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Characterization of Suspended Sediment Particle Size Classes and Evaluation of their Phosphorus Binding Characteristics: Implications for Availability, Transport and Transformation in Stream Ecosystems
The current research focus supports the goal of evaluating best management practices (BMP) effectiveness by increasing fundamental understanding of ecoregional variations in sediment, phosphorus and nitrogen biogeochemistry and transport. One initial research goal is to evaluate laboratory and field methodologies that are capable of isolating or measuring key fractions of suspended sediment and colloidal particles in aqueous samples. Various field and laboratory methods (e.g., Beckman-Coulter LS230 particle size analyzer) will be used to measure particle size distributions in natural water samples (see below). Field research methods will isolate sand and silt fractions from natural water samples using sieves and membrane filters, and laboratory research methods will isolate clays and organic colloids and separate them from smaller natural organic matter colloids via tangential-flow filtration. Laboratory methods will be used to determine the phosphorus load and binding capacity for each of the isolated fractions. The results will be used to evaluate the relative importance of different particle size fractions in relation to their ability to sequester, transform and/or transport contaminants between ecological compartments, and how this relationship changes in response to varying discharge conditions (base and stormflow), land use, scale and management practices.
Contact: Matthew Morrison, 513/569-7441, (EIMS#80104)