The freshwater phosophorus cycle and the fate of water-borne pathogens

淡水磷循环和水生病原体的命运

• 批准号: 8110-2006
• 负责人: Taylor, William
• 金额: $ 2.84万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2006
• 资助国家: 加拿大
• 起止时间: 2006-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=335074
• 关键词: freshwater; phosophorus; cycle; fate; water

During the tenure of the proposed NSERC Discovery Grant, three PhD students will conduct research on the phosphorus cycle in lakes and rivers, and one will work on the persistence of pathogenic microbes in rivers.  At the Dorset Environmental Science Centre we will use new techniques developed with previous NSERC DG funding to determine what environmental factors determine the concentration of phosphate available to bacteria and algae in the plankton, and hence their productivity.  Initially, we will address the hypothesis that food web structure and light (determined by mixing depth and water transparency) are the key variables.  The second fundamental problem we will address at DESC is the residence time of P in the epilimnion of lakes and therefore the total amount of biomass that will be present for a given nutrient loading.  To do this we will exploit naturally occurring radioisotopes that can be used to measure the age of P in the epilimnion.   A major environmental problem for eutrophic rivers is excess biomass of aquatic plants caused by high phosphorus loading from sewage and agriculture, leading to low dissolved oxygen at night.  To understand phosphate concentration available to plants during summer low flow periods, when nutrients likely control plant growth, we will estimate how much of the P at summer low flow is sequestered in different communities, and we will determine whether each of these is a net source or sink for phosphate as a function of phosphate concentration.  This research will lead to a model predicting phosphate concentrations at low flow for rivers with different relative abundances of these communities.   Concentrations of pathogens in surface waters are determined by both loading and persistence. We will study the removal of pathogens by different aquatic communities, including seston, sediments, biofilms on hard surfaces, and biofilms associated with macrophytes.  This information will inform as to how river communities interact with pathogen loading to determine pathogen levels.

在拟议的NSERC发现补助金的任期内，三名博士生将进行湖泊和河流中磷循环的研究，一名将研究河流中病原微生物的持久性。在多塞特环境科学中心，我们将使用以前NSERC DG资助开发的新技术来确定哪些环境因素决定浮游生物中细菌和藻类可获得的磷酸盐浓度，从而提高生产力。最初，我们将讨论食物网结构和光（由混合深度和水透明度决定）是关键变量。我们将在DESC解决的第二个基本问题是P在湖泊上层的停留时间，因此对于给定的营养负荷，将存在生物量的总量。为了做到这一点，我们将利用自然发生的放射性同位素，可用于测量磷的年龄在表层。 富营养化河流的一个主要环境问题是由于污水和农业的高磷负荷导致水生植物的生物量过剩，导致夜间溶解氧降低。为了了解夏季低流量期间植物可利用的磷酸盐浓度，当营养盐可能控制植物生长时，我们将估计夏季低流量期间不同群落中有多少磷被隔离，我们将确定这些群落是磷的净源还是净汇，作为磷浓度的函数。2这项研究将建立一个模型，预测这些群落相对丰度不同的河流在低流量时的磷浓度。 沃茨中病原体的浓度取决于载量和持久性。我们将研究不同水生生物群落对病原体的去除，包括悬浮物、沉积物、硬表面上的生物膜以及与水生植物相关的生物膜。这些信息将有助于了解河流群落如何与病原体负荷相互作用，以确定病原体水平。