Recent advancements in the mitigation of obnoxious nitrogenous gases

Nitrogenous gaseous emissions commonly have an obnoxious odor associated with it, which when discharged into the environment results in serious environmental problems and health hazards. Several strategies for mitigation of nitrogenous odorants have been reported which include physical, chemical and biological methods. Biological treatments are widely employed because of their efficiency even at low concentration, where physical and chemical methods are not effective. Most commonly used biological treatment methods are biofiltration, biotrickling filters and membrane bioreactors with innovative reactor design, mixing pattern, and air sparging, for example FEBR, ALR, etc. These treatment methods require a critical assessment for the mitigation of obnoxious nitrogen emissions, especially in the context of environmental protection. This review offers a critical evaluation of treatment methods for the mitigation of nitrogenous odorous compound with a key emphasis on biological treatment systems. Also, various mathematical modelling techniques required for optimized operation of biotreatment systems has been discussed.