Fact Sheets

Bioreactors for Drainage Water Treatment - by Chris Hay and Jeppe Kjaersgaard, South Dakota State University

Bioreactors - by Keegan Kult, the Iowa Soybean Association

Woodchip Bioreactors for Nitrate in Agricultural Drainage - by Laura Christianson, Iowa State University 

Woodchip Bioreactors- Minnesota Department of Agriculture

Constructed Wetlands- US EPA


Case Studies
Constructed Wetlands:

Agricultural pollutant removal by constructed wetlands - UC Davis

Effectiveness of constructed wetlands in reducing nitrogen and phosphorus export from agricultural tile drainage - Univ. of Illinois

Multi-year nutrient removal performance of three constructed wetlands intercepting tile drain flows - New Zealand

Nutrient Management of Nursery Runoff Water using Constructed Wetland Systems - Clemson University  

Nitrate removal in surface-flow constructed wetlands treating dilute agricultural runoff in the Lower Yakima Basin, Washington - Washington State University

Nitrogen cycling in constructed and natural coastal wetlands: Assessment using nitrogen stable isotopes -UMass Amherst

Estimating nitrate load reductions from placing constructed wetlands in a HUC-12 watershed using LiDAR data -USDA

Anoxic treatment wetlands for denitrification - UC Davis

Factors affecting nitrogen retention in small constructed wetlands treating agricultural non-point source pollution- Norway

Denitrifying Bioreactors:

Alternative systems to reduce nitrogen from artificially drained fields - USDA-ARS

Comparing Carbon Substrates for Denitrification of Subsurface Drainage Waters - Iowa State University & USDA-ARS

Efficacy of a denitrification wall to treat continuously high nitrate loads - University of Florida

Nitrate removal and hydraulic performance of organic carbon for use in denitrification beds - New Zealand

Nitrate removal from three different effluents using large-scale denitrification beds - New Zealand

Pilot Tests - Iowa State University

Treatment of Hydroponic Glasshouse Waste: Temperature and Carbon Limitations - New Zealand

Nitrogen balance in and export from agricultural fields associated with controlled drainage systems and denitrifying bioreactors - University of Illinois

Maximum Rates of Nitrate Removal in a Denitrification Wall - New Zealand

Nitrate removal rates in woodchip media of varying age- University of Waterloo, Canada

Nitrate removal and greenhouse gas production in a stream-bed denitrifying bioreactor- University of Waterloo, Canada



Denitrifying Bioreactors:

Bioreactors, saturated bufferes reduce nitrate levels. KCCI Des Moines, IO news segment (Posted June 2016)

Keeping nitrogen in our fields, and out of our water supply - The Conservation Fund. Posted Aug 2014. (Bioreactor discussion is at ~3 minutes)

Nabbing nitrates before water leaves the farm: Bioreactors - Leopold Center. Posted July 2014

Installation and description of denitrifying bioreactors in Maryland - Midshore Riverkeeper Conservancy. Posted Jan 2014.

Installation of denitrifying bioreactor in Iowa - Lanehaven Farms, Inc. Posted Nov 2013.

Denitrification beds and walls - Science Learning Hub with Louis Schipper. Posted July 2013.

Curbing pollution, saving agriculture - Virginia Tech Innovations. Posted Oct 2012.

How Bioreactors are making a difference - Iowa's Boone River Watershed, The Nature Conservancy. Posted Dec 2012.

Improving Water Quality- Bioreactor Installation Project, South Dakota State University. Posted Sept 2012.

Evaluating Denitrifying Bioreactors - Alok Bhandari, Iowa State University, is researching denitrifying bioreactors as a method of removing nitrates from drainage water and as a nitrogen management option for farmers in Iowa. Filmed June 2009.  

Bioreactor Demonstration Project - Iowa Soybean Association’s Environmental Programs (with Agriculture's Clean Water Allisance - ACWA and Sand County Foundation) break ground for the ACWA Bioreactor Demonstration Project. Filmed in Spring 2008.

Denitrifying Bioreactors - Louis Schipper, Universtity of Waikato, discusses his work in developing the concept of denitrification walls for removing nitrate from shallow groundwater. Filmed in 2007.

Bioreactors - Missouri & Mississippi Divide Resource Conservation & Development Inc.

Constructed Wetlands:

Tile Drainage and Wetlands- Mark David, University of Illinois, discusses the use of tile drainage.

Working Wetlands- Missouri & Mississippi Divide Resource Conservation & Development Inc.

Workshop Presentations

2014 ASA Meeting: Managing Denitrification in Agronomic Systems - Innovations and Challenges, November 2014

Evaluating Woodchip Bioreactors for Nitrate Removal from Tile Drainage Water.
Lowell E. Gentry, Univ. of Illinois
Jeppe H. Kjaersgaard, Minnesota Dept. of Agriculture
Managed Denitrification with Woodchip Bioreactors: Pilot-Scale Testing to Address Aquaculture Wastewater Treatment Challenges.
Laura Christianson, The Conservation Fund Freshwater Institute
Combining Denitrification and Phosphorus Uptake in Edge-of-Field Bioreactors.
Marta B. Roser, Univ. of Minnesota
Development of an Equation for Flow Measurement in Agridrain Control Structures.
Jeppe H. Kjaersgaard, Minnesota Dept. of Agriculture
Denitrification Bioreactor Performance: Effects of Media and Temperature on Nitrate Removal.
Gary W. Feyereisen, USDA-ARS
A Meta-Analysis of Denitrifying Bioreactors: Implications for Nitrate Abatement.
Arthur J. Gold, Univ. of Rhode Island

2013 AWRA Spring Specialty Conference- Agricultural Hydrology and Water Quality II, March 2013.

Advancing the adoption of artificial nitrogen sinks
Jill Ravel et al., Univ. of Rhode Island
Managing Denitrification in Tile-Drained Agricultural Wetalnds
Mark David, Univ. of Illinois

Case Studies in Managing Denitrification in Agronomic Systems, Poster Session, ASA Meeting, October 2012.

First Author
Managing Denitrification in the Corn Belt With Bioreactors and Wetlands
Mark David, Univ. of Illinois
Advancing the Adoption of Artificial Nitrogen Sinks
Kelly Addy, Univ. of Rhode Island
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Denitrification Within Saturated Riparian Buffers Re-Designed to Remove Nitrate From Artificial Subsurface Drainage
Dan Jaynes, USDA-ARS
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Conservation Drainage Practices to Remove Nitrate From Tile Drain Water
Jeppe Kjaersgaard, South Dakota State Univ.
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Role of Temperature and Nitrate Concentration in Controlling Denitrification in Field Scale Denitrification Beds
Ann Carter, Univ. of Waikato, New Zealand
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Nutrient Removal and Greenhouse Gas Fluxes In 19 Year Old Constructed Wetlands: A Temporal Analysis and Comparison
Tyler Groh, Univ. of Illinois
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Demonstrating the Nitrate-Nitrogen-Removal Effectiveness of Denitrifying Bioreactors in South Dakota for Improved Drainage Water Management
Cynthuja Partheeban, South Dakota State Univ.
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Performance of a Woodchip Bioreactor Receiving Agricultural Tile Drainage
Lowell Gentry, Univ. of Illinois
Denitrification Woodchip Bioreactor Treatment of Wastewater From Land-Based Recirculating Aquaculture Systems
Laura Christianson, The Conservation Fund, Freshwater Institute
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Effect Of Seasonal Variations In Flow On Woodchip Bioreactor Design In Tile-Drained Watersheds
Thomas Moorman, USDA-ARS
Controlled Drainage As Measure to Reduce Nitrate Leaching in a Wheat Cropping System
Christen Duus Borgesen, Aarhus University, Denmark
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Towards the Implementation of Permeable Reactive Interceptors On Agricultural Landscapes in Ireland
Tristan Ibrahim, Teagasc, Ireland
Side-By-Side Comparison of Denitrification Performance Between a Woodchip Bioreactor and a Wetland System
Andry Ranaivoson, Univ. of Minnesota


Managing Denitrification in Agronomic Systems to Reduce Nitrate Loss: Methods, Unknowns, and Limits to Adoption, ASA Meeting, October 2012.

First Author
Voice narrated pdf
Artificial Sinks: Opportunities and Challenges for Managing Offsite Nitrogen Losses
Art Gold, University of Rhode Island
A Synthesis of Removal Rates, Controls and Utility
Louis Schipper, University of Waikato
Using Riparian Buffer Strips to Manage Denitrification
Richard Lowrance, USDA-ARS
Managing Denitrification in Constructed Wetlands
Mark David, University of Illinois
Conservation Drainage: Managing Drainage for Yield and Water Quality Benefits
Richard Cooke, University of Illinois
Biophysical Limits to Adoption of Denitrification Management Systems
Brian Needelman, University of Maryland
Challenges within the Human Dimensions of Agricultural Nitrogen Management and Water Quality
Courtney Flint, University of Illinois

You can also view the video presentations on the ASA website.

2012 Land Grant - Sea Grant National Water Conference, May 2012

Constructed Wetlands and Carbon Bioreactors for controlling offsite Nitrogen losses
Art Gold, University of Rhode Island
Denitrifying Bioreactors: A Synthesis of Removal Rates, Controls and Utility
Louis Schipper, University of Waikato
Protocol and Interactive Routine for the Design of Subsurface Bioreactors in the Midwest
Richard Cooke, University of Illinois
Overview of Constructed Wetlands
Mark B David, University of Illinois
Water Quality performance of Wetlands receiving NPS loads: Case studies of Nitrogen removal efficiency and Load reductions of wetlands in the Western Corn Belt  
William G. Crumpton, Iowa State University
Geospatial data and Soil survey Interpretations for siting Artificial Nitrogen sinks
Brian A. Needleman, University of Maryland
Web and Atlas resources to promote Constructed Wetlands and Carbon Bioreactors
Kelly Addy, University of Rhode Island
Emerging Bioreactor Research in Iowa: Design and Performance
Laura Christianson, Iowa State University
Emerging Bioreactor Research: Treating High Nitrogen Loads in warm climates
Casey Schmidt, University of Florida
Bioreactors and NRCS: Getting them in the ground
Pat Willey, USDA-NRCS

Journal Articles

Gold, A.J., K. Addy, M.B. David, L.A. Schipper, and B.A. Needelman.  2013.  Artificial sinks: Opportunities and challenges for managing offsite nitrogen losses.  Journal of Contemporary Water Research and Education 151:9-19



Curricula coming soon!