Collaborative Research: Investigating how transient electrical and magnetic signals relate to changes in recharge-driven redox state and iron mineral transformations

合作研究：研究瞬态电信号和磁信号如何与充电驱动的氧化还原状态和铁矿物转变的变化相关

• 批准号: 1742943
• 负责人: Carl Isaacson
• 金额: $ 9万
• 依托单位: Bemidji State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1742943&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; how; transient

Hydrocarbon source zones resulting from oil spills and/or crude oil pipeline ruptures result in persistent, long-term source of contamination of the aquifers that store potable groundwater in the Earth. This project serves the national interest by advancing the science needed to understand the long-term fate of hydrocarbon contaminants in the Earth. Geophysical tools that have been traditionally implemented to locate oil reservoirs and mineral deposits will be used to explore how geophysical signals provide diagnostic information on the progress of contaminant transformations that are largely driven by microbes in the Earth. This exploration of the linkages between biogeochemical processes and geophysical signals over time at an oil contaminated site may provide the knowledge needed to reliably deploy relatively simple geophysical measurement systems to monitor the long-term fate of oil spills. In the same way that medical imaging uses non-invasive sensing of the human body, non-invasive geophysical sensing of contaminant plumes might ultimately be used to understand the subsurface Earth without the need to drill into it. A non-invasive approach to monitoring the health of the human-impacted subsurface Earth would limit exposure of humans and animals to contaminants and negate unwanted transport of contaminants along pathways caused by invasive drilling methods. The research will be performed by undergraduate students performing field-based research in collaboration with government scientists from the United States Geological Survey (USGS). The project will engage minority undergraduate geoscience students from urban, economically disadvantaged neighborhoods in northern New Jersey. Results of the research will be shared with other scientists and students by running a workshop on geophysical signals associated with contaminant plumes. Transitional environments such as hyporheic and water table fluctuation zones (WTFZ) are biogeochemical hotspots where hydrologic processes driven by recharge events cause electron donor/acceptor mixtures that enhance microbial metabolism. Hydro-biogeochemical processes in transitional environments are challenging to study using hydrological, microbial and geochemical proxies due to the spatio-temporal and dynamic nature of these systems. Geochemical and microbial processes/transformations occurring within the WTFZ at organic-rich contaminated sites give rise to magnetic susceptibility (MS) and self potential (SP) electrical signals that show evidence of being regulated by recharge events and changes in water level. Understanding of the biogeochemical factors resulting in the measured geophysical responses, as needed to apply these techniques to investigate hydro-biogeochemical processes at field sites, remains incomplete. This project will pursue interdisciplinary research at a highly characterized site where decades of hydrological, geochemical and microbiological data are available to interpret the driving mechanisms causing geophysical signatures. It will integrate undergraduate education with basic research to advance understanding of the origins of such biogeophysical signatures and how they are regulated by variable hydrologic conditions. Supporting laboratory studies will be performed to constrain the linkages between iron cycling and biogeophysical signatures within the WTFZ. Datasets will be acquired to address the following hypotheses: [1] Transient magnetic susceptibility profiles result from hydrologically-driven iron cycling in the source zone; [2] Magnetic susceptibility changes in hydrocarbon source zones result from the consumption of iron-oxyhydroxides initially present on the sediments; [3] Transient self potential signatures are associated with recharge-driven modifications of dissolved or gas phase electron acceptors; [4] A microbial-mediated Fe(II)/Fe(III) redox couple drives a biogeobattery causing an anomalous self potential profile through the WTFZ in the source zone. Hypotheses will be explored by a combination of field geophysical measurements, in situ geochemical measurements on sediment packets suspended in boreholes and laboratory simulations of the WTFZ zone.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

石油泄漏和/或原油管道破裂造成的烃源区是地球上储存可饮用地下水的含水层的持久、长期污染源。这个项目通过推动了解碳氢化合物污染物在地球上的长期命运所需的科学来服务于国家利益。传统上用于定位油藏和矿床的地球物理工具将用于探索地球物理信号如何提供主要由地球微生物驱动的污染物转化过程的诊断信息。这种对石油污染地点的生物地球化学过程和地球物理信号之间随时间变化的联系的探索，可能为可靠地部署相对简单的地球物理测量系统以监测石油泄漏的长期命运提供所需的知识。就像医学成像使用对人体的非侵入式传感一样，对污染物羽流的非侵入式地球物理传感最终可能被用来了解地下地球，而无需钻到地下。采用一种非侵入性方法监测受人类影响的地下地球的健康状况，将限制人类和动物接触污染物，并消除侵入性钻探方法造成的有害污染物沿通道输送。该研究将由本科生与美国地质调查局（USGS）的政府科学家合作进行实地研究。该项目将招收来自新泽西州北部城市经济弱势社区的少数族裔地球科学本科生。研究结果将与其他科学家和学生分享，通过举办一个与污染羽流有关的地球物理信号研讨会。低水位和地下水位波动带（WTFZ）等过渡环境是生物地球化学热点，在这些环境中，由补给事件驱动的水文过程导致电子供体/受体混合，从而增强微生物代谢。由于这些系统的时空和动态性质，利用水文、微生物和地球化学代理研究过渡环境中的水文生物地球化学过程具有挑战性。富有机物污染区发生的地球化学和微生物过程/转化产生磁化率（MS）和自电位（SP）电信号，这些电信号显示出受补给事件和水位变化调节的证据。对导致测量到的地球物理响应的生物地球化学因素的理解，如需要应用这些技术来调查现场的水文-生物地球化学过程，仍然不完整。该项目将在一个高度特征的地点进行跨学科研究，在那里可以获得数十年的水文、地球化学和微生物数据，以解释导致地球物理特征的驱动机制。它将把本科教育与基础研究结合起来，以促进对这种生物地球物理特征的起源以及它们如何受到可变水文条件的调节的理解。将进行支持性实验室研究，以限制WTFZ内铁循环与生物地球物理特征之间的联系。将获取数据集以解决以下假设：[1]源区由水文驱动的铁循环导致的瞬态磁化率剖面；烃源带磁化率的变化是由于沉积物中初始氧化铁的消耗所致；瞬态自电位特征与溶解或气相电子受体的充电驱动修饰有关；微生物介导的Fe(II)/Fe（III）氧化还原偶对驱动生物地理电池，导致通过源区WTFZ的异常自电位分布。将结合实地地球物理测量、钻孔中悬浮沉积物包的现场地球化学测量和WTFZ区的实验室模拟来探索各种假设。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Microbially Induced Anaerobic Oxidation of Magnetite to Maghemite in a Hydrocarbon‐Contaminated Aquifer

• DOI: 10.1029/2021jg006560
• 发表时间: 2022-04
• 期刊: Journal of Geophysical Research: Biogeosciences
• 作者: L. Ohenhen;J. Feinberg;L. Slater;D. Ntarlagiannis;I. Cozzarelli;M. Rios-Sanchez;C. Isaacson;Alexis Stricker;E. Atekwana

Methanogens and Their Syntrophic Partners Dominate Zones of Enhanced Magnetic Susceptibility at a Petroleum Contaminated Site

• DOI: 10.3389/feart.2021.598172
• 发表时间: 2021-03-15
• 期刊: FRONTIERS IN EARTH SCIENCE
• 影响因子: 2.9
• 作者: Beaver, Carol L.;Atekwana, Estella A.;Rossbach, Silvia
• 通讯作者: Rossbach, Silvia