SusChEM: Redox and mineral controls maximizing Phosphorus mobility and bioavailability

SusChEM：氧化还原和矿物质控制最大限度地提高磷的流动性和生物利用度

• 批准号: 1560933
• 负责人: Gregory Druschel
• 金额: $ 27.58万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1560933&HistoricalAwards=false
• 关键词: SusChEM; Redox; mineral; controls; maximizing

Understanding phosphorus (P) behavior in the environment is critical to society, as P often plays a central role in promoting productive agriculture as a fertilizer. Yet phosphorus is also a contaminant in aquatic environments, where human-derived enrichment of P in water and sediment can promote harmful algal blooms. Worldwide reserves of P are limited, especially in the U.S., and sustaining agricultural production will require the recovery and recycling of P. The protection of water resources is also an increasingly critical area of concern to promote sustainable clean drinking water, healthy fisheries, and economically vital recreational resources. These issues require improved understanding of how P is, and can be, mobilized in different geological and engineered settings. P interaction with other elements, especially iron, manganese, and carbon, often controls P mobility, and understanding this interaction is therefore key to developing strategies for more sustainable agriculture and water quality. This research program's goal is to develop a conceptual framework of the environmental conditions that maximize phosphorus mobility in sediment-water systems. The project will integrate with NSF-EPSCoR program investigating lake water quality. Research on these topics will be integrated with outreach opportunities to teach local schoolchildren and stakeholders about responsible nutrient management and how to better protect water resources.Phosphorus is generally partitioned in sediment-water systems between mineral, dissolved, and organic pools. Determining the response times for different pools of P species to changing redox conditions is a major hurdle in understanding the drivers of phosphorus mobility and bioavailability in sediment-water systems. Static models describing P partitioning and mobility between these pools are voluminous but do not capture key factors. The redox conditions near the sediment-water interface (SWI) are a critical control on the reactivity of P and associated redox-active elements (Fe, Mn, S, N especially) in shallow freshwater and marine systems, and can fluctuate on diel, seasonal, and more chaotic event-based timescales. The central hypothesis of this project is that the mobility of specific P pools is maximized by changes in redox conditions at the SWI over short (minutes to hours) time spans, and that the duration and severity of these redox oscillations drives the partitioning and behavior of P (and Fe) species over time near the SWI. To test this requires a comprehensive investigation of P speciation and mobility that couples field and laboratory approaches designed to elucidate the drivers and dynamics of this complex system. Analysis of the specific P pools and related elements will utilize advanced techniques to examine the partitioning of different P forms in different pools under changing redox conditions. Specifically, high-resolution in-situ monitoring of natural and manipulated SWI redox dynamics using environmental voltammetric techniques, combined with a suite of targeted analyses to describe the redox-driven evolution of sediment-water P pools including: 1) sediment P mineralogical composition and extractability, 2) P and Fe speciation, and 3) enzyme digestion and NMR techniques to determine organic P speciation will provide the data needed to develop a molecular-based and temporally constrained model of P speciation and mobility in sediment-water systems.

理解环境中的磷（P）行为对社会至关重要，因为P通常在促进生产性农业作为肥料方面起着核心作用。然而，磷在水生环境中也是一种污染物，在水和沉积物中p富集P可以促进有害的藻华。 p的全球储备是有限的，尤其是在美国，维持农业生产将需要恢复和回收。保护水资源也是一个越来越关键的关注领域，以促进可持续的清洁饮用水，健康的渔业和经济上重要的娱乐资源。这些问题需要提高对P在不同地质和工程环境中动员P的理解。 P与其他元素（尤其是铁，锰和碳）的相互作用通常控制P移动性，因此了解这种相互作用是制定更可持续的农业和水质策略的关键。该研究计划的目标是开发一个概念框架的环境条件，以最大程度地提高沉积物 - 水系统中的磷迁移率。 该项目将与调查湖水质量的NSF-EPSCOR计划集成。对这些主题的研究将与外展活动相结合，以向当地的学童和利益相关者传授负责任的营养管理以及如何更好地保护水资源。磷通常在矿物质，溶解和有机池之间的沉积物 - 水系统中分配。确定P物种对改变氧化还原条件的不同池的响应时间是理解磷迁移率和沉积物 - 水系统生物利用度的驱动因素的主要障碍。描述这些池之间的P分区和移动性的静态模型是庞大的，但不会捕获关键因素。 沉积物 - 水界面（SWI）附近的氧化还原条件是对浅水和海洋系统中P和相关的氧化还原活性元件（Fe，Mn，Mn，S，N）的反应性的关键控制，并且可以在DIEL，季节性以及基于混乱的事件发生时间表上波动。该项目的核心假设是，特定P池的迁移率在短时间（分钟至小时）时间内通过SWI的氧化还原条件的变化最大化，并且这些氧化还原振荡的持续时间和严重程度驱动了SWI附近P（和FE）物种的分配和行为。 为了测试这一点，需要全面研究P形成和活动性，旨在阐明该复杂系统的驱动因素和动态的现场和实验室方法。 对特定P池和相关元素的分析将利用高级技术来检查在变化的氧化还原条件下不同池中不同P形式的分区。 Specifically, high-resolution in-situ monitoring of natural and manipulated SWI redox dynamics using environmental voltammetric techniques, combined with a suite of targeted analyses to describe the redox-driven evolution of sediment-water P pools including: 1) sediment P mineralogical composition and extractability, 2) P and Fe speciation, and 3) enzyme digestion and NMR techniques to determine organic P speciation will provide开发基于分子和时间限制的P物种形成和迁移率在沉积物 - 水系统中所需的数据。