UNS: Collaborative Research: Effects of Nano-Bio Interactions on Nanoparticle Fate and Transport in Porous Media

尽管工业和消费品中工程纳米材料的生产和使用大幅增加，但人们对纳米颗粒释放到环境中后的命运和运输知之甚少。该项目的总体目标是更好地了解工程纳米颗粒与微生物群落之间的相互作用，并利用这些信息来改进对纳米颗粒在土壤、地下水和水处理系统中积累和迁移的预测。为了扩大这项工作的教育范围和实际影响，该项目包括为本科生提供研究经验，并开发交互式多媒体教学工具，这些工具将纳入工程教育和外联中心以及科学、技术、工程和数学多样性中心开展的教育和培训计划。过去十年进行的研究极大地提高了我们对纳米颗粒在一系列与环境有关的条件下的聚集和移动性的了解，并推动了能够描述纳米颗粒在膜、滤床和含水层材料中的传输和保留的数学模型的发展。与此同时，许多研究探索了纳米颗粒对细胞系统、水生无脊椎动物、鱼类和微生物的影响。本研究项目的总体目标是将这两条研究路线结合起来，以调查纳米生物相互作用对纳米颗粒在多孔介质中的命运和传输的作用。该研究项目将纳米颗粒表征和生物实验与动态迁移研究相结合，以量化纳米生物相互作用对具有代表性的工程纳米材料(氧化铁和氧化镁)在含水层材料和自然土壤中的流动性和命运的影响。研究活动围绕三项任务展开，(1)利用石英晶体微天平测定纳米颗粒的沉积和释放与表面涂层老化、生物聚合物和溶液组成的关系，(2)评估生物聚合物对纳米材料在非生物柱中的迁移和保留的影响，以及(3)测量纳米颗粒在好氧和厌氧生物活性土柱中的迁移、沉积和老化。研究的新方面包括微生物-颗粒相互作用与运输的直接耦合，生物相关沉积的评估，使用流动扫描电子显微镜和低温透射电子显微镜技术直接观察纳米颗粒的行为。这项工作的结果正被用于探索微生物群落在老化的纳米颗粒表面涂层中的作用，以及过滤器成熟和位置阻塞对纳米颗粒附着过程和环境中流动性的影响。为了将这项工作的影响扩展到传统的学术边界之外，正在将研究成果纳入基于模型的教程、简短的教学视频以及说明性的案例研究和建模工具中，这些研究成果将通过与科学技术、工程和数学多样性中心、塔夫茨工程成功之桥以及布朗工程教育和推广中心的合作和参与倡议来传播。

Despite dramatic increases in the production and use of engineered nanomaterials in industrial and consumer products, very little is known about the fate and transport of nanoparticles following their release into the environment. The overall goal of this project is to better understand the interactions between engineered nanoparticles and microbial communities, and to use this information to improve predictions of nanoparticle accumulation and mobility in soils, groundwater, and water treatment systems. To broaden the educational outreach and practical implications of this work, the project includes research experiences for undergraduate students and the development of interactive, multi-media instructional tools that will be incorporated into educational and training programs run by the Center for Engineering Education and Outreach and Center for Science, Technology, Engineering and Math Diversity. Research conducted over the past ten years has greatly improved our knowledge of nanoparticle aggregation and mobility over a range of environmentally-relevant conditions, and has informed the development of mathematical models capable of describing nanoparticle transport and retention in membranes, filter beds and aquifer materials. At the same time, numerous studies have explored the impacts of nanoparticles on cellular systems, aquatic invertebrates, fish, and microorganisms. The overall goal of this research project is to combine these two lines of research to investigate the role of nano-bio interactions on nanoparticle fate and transport in porous media. The research project is coupling nanoparticle characterization and biotic experiments with dynamic transport studies to quantify the effects of nano-bio interactions on the mobility and fate of representative engineered nanomaterials (iron oxide and magnesium oxide) in aquifer materials and natural soils. Research activities are being structured around three tasks, (1) determination of nanoparticle deposition and release as a function of surface coating aging, biopolymers, and solution composition using a quartz crystal microbalance, (2) assessment of the effects of biopolymers on nanomaterial mobility and retention in abiotic columns, and (3) measurement of nanoparticle transport, deposition, and aging in aerobic and anaerobic bio-active soil columns. Novel aspects of the research include the direct coupling of microbial-particle interactions with transport, assessment of bio-related deposition, direct observation of nanoparticle behavior using flow-through scanning electron microscopy and cryo-transmission electron microscopy techniques. Results obtained from this work are being used to explore the role of microbial communities in the aging nanoparticle surface coatings, and the impacts of filter ripening and site blocking on nanoparticle attachment processes and mobility in the environment. To extend the impact of this work beyond traditional academic boundaries, research outcomes are being incorporated into model-based tutorials, short instructional videos, and illustrative case studies and modeling tools that will be disseminated through collaborations and participation in initiatives with the Center for Science Technology, Engineering and Math Diversity, the Bridge to Engineering Success at Tufts, and the Center for Engineering Education and Outreach at Brown.