Effectiveness of Denitrifying Bioreactors on Water Pollutant Reduction from Agricultural Areas

Highlights Denitrifying woodchip bioreactors treat nitrate-N in a variety of applications and geographies. This review focuses on subsurface drainage bed-style designs (including in-ditch). Monitoring reporting recommendations are provided to advance bioreactor science engineering. Abstract. enhance the natural process denitrification practical way nitrate-nitrogen (N) N-laden water matrices. The design construction for treatment U.S. is guided by USDA-NRCS Conservation Practice Standard 605. consolidates state denitrifying using case studies from across globe with an emphasis full-size removal cost-effectiveness. focus in-ditch modifications), although there mention walls, which broaden applicability technology some areas. Subsurface have been assessed as removing 20% 40% annual loss Midwest, evaluation peer-reviewed literature published over past three years showed that around world generally consistent (N load reduction median: 46%; mean ±SD: ±26%; n = 15). Reported N rates were order 5.1 g m-3 d-1 (median; 7.2 ±9.6 d-1; 27). installation costs ranged less than $5,000 $27,000, estimated cost efficiencies ranging $2.50 kg-1 year-1 roughly $20 (although they can be high $48 year-1). A suggested monitoring setup described primarily context conservation practitioners watershed groups assessing performance bioreactors. Recommended minimum measures comparing include: dimensions date; fill media size, porosity, type; concentrations temperatures; flow details; basic system characteristics; rate efficiency. Keywords: Groundwater, Nitrate, Nonpoint-source pollution, drainage, Tile.