To obtain a comprehensive understanding of nitrous oxide (N2O) emission from water to air, the impacts of external disturbances including wind, stirring and aeration on N2O emissions were investigated by continuously monitoring N2O concentration variations in water. The volumetric mass transfer coefficient of N2O from water to air (KLaN2O) under different conditions was determined by using exponential regression to fit the monitoring data. The results showed that KLaN2O was 0.0017 min–1 at the stable condition, and with the increase of wind velocity, stirring velocity and aeration rate, the diffusion of N2O from water to air was enhanced. It was also observed that KLaN2O linearly increased with the increase of wind velocity and aeration rate, and exponentially increased with the increase of stirring velocity. The sequencing of the impacts of the three factors on N2O emission was aeration > stirring > wind. As turbulence and the mixing intensity of the liquid phase under the aeration condition were more vigorous than those of the wind and the stirring, the impact of aeration on N2O emission was greater than those of wind and stirring. When predicting N2O emissions from water to air, external disturbances, either environmental factors or operational factors, should be taken into consideration.
Experimental study of the impacts of external disturbances on N2O emission from water to air
Bo Hu, Shan He, Jianqiang Zhao, Ying Chen; Experimental study of the impacts of external disturbances on N2O emission from water to air. Water Sci Technol 1 October 2014; 70 (8): 1307–1313. doi: https://doi.org/10.2166/wst.2014.360
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