Author(s): Carlos Reiher; Alberto De La Fuente; Yarko Nino; Manuel Contreras
Linked Author(s): Yarko Niño, Alberto de la Fuente
Keywords: Sediment/water interface; Dissolved oxygen transfer; Sediment oxygen demand; Benthic chambers; Salar Punta Negr
Abstract: A 1D vertical model developed by Higashino et al. (2004) for the unsteady response of dissolved oxygen uptake at a sediment/water interface (SOD) and dissolved oxygen (DO) profiles in the water column near that interface, was adapted to improve the representation of turbulent diffusion within the wall boundary layer and the biological processes taking place within the sediments. Biochemical activity in the sediments is modeled using MichaelisMenten kinetics to represent decay of organic matter, together with a zero order model for benthic microphyte photosynthesis and respiration. The model was applied to simulate conditions prevailing in aquatic systems within salt lakes in northern Chile and the results were compared against field measurements of SOD using benthic chambers in one of these systems. A layer-averaged model was used to calibrate parameters characterizing biochemical activity in the sediments using the field data. These parameters were also determined using the 1D vertical model. It is found that phytoplankton photosynthesis is mainly responsible for oxygen balance at the sediment/water interface of the system studied.