Laboratory Studies of Gas Tracers for Reaeration

Prediction of the volatilization rates of high-volatility chemicals from natural water bodies

“…The experimental data for the other compounds listed in Table II were similar. These data confirm the literature reports that, for high-volatility compounds (Hc > 3500 torr M-1), the ratio kvc/kv°i s independent of kv°over a wide range (0.05-15 h-1) and, therefore, independent of the turbulence level (1,(9)(10)(11)(12)17). The data for benzene (Figure 2) also show that within experimental error the ratio is independent of temperature between 4 and 50 °C and of the presence of a surface film, a salt mixture approximating seawater, and the components of a natural pond water.…”

“…If the view is correct that = 1 in the environment because the turbulence is low, then it may be appropriate to raise the value of (fevc/fev0)iab to the 1/0.61 = 1.6 power to improve the accuracy of predictions in lakes and ponds. Thus (fcvC)env = (kvC/kv°)lah1-6(kv°)env (17) may be correct for lakes and ponds.…”

“…Second, in cases where both diffusion coefficients had been measured, there was still a large potential error. Rathbun (17) assumed that film theory obtained ( = 1) and calculated a Df/Df1 ratio for ethylene by using diffusion coefficients for oxygen and ethylene that were measured by several investigators.…”

“…Acid forms of sulfate have been identified as a major contributor to the acidity of precipitation impacting aquatic and terrestrial ecosystems (6,14,15). The concurrent formation of sulfate along with ozone and other photochemical smog products has been considered (16)(17)(18).…”

Mass transfer of volatile organic contaminants from aqueous solution to the atmosphere during surface aeration

“…17 0.5-0.67. On the other hand, some investigators (5,10,26) perceive their results as confirming the validity of the film theory, according to which KLa is proportional to the diffusivity to the first power.…”