Armon Parsi

As the Mississippi River flows into the Gulf of Mexico, there exists a hypoxic zone that can mainly be attributed to the accumulation of nitrate (NO3-) in upper Midwest waterways (David et al, 2010). Nitrate is a naturally occurring compound that can be found in most soils because of decaying organic matter; however, the use of nitrogen-based fertilizers on cropland has added more nitrate to the groundwater than natural systems can handle (Cooke et al., 2015). Decreasing the amount of fertilizer could have damaging effects on the productivity of these farmlands, harming global food supply. One proactive measure that has been taken in recent times to reduce the amount of nitrate runoff is the installation of denitrifying bioreactors on farms. These cost-effective bioreactors consist of a bed of carbon-based material (usually woodchips) that denitrify the tile drainage water and transform the nitrate into neutral, gaseous nitrogen (N) that can be released into the atmosphere without harmful effects. A permeameter is being designed and constructed to test the hydraulic properties of bioreactor bed media to further optimize their performance. A smaller permeameter will allow researchers to run tests with smaller media loads and make transferring easier, increasing accessibility for bioreactors outside of the metro area.