Modification of a dual‐chamber denitrification bioreactor with a surface water pumping system

Abstract

Abstract Denitrification bioreactors are an edge‐of‐field conservation practice being implemented to reduce nonpoint nitrogen pollution to downstream waterbodies. In the Midwestern region of the United States, these bioreactors are commonly used for the treatment of nitrate‐laden subsurface drainage systems. Innovative strategies will be needed to reach the nutrient reduction goals established; here, a typical denitrification bioreactor was retrofitted with a supplemental surface water pumping system to enhance the bioreactor use and performance. Potential benefits of the pumped bioreactor system include extended treatment beyond the typical drainage season, increased nitrate mass removal, extended bioreactor lifespan, and extended applications of the bioreactor such as treatment of surface waters. Current challenges associated with pumped bioreactors exist with the timing of the pumping and water source identification. Considerations include the water availability and the potential need to obtain a permit for the water extraction, and nitrate concentration, temperature, and carbon content of the source to be pumped from. Conditions that would promote complete nitrate removal should be avoided. Additional potential applications for these pumped bioreactors have been identified and include, but are not limited to, the treatment of additional surface water sources, irrigation waters, drainage ditches, and groundwater.