Location: Agroecosystems Management ResearchTitle: Evaluation of woodchip bioreactors for improved water quality Author
|Soupier, Michelle - Iowa State University|
|Hoover, Natasha - Iowa State University|
|Moorman, Thomas - Tom|
|Jones, Chris - Iowa State University|
|Kult, Keegan - Iowa State University|
Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/26/2015
Publication Date: 7/26/2015
Citation: Soupier, M.L., Hoover, N., Moorman, T.B., Jones, C., Kult, K. 2015. Evaluation of woodchip bioreactors for improved water quality. ASABE Annual International Meeting [abstract]. ASABE Annual International Meeting, 07/26-29/2015, New Orleans, LA.
Technical Abstract: Woodchip bioreactors are gaining popularity with farmers because of their edge-of-field nitrate removal capabilities, which do not require changes in land management practices. However, limited research has been conducted to study the potential of these bioreactors to also reduce downstream transport of contaminants commonly detected in manure-amended cropland, including pathogens and phosphorous. The results of a controlled laboratory-scale study are presented with field-scale studies of bioreactor phosphorous and fecal indicator bacterial removal. The lab-scale bioreactor column study was initiated to quantify the impact of hydraulic residence time, temperature, and limestone amendment on the removal of nitrate, phosphorous, and fecal indicator bacteria by woodchip bioreactors. To quantify fecal indicator bacteria removal, synthetic tile drainage, which was periodically augmented with E. coli, Salmonella enterica, and Enterococcus bacteria, was pumped through two sets of three bioreactor columns. One set at room temperature, and the other at a controlled 10°C. Hydraulic retention time (HRT) was systematically altered between 12-hour and 24-hour HRT. Preliminary results in year one of the field component showed reductions in E. coli concentrations (40%) and enterococci concentrations (59%) in drainage water exiting the bioreactor. However, nitrate reductions were also low (3%-8%) indicating insufficient HRT. No measurable differences were detected in PO4-P concentrations in the inlet and outlet samples.