Fate and Transport of Biocolloids in Beach Sand

海滩沙中生物胶体的归宿和运输

• 批准号: 0933230
• 负责人: Jin Li
• 金额: $ 49.87万
• 依托单位: University of Wisconsin-Milwaukee
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933230&HistoricalAwards=false
• 关键词: Fate; Transport; Biocolloids; Beach; Sand

0933230LiElevated level of bacteria associated with fecal contamination from a myriad of point and non-point sources is the major factor leading to beach closings and health advisories. Bathing water and beach sand contaminated with human and animal wastes pose a serious health risk to swimmers and beachgoers. While local public authorities routinely monitor the level of fecal indicators in bathing water to assess the health threat for swimmers, the risk of pathogen exposure for those who come into direct contact with sand has been largely neglected. Currently, no water quality criterion exists for testing beach sand and its pore water, even though studies have revealed that indicator organisms and pathogens can occur in high numbers and persist in subsurface sediment collected near freshwater shorelines.Thus, the overall goal of the proposed research is to improve the basic understanding of mechanisms governing the fate and transport of biocolloids, e.g., viruses, bacteria and protozoa, in the swash zone on sandy beaches. The specific objectives include: (1) Develop mathematical models that characterize biocolloids transport and retention in porous media under flow conditions relevant to the swash zone.(2)Study the transport mechanisms and survival characteristics of colloidal particles in well-controlled laboratory scale columns and a laboratory model sandy beach; determine the deposition rate under various flow conditions. (3)Extend the results from modeling studies and laboratory experiments to real-world situations and verify the transport model through field investigations.Understanding of the fundamental mechanisms governing the transport of indicator organisms and pathogens into sand and factors contribute to their subsequent survival opens a new paradigm in beach pollution monitoring and mitigation. The systematic integration of mathematical modeling, laboratory scale experiments and field investigation is an innovative aspect of this research. For the past a few years the PI has been investigating the fate and transport of bacteria in porous media, developing models for stormwater management for the Greater Milwaukee Watershed and studying microbial ecology of biofilms. The Co-PI has been developing a versatile in-situ Underwater Miniature PIV System (UWMPIV) system to investigate small-scale turbulence structures near water-sediment and water-air interfaces in Rivers, Lakes and Oceans. This project is built upon both PI?s expertise in environmental microbiology and hydrodynamics as documented in their recent publications and projects. It is expected that results from this research will advance the current knowledge in both fields.The intellectual merit of this project will provide a firm foundation for teaching, training and learning. A new inquiry based laboratory course that brings together undergraduate and graduate students from a diverse background including, biology, chemistry and geoscience, will be developed. The research results from this project will be added as ?hot topics? modules to the new course. Previous and current graduate students will have the opportunity to serve as mentors for undergraduate students recruited across the campus. By introducing environmental engineering issues to students majoring in science, it is possible to attract more women and minority undergraduate students to the engineering graduate program. The research results will be disseminated to policy makers, water quality managers, public health and environmental groups, researchers, and the public, through participation in local, national and international conferences and publication in peer-reviewed journals. An international workshop will be organized to provide a forum for researchers in the US and Asia to discuss the challenges in beach water monitoring and management. The PIs will also work with the EWB student chapter at UWM to provide safe drinking water and recreational water to villagers in Guatemala and Kenya.

0933230 Li与来自无数点源和非点源的粪便污染相关的细菌水平升高是导致海滩关闭和卫生灾难的主要因素。受人类及动物废物污染的泳滩水及海滩沙，对泳客及泳客的健康构成严重威胁。虽然地方公共当局定期监测洗澡水中的粪便指标水平，以评估游泳者的健康威胁，但直接接触沙子的人接触病原体的风险在很大程度上被忽视了。目前，没有水质标准存在测试海滩砂及其孔隙水，即使研究表明，指示生物和病原体可以出现在大量和持续存在于淡水海岸线附近收集的地下沉积物中。因此，拟议研究的总体目标是提高对生物胶体的命运和运输机制的基本理解，例如，病毒，细菌和原生动物，在桑迪的冲刷区。 具体目标包括：（1）开发数学模型，描述生物胶体在与冲流区相关的流动条件下在多孔介质中的迁移和滞留特征。（2）研究胶体颗粒在控制良好的实验室尺度柱和实验室模型桑迪海滩中的输运机理和存活特性，测定不同水流条件下的沉积速率。（3）将模拟研究和实验室实验的结果推广到实际情况，并通过实地调查验证迁移模型，了解指示生物和病原体迁移到沙子中的基本机制以及有助于它们随后存活的因素，为海滩污染监测和缓解开辟了新的范式。将数学模型、室内试验和野外调查有机地结合起来是本研究的创新之处。在过去的几年里，PI一直在研究多孔介质中细菌的命运和运输，为大密尔沃基流域开发雨水管理模型，并研究生物膜的微生物生态学。Co-PI一直在开发一个多功能的原位水下微型PIV系统（UWMPIV）系统，以调查河流，湖泊和海洋中水-沉积物和水-空气界面附近的小尺度湍流结构。这个项目是建立在两个PI？在环境微生物学和流体力学方面的专业知识，如他们最近的出版物和项目所记录的。预期本研究的成果将促进这两个领域的现有知识。本项目的智力价值将为教学、培训和学习提供坚实的基础。一个新的调查为基础的实验室课程，汇集了来自不同背景的本科生和研究生，包括生物学，化学和地球科学，将开发。该项目的研究成果将被添加为？热门话题？新课程的模块。以前和现在的研究生将有机会担任整个校园招募的本科生导师。通过向理科学生介绍环境工程问题，有可能吸引更多的妇女和少数民族本科生参加工程研究生课程。研究结果将通过参加地方、国家和国际会议以及在同行评审的期刊上发表，传播给决策者、水质管理人员、公共卫生和环境团体、研究人员和公众。将组织一个国际研讨会，为美国和亚洲的研究人员提供一个论坛，讨论海滩水监测和管理方面的挑战。PI还将与UWM的EWB学生分会合作，为危地马拉和肯尼亚的村民提供安全的饮用水和娱乐用水。