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

CBET-0651968詹妮弗·杰，加州大学洛杉矶分校(牵头)CBET-0651678，MIT查尔斯·哈维合作研究：调查孟加拉国Munshiganj田间场地的水文和生物地质化学控制砷的动员这个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，以及通过田间和实验室微观/中观实验，调查最近观察到的现象如何影响砷的动员。具体地说，最近对该地点的初步研究发现了土壤中犁底板下存在气相的证据，也有证据表明渗入的水迅速向下移动。地球化学和水力特征的趋势表明，可能由植物引起的昼夜过程可能是重要的。该项目将检验这一假设，即水文过程(由于气压变化和植物蒸散)和植物诱导的化学变化(由于根氧释放和地表水变化)驱动在现场观察到的每日振荡。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测来研究这一问题。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，在孟加拉国已经造成了可怕的健康后果。拟议的研究应该提供重要的信息，以提高我们对AS动员的环境控制的理解。一个创新的教育/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)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.