Microbial community samples taken from a membrane aerated biofilm reactor treating synthetic wastewater. Raw sequence reads

Nitrogen is a common environmental pollutant found in wastewater, so it is important to remove it at a water resource recovery facility before the treated wastewater is released into a lake, river, or ocean. If it is not removed, nitrogen can cause eutrophication which causes plants to grow quickly and animal life to die due to the lack of oxygen in the water. Nitrogen removal uses a lot of energy, so we are researching new methods that are more energy efficient. One new technology that we are researching is the membrane aerated biofilm reactor (MABR) which can be up to four times more energy efficient than traditional wastewater reactors. The efficiency of the MABR can also be improved by incorporating a group of nitrogen removing bacteria called anammox. Anammox bacteria remove nitrogen very efficiently, but they are hard to grow and can be sensitive to different wastewater conditions. Using an MABR in our lab, we compared different MABR operational strategies to see if we could increase the amount of anammox bacteria in the reactor and increase the amount nitrogen that was removed by the reactor.