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Impact of Hydraulic Residence Time on Anammox Enrichment: System Performance and Microbial Ecology

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2018 Mid Atlantic Section Fall Meeting


Brooklyn Technical High School, Brooklyn, New York, New York

Publication Date

October 26, 2018

Start Date

October 26, 2018

End Date

October 27, 2018

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Paper Authors

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Daniel Takeda Brown

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Jae Young Suh


Matthew Baideme U.S. Military Academy Orcid 16x16

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Matthew Baideme is an Assistant Professor at the United States Military Academy (USMA) in the Department of Geography and Environmental Engineering. He is currently pursuing his PhD at Columbia University prior to returning to USMA.

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Energy and cost-intensive conventional biological nitrogen removal (BNR) processes have historically been used to treat nitrogenous waste streams. The discovery of anaerobic ammonium oxidation (anammox) bacteria provided an alternative method of nitrogen removal that could significantly reduce carbon and oxygen requirements when combined with short-cut BNR processes. However, the enrichment of anammox bacteria can be challenging depending on waste stream and process characteristics. This student research study presents a mitigation technique by manipulating the hydraulic residence time (HRT) as a process control to enrich the anammox fraction of a bioreactor. This study is the result of a summer research internship that capitalized on a faculty-student connection in preparation for the students’ future semester-long capstone project.

The inherent risks with anammox bacteria are out-competition due to their slow growth rate and excessive nitrite (NO2-) inhibition or poisoning. Appropriate enrichment of an anammox fraction in relation to the influent characteristics ensures that anammox activity is high enough to effectively mitigate the impacts of excessive NO2-. Herein, the HRT was manipulated to provide sufficient time for the anammox reaction and prevent inhibitory conditions for anammox growth and enrichment. Anammox activity was measured via chemical analysis of nitrogen species. Molecular analysis was used to quantify anammox bacteria and enrichment was correlated to activity in terms of total inorganic nitrogen removal. With no direct requirements for exogenous carbon or oxygen, the incorporation of an enriched anammox fraction into a short-cut BNR system could significantly reduce a facility’s energy and chemical demands thus saving operational costs.

Brown, D. T., & Suh, J. Y., & Baideme, M. (2018, October), Impact of Hydraulic Residence Time on Anammox Enrichment: System Performance and Microbial Ecology Paper presented at 2018 Mid Atlantic Section Fall Meeting, Brooklyn Technical High School, Brooklyn, New York, New York.

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