Nitrate removal and nitrous oxide production from upflow and downflow column woodchip bioreactors. Issue 1 (10th August 2020)

• Record Type: Journal Article
• Authors: Feyereisen, Gary W.; Spokas, Kurt A.; Strock, Jeffrey S.; Mulla, David J.; Ranaivoson, Andry Z.; Coulter, Jeffrey A.
• Is Part Of: Agricultural & environmental letters. Volume 5:Issue 1(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-10
• Subjects: Agriculture -- Periodicals; Agriculture -- Environmental aspects -- Periodicals; Agriculture; Agriculture -- Environmental aspects; Periodicals; 630
• DOI: 10.1002/ael2.20024
• Languages: English
• ISSNs: 2471-9625

Abstract

Abstract: Woodchip denitrifying bioreactors (WDBR) reduce off‐field tile drainage nitrogen (N) losses from agricultural fields. Limited evaluation exists regarding the influence of flow direction through WDBRs. Changing flow direction could reduce short circuiting. This study evaluated the dependency of nitrate‐N removal and dissolved nitrous oxide ( d N2 O) production rates on vertical flow direction in triplicate column bioreactors at 12‐h (without carbon dosing) and 2‐h (with carbon dosing) hydraulic residence times. Results presented demonstrate that there was no significant difference in overall N removal rates from these column bioreactors as a function of flow direction. There was the suggestion of lower N2 O production in the downflow direction, although this was not statistically significant due to the high variability of the N2 O production observed in the upflow direction. Carbon addition led to bioclogging of downflow columns; future work needs to identify dosing rate, placement, and conditions that prevent biofilm formation.