Reaeration Measurements Using a Methane Tracer at Six Dams in the Ohio River Basin

摘要

The reaeration process across hydraulic structures on the Ohio River was evaluated using in situ methane as a tracer. Reaeration rates determined from dissolved oxygen (DO) measurements are often unreliable when upstream DO concentration is near saturation. In such cases, the increase in DO as the flow passes the structure is small, leading to relatively large measurement uncertainties. Naturally occurring methane can be used as a tracer for DO because the difference between upstream and downstream dissolved methane concentration is sufficiently large for current analytical techniques. The relationship between methane and oxygen transfer is well documented.