ARS | Publication request: Sequestering Dissolved Phosphorus from Ditch Drainage Water

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 23, 2007
Publication Date: July 1, 2007
Citation: Penn, C.J., Bryant, R.B., Kleinman, P.J., Allen, A.L. 2007. Removing dissolved phosphorus from drainage ditch water. Journal of Soil and Water Conservation. 62:269-276.

Interpretive Summary: Due to current issues with surface water eutrophication and the ecological and economical problems associated with it, there is a need to reduce phosphorus (P) loading to surface water bodies. Although particulate P losses to surface waters can be minimized by controlling erosion, decreasing dissolved P loss via overland flow from agricultural soils high in P is more difficult. For agricultural systems that rely on open ditch drainage, a P removal structure that treats ditch drainage water affords a means of reducing soluble P losses from large acreages of land upstream of the structure. This study involved the design and testing of a P removal structure intended to sequester dissolved P from passing ditch water by use of P sorbing materials (PSMs). Several PSMs were characterized for use in a P removal structure, tested on a pilot scale, and one PSM was used in a field experiment. For the first major runoff event, the P removal structure constructed for this study was able to remove 99% of dissolved P in captured ditch flow. In addition, the structure was also found to remove certain trace metals (copper, zinc, arsenic, and nickel) and total nitrogen from passing ditch flow. This paper provides general guidelines and approach for designing a P removal structure.

Technical Abstract: Phosphorus (P) transport via agricultural drainage ditches can be considered a point source location for potential conservation efforts. This study involved the design and testing of a P removal structure intended to sequester dissolved P from passing ditch water by use of P sorbing materials (PSMs). Such a structure can remove dissolved P from the system rather than simply reduce P solubility. Several PSMs were characterized for use in a P removal structure, tested on a pilot scale, and one PSM used in a field experiment. For the first major runoff event, the P removal structure constructed for this study was able to remove 99% of captured ditch flow dissolved P. In addition, the structure was also found to remove certain trace metals (copper, zinc, arsenic, and nickel) and total nitrogen from passing ditch flow. This paper provides general guidelines and approach for designing a P removal structure.