SS2.02 Biogeochemical Process at the Sediment-Water Interfaces
Date: Tuesday, June 11, 2002
Location: Poster Session - VCC
 
O'ConnorBL, University of Minnesota, Minneapolis, USA, ocon0091@tc.umn.edu
Hondzo, M, , University of Minnesota, Minneapolis, USA, mhondzo@tc.umn.edu
Brezonik, P, L, University of Minnesota, Minneapolis, USA, brezo001@tc.umn.edu
 
THE EFFECTS OF TURBULENCE ON NITROGEN FLUX AT THE SEDIMENT-WATER INTERFACE
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Extensive work has been done pertaining to nitrogen cycling and transport in streams. The sediment-water interface is an important region for nitrogen flux and transformation because it is a biologically active area with exchange pathways for nitrogen species, organic carbon, and water. The goal of this study is to determine the overall direction and magnitude of nitrogen flux, the speciation of nitrogen in the water and in the sediments, and how environmental factors relating to nitrogen cycling are affected under varying turbulence conditions at the sediment-water interface. Turbulence in known to increase the flux of dissolved oxygen into the sediments, which alters the aerobic and anaerobic zones that are important for biological nitrogen transformations in sediments. Currently, batch flux experiments are underway using natural and synthetic sediments under stagnant and turbulent conditions with different amounts of dissolved oxygen in the water column. The next step will be to measure nitrogen flux from sediments in a laboratory flume. Turbulence conditions will be characterized using a acoustic Doppler velocimeter (ADV) that can characterize the three-dimensional flow field at the sediment-water interface.