Dynamic Behavior of Micobial Growth and Activity in Mixing-Controlled Contaminant Plumes

混合控制污染物羽流中微生物生长和活动的动态行为

• 批准号: 195631779
• 负责人: Professor Dr.-Ing. Olaf A. Cirpka
• 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 Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/195631779?language=en
• 关键词: Dynamic; Behavior; Micobial; Growth; Activity

Organic contaminants, e.g. petroleum hydrocarbons, are frequently released into aquifers, forming plumes depleted in dissolved electron acceptors. Biodegradation of such plumes requires a dissolved reaction partner provided by transverse dispersive mixing. Analytical expressions for the plume length and the overall reaction rates have been developed for steady-state conditions. Under field conditions, however, steady state seldom prevails. Both the lateral position of a contaminant plume and the chemical composition of the mixing waters may change over time. For the predominantly immobile, active microbial biomass it may be difficult to cope with these changes so that the overall degradation of mixing-controlled plumes may be hampered. Dynamic changes in local chemical conditions may also induce shifts in the relative abundance of bacterial populations in a microbial community. We will conduct well controlled laboratory experiments of mixing-controlled bioreactive transport in quasi two-dimensional flow-through systems applying dynamic boundary conditions to elucidate the influence of such hydraulic and chemical dynamics on the overall degradation and the microbial communities involved. These experiments will be analyzed by numerical simulation of all relevant processes facilitating the transfer of results to conditions not covered within the experiments. We hypothesize that the importance of dynamic boundary conditions depends on relative time scales of these changes in comparison to the time scales of physical transport, biomass growth/decay and activation/deactivation.

有机污染物，例如石油烃经常被释放到含水层中，形成溶解电子受体耗尽的羽流。这种羽流的生物降解需要通过横向分散混合提供溶解的反应伙伴。已经针对稳态条件开发了羽流长度和总反应速率的分析表达式。然而，在现场条件下，稳态很少出现。污染物羽流的横向位置和混合水的化学成分都可能随时间而变化。对于主要是固定的、活跃的微生物生物质来说，可能难以应对这些变化，因此混合控制羽流的整体降解可能受到阻碍。局部化学条件的动态变化也可能引起微生物群落中细菌种群相对丰度的变化。我们将应用动态边界条件，在准二维流通系统中进行混合控制生物反应运输的良好控制实验室实验，以阐明这种水力和化学动力学对整体降解和所涉及的微生物群落的影响。这些实验将通过所有相关过程的数值模拟进行分析，以便将结果转移到实验中未涵盖的条件。我们假设动态边界条件的重要性取决于这些变化与物理运输、生物量生长/衰变和激活/失活的时间尺度相比的相对时间尺度。