Conventional wastewater treatment does not normally remove nutrients to a remarkable extent. Pollution of water bodies due to discharge of nitrogen and its compounds are among one of the major problems. Nitrogen is present in the effluent of various industries, landfill leachates, and sludge digester effluent. Excess nitrogen discharge in water streams leads uncontrolled eutrophication, considerable loss of oxygen and unwanted changes in aquatic population. Biological nutrient removal technologies have been developed and more emphasis has been placed on limiting the nutrient discharge in water streams. New nitrogen removal technologies like single reactor system for high ammonia removal over nitrite (SHARON) process, completely autotrophic nitrogen removal over nitrite (CANON), anaerobic ammonium oxidation (ANAMMOX) process and granular sludge technology are easy in operation and cost effective. This paper presents a review on biological nitrogen removal technologies suitable for wastewater treatment.
Keywords: Aerobic granules, Ammonium, ANAMMOX, Anoxic, Autotrophic, BOD, CANON, COD, Denitrification, Dinitrogen, Granular Sludge, Heterotrophic, HRT, Nitrate, Nitrification, Nitrite, Nitrogen SBR, SHARON, SRT.