Denitrifying Woodchip Bioreactors

A denitrifying bioreactor is a trench in the ground packed with carbonaceous material such as wood chips that allow colonization of soil bacteria that convert nitrate in drainage water to nitrogen gas. This project evaluates woodchip bioreactors as a cost-effective, farm-scale practice for nitrate removal from agricultural drainage. When placed strategically in drained watersheds, these bioreactors can reduce nitrate loadings to surface streams and help meet EPA's call for a >45% reduction in total N loads from the Upper Mississippi River Basin to the Northern Gulf of Mexico.These small foot-print, passive systems can treat drainage from 40 to 60 acres of farmland, require low maintenance, and have a life-span of 10 years or more. Ongoing research includes laboratory-scale experiments, pilot-scale investigations, field-scale monitoring, and modeling to improve in-field performance and reliability of these systems in the tile-drained landscapes of Iowa and the Upper Midwest. This project is supported by the Leopold Center for Sustainable Agriculture, the USDA North Central Region's Sustainable Agriculture Research and Education Program (NCR-SARE), and Sigma Xi. Other project partners include ISU's Northeast Iowa Research Farm, the Coldwater/Palmer Watershed Council, and Agriculture's Clean Water Alliance.

Videos

"Evaluating Denitrifying Bioreactors" - On the Ground with the Leopold Center 

"Bioreactors: Benefits and Potential Challenges" - Iowa Learning Farms Webinar

PUBLICATIONS

Peer-Reviewed Publications

1. Christianson, Laura, Alok Bhandari, Matt Helmers, Keegan Kult, Todd Sutphin, and Roger Wolf. (Under review). Performance evaluation of four field-scale agricultural drainage denitrification bioreactors in Iowa. 
2. Christianson, Laura and Matthew Helmers. 2011. Woodchip bioreactors for nitrate in agricultural drainage. Iowa State University Extension Publication. PMR 1008. 
3. Christianson, Laura E., James Hanly, and Mike Hedley. 2011. Optimized denitrification bioreactor treatment through simulated drainage containment. Agricultural Water Management99(1):85-92.
4. Christianson, L., and J. Tyndall. 2011. Hoping for a dialog: Targeted technologies for sustainable agricultural systems in the US Corn Belt. Sustainability: Science, Practice, & Policy 7(2)Published online Sep 02, 2011.
5. Christianson, Laura, Alok Bhandari, and Matthew J. Helmers. 2011. Pilot-scale evaluation of denitrification drainage bioreactors: Reactor geometry and performance. Journal of Environmental Engineering 137(4): 213-220.
6. Christianson, L., A. Castelló, R. Christianson, A. Bhandari, and M. Helmers.  2010.  Technical note: Hydraulic property determination of denitrifying bioreactor fill media. Applied Engineering in Agriculture 26(5): 849‐854.

Theses and Reports

1. Christianson  Laura. 2011. Design and Performance of Denitrification Bioreactors for Agricultural Drainage. Ph. D. dissertation. Agricultural and Biosystems Engineering, Iowa State University. Ames, Iowa, USA.
2. Ajmani, Manu. 2011. Sorption of veterinary antibiotics to woodchips. Masters of Science report. Department of Civil Engineering, Kansas State University. Manhattan, Kansas, USA.
3. Hoover, Natasha. 2012. In Press. Iowa State University. Ames, Iowa, USA.

Conference Proceedings (Presenter in Bold)

1. Christianson, Laura, Natasha Hoover, Alok Bhandari, and Matt Helmers. 2011.  The Potential of Municipal Yard Waste to be Denitrification Bioreactor Fill. Oral presentation at the American Society of Agricultural and Biological Engineers (ASABE) 2011 Annual International Meeting. Louisville, Kentucky. 7-10 August 2011. Paper No. 1111036.
2. Christianson, Laura, Alok Bhandari, Matt Helmers. 2011. Potential Design Methodology for Agricultural Drainage Denitrification Bioreactors. Oral presentation at World Environmental and Water Resources Congress (EWRI). Palm Springs, California. 22-26 May 2011.
3. Christianson, Laura, Mike Hedley, Marta Camps, Helen Free and Surinder Saggar. 2011. Influence of Biochar Amendments on Denitrification Bioreactor Performance. Poster presentation at: Adding to the knowledge base for the nutrient manager from the 24th Annual Fertilizer and Lime Research Centre Workshop. Eds L.D. Currie and C L. Christensen. Occasional Report No. 24. Fertilizer and Lime Research Centre, Massey University, Palmerston North, New Zealand.
4. Christianson, Laura, Dave Horne, James Hanly, Alok Bhandari, and Matt Helmers. 2010. Denitrification Bioreactors for Agricultural Drainage Nitrate Treatment in New Zealand.  Poster presentation at 19th World Congress of Soil Science, Soil Solutions for a Changing World. Brisbane, Australia. 1-6 Aug.  2010.   
5. Christianson, L., M. Helmers, and A. Bhandari. 2010. Bioreactor Design Geometry Effects on Nitrate Removal. Oral presentation at ASABE’s 9th International Drainage Symposium: Sustainable Drainage Water Management in a Changing Environment. Québec City, Canada. 13-16 June 2010. Paper No. IDS-CSBE100073
6. Christianson, Laura E., Alok Bhandari, Matthew H. Helmers, and Martin St. Clair. 2009. Denitrifying Bioreactors for Treatment of Tile Drainage. Oral presentation at World Environmental and Water Resources (EWRI) Congress. Kansas City, Missouri. 17-21 May 2009.

Non-Peer Reviewed Publications and Reports

1. Christianson, Laura, Matthew Helmers, and Carl Pederson. 2012 – In Press. Hydraulic Performance of the NERF Denitrification Bioreactor. Iowa State University, Northeast Research and Demonstration Farm Annual Report.
2. Christianson, Laura, Matthew Helmers, and Carl Pederson. 2011. Denitrification Bioreactor in Northeast Iowa RFR-A1099. Iowa State University, Northeast Research and Demonstration Farm Annual Report ISRF10-13. Pages 56-57.
3. Christianson, Laura, Alok Bhandari, and Matt Helmers. 2009. Emerging technology: Denitrification bioreactors for nitrate reduction in agricultural waters.  Journal of Soil and Water Conservation 64(5):139A-141A.
4. Christianson, Laura, Alok Bhandari, Matt Helmers. 2009.  Woodchip Bioreactors: A New Nitrate Reduction Option. Getting into Soil and Water 2009 Volume 1: 13.

PRESENTATIONS (Presenter in Bold, not including presentations with proceedings)

Conference Oral Presentations

1. Christianson, Laura and Matt Helmers. 2011. Denitrification bioreactors for agricultural drainage: Internal hydraulics and dynamics. Eastern South Dakota Water Conference Water Management in Extreme Conditions. Brookings, SD. October 13, 2011.
2. Bhandari, Alok, Laura Christianson, Natasha Hoover, and Matthew Helmers. 2010.  Carbon Losses in Denitrifying Drainage Bioreactors. American Society of Agricultural and Biological Engineers (ASABE) Annual International Meeting. Pittsburg, Pennsylvania. 20-23 June 2010.
3. Hoover, N.L. and A. Bhandari. 2010. Denitrification columns for treatment of agricultural drainage: Reactor startup and initial trends. Oral presentation at the Mid-Central ASABE Meeting, St. Joseph, MO, 9-10 April 2010.
4. Ingels, C., L. Christianson, M. Helmers, A. Bhandari, M. St. Clair. 2009. Evaluating the Initial Application of Field‐Edge Denitrifying Bioreactors. National NPS Monitoring Conference. New Orleans, Louisana.
5. Christianson, L., A. Bhandari, and M. Helmers. 2009. Evaluating Bioreactor Designs for Drainage Water Treatment. ASABE Annual International Meeting. Reno, Nevada. 21-24 June 2009.

Conference/Symposium Poster Presentations

1. Christianson, Laura, Matt Helmers, Ramesh Kanwar, and Reid Christianson. 2011. A Path to a Nitrate Solution: Enhanced Denitrification Treatment in a Global Context. Water for Food: Paths to Solutions. Lincoln, Nebraska. 1-4 May 2011.
2. Christianson, Laura, Matt Helmers, and Alok Bhandari. 2011. Reducing Nitrate in Tile Drainage: Denitrification Bioreactors. Iowa Water Conference. Ames, Iowa. 7-8 March 2011.
   • Also presented at Iowa State University Sustainability Symposium. 22 February 2011.
3. Christianson, Laura, Mike Hedley, Marta Camps, Helen Free, and Surinder Saggar. 2011. Influence of Biochar Amendments on Denitrification Bioreactor Performance. New Zealand 2011 Biochar Workshop: Opportunities, Risks and Acceptance. Palmerston North, New Zealand. 10 - 11 February 2011.
   • Also presented by Hailong Wang at the International Symposium on Environmental Behavior and Effects of Biomass-derived Charcoal. Hangzhou, China. 9-11 October 2010.
4. Bhandari, Alok, Natasha L. Hoover, Laura Christianson, Matthew Helmers, Michelle Soupir. 2010. Denitrification ‘Woodchip’ Bioreactors for Agricultural Drainage Water Treatment. Kansas Water Conference. Topeka, Kansas. 26 October 2010.
5. Bhandari, A., L. Christianson, and M. Helmers. 2010. Denitrification Bioreactors for Treatment of Agricultural Drainage.  Iowa State University Sustainability Symposium. Ames, Iowa. 23 February 2010.
6. Christianson, L., A. Bhandari, and M. Helmers. 2009. Advances in Denitrification Bioreactor Design. Science to Solutions Workshop. Des Moines, Iowa. 9-11 December 2009. 
7. Rodriguez, W., A. Bhandari, and M. Palomo. 2009. Denitrifying bioreactors: Nitrate removal efficiency from tile effluent at different retention times. Southern California Conference for Undergraduate Research.  Carson, CA. 21 Nov 2009.
8. Christianson Laura, Alok Bhandari, Matt Helmers, Carl Pederson. 2009. Nitrogen Removal in Drainage Bioreactors. Association of Environmental Engineering and Science Professors (AEESP) Annual Conference. Iowa City, Iowa. 26-29 July 2009.
   • Also presented at the ISU-ABEGO Poster Symposium, Ames, IA Aug 18, 2009.
   • Also presented at ISU College of Agriculture and Life Sciences meeting with the Corn and Soybean Initiatives partners, Ames, IA, Aug 25, 2009.
   • Also presented at U. S. Committee on Irrigation and Drainage National Annual Meeting. Salt Lake City, Utah. 3-6 November 2009.
9. Andrews, S., D. Vaughn, M. Ajmani, W. Rodriguez, and A. Bhandari. 2009. Denitrification of tile water using woodchip bioreactors.  DoE Ames Laboratory, Academies Creating Teacher Scientists Program Symposium. Ames, IA. 24 July 2009.
10. Christianson, L., A. Bhandari, and M. Helmers. 2009. Denitrification Bioreactors for Agricultural Water Treatment. Dahlia Greidinger International Symposium. Haifa, Israel. 2-5 March 2009.
    • Also presented at Iowa Water Conference. Ames, Iowa. 9-10 March 2009.

Invited and Extension Presentations

1. Christianson, Laura and Ken Pecinovsky.  2011. ISU Research Farm Nitrogen Bioreactor and Water Quality Studies. The Upper Cedar River Watershed Tour (tour stop: Northeast Research and Demonstration Farm, Nashua, Iowa). 13 September 2011.
2. Christianson, Laura. 2011.  Cost Comparison of Practices that Reduce Nitrate in Drainage.  Iowa Learning Farms Field Events:
   • Dallas County CREP Wetland Tour.  23 June 2011. Dallas Center-Grimes, Iowa. 
   • Silver Lake Watershed Field Day. 5 July 2011. Lake Park, Iowa.  
   • Elkader Field Day. 13 July 2011. Elkader, Iowa.   
   • Smeltzer Trust Farm Field Day. 20 July 2011. Otho, Iowa.   
   • Nashua CREP Wetland Tour.  24 August 2011. Nashua, Iowa.   
3. Christianson, Laura. 2011. Bioreactors: Benefits and Potential Challenges. Iowa Learning Farms webinar. 18 May 2011. (last accessed: 20 June 2011)
4. Christianson, Laura. 2011. Denitrification Bioreactors: Fancy Name, Simple Idea.  Iowa Water Conference. Ames, Iowa. 7-8 March 2011.
5. Christianson, L. 2011. “Denitrification Bioreactors: Why, What, How, When, Where?” at:
   • Boone and Greene Counties, Iowa NRCS Drainage Contractor Meeting. 3 March 2011. Grand Junction, Iowa.  
   • Franklin and Butler Counties, Iowa NRCS Drainage Contractor Meeting. 24 February 2011. Hampton, Iowa. 
6. Christianson, L. 2010. Preliminary Results:  Optimized Denitrification Bioreactor Treatment for Agricultural Drainage through Containment. Plant and Food Research, Crown Research Institute. Palmerston North, New Zealand. 7 September 2010.
7. Bhandari, A. and K. Kult. 2010. Denitrifying drainage bioreactors: Woodchip bioreactors. Presentation to the Ag BMP Expert Panel for the Raccoon River Basin Water Quality Master Plan. Storm Lake, IA, 7 June 2010.
8. Bhandari, A. 2010. Denitrification bioreactors for drainage water treatment. Seminar in the Department of Civil, Construction, and Environmental Engineering, Iowa State University. Jan 26, 2010.
9. Bhandari, A. 2010. Woodchip bioreactors for drainage water treatment. Annual Drainage Engineers Meeting, IA Department of Agriculture and Land Stewardship.  Fort Dodge, IA. 14 Jan 2010.
10. Bhandari, A. 2009. Woodchip bioreactors: A farm-scale practice for nitrate reduction in drainage water. Annual IA-MN Drainage Forum.  Ames, IA. 10 Nov 2009.
11. Bhandari, A., L. Christianson, and M. Helmers. 2009. Innovations in agricultural conservation practices: Woodchip bioreactors for nitrogen removal from tile drainage.  Upper Mississippi River Conference. Moline, IL. 23-25 Sep 2009.