CAREER: Impact of Urbanization on Organic Carbon-Metal Interactions and Trophic Transfer in Streams

1454448 VadasCAREER：城市化对河流中有机碳-金属相互作用和营养转移的影响在日益城市化的景观中，雨水和废水中的金属对河流中生物的负面影响将继续上升。虽然流生物的金属生物利用度模型的重点是对环境暴露于溶解的金属相，这项拟议的研究还解决了不可分割的作用，控制生物吸收的金属的附着和摄取的有机物。在生态系统尺度上，金属吸收和滞留的生物动力学与金属和有机质特性、暴露模式和河流生物的摄食行为有关。评估金属形态和大小分布以及有机物的特点，有关金属吸收的生态系统一级的风险评估模型，是有用的建立流管理战略的发展所需的知识。除了拟议的研究外，教育计划还将支持培训1名硕士。一个PhD学生和至少2名本科研究人员。加强学生培训将侧重于相关学科的额外课程和沟通技巧，以促进未来的跨学科研究。将根据国家教育指导方针为K-12教室开发教育模块。这些模块将通过康涅狄格大学的达芬奇计划传播，以扩大其影响范围，超越个别教室。该项目的一个重要方面将是通过关注跨学科的基本理解和沟通，将生态学和环境工程融入各级教育：将为大学教育和知识产权开发几个跨学科的基于问题的学习练习，将开发和广泛分发12个与流障碍有关的教育模块。为城市地区受损河流制定更有效的管理战略的挑战。评估和管理受损河流的现有框架没有解决河流中存在的动态和独特条件。铜和锌等金属是必需的，也是有毒的，这取决于浓度，并且是最常见的损伤原因之一。然而，强相互作用与有机物在所有大小范围和差异的暴露模式的污水和雨水源的损害是戏剧性的。总金属负荷不一定是生物吸收的良好指标，必须考虑金属不稳定性和不同有机金属颗粒的摄入。为了解决与不同金属源相关的河流损害问题，需要更全面地了解城市河流条件下的金属生物吸收。 为了实现这一点，以下目标和方法将是：1）量化的变化，金属形态和尺寸分布在不同的流源沃茨在空间和时间：自动采样器将收集时间间隔和流量加权样本的污水和雨水径流，分别在受损的网站在城市到郊区的网站。样品将被分成与生物吸收有关的大小部分，并分析总金属、有机物、胶体金属和有机物的大小分布，以及有机物的光学、化学和金属结合特性。2)确定初级生产者和更高营养级生物体中生物吸收的金属形态和尺寸分布预测因子以及对金属负载动力学的依赖性：金属吸收和附着将作为不同来源沃茨中有机物的尺寸分布和化学特性的函数进行分析。生物动力学模型将评估藻类对金属的净吸收以及随后向更高营养级生物的转移。这些将在模拟水流的暴露制度下进行检查，例如，对于流出物来源，源水与溪流水的比例不同，对于雨水径流，暴露浓度不同。

1454448VadasCAREER: Impact of Urbanization on Organic Carbon-Metal Interactions and Trophic Transfer in StreamsIn an increasingly urbanizing landscape, the negative impact of metals from both stormwater and wastewater effluent on organisms in streams will continue to rise. While the focus of most metal bioavailability models for stream organisms is on ambient exposure to dissolved metal phases, this proposed research also addresses the integral role of attachment and ingestion of organic matter in controlling bio-uptake of metals. At the ecosystem scale, the biodynamics of metal uptake and retention relate to both metal and organic matter characteristics, exposure patterns and feeding behavior of stream organisms. Assessment of metal speciation and size distribution as well as organic matter characteristics as related to metal uptake is required knowledge for the development of ecosystem level exposure assessment models that are useful for establishing management strategies for streams. In addition to the proposed research, the education plan will support the training of 1 M.S. and 1 Ph.D. student and at least 2 undergraduate researchers. Enhanced student training will focus on additional coursework in related disciplines and communication skills to promote interdisciplinary research in the future. Educational modules will be developed for K-12 classrooms according to State education guidelines. These modules will be disseminated through the DaVinci program at the University of Connecticut to broaden their reach beyond an individual classroom. A significant aspect of this project will be integrating ecology and environmental engineering across all levels of education through a focus on basic understanding and communication across disciplines: Several interdisciplinary problem-based learning exercises will be developed for university level education and K-12 education modules related to stream impairment will be developed and distributed widely.This career development plan addresses the research and education challenges associated with developing more effective management strategies for impaired streams in urban areas. The existing framework to assess and manage impaired streams does not address the dynamic and unique conditions present in streams. Metals such as copper and zinc are both necessary and toxic depending on the concentration, and are one of the most common causes of impairment. However, the strong interaction with organic matter across all size ranges and differences in exposure patterns of the effluent and stormwater sources of impairment are dramatic. Total metal loads are not necessarily good indicators of bio-uptake and both metal lability and ingestion of the different organic-metal particulates must be considered. In order to address the stream impairment issues associated with different metal sources, a more complete understanding of metal bio-uptake under urban stream conditions is required. To accomplish this, the following objectives and approach will be: 1) Quantify the variability of metal speciation and size distribution in different stream source waters across space and time: Automated samplers will collect time interval and flow-weighted samples of effluent and stormwater runoff, respectively, at impaired sites across a range of urban to suburban sites. Samples will be separated into size fractions relevant to biotic uptake and analyzed for total metals, organic matter, colloidal metal and organic matter size distribution, and organic matter optical, chemical and metal binding characteristics. 2) Identify metal speciation and size distribution predictors of biological uptake in primary producers and higher trophic level organisms and the dependence on metal loading dynamics: Metal uptake and attachment will be analyzed as a function of size distribution and chemical characteristics of the organic matter in different source waters. Biodynamic modeling will assess the net metal uptake into algae and subsequent transfer to higher trophic level organisms. These will be examined under exposure regimes that mimic the stream, e.g. with different ratios of source water to stream water for effluent sources and varying exposure concentrations for stormwater runoff.