义。⑶AN-1在含水层中迁移的强化皂素对AN-1无毒害作用。当0.1%、0.3%或0.5%皂素存在时,AN-1对苯胺的降解速率比无皂素时略高,生物量略大。确立了0.1%为皂素冲洗溶液的最佳浓度,该浓度下AN-1—液体—固体介质三者构成体系的界面表面能最小、吉布斯自由能最大、细菌截留量最小。采用0.1%皂素溶液冲洗的方法(不用皂素对AN-1进行预处理,直接注入含水层,再用0.1%皂素溶液进行冲洗),是强化AN-1在含水层中迁移最经济、最有效的方式。该技术方法可使AN-1在含水层中发生有效的二次迁移,进一步扩大潜在的生物强化修复范围。离子不影响皂素对AN-1的促迁移作用。当皂素与离子共存时,与离子单独存在相比,皂素显著提高了AN-1与介质颗粒之间的能量壁垒,基本消除了离子对AN-1迁移的抑制作用,促进了AN-1在饱和多孔介质中的迁移。⑷AN-1修复模拟苯胺污染含水层在模拟苯胺污染含水层中,AN-1能够较好的存活,表现出良好的降解性能,并可维护土著微生物群落结构,使种群适应苯胺的冲击。从注入井至降解菌羽锋面,可形成连续的微生物反应带,有效的修复范围包括游离菌羽区域和后方的降解菌附着区域。当降解菌在污染含水层中注入时,降解菌会大量附着生长并聚集在注入井的附近,虽然该区域对苯胺的降解速率较大,为主要降解区域,但可能会形成潜在的生物堵塞。降解菌聚集区域会随水流缓慢向下游运移、扩大,并伴随游离细胞的不断剥落、随水流向下游迁移。AN-1对模拟苯胺污染含水层具有良好的生物强化修复效能。本论文的主要创新体现在:构建了一种新的GFP标记结合光投射技术的方法体系,直观并实时监测了降解菌在模拟含水层中迁移,实现了无扰动同时捕捉游离菌和附着菌的迁移动态,首次直观的揭示了生物强化的有效修复范围;建立了一种新的运用皂素强化降解菌在含水层中迁移的技术方法,具有相对经济、有效且环境友好的特点,并阐明了其强化机理;首次验证了高效苯胺降解菌Pseudomonas migulae AN-1在模拟苯胺污染含水层中的存活、迁移和修复效能,系统且全面的研究了含水层中降解菌存活、降解菌迁移和生物强化修复效率三者之间的内在关系。综上所述,本论文为实际生物强化原位修复苯胺污染地下水奠定了理论基础,对实际工程应用具有重要的指导意义。
[Abstract]:With the rapid development of city economy and society, the serious pollution of groundwater due to the leakage of pollutants, especially widespread organic pollution, constitutes a serious threat to human safety of drinking water. Aniline is commonly used materials of modern agriculture, medicine and chemical products, a very wide range of applications, the pollution of groundwater due to cancer is relatively common. Aniline has on the human body, toxicity, mutagenicity and persistence in the environment, the prevention and control of groundwater pollution was affected by people's attention. In the remediation of groundwater contaminated by aniline method, physical repair technology of energy consumption and high cost of processing, chemical remediation technology is easy to cause two pollution on the environment, and in situ bioremediation due to its relative economic characteristics, effective and environmentally friendly and easy to repair and various means of combination, has obvious advantages. Among them, bioaugmentation through to the underground Exogenous degrading bacteria into the environment, to shorten the time to repair, improve the repair efficiency. However, the actual repair is often due to exogenous degrading activity in the added site and quantity is greatly reduced, lead to enhanced biological failure. Therefore, exogenous degradation bacteria in underground environment is vital to the survival and migration of bioaugmentation. Through the study on degrading bacteria in water containing survival, the relationship between migration and degradation bacteria bioaugmentation remediation efficiency of three, provide a theoretical basis for the actual biological remediation of groundwater pollution. Through the study of aniline ago showed that Pseudomonas migulae AN-1 is a cold, high efficient aniline degrading bacteria, in the low temperature the performance degradation is clear, the degradation conditions were also optimized, but the survival of AN-1 in the underground environment, and the migration of aniline contaminated aquifer on the repair efficiency is not yet clear. This paper studies the performance of AN-1 survival and migration in the aquifer; build a new green fluorescent protein (Green fluorescent protein, GFP) marker combination method system of optical projection technology, visual and real-time monitoring of the degrading bacteria in water in the simulation of migration, the first migration dynamic disturbance at the same time capture the free bacteria and attached bacteria, revealing the mechanism of migration in the aquifer degrading bacteria, has an important guiding significance to clear the scope and strengthen the regulation of repair of bioremediation; using saponin on degrading bacteria migration in the aquifer are strengthened by surface thermodynamic study of AN-1 liquid - solid medium three properties. The interface surface energy, Gibbs free energy and the DLVO interaction energy, and further clarified the mechanism for strengthening saponin migration, bioremediation and mitigation of Biological Clogging in theory and technology laid the foundation The basic investigation and verification of the AN-1; in the simulation of aniline polluted aquifer containing survival, migration and repair efficiency, establishes a relatively complete set of in situ bioremediation of aniline polluted groundwater system, has important reference value for the actual repair. Through the above research, this thesis mainly draws the following conclusions: the survival of AN-1 in aquifer in the migration and relevant characteristics of AN-1 can adapt to changes in the concentration of aniline, automatically adjust their cell membrane permeability, hydrophobicity and self aggregation of.AN-1 with the attached film forming ability of biofilm formation of AN-1, and also has good impact properties of aniline degradation and anti aniline. Groundwater in Ca2+ and SO42- (m M = 5) on AN-1 film role, the inhibitory effect of Fe2+. The migration mechanism of AN-1 in the aquifer by labeling with GFP optical transmission technology, without disturbance while capturing the simulated aquifer in the free and attached bacteria The dynamic migration of bacteria, intuitive and quantitative reveals the mechanism of AN-1 migration in the aquifer, the migration of degrading bacteria in the aquifer by its biological characteristics and groundwater convection, dispersion interaction, for the common effect of biological factors and hydrogeological factors. (1) degradation bacteria migration speed: AN-1 migration speed the ratio of groundwater flow fast and aquifer and the smaller the particle size of AN-1, promote the migration speed is bigger, faster and faster. The migration of AN-1 (2) degradation bacteria migration: the aquifer of larger particle size, groundwater flow is fast, the smaller the ionic strength in groundwater, dissolved organic matter more, the quality of AN-1 recovery in a saturated porous medium rate is greater, the coefficient of deposition rate is small, the more easy migration in the aquifer. The same ionic strength, the same anion, the two divalent cations than monovalent cations in inhibition of AN-1 migration; the same ionic strength, the same cation Two, anion than monovalent anions inhibit the migration of AN-1. (3) degradation bacteria dynamic migration: for the initial shape of the plume plume in bacteria, bacteria in the sand along the injection well to form a narrow band, in the sand to form a ellipsoid in underground injection part; for bacteria plume area. A linear relationship with time, and the injection amount in the same degrading bacteria, the same time, the same groundwater flow conditions in the sand in the area is larger than the range of bacteria for coarse sand; Yu, from the injection well to the degradation of feather fronts, which form a continuous microbial zone, including free plume region and the rear of the attachment of bacteria by region, has an important guiding significance to the clear repair scope and enhanced bioremediation. The regulation of AN-1 migration in the aquifer to strengthen saponin has no toxic effect on AN-1. When there are 0.3% or 0.1%, 0.5% saponin, AN-1 degradation rate of aniline is slightly higher than when no saponin, The biomass is slightly larger. The optimum concentration of 0.1% saponin washing solution, the concentration of AN-1 in liquid - solid medium three form interface surface energy of the system is minimum, Gibbs free energy, the minimum amount of bacteria retention method using 0.1% saponin flushing (without saponin pretreated for AN-1 direct injection containing water, then 0.1% saponin solution flushing), is to strengthen the AN-1 migration in the aquifer in the most economical, the most effective way. This method can make the AN-1 two effective migration in the aquifer, further expand the scope of strengthening the potential biological repair. Ion does not affect the function of promoting migration of saponin. When AN-1 saponin and ions, and ion alone compared to saponin significantly increased between AN-1 and medium particle energy barriers, the inhibition of AN-1 ion migration basically eliminated, promote AN-1 in saturated The migration in porous media. The AN-1 repair aniline contaminated aquifer in simulated aniline polluted aquifer, AN-1 can better survive, showed a good degradation performance, and can maintain the indigenous microbial community structure, make the population adapt to aniline impact. From injection well to degradation of plume fronts, can form a continuous microbial reaction with the effective range of the repair degrading bacteria free bacteria including the plume region and the rear of the attachment region. When injected in degrading bacteria in the aquifer polluted, degrading bacteria can adhesion growth and aggregation in the injection wells nearby, although the larger degradation rate of the area of aniline, the main degradation region, but may the formation of potential biological clogging. Degrading bacteria gathering area with water slowly moves downstream, and continue to expand, with peeling free cells, along with the water flow to the downstream migration of.AN-1 on aniline pollution water layer. Have good biological strengthening repair efficiency. The main innovation of this thesis lies in: to construct a new GFP marker combining method system of light projection technology, visual and real-time monitoring of the degrading bacteria in simulated migration in the aquifer, realizes dynamic migration without disturbance also capture free bacteria and bacterial attachment, the first intuitive to reveal the effective repair range bioaugmentation; establish a new use of saponin strengthen degrading bacteria migration in aquifer techniques, with relative economic, effective and environmentally friendly, and expounds its strengthening mechanism; the first to verify the efficient aniline degrading bacteria Pseudomonas migulae AN-1 in the simulation of aniline polluted with survival in the water, migration and repair efficiency, systematic and comprehensive research on water degradation bacteria survival layer, the intrinsic relationship between migration and degradation bacteria bioaugmentation remediation efficiency of three. To sum up This paper lays a theoretical foundation for the actual biological reinforcement of the remediation of groundwater contaminated by aniline in situ, and has important guiding significance for practical engineering applications.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X172

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