Characterization of Anaerobic Chemical Processes in Reservoirs: Problem Description and Conceptual Model Formulation

摘要

The occurrence of dissolved oxygen depletion and anaerobic processes in the hypolimnion of Corps of Engineers (CE) reservoirs can adversely impact water quality and directly affect CE Civil Works activities. A literature review, a consultation with authorities on anaerobic systems, and a workshop indicated the feasibility of developing a conceptual model to depict major pathways for nutrient regeneration and metal mobilization under anaerobic conditions. The product of subsequent model development and experimental studies, Dissolved Oxygen Subroutine with Anaerobic Processes (DOSAP), is presented herein and its operation is described in detail. The DOSAP model is presented as a series of seven linked geochemical steps (phases) of increasingly anaerobic (reduced) conditions. Major factors influencing the rate and duration of each of the major pathways are discussed. The DOSAP model has subsequently been transformed into a mathematical subroutine for the CE one-dimensional reservoir water quality model, CE-QUAL-R1. A literature search revealed a paucity of information on various physicochemical and biological rates affecting geochemical/water quality conditions in reservoirs, although abundant data for some parameters exist for other freshwater systems and marine environments.