【作者】 郑昭贤；

【导师】 林学钰；

【作者基本信息】 吉林大学 ， 地下水科学与工程， 2012， 硕士

【摘要】 石油在勘探、开采、炼制、加工和运输过程中，往往会以“跑、冒、滴、漏”形式进入环境，成为地下水土的长期污染源，又因其“三致性”严重危害人体健康和地下水土生态环境。因此石油类有机污染已成为公认的世界性环境难题。研究石油污染浅层地下水氯代烷烃微生物响应规律有助于了解石油污染场地地下环境中氯代烷烃在微生物作用下的的环境行为、转化归宿及其降解机理提供理论依据，并为研究区及其类似石油污染浅层地下水氯代烷烃污染的防控和治理技术体系的建立提供科学依据。本文以《典型石油类污染物分布、迁移转化及其对地下水污染机理研究—以东北某油田为例》专题项目为依托，以东北某油田石油管道泄漏区作为研究区，在充分了解水文地质条件的基础上，分析土壤石油烃污染特征、地下水有机污染特征，确定氯代烷烃-二氯甲烷、三氯甲烷作为本次研究的特征污染物，进而对氯代烷烃生物降解的地下水化学响应规律、氯代烷烃生物降解的微生物群落结构和功能响应规律进行了系统的研究工作。具体研究成果为：一、地下水土壤石油烃污染特征（1）采用污染场地及其周边68个表层土样和50个钻孔土样的总石油烃浓度测试数据，运用累积概率分布曲线法确定污染场地及其周边土壤总石油烃背景值，并用监测断面法、比拟法对所得结果进行验证，最终确定其值为10mg/kg。水平方向上，整体表层土壤总石油烃浓度空间变异性较大，表现出明显的点源污染特征，即离污染源越远，土壤中石油烃含量迅速降低，并趋于背景值；垂向上，污染场地深层土壤总石油烃浓度明显低于表层土壤，最大值出现在0～0.2m土层，随着深度加深石油烃含量逐渐降低，接近土壤总石油烃背景值。（2）根据污染场地浅层地下水有机污染现状评价和风险评价结果可知，二氯甲烷和三氯甲烷污染最为严重，且两者性质相似，在含水层中的淋溶迁移性也比其它有机物强，对地下水的污染风险最大。（3）通过对污染场地污染源处和污染源下游地下水中有机物定量测试分析数据和土壤分层取样TPH数据分析，判断地下水污染途径为以直接穿透式污染为主，垂向淋滤式污染为辅的复合污染模式。二、氯代烷烃生物降解的地下水化学响应特征对污染场地浅层地下水化学指标时空变化特征分析结果显示：2010年6月，事故发生约1年之际，在ZK1-ZK3-ZK6纵向剖面上生物降解过程中充当电子受体的水化学组分(Fe³⁺、Mn⁴⁺、SO₄^2-)、第一基质（CH2Cl2、BTEX）和代表地下水环境的主要理化指标（pH、Eh）从上游到下游均呈递增规律，而相关还原产物(Fe²⁺、Mn²⁺、HCO-3)则成递减规律。2010年6月氯代烷烃天然生物降解评价表明ZK1属微生物降解证据充足；ZK3观测井属微生物降解证据有限；ZK6观测井属微生物降解证据不足。而2011年5月，事故发生约2年之际，封堵污染源后随污染晕中心的向下游迁移，ZK3观测井中生物降解作用逐渐明显，在ZK3-ZK6纵向剖面上地下水化学指标呈现上述响应规律，而ZK1观测井诸多水化学指标在上游未污染地下水的补充更新下逐渐趋向污染前背景值。三、氯代烷烃生物降解的微生物群落响应特征通过PCR-DGGE指纹图谱技术研究石油污染场地不同深度、不同点位土壤-地下水环境生态结构和功能特点，了解微生物对污染物的响应规律。其主要结论为：（1）从不同土壤-地下水环境微生物群落α多样性指数分析得出，背景点群落多样性指数在包气带中从表层（0.2m）到浅表（0.5m）呈下降趋势，而浅表到潜水变幅带（1.0m）又呈上升趋势，且在整个垂向深度上其指数达到峰值，之后在饱水带随深度的增加逐渐下降并趋于一定值。不同程度的污染影响群落多样性，但不是简单的负相关关系，重度污染水平使群落多样性显著降低，而中等污染水平使群落多样性有所上升。以上结论在污染场地不同点位和不同深度均被验证。（2）从土壤-地下水环境微生物群落β多样性指数分析得出，在0.5相似度下未污染背景钻孔不同深度的群落可分为三大簇，具体为表层（0.2m）、浅表-潜水变幅带（0.5-1.0m）和饱水带（1.5-1.8m），但各层位土样中群落相似度均小于0.6，说明原始状态下垂向上不同深度代表不同生境。石油污染和岩性变化均影响微生物群落β多样性，使不同深度群落多样性分类相比背景钻孔有一定的变化。（3）通过土壤呼吸熵分析土壤-地下水环境微生物群落总活性得出，各钻孔垂向剖面上，土壤总活性随土层深度的增加，呈递减趋势；水平ZK1-ZK3-ZK6纵向剖面上，土壤呼吸熵表现为ZK3钻孔〉ZK6钻孔〉ZK1钻孔的特点，即中等污染水平土壤-地下水环境微生物群落总活性大于未污染背景点位，未污染土壤-地下水环境微生物群落总活性大于重度污染水平点位。（4）通过测序结果分析得出，研究区在石油污染作用下，经过群落结构和种群数量的变化，使地下水-土壤环境中分布诸多石油类相关微生物种群，如耐石油甲烷氧化菌、石油降解菌等，且在污染较重区其含量相对丰富。本次切胶测序，因DGGE指纹图谱中条带众多，未能一一进行测序分析，但推测在未测序的条带中存在本文研究特征污染物—氯代烷烃的相关降解菌，且其含量在水平ZK1-ZK3-ZK6断面和垂向剖面具有一定的规律。更多还原

【Abstract】 The petroleum would be long-term pollution sources of soil and groundwaterwhich come from process of exploration, mining, refining and transportation byaccident. Meanwhile, petroleum would be serious harm to human health and ecologicalenvironmental of soil and groundwater because of its toxicity and carcinogenicity. Sopetroleum pollution have been became one of the most serious global environmentalproblems. Research on Microbial Response Law of Natural Biodegradation ofChloralkane Solvents in a Petroleum Hydrocarbon Contaminated Shallow Groundwaterwill be contributed to understand environmental behavior and biodegradationmechanism of Chloralkane Solvents in groundwater, then supply scientific foundationof building Chloralkane Solvents control and management technology in similarcontaminated sites.This paper was based on the project of “Distribution, migration and transformationof typical petroleum pollution in groundwater—case study in a certain oilfield innortheast China”, selecting a oil pipeline leakage area as study area, analyzingcontamination characteristics of soil and groundwater to identify CH2Cl2, CHCl3asfeatured pollutants, then study the Response Law of Natural Biodegradation ofChloralkane Solvents systemically. Theses study shows that:Characteristics of contaminated groundwater and soil in contaminated site(1) Based on68surface soil samples and50drilling soil samples which wereobtained from contaminated site and surrounding area,10mg/kg is appropriate for thelocal TPH background (threshold) concentration in soil of contaminated site using theCumulative Probability Plots, monitoring cross section method and analogue method.Overall surface soils TPH concentrations have a high spatial variability，showingsignificant point source pollution characteristics． For the longitudinal section soils，most of the high contamination level soil samples assembled in the soil layer at0-0.2m，below these layers the TPH concentrations are almost in the background (threshold) concentration scope.(2)According to the status evaluation and risk evaluation of organic pollution of theshallow groundwater of contaminated sites of the results, dichloromethane andchloroform pollution are the worst situations. Their nature is similar. Their leachingmobility in the aquifer than any other organic matter which is the greatest risk ofgroundwater pollution.(3) Anglicizing the quantitative test data of organic matter which in the pollutionsources and pollution sources’ downstream groundwater and sampling TPH data of soilstratified, and we can get a conclusion that the main way of groundwater pollution isdirect transmission, and supplemented by vertical leaching pollutionHydrogeochemical response law of natural biodegradation of chloralkane solventsThe analyses for the spatial and temporal variation characteristics of shallowgroundwater chemical index in the pollution field show that: in June2010, after theaccident happened about1year, in ZK1-ZK3-ZK6longitudinal section, the waterchemical components (Fe2+, Mn4+, SO42-) which act as electron acceptors forbioremediation, and the main physicochemical index (pH, Eh), which indicate thegroundwater environment, both have increased from upstream to downstream. Howeverthe first matrix (CH2Cl2, BTEX) and related reduction product (HCO-3) have decreasedfrom upstream to downstream. In June2010, the evaluation of chlorinated solventsnatural biodegradation indicates that for ZK1observation Wells, there are enoughevidences of microbial degradation; for ZK3observation Wells, the evidences ofmicrobial degradation are limited; for ZK6observation Wells, the evidence of microbialdegradation is insufficient. And in May2011, about2years after the accident, Thesealing pollution sources have moved to downstream with the center of the pollutiondizzy, the degradation in ZK3observation Wells is more and more obvious, thegroundwater chemical index in ZK3-ZK6longitudinal section presents the responsepatterns, and in ZK1observation Wells, many chemical indexes are gradually incline tobackground values before pollution with the supplement of the unpolluted upstreamwater.Microbial community response law of natural biodegradation of chloralkanesolvents Research of soil-groundwater Ecological structure and function characteristic havebeen preceded in different points and depth with application of PCR-DGGEFingerprinting Technology, to learn microbial community response law of naturalbiodegradation of chloralkane solvents. The main results show that:(1) Learn from analysis of α diversity index, community diversity of backgrounddrilling declined from0.2m to0.5m in aeration zone, then rise from0.5m to1.0m intransitional zone of unsaturated zone to saturated zone to the pick value, after thendecline to the constant value in saturated zone. Different pollution level affectCommunity diversity, but it is not a simple negative correlation. Severe pollution levelmakes community diversity reduce, but moderate pollution levels make it rise.(2) Learn from β diversity index, the community can be classified as three majorcategories at the background drilling indicate different depth represent different habitat.Both petroleum pollution and lithological changes affect β community diversity; makesome changes in classification of different depth at contaminated drilling.(3) Analyzing total activity by using qCO2, we know that it decreased with the soildepth in vertical section; in the ZK1-ZK3-ZK6horizontal section, the qCO2show ZK3〉ZK6〉ZK1that means total activity of moderate polluted site is bigger than backgroundsite, then background site bigger than severe polluted site.(4) Analysis of the sequencing result, after changing the community structure andpopulation, in the study area groundwater-soil environment effected by oil pollution,there is distribution of many oil-related microbial populations, such asmethane-oxidizing bacteria, petroleum oil degradation bacteria etc, and its content isrelatively abundant in seriously polluted areas. The rubber cutting sequencing, due to alot of DGGE fingerprint bands, not all were sequenced, but there will be characteristicsof pollutants-degrading bacteria chlorinated solvents, and it content with a certainregularity in the ZK1the-ZK3-ZK6section and the vertical profile.更多还原