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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Research Project #431557

Research Project: Optimizing the Performance of Denitrifying Bioreactors to Improve Water Quality from Tile Drained Agricultural Landscapes

Location: Soil and Water Management Research

Project Number: 5062-12130-007-009-N
Project Type: Non-Funded Cooperative Agreement

Start Date: May 1, 2017
End Date: Dec 31, 2021

The objective of this project is to develop denitrifying bioreactors that remove nitrate-nitrogen (N) at higher rates than presently used technologies and to incorporate phosphorus (P) removal into an improved nutrient filtration system. The goals of this project are to: (1) develop bioreactors that remove nitrate-N at higher rates than current woodchip bioreactors and (2) demonstrate consistent removal of phosphorus within the optimized bioreactor system.

Candidate materials (carbon-sourced for nitrate removal; absorptive or precipitation mechanisms for phosphorus removal) will be evaluated at bench scale and with scale up to flow columns. The materials with the best performance in the laboratory will be used in pilot field trials. These field sites will include (1) Lamberton, MN; and (2) Willmar, MN. The pilot trials at Lamberton will test combinations of materials to remove nitrate-N and P from tile drainage water at high flow rates / short hydraulic residence times with various rates of labile carbon additions. The experiments at Willmar also will investigate the effect of labile C additions as well as bioaugmentation of bioreactor beds with microbes selected for cold-temperature denitrification performance. In addition, the potential for use of electrokinetic methods for reduction of nitrate will be evaluated in a similar fashion.