CMG Research: Impact of Mineral Precipitating Biofilms on the Physical and Chemical Characteristics of Porous Media

拟议的工作将开发实验室，建模和计算工具的矿物沉淀微生物群落的地质影响的研究，旨在阐明基本原理，并提供定量描述的水文地球化学条件和过程中的碳酸盐矿物沉淀生物膜在多孔介质中。结果将是（1）表征影响孔隙系统的重要物理（例如平流和扩散运输）、化学（例如pH分布）和生物（例如微生物代谢活动）现象，以及（2）开发具有适当空间和时间分辨率的用于识别相关参数的测量技术。为了实现这一目标，将构建模型，允许观察和洞察流体力学，化学，电化学，微生物学和热力学的作用，需要详细描述生物膜与多孔介质的相互作用。热力学原理将被使用，必要的改进生物膜在其自然地球化学作用的热力学机器的描述。将采用的实验系统将允许空间和时间分辨的非破坏性观察相结合的生物膜的发展和矿物沉淀在毛细管和多孔介质流反应器。他们将有助于关闭非流动（批处理）系统之间的现有知识的差距，经常用来阐明地球化学过程和经常观察到的流体动力学对地球化学过程的影响，在meso-和macroscale.The拟议的研究重点是微生物引起的碳酸钙矿化。碳酸钙的形成是形成浅海和深海（如珊瑚礁和硅藻外骨骼）以及陆地环境中巨大规模特征的原因。碳酸盐岩（如石灰石、大理石和白垩）可能是地球上最大的无机碳储存库，含有约6500万千兆吨碳。碳酸盐矿物的形成和溶解是全球碳循环的重要组成部分，具有结合或释放大量二氧化碳的潜力，因此可能会影响全球气候。此外，工程化的微生物介导的碳酸盐沉淀已被提议作为一种策略，以改善地质碳封存，并促进重金属和放射性核素从受污染的地下水中沉淀。研究人员将开发实验室和计算工具，以更好地了解微生物群落在所有这些过程中的作用并利用其在环境中的潜力。

The proposed work will develop laboratory, modeling and computational tools for the study of the geological impact of mineral precipitating microbial communities, aiming at elucidating fundamentals and providing quantitative descriptions of the hydrobiogeochemical conditions and processes in carbonate mineral precipitating biofilms in porous media. Outcomes will be (1) characterization of the important physical (e.g. advective and diffusive transport), chemical (e.g. pH distribution), and biological (e.g. microbial metabolic activity) phenomena impacting pore systems, and (2) development of measurement techniques for identified relevant parameters with suitable spatial and temporal resolution. To accomplish this, models will be constructed that allow observation and insight into the roles of hydrodynamics, chemistry, electrochemistry, microbiology, and thermodynamics in the detail that are needed for description of interaction of biofilms with porous media. Thermodynamic principles will be used, necessary for improved description of biofilms in their natural geochemical role as thermodynamic machines. The experimental systems to be employed will allow spatially and temporally resolved non-destructive observation of combined biofilm development and mineral precipitation in capillary and porous media flow reactors. They will aid in closing the existing gap of knowledge between non-flowing (batch) systems often used to elucidate biogeochemical processes and the frequently observed influence of hydrodynamics on biogeochemical processes on the meso- and macroscale.The proposed research focuses on microbially-induced calcium carbonate mineralization. Calcium carbonate formation is responsible for the development of features with enormous scales in the shallow and deep ocean (e.g. reefs and alga and diatom exoskeletons) and in the terrestrial environment. Carbonate rocks (such as limestone, marble, and chalk) are probably the single largest reservoir of inorganic carbon on earth containing approximately 65 million gigatons of carbon. Carbonate mineral formation and dissolution are important parts of the global carbon cycle, have the potential to bind or release large amounts of carbon dioxide, and may therefore affect the global climate.Additionally, engineered, microbially mediated carbonate precipitation has been proposed as a strategy to improve geologic carbon sequestration and to facilitate the precipitation of heavy metals and radionuclides from contaminated groundwater. The investigators will develop laboratory and computational tools to better understand the role and utilize the potential in the environment of microbial communities in all of these processes.