E2.07 Gonthier 2018 ReNUWIt Annual Meeting Poster

The amount of reactive nitrogen in the environment has increased by 33-55 % globally since the rise of the twentieth century and especially in recent decades.1 This increase in reduced nitrogen in the environment has led to the acidification of freshwater systems and added to the eutrophication of aquatic ecosystems. Eutrophication induced by nutrient pollution fuels harmful algal blooms that result in hypoxia or anoxia,
leading to fish kills and dead zones.2
Anammox bacteria are anaerobic, autotrophic bacteria that occupy a unique and underutilized niche in the global nitrogen cycle. The anammox process involves the biological conversion of ammonium to nitrogen gas using nitrite as the electron acceptor (Figure 1). Conventional municipal nitrogen removal involves sequential nitrification-denitrification processes that require significant aeration and exogenous carbon sources. Because anammox bacteria are anaerobic primary producers that directly convert ammonium and nitrite into nitrogen gas, anammox bioreactors are 60% more energy efficient compared to conventional nitrification-denitrification techniques, offering compelling reductions in greenhouse gas emissions. Moreover, they can be operated at 10% of the cost, a powerful financial incentive. 3
However, anammox bacteria are slow to grow and easily inhibited by constituents commonly found in wastewater as well as varying effluent conditions. Coupling anammox bacteria with zeolites (naturally abundant porous aluminosilicate solids that are capable of ion exchange, with an especially high affinity for ammonium sorption) has the potential to stabilize the anammox process in wastewater treatment facilities.