Water is an essential and nonrenewable element for all living beings. In current scenario due to pollution and excessive use make its scarcity, and in future its demand increase at higher level. Therefore, it is necessary to use the wastewater, which release form various industry for reduce its scarcity. Several methods used for the wastewater treatment including the physical, chemical, and biological. Among them biological method is more suitable for the treatment of wastewater due its low cost, less toxic and environment sustainable approach. It is a crucial process, in which microorganisms treat the wastewater through break down of pollutants. This review explores the use of nitrifiers in wastewater treatment, emphasizing their importance in reducing nitrogen load and preventing eutrophication in aquatic ecosystems. It also describes the anammox process, an emerging method used for the treatment of ammonium-rich wastewater with lower oxygen and carbon requirements as compared to conventional methods. This review discusses role of mixed microbial consortia in anammox process in the presence of organic compounds and highlights the impact of different paraments on anammox process. Conclusively, it provides a deep knowledge about the annamox methods, its process, types and application in different field for the wastewater treatment.