ABSTRACT
Sediment oxygen demand (SOD) is a major contributor to the degradation of Chesapeake Bay. Sediment releases of nutrients support the algal population of the Patuxent Estuary and contribute to blooms in the tidal Potomac. Diagenetic processes start with the deposition of particulate organic matter at the sediment-water interface. The Redfield ratios and redox stoichiometry indicate that nitrogenous demand comprises 20% of total SOD, provided both carbon and nitrogen are completely oxidized using oxygen as the electron acceptor. Sequences of oxidation-reduction reactions, ordered according to the free energy released, may be found in standard texts. Properly formulated empirical models are consistent with the conceptual model and lend insight into the processes that occur in the sediments studied. Empirical models can be of great utility in the calibration and application of eutrophication models. Water quality problems such as algal blooms and summer anoxia are among the processes of primary interest in the examination of eutrophication.
