Submitted to: Critical Reviews in Environmental Science Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/19/2006
Publication Date: 11/1/2007
Citation: Ro, K.S., Hunt, P.G., Poach, M.E. 2007. Wind-driven surficial oxygen transfer. Critical Reviews in Environmental Science and Technology. 37:539-563. Interpretive Summary: Lagoons are frequently used to store and partially treat animal wastewater. Scientists have generally thought that inert, atmospheric dinitrogen gas was not produced in large quantities from these lagoons because oxygen was insufficient to support the microbial processes that convert wastewater nitrogen into dinitrogen gas. However, researchers have recently postulated that the amount of atmospheric oxygen absorbed through the water surface should be adequate for production of significant dinitrogen gas. The objective of this research was to estimate the amount of atmospheric oxygen that can be absorbed into these lagoons by using the relevant research data of the last 5 decades. Wind speed was found to be an important factor in oxygen absorption into non-moving water bodies such as lagoons, especially at higher speeds. Furthermore, development of more precise computations for oxygen absorption rate into the lagoons was shown to be possible.
Technical Abstract: Recently the aerobic-anaerobic status of animal waste lagoons has become somewhat of an enigma. Although the lagoons contain reduced nitrogen compounds, they have been reported to produce large quantities of dinitrogen gas, which would seem to require significant precursor oxygen. Resolution of this enigma is difficult because the factors that control oxygen transfer to lagoons are variable and difficult to measure. However, wind is well known to be one of the major factors. The objective of this paper was to review and analyze research conducted during the last 5 decades on gas transfer into non-moving, open water bodies, in which wind was the major turbulence agent in the gas exchange processes. Correlations for various gases were normalized to oxygen. Generally, low wind speed did not significantly influence the transfer coefficient; but the transfer coefficient increased greatly with higher wind speeds. However, estimating oxygen absorption rate into treatment lagoons was not successful because of the large variations among existing correlations. Fortunately, there were sufficient numbers of gas transfer data in the literature to provide a solid basis for a new unified formulation for oxygen transfer into treatment lagoons.