Characteristics of N2O Emission in Distilled Water and Activated Sludge Mixture
To investigate the emission characteristics of the dissolved N2O in distilled water and activated sludge mixture, the total volume mass transfer coefficients of N2O in distilled water and activated sludge mixture were determined by batch experiments. The results indicated a difference between emission processes of N2O in distilled water and activated sludge mixture. At different initial N2O concentrations, the total volume mass transfer coefficients of N2O in distilled water were relatively stable, while the total volume mass transfer coefficients of N2O in activated sludge mixture increased with increasing initial N2O concentrations, due to endogenous denitrification by microorganisms in the mixture. Since N2O was reduced and consumed by heterotrophic bacteria in activated sludge, biochemical reactions were involved in the transfer process of N2O escaping from the mixture to the atmosphere. Therefore, use of distilled water was suggested to determine the total volume mass transfer coefficient in experiments calculating N2O emission rates for biological nitrogen removal processes.
KeywordsN2O emission Emission rate Total volume mass transfer coefficient N2O production N2O determination Emission characteristics
This work was supported by the National Natural Science Foundation of China (Grant No. 51778057) and the Ph.D. program of Xi’an University of Science and Technology (Grant No. 2017QDJ062).
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Conflict of Interest
The authors declare that they have no conflict of interest.
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