Collaborative Research: The dynamic iron curtain surrounding fluctuating rivers and its impacts on arsenic fate and transport

合作研究：波动河流周围的动态铁幕及其对砷归宿和迁移的影响

• 批准号: 1940772
• 负责人: Saugata Datta
• 金额: $ 29.35万
• 依托单位: University of Texas at San Antonio
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-09 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1940772&HistoricalAwards=false
• 关键词: Collaborative; Research; dynamic; iron; curtain

Dissolved arsenic in groundwater is a global threat to millions of people. This arsenic is released from minerals within groundwater aquifers. People that regularly drink toxic levels of dissolved arsenic are at risk of getting deadly diseases. Some rocks and sediments contain enough arsenic to contaminate groundwater under certain conditions. This project aims to understand the conditions under which arsenic is trapped or released. One setting in which great quantities of arsenic is trapped is in riverbank sediments. Rivers continue to flow during dry periods by contributions from groundwater. Groundwater that has lots of iron and arsenic carries huge amounts of these elements to the riverbank sediments. It is important to understand the fate of this trapped arsenic and iron. The goal of this study is to develop a theory on the growth and fate of these iron-arsenic deposits. This project accomplishes this goal by observing which minerals the arsenic is bound to within sediments on the edge of the Meghna River in Bangladesh. Bangladesh has some of the highest naturally occurring levels of arsenic in aquifers in the world. Laboratory experiments will test the impact of tidal fluctuations on the nature of these iron-arsenic deposits. The movement of water and elements will be measured in the field between aquifers and the Meghna River. This project supports the research of U.S.-based undergraduate and graduate students and prepares the next generation of U.S. and Bangladeshi scientists to understand the movement of toxic elements between aquifers and rivers. Arsenic-contaminated water resources are prevalent in fluvio-deltaic aquifers whose sediment are the geogenic source. The fate of As in groundwater discharging to rivers, however, remains unknown despite advances in understanding the origin and transport of As in groundwater. A few observations have suggested that As is stored within shallow, permeable, riverbank sediment through sorption on iron-oxide surfaces, referred to herein as Permeable Natural Reactive Barriers (PNRB). These accumulations threaten the communities along rivers should there be a reversal in groundwater flow induced by pumping, or should this high-As sediment be scoured and then re-deposited along a segment of the river where infiltration occurs. In deltaic regions, aquifers are connected to large rivers subject to periodic forcing driven by tides and seasonal flooding. Thus, the dynamics of groundwater-borne As transported to and from rivers should also be driven by similar periodic forcing. The amplitude and period of these fluctuations will uniquely determine the properties of these PNRBs, and knowing this, combined with knowledge of the iron (Fe) and As concentrations of the aquifers, should allow regional prediction of the accumulation of As in riverbank sediment. This project investigates the dynamics of a Fe-oxide PNRB through complementary detailed field characterization of sites along the Meghna River in Bangladesh along with laboratory experimentation and advanced coupled flow and reactive transport simulations. The data-driven modeling is used to assess the occurrence of PNRBs in similar tidal river-aquifer settings through sensitivity analysis. The anticipated findings will advance the understanding of the cycling of geogenic As in shallow, reducing alluvial aquifers connected with rivers in Asia. Critical knowledge on coupled hydrologic and biogeochemical processes for the protection and management of water resources will be provided to both the local communities dealing with As contamination and the broader scientific body. Local stakeholders will be directly involved in the research and project findings will be translated for policy makers to reach affected communities. This study funds the research projects of undergraduate and graduate students, and post-doctoral investigators and expands the infrastructure for studying groundwater-river water exchange along the Meghna River in Bangladesh.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.

地下水中解散的砷是对数百万人民的全球威胁。这种砷从地下水含水层内的矿物质中释放出来。定期喝有毒水平的溶解砷的人有患致命疾病的风险。在某些条件下，一些岩石和沉积物含有足够的砷以污染地下水。该项目旨在了解砷被困或释放的条件。河岸沉积物中，大量砷被困的一种环境。河流在干燥期间通过地下水的贡献继续流动。拥有大量铁和砷的地下水将大量这些元素带到河岸沉积物中。重要的是要了解这种被困的砷和铁的命运。这项研究的目的是开发有关这些铁疗养沉积物的生长和命运的理论。该项目通过观察矿物质的砷在孟加拉国梅格纳河边缘的沉积物内界定来实现这一目标。孟加拉国拥有世界上含水层的砷含量最高。实验室实验将测试潮汐波动对这些铁疗中沉积物性质的影响。水和元素的运动将在含水层和梅格纳河之间的田野中进行测量。该项目支持了美国的本科生和研究生的研究，并准备下一代美国和孟加拉国科学家了解含水层和河流之间有毒元素的运动。砷污染的水资源普遍存在，在荧光含量的含水层中，沉积物是地球源。然而，尽管在理解地下水的起源和运输方面取得了进步，但在地下水中的AS命运仍然未知。一些观察结果表明，通过在铁氧化物表面上吸附在浅层，可渗透的河岸沉积物中，此处称为可渗透的自然反应性屏障（PNRB）。如果抽水引起的地下水流动逆转，或者是在渗透发生的河段沿河段重新沉积，这些积累威胁着河流沿河的社区。在三角洲地区，含水层与潮汐和季节性洪水驱动的大型河流相连。因此，从河流运输和从河流运输的地下流体的动力学也应由类似的周期性强迫驱动。这些波动的幅度和周期将唯一确定这些PNRB的特性，并知道这一点，结合了铁（Fe）的知识，作为含水层的浓度，应允许区域预测河岸沉积物中AS的积累。该项目通过对孟加拉国梅格纳河沿线的互补详细场所表征进行氧化氧化物PNRB的动力学，以及实验室实验和高级耦合流和反应性传输模拟。数据驱动的建模用于评估通过灵敏度分析在类似的潮汐河水隔离器设置中PNRB的出现。预期的发现将提高对地球循环的理解，如浅层，从而减少了与亚洲河流相关的冲积含水层。关于保护和管理水资源的耦合水文和生物地球化学过程的批判性知识将向处理AS污染和更广泛的科学机构的当地社区提供。当地利益相关者将直接参与研究，项目结果将被翻译成政策制定者到达受影响的社区。这项研究为本科和研究生的研究项目提供了资金，并扩大了博士后调查人员的研究，并扩大了沿孟加拉国梅格纳河沿线研究地下水河流交换的基础设施。这一奖项反映了NSF的法定任务，并通过使用基金会的知识优点和广泛影响来评估NSF的法定任务，并被认为是值得的支持。

项目成果

Redox trapping of arsenic in hyporheic zones modified by silicate weathering beneath floodplains

漫滩下硅酸盐风化作用改变的潜流带中砷的氧化还原捕获

• DOI: 10.1016/j.apgeochem.2023.105831
• 发表时间: 2023
• 期刊: Applied Geochemistry
• 影响因子: 3.4
• 作者: Jewell, Katrina;Myers, Kimberly D.;Lipsi, Mehtaz;Hossain, Saddam;Datta, Saugata;Cardenas, M. Bayani;Aitkenhead-Peterson, Jacqueline;Varner, Tom;Kwak, Kyungwon;Raymond, Anne
• 通讯作者: Raymond, Anne

Application of electrical resistivity to map the stratigraphy and salinity of fluvio-deltaic aquifers: case studies from Bangladesh that reveal benefits and pitfalls

• DOI: 10.1007/s10040-021-02342-y
• 发表时间: 2021-04
• 期刊: Hydrogeology Journal
• 影响因子: 2.8
• 作者: Micaela N. Pedrazas;M. Cardenas;A. Hosain;Cansu Demir;Kazi Matin Uddin Ahmed;S. H. Akhter;Lichun Wang;S. Datta;P. Knappett

Contribution of sedimentary organic matter to arsenic mobilization along a potential natural reactive barrier (NRB) near a river: The Meghna river, Bangladesh

沉积有机质对河流附近潜在天然反应屏障 (NRB) 砷迁移的贡献：孟加拉国梅格纳河

• DOI: 10.1016/j.chemosphere.2022.136289
• 发表时间: 2022
• 期刊: Chemosphere
• 影响因子: 8.8
• 作者: Varner, Thomas S.;Kulkarni, Harshad V.;Nguyen, William;Kwak, Kyungwon;Cardenas, M Bayani;Knappett, Peter S.K.;Ojeda, Ann S.;Malina, Natalia;Bhuiyan, Mesbah Uddin;Ahmed, Kazi M.
• 通讯作者: Ahmed, Kazi M.

Diverse sedimentary organic matter within the river-aquifer interface drives arsenic mobility along the Meghna River Corridor in Bangladesh

• DOI: 10.1016/j.apgeochem.2023.105883
• 发表时间: 2024-01-12
• 期刊: APPLIED GEOCHEMISTRY
• 影响因子: 3.4
• 作者: Varner，Thomas S.;Kulkarni，Harshad;Datta，Saugata
• 通讯作者: Datta，Saugata

Mineralogical Associations of Sedimentary Arsenic within a Contaminated Aquifer Determined through Thermal Treatment and Spectroscopy

• DOI: 10.3390/min13070889
• 发表时间: 2023-06
• 期刊: Minerals
• 影响因子: 2.5
• 作者: Thomas S. Varner;H. Kulkarni;M. U. Bhuiyan;M. Cardenas;P. Knappett;S. Datta