Nitrification and denitrification systems are used to control ammonia levels and turn nitrate into gaseous nitrogen species. Denitrification is a biochemical process that removes nitrogen from a treatment facility’s discharge through a combination of chemical additives and bacterial degradation. Nitrification and denitrification systems that are used with carbons present in raw sewage can be used to provide denitrification in a singe vessel with alternating aerobic and anaerobic zones. Nitrification and denitrifcation systems are also used for treating food-processing wastewater. For example, activated sludge processes with nitrification-denitrification are an aerobic treatment system used at sugar beet factories. At these facilities, a small flow of raw, high-strength wastewater is used as a carbon source for proper denitrification.

Nitrification and denitrification systems can be used at plants that treat oil/tar separation, equalization, steam distillation for removal of free ammonia and acid gases, and activated sludge. A nitrification system can convert nitrogen to nitrate for conservation of nitrogen fertilizer on farms. A denitrification system is commonly used to remove nitrogen by converting nitrate to nitrogen gas under anaerobic conditions when sufficient organics or energy is available. An ammonia refrigeration system is commonly used in the food, beverage, petrochemical, and cold storage industries due to ammonia’s ability to liquefy easily by compression or cooling and absorb large amounts of heat from its surroundings when returned to its gaseous state.

Nitrification and wastewater systems are used to remove nitrogen in a biological method from municipal wastewater. Nitrogen-removal systems employ nitrification and denitrification systems using biological reactions to remove nitrogen. Denitrification in process wastewater is collected in a treatment facility and, through bacterial degradation, high levels of ammonia are converted into nitrates. Nitrification and denitrification systems are used in a wastewater treatment process to control levels of ammonia and nitrogen, which is a nutrient that will encourage undesirable, oxygen depleting growth in rivers and lakes, and is poisonous for fish and microorganisms.