Corncobs in bioreactors

Title: How long will corncobs improve nitrogen removal in bioreactors? 

Practice: Edge-of-Field

Location: Boone

Time Period: 2025 -2027

Research Team: Michelle Soupir, Leigh Ann Long, Barbara Tran

Project Description: Nine pilot-scale bioreactors were constructed in 2014 using woodchips. These experimental bioreactors were designed to evaluate nutrient removal performance under varying hydraulic retention times and influent nutrient concentrations. In 2018, six of the bioreactors were partially excavated, and a portion of the original woodchips was replaced with corncobs. The objective of this phase of the research is to compare the nitrate removal performance of corncobs versus woodchips and to assess the long-term effectiveness of corncobs for nitrate removal.

Publications: 

Martin, E. A., Davis, M. P., Moorman, T. B., Isenhart, T. M., & Soupir, M. L. (2019). Impact of hydraulic residence time on nitrate removal in pilot-scale woodchip bioreactors. Journal of Environmental Management, 237, 424–432.

Hoover, N. L., Soupir, M. L., VanDePol, R. D., Goode, T. R., & Law, J. Y. (2017). Pilot-scale denitrification bioreactors for replicated field research. Applied Engineering in Agriculture, 33(1), 83–90.

Law, J. Y., Slade, A., Hoover, N., Feyereisen, G., & Soupir, M. (2023). Amending woodchip bioreactors with corncobs reduces nitrogen removal cost. Journal of Environmental Management, 330, 117135.

Funders: Iowa Nutrient Research CenterI