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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #318633
Title: Simulating woodchip bioreactor performance using a dual-porosity model

Author
item Jaynes, Dan
item Moorman, Thomas
item Parkin, Timothy
item Kaspar, Thomas

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2016
Publication Date: 4/25/2016
Citation: Jaynes, D.B., Moorman, T.B., Parkin, T.B., Kaspar, T.C. 2016. Simulating woodchip bioreactor performance using a dual-porosity model. Journal of Environmental Quality. 45(3):830-838. doi: 10.2134/jeq2015.07.0342.

Interpretive Summary: Nitrate in the Nation's surface waters has been a persistent health and ecological problem. The major source of nitrate in the Midwest is tile drainage from agricultural row crops. Bioreactors - soil trenches filled with wood chips or other organic material - have been shown to be effective in removing much of the nitrate from tile drains. While we understand in general how these bioreactors function, we do not have the detailed understanding that would allow for effective designs and predictions of their nitrate removal capacity over time. In this study, we installed and measured for two years nitrate removal of a bioreactor filled with woodchips. We showed that a computer model we modified could accurately predict nitrate removal by the bioreactor. The modeling approach used here will help other researchers develop accurate models for bioreactors that will allow for better design and determination of bioreactor performance. This research will be of value to researchers, action agencies at the state and federal level, NRCS, and farmers across the Midwest.

Technical Abstract: Nitrate in the Nation's surface waters has been a persistent health and ecological problem. The major source of nitrate is tile drainage from agricultural row crops. Denitrification bioreactors have been shown to be effective in removing much of the nitrate from tile drains. While we understand in general how these bioreactors function, we do not have the detailed understanding that would allow for proper designs and predictions of their performance over time. In this study, we installed and monitored the performance of a denitrificating bioreactor for two years. We adopted a computer model that describes the unique flow properties of the woodchips that compose bioreactors. We showed that the model is robust and can accurately simluate bioreactor performance. The modeling approach used here will help other researchers develop accurate simulation models for bioreactors that will allow for better design and determination of their overall performance. This research will be of value to researchers, action agencies at the state and federal level, NRCS, and farmers across the Midwest.