Anammox Bacteria and Their Application in Wastewater Treatment Plants

Anaerobic ammonia oxidation (anammox) is considered as an innovative technology designed for the treatment of wastewater with very high ammonia nitrogen concentrations. This process has significant advantages over other processes as it is energy saving and produces a much reduced amount of sludge. It is also considered as an eco-friendly, cost effective process and is associated with less greenhouse gas emissions. Anaerobic ammonium oxidation (anammox) bacteria were discovered as early as the 1990s and they have the unique metabolic ability to combine ammonium and nitrite or nitrate to form nitrogen gas. These groups of microorganisms are responsible for nearly 50% of the total nitrogen turnover. The anammox bacteria comprise a wide range of microorganisms that are capable of doing a wide range of functions, such as nitritation and denitritation, which have much reduced oxygen and organic matter consumption. This present chapter mainly deals with the types of anammox bacteria and their mode of action in wastewater treatment systems. The impact of environmental factor on the metabolic activity of these group has also been discussed in detail. Also, focus is given to the potential application of anammox bacteria on an industrial scale.