Fate and Transport of Biocolloids in Beach Sand

0933230Li与大量点源和非点源粪便污染相关的细菌水平升高是导致海滩关闭和健康建议的主要因素。被人类和动物排泄物污染的洗澡水和海滩沙子对游泳者和海滩游人的健康构成严重威胁。虽然地方公共当局经常监测洗澡水中粪便指标的水平，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，没有水质标准来测试海滩沙及其孔隙水，尽管研究表明，指示性生物和病原体可能大量出现并持续存在于淡水海岸附近的地下沉积物中。因此，拟议研究的总体目标是加强对控制生物胶体在沙滩潮汐带的命运和运输机制的基本了解，例如病毒、细菌和原生动物。具体目标包括：(1)建立数学模型，描述生物胶体在与冲刷区相关的流动条件下在多孔介质中的迁移和滞留；(2)研究胶体粒子在控制良好的实验室比例尺柱和实验室模型沙滩中的迁移机制和生存特性；确定不同流动条件下的沉积速率。(3)将模型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传输模型。了解指示生物和病原体向沙子中传输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。数学建模、实验室规模实验和野外调查的系统集成是本研究的创新之处。在过去的几年里，PI一直在调查细菌在多孔介质中的去向和传输，开发大密尔沃基分水岭的雨水管理模型，并研究生物膜的微生物生态。Co-PI一直在开发一种多功能的原位水下微型PIV系统(UWMPIV)，用于研究河流、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。该项目建立在皮埃尔？S在环境微生物学和水动力学方面的专业知识的基础上，如他们最近的出版物和项目所述。预计本研究的成果将促进这两个领域的现有知识，本项目的智力优势将为教学、培训和学习提供坚实的基础。将开发一门新的以探究为基础的实验室课程，将来自生物、化学和地球科学等不同背景的本科生和研究生聚集在一起。该项目的研究成果将被添加为？热门话题？将模块添加到新课程。以前和现在的研究生将有机会成为校园内招收的本科生的导师。通过向理科专业的学生介绍环境工程问题，有可能吸引更多的女性和少数族裔本科生参加工程学研究生课程。研究成果将通过参加地方、国家和国际会议以及在同行评议的期刊上发表，向政策制定者、水质管理人员、公共卫生和环境团体、研究人员和公众传播。将举办一个国际研讨会，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。PIS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。

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.