Can iron enhanced sand filtration capture total phosphorus and soluble phosphorus (phosphate) from agricultural tile drainage? A monitoring study measured the total phosphorus and phosphate capture performance of an iron enhanced sand filter (IESF) installed to treat agricultural tile drainage inWright County, MT, USA. Overall, for natural rainfall-induced tile drainage events monitored between June and November 2015 and again in 2016, the IESF captured 66% ± 7% (α = 0.05, n = 21) of the influent total phosphorus mass and 64% ± 8% (α = 0.05, n = 31) of the influent phosphate mass. Removal of total phosphorus and phosphate was approximately uniform for large and small rainfall-induced tile drainage events and varied from 42% to 95% for total phosphorus and 9% to 87% for phosphate. The IESF treated 290 m of treated depth since installation, and results indicate that performance is similar or better than constructed wetlands or other IESFs, though not as good as laboratory experiments of IESFs. Routine and non-routine maintenance was performed throughout the project to ensure adequate phosphorus capture and flow rate through the IESF.
Bibliographical noteFunding Information:
Acknowledgments: This project was funded by the Minnesota Pollution Control Agency through the Federal Clean Water Act Section 319 grant program, SWIFT Contract No. 66692; Award No. 44095, with David Wall as Project Manager. David’s assistance and support throughout this project was greatly appreciated. The Wright Soil and Water Conservation District provided in-kind match and assistance throughout the project. Support from the Wright Soil and Water Conservation District including Joe Jacobs, Dan Nadeau, Alicia O’Hare, Kerry Saxton, and summer support staff was greatly appreciated. In addition, the assistance and support from St. Anthony Falls Laboratory (SAFL) staff and students including Peter Corkery, Jenni Snyder, David Liddell, Tyler Olsen, Poornima Natarajan, Rob Gabrielson, Ben Erickson, Dick Christopher, Seth Strelow, and Raphael Martins was appreciated. Comments from anonymous reviewers and timely response from the journal editors were also greatly appreciated. Participation by volunteer industry professionals to become members of the Technical Advisory Panel was appreciated. Funds were not received for covering the costs associated with publishing this article in an open access journal.
- Tile drainage