Nano- and Macroscale Physico-chemical Processes Impacting Arsenic Mobilization

影响砷迁移的纳米和宏观物理化学过程

• 批准号: 1424927
• 负责人: Young-Shin Jun
• 金额: $ 34.06万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1424927&HistoricalAwards=false
• 关键词: Nano; Macroscale; Physico; chemical; Processes

Managed aquifer recharge (MAR) is one water reuse technique with the potential to meet growing water demands. In MAR, reclaimed wastewater is injected into aquifer formations for later use. Although filtration and adsorption in the vadose zone and underlying aquifer can remove some contaminants from reclaimed water, unfavorable soil-water interactions can mobilize arsenic from arsenic-bearing aquifer formations. This work will investigate how the interactions between water and arsenic-bearing pyrite, such as arsenopyrite/arsenian pyrite, impact arsenic mobility during MAR, and investigators will provide new quantitative and qualitative fundamental information on the redox-promoted dissolution mechanisms of arsenic-bearing pyrite and the consequent nucleation, growth, and phase transformation of iron (hydr)oxide nanoparticles, which are closely linked with arsenic mobilization and attenuation. By combining novel multidisciplinary approaches and in situ observations, including atomic force microscopy using an electrochemical control, small angle X-ray scattering, and batch reactor experimental measurements, they will obtain quantitative parameters and clearer qualitative descriptions of the thermodynamics and kinetics of initial iron (hydr)oxide nuclei evolution at the mineral-water interface. For the first time, new information on nucleation will be incorporated into geochemical reactive transport models to improve the prediction accuracy. The experimental results will also be compared with available data from pilot-scale column experiments at the U.S. EPA's Test & Evaluation Facility in Cincinnati, OH, and from MAR field sites. The results will help determine pretreatment requirements for reclaimed water sources and will provide a basis for developing more sustainable MAR operation guidelines. Beyond this application, the knowledge gained can be applied to related geochemical systems, including regions struggling with pervasive arsenic contamination of groundwater and environments where quantification of arsenic sorption onto nanoscale iron (hydr)oxide precipitates is a source of great uncertainty. The proposed outreach plan will provide educational, research, public engagement, and professional development opportunities for middle school, high school, undergraduate, and graduate students. It will have far-reaching societal impacts. In addition, the participation of traditionally underrepresented students will be encouraged. To achieve this goal, investigators will develop a "Hot Topics" website and related workshops focused on water quality concepts, in collaboration with Washington University's Institute for School Partnership and teachers from St. Louis' middle and high schools. To encourage high school and undergraduate students' early involvement in science and engineering, they will provide scientific research projects and offer public lectures on water quality.

托管含水层补给（MAR）是一种水再利用技术，有可能满足不断增长的水需求。在3月，将回收的废水注入含水层地层以供以后使用。尽管vadose区和基础含水层的过滤和吸附可以从再生水中去除一些污染物，但不利的土壤水相互作用可以动员含砷含水层的含水层的砷。 This work will investigate how the interactions between water and arsenic-bearing pyrite, such as arsenopyrite/arsenian pyrite, impact arsenic mobility during MAR, and investigators will provide new quantitative and qualitative fundamental information on the redox-promoted dissolution mechanisms of arsenic-bearing pyrite and the consequent nucleation, growth, and phase transformation of iron (hydr)oxide nanoparticles, which are与砷动员和衰减密切相关。通过结合新型的多学科方法和原位观测，包括使用电化学控制，小角度X射线散射以及批处理反应器实验测量的原子力显微镜，它们将获得定量参数和更清晰的定性描述。首次将有关成核的新信息纳入地球化学反应性传输模型，以提高预测准确性。还将将实验结果与来自俄亥俄州辛辛那提市EPA测试和评估设施以及MAR野外地点的EPA测试和评估设施的Pilot尺度柱实验的可用数据进行比较。结果将有助于确定回收水源的预处理要求，并为制定更可持续的MAR操作指南提供基础。除了这种应用之外，获得的知识还可以应用于相关的地球化学系统，包括在地下水和环境中挣扎的砷污染和环境中挣扎的地区，在这些区域将砷吸附到纳米级铁（氢）氧化物（氧化物）沉淀上是极大的不确定性来源。拟议的外展计划将为中学，高中，本科和研究生提供教育，研究，公共参与和专业发展机会。它将产生深远的社会影响。此外，将鼓励传统上代表性不足的学生的参与。为了实现这一目标，调查人员将与华盛顿大学的学校合作伙伴研究所以及圣路易斯中学和高中的教师合作，开发一个“热门话题”网站和关注水质概念的相关研讨会。为了鼓励高中和本科生早期参与科学和工程学，他们将提供科学研究项目，并提供有关水质的公开演讲。