Nitrification is a biological process that occurs during wastewater treatment and is used to remove nitrogen from the wastewater. The process involves the conversion of ammonia, which is toxic to aquatic life, into nitrate, a less harmful form of nitrogen. This is achieved through the activity of two different groups of bacteria. The first group oxidizes ammonia to nitrite, and the second group oxidizes nitrite to nitrate. The nitrification process requires oxygen and is typically carried out in an aerobic environment. Once nitrification is complete, the nitrate can be removed from the wastewater through further treatment processes, such as denitrification. Nitrification is an important step in the treatment of wastewater, as high levels of nitrogen can lead to eutrophication in bodies of water, which can cause algae blooms, fish kills, and other negative environmental impacts.