Sediment Oxygen Demand in a Shallow Oxbow Lake

摘要

In-situ sediment oxygen demand (SOD) measurements were made during the summer-fall of 1978 in Horseshoe Lake (in the Mississippi River flood plain) in conjunction with a water quality sampling program. This report presented only the findings of the SOD investigation. Sediments throughout Horseshoe Lake exert a significant oxygen demand on the overlying water, with the highest demands in dead zones of the lake. Bacteria and other microorganisms are the principal cause of the demand; macroinvertebrates cause about 1% or less. A simple mathematical model developed and verified to predict DO concentrations under warm, quiescent, dark conditions indicated that only about 36 hours would be needed to totally deplete DO under these conditions. The information generated by this study provides a good base from which to evaluate the degraded conditions of the sediments and the effects of these sediments on the oxygen resources of the lake.