In this project, investigators at the Old Dominion University and the Ohio State University will integrate the determination of molecular-level chemical characteristics of natural dissolved organic matter (DOM) with investigations that quantitatively explore the reactivity of DOM with model compounds. Their preliminary work shows that compositional differences in DOM attributed to both season and source can influence the bulk chemical properties of natural waters so as to induce changes in, for example, the solubility of specific compounds. The team will investigate changes in composition and reactivity of DOM as a function of season (over 2.3 years), organic matter source (6 sites from upstream blackwater rivers to the coastal ocean) and water chemistry (pH, salinity, etc.). A rigorous sampling regime, combined with laboratory work designed to detail both the bulk chemical composition and reactivity of the DOM will allow for more comprehensive quantitative models of DOM chemistry and interactions with anthropogenic compounds. As part of this work, the researchers plan to use NMR, IR, HLPC and several mass spectral approaches to fully characterize the DOM and use NMR and IRMS to quantitatively follow its chemical interactions with isotopically labeled model compounds.
Broader Impacts: This study will provide significant advancements in the areas of aquatic/marine and analytical chemistry, contaminant transport and the impact of anthropogenic compounds in aqueous systems and organic matter sequestration and preservation. Both Old Dominion University and Ohio State University are strongly committed to the training of graduates, undergraduates and K-12 students. This work will provide direct support for three graduate students whose dissertation topics will be centered in DOM characterization, variability and molecular interactions. Undergraduate students will be trained in advanced analytical and instrumental techniques as well as in the interpretation of their results. The project will also be augmented through association with the NSF-sponsored REU-MUST program in ocean science at ODU and environmental molecular science at OSU.
