Collaborative Research: Investigation of hydrologic and biogeochemical controls on arsenic mobilization at a field site in Munshiganj, Bangladesh

查尔斯·哈维，麻省理工学院合作研究：在孟加拉国Munshiganj的一个田间地点对砷动员的水文和生物地球化学控制的调查该项目将通过在孟加拉国的一个稻田地点部署水文和地球化学传感器，并通过现场和实验室的微观/中尺度实验，调查最近观察到的现象如何影响砷（As）的动员。具体来说，最近在该地点进行的初步研究发现了土壤中犁盘下存在气相的证据，以及渗透水快速向下运动的证据。地球化学和水力特征的趋势表明，可能由植物引起的日过程可能很重要。该项目将测试水文过程（由于气压变化和植物蒸散作用）和植物诱导的化学变化（由于根部氧气释放和地表水变化）驱动现场观察到的每日振荡的假设。这是一个具有挑战性的科学问题，将使用嵌入式传感器网络进行一系列全面的实验和观察来研究这个问题。这项研究的社会影响很大。砷在美国和全球都是一个严重的污染问题，它在孟加拉国造成了可怕的健康后果。建议的研究应提供重要的信息，以提高我们对As动员的环境控制的认识。创新的教育/推广部分包括由加州大学洛杉矶分校PI教授的服务学习课程，在此期间，本科生将把有关环境传感器的新信息带到中学（六年级）的教室。

CBET-0651968 Jennifer Jay, UCLA (lead)CBET-0651678 Charles Harvey, MITCollaborative Research: Investigation of hydrologic and biogeochemicalcontrols on arsenic mobilization at a field site in Munshiganj, BangladeshThis project will investigate how recently observed phenomena influence arsenic (As) mobilization through deployment of hydrologic and geochemical sensors at a rice paddy site in Bangladesh and through field and laboratory microcosm/mesocosm experiments. Specifically, recent preliminary studies at the site yielded evidence for a gas phase under the plough pan in the soil and also evidence for rapid downward movement of infiltrating water. Trends in geochemical and hydraulic characteristics suggest that diurnal processes, possibly plant-induced, may be important. The project will test the hypothesis that hydrological processes (due to barometric changes and plant evapotranspiration) and plant-induced chemical changes (due to root oxygen release and surface water changes) drive daily oscillations observed at the site. This is a challenging scientific problem, and a comprehensive set of experiments and observations made with an imbedded sensor network will be used to study the problem. The societal impacts of the research are high. Arsenic is a serious pollution problem in the U.S. and globally, and it has had dire health consequences in Bangladesh. The proposed studies should provide important information to improve our understanding of the environmental controls on As mobilization. An innovative educational/outreach component involves a service learning course taught by the UCLA PI, during which undergraduate students will take new information about environmental sensors to middle school (6th grade) classrooms.