Collaborative Research: Microbial Arsenate Reduction Control on Arsenic in Groundwater

摘要：拟议的研究解决了含水层中砷含量升高的自然现象，这对美国和世界各地的大量人口都是一个引人注目的公共健康危害。我们的重点是微生物在控制含水层中砷浓度方面的作用，特别是在低值但仍高于饮用水标准的情况下。拟议的研究将定量确定微生物砷酸盐减少在美国俄勒冈州南威拉米特盆地基岩含水层中的作用。砷在含水层中自然存在，浓度高达十亿分之二。该含水层可作为研究长英质火山岩及相关冲积沉积物含水层中砷污染的模型。我们将进行现场生物刺激实验和生物地球化学反应输运建模，以验证微生物砷酸盐还原控制缺氧含水层中砷的衰减和动员的假设。本研究结果将定量地确定不同微生物功能群在调节含水层中砷浓度中的意义。本研究的理论组成部分将推进微生物代谢与地球化学反应耦合的生物地球化学反应模型。研究结果还将为政府机构制定有效的地下水资源管理、监测和保护策略和法规提供重要信息。我们将与考点附近高中的科学教师合作，在他们的科学课程中编写可复制和可持续的关于砷的课堂课程。砷课的教学资料集将分发给俄勒冈州所有K-12教育工作者，以帮助俄勒冈州公立学校更好地准备俄勒冈州教育委员会对具有实验室经验的科学课的新要求。

Title: Microbial Arsenate Reduction Control on Arsenic in GroundwaterAbstract The proposed research addresses natural occurrences of elevated arsenic in aquifers, a compelling public health hazard to a large population in both the United States and areas around the world. We focus on the role of microorganisms in controlling arsenic concentrations in aquifers, particularly at low values but still above the drinking water standards. The proposed study will determine quantitatively the role of microbial arsenate reduction in the bedrock aquifer in the Southern Willamette Basin, Oregon, USA. Arsenic occurs naturally in the aquifer at concentrations as high as 2000 parts per billion (ppb). This aquifer serves as a model for studying arsenic contamination in aquifers of felsic volcanic rocks and related alluvial sediments. We will conduct field biostimulation experiments and biogeochemical reactive transport modeling to test the hypothesis that microbial arsenate reduction controls significantly arsenic attenuation and mobilization in anoxic aquifers. Results of this study will pinpoint quantitatively the significance of different microbial functional groups in regulating arsenic concentrations in the aquifer. The theoretical component of this study will advance biogeochemical reaction modeling that couples microbial metabolisms with geochemical reactions. Results of this study will also provide critical information concerning groundwater microbiology for government agencies in designing effective strategies and regulations for groundwater resource management, monitoring, and protection. We will collaborate with science instructors at high schools near the field site to develop a replicable and sustainable classroom lesson on arsenic into their science curriculum. The teaching portfolio of the arsenic lesson will be distributed to all Oregon K-12 educators to help Oregon public schools better prepared for a new requirement of a science class with laboratory experience by the Oregon State Board of Education.