The anammox process is a biological nitrogen removal process that converts ammonium to dinitrogen gas under anaerobic conditions. Anammox stands for anaerobic ammonium oxidation, and it is carried out by a specific group of bacteria known as anammox bacteria. This process is important for removing nitrogen from wastewater treatment plants and reducing the environmental impact of nitrogen pollution. Anammox is a cost-effective and energy-efficient method of nitrogen removal compared to traditional methods such as nitrification and denitrification. Research in this area focuses on understanding the microbial communities involved in the anammox process, optimizing operating conditions, and improving the overall efficiency of the process.