International Planning Visit: Investigating the Interactions Between Dissolved Organic Matter, Microbial Communities, and Arsenic Biogeochemistry in Groundwater of a Pristine Delt

这次计划访问将制定一个国际合作研究和培训项目，主题是博茨瓦纳奥卡万戈三角洲地下水中溶解有机物、微生物群落和砷生物地球化学之间的相互作用。计划中的访问将汇集科罗拉多大学和堪萨斯州立大学的美国科学家和工程师，以及博茨瓦纳地质调查局和奥卡万戈研究所（ORI）的科学家，共同制定一项引人注目的研究计划，收集样本进行初步分析，并与莫恩高中的科学教师会面，为美国K-12教师规划未来的教育推广活动。研究小组还将检查ORI的实验室设施，确定实地研究地点，为参与研究的研究生确定适当的国内导师，并开始准备针对NSF EAR水文科学（HS）部门的研究计划。知识价值：地下水中自然存在的砷是一个全球性问题，对全世界数百万人的健康造成严重后果，但人们对砷从沉积物中运移的过程还不太了解。这次计划访问将协调未来的研究，以发展对富金属氧化物沉积物中影响地下水中砷动员的有机物和微生物之间反应的过程级理解。提高对地下水流道中溶解有机物质转化的认识，以及与流道相关的微生物群落组成变化，对于理解（和预测）不同地下水环境中砷的动员非常重要。奥卡万戈三角洲岛屿的特征是由蒸发作用驱动的地下水流动，这为研究与微生物群落进化和导致砷动员的相关生物地球化学过程有关的问题提供了独特的机会。更广泛的影响：除了扩大科学界对全球地下水砷污染问题的理解之外，这次规划访问还将支持两名研究生，他们将有机会从项目的概念开始参与其中。美国科学家和Maun高中教师之间的会议将建立新的关系，这是未来教育推广的基础，以教师研究经验和本科生研究经验的形式。

This planning visit will develop an international collaborative research and training project on the topic of interactions between dissolved organic matter, microbial communities, and arsenic biogeochemistry in groundwater of the Okavango Delta, Botswana. The planning visit will bring together U.S. scientists and engineers from the University of Colorado and Kansas State University with scientists from the Botswana Geologic Survey and the Okavango Research Institute (ORI) to develop a compelling research plan, collect samples for preliminary analyses, and meet with science teachers from Maun Senior Secondary School to plan future educational outreach activities for U.S. K-12 teachers. The research team will also examine the laboratory facilities at ORI, identify field research sites, identify appropriate in-country mentors for graduate students involved in the research, and begin preparation of a research proposal targeted for the NSF EAR Hydrologic Sciences (HS) division. Intellectual merit: Naturally-occurring arsenic in groundwater is a global problem with serious health consequences for millions of people worldwide, yet the processes by which arsenic is mobilized from sediments are not well understood. This planning visit will coordinate future research to develop a process-level understanding of the reactions between organic matter and microorganisms in metal oxide-rich sediments that influence arsenic mobilization in groundwater. The improved understanding of dissolved organic material transformations along groundwater flow paths and flow path-related shifts in microbial community composition is extremely important for understanding (and predicting) arsenic mobilization in diverse groundwater environments. The evapotranspiration-driven groundwater flow that is characteristic of islands in the Okavango Delta provides a unique opportunity to investigate questions related to the evolution of microbial communities and associated biogeochemical processes that lead to arsenic mobilization. Broader impacts: In addition to broadening the understanding of the scientific community understanding on the global problem of groundwater arsenic contamination, this planning visit will support two graduate students, who will have the opportunity to be involved in the project from its conception. Meetings between US scientists and teachers at Maun Senior Secondary School will build new relationships that are the basis for future educational outreach in the form of Research Experience for Teachers and Research Experience for Undergraduates.