3 Significant role of nitrogen cycle in wastewater treatment

Reactive nitrogen compounds such as NH3, N2O, and NO3 − are the major pollutants of wastewater due to their effect on the oxygen contents of water and their role in eutrophication. Excessive reactive nitrogen in the environment has the potential to cause a deleterious effect on our ecosystem. The reactive forms of nitrogen are mainly released into the environment by the wastewater treatment plants. Particular types of microorganisms play an essential role during nitrogen cycling in the removal of reactive nitrogen from wastewaters. In nitrifying and denitrifying processes, ammonia is converted to nitrate, and nitrate is converted to nonreactive dinitrogen gas by ammoniaoxidizing and nitrite-oxidizing bacteria. Ammonia is converted to nitrogen gas by using nitric oxide as an oxidant by anaerobic ammonia-oxidizing bacteria or anammox. The operational cost of this process is very low and is environmentally friendly.