Effects of mixing processes on microbial degradation and the distribution of microorganisms in stationary and non-stationary contaminant plumes

混合过程对微生物降解以及微生物在固定和非固定污染物羽流中分布的影响

• 批准号: 5419180
• 负责人: Professor Dr. Christian Griebler
• 金额: --
• 依托单位: Department für Funktionelle und Evolutionäre Ökologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5419180?language=en
• 关键词: Effects; mixing; processes; microbial; degradation

In the proposed project we want to study the effects of mixing processes and changing groundwater flow regimes on the microbial degradation potential in contaminated aquifers. Microbial degradation activities will be quantified by compound-specific isotope analysis (CSIA), i.e. the stable isotope fractionation of 13C/12C and D/H in the residual, not yet degraded contaminant fraction. In laboratory tank experiments artificial contaminant plumes (e.g. toluene) will be produced under stationary or transient flow conditions. The augmentation of the tank system with well defined bacterial cultures and the supply of mixtures of deuterated and non-deuterated contaminants will allow to quantify microbial degradation at a high resolution (mm-scale). Because of extremely different fractionation properties of aerobic and anaerobic strains we will be able to differentiate between the respective contributions of the two to the overall degradation processes. Furthermore, the effects of stationary and non-stationary flow conditions on the introduced microorganisms will be investigated. Here the overall question is how tolerant and/or flexible are microorganisms which are confronted with frequently changing environmental conditions (e.g. oxic-anoxic) and how long after a disturbance it might take to initiate and resuscitate a pronounced degradation. The concept will also be investigated in the field where a cross section through a contamination plume with a 50 x 50 cm resolution of the sampling spots will be sampled. CSIA will provide information on the spatial distribution of biodegradation activities in situ. By means of molecular methods the field samples will also be analysed for the presence of different groups (e.g. sulfate-reducing and iron-reducing bacteria) and individual strains of microorganisms (the ones we isolated from the actual site). Comparisons of results from laboratory and field investigations should reveal general insights into the effect of mixing and non-stationary flow conditions on natural attenuation processes in contaminated aquifers.

在拟议的项目中，我们希望研究混合过程和改变地下水流动方案对受污染含水层中微生物降解潜力的影响。微生物降解活性将通过复合特异性同位素分析（CSIA）进行量化，即在残留中的13C/12C和D/H的稳定同位素分馏，尚未降解污染分数。在实验室储罐实验中，人工污染物羽毛（例如甲苯）将在固定或瞬态流动条件下产生。具有良好定义的细菌培养物的储罐系统的增强以及氘化和非污染物的混合物的供应将允许以高分辨率（MM尺度）量化微生物降解。由于有氧和厌氧菌菌株的分馏特性极为不同，因此我们将能够区分两者对整体降解过程的贡献。此外，将研究固定和非平稳流条件对引入的微生物的影响。这里的总体问题是，微生物是如何耐受和/或灵活的，这些微生物是面临经常变化的环境条件（例如，毒性 - 毒素）的耐受性，以及在干扰后需要多长时间才能启动和复苏明显的降解。该概念还将在现场进行研究，在该田地中，将采样，通过50 x 50 cm分辨率的采样斑点进行采样。 CSIA将提供有关原位生物降解活动空间分布的信息。通过分子方法，还将分析现场样品的存在，以存在不同基团（例如硫酸盐还原和还原细菌）和微生物（我们从实际部位分离的）的单个菌株。比较实验室和现场调查的结果应揭示对混合和非平稳流条件对受污染含水层自然衰减过程的影响的一般见解。