The gas transfer which occurs at hydraulic structures is the subject of this thesis. Attempts which have been made to predict the reaeration which occurs at the base of a free overfall or weir are reviewed. Because of the uncertainties involved in the prediction and measurement of oxygen transfer at hydraulic structures, a hydrocarbon gas tracer method, previously used for the measurement of open channel reaeration, was adapted to hydraulic structures. A simple headspace gas chromatographic technique was applied to the measurement of two dissolved light hydrocarbon tracer gases: propane, a gas that is nearly biologically inert and commercially available, and naturally occurring methane, which is proposed as a tracer gas for use at hydraulic structures. A detailed uncertainty analysis was performed on the measurement technique. Laboratory gas transfer measurements were made at a field-scale weir. The results from the injected propane measurement had a low uncertainty and compared favorably with the predictive equations available.
|Original language||English (US)|
|Title of host publication||Project Report - University of Minnesota, St. Anthony Falls Hydraulic Laboratory|
|State||Published - Jan 1 1989|