What is the correct sequence of the nitrification cycle?

The correct sequence of the nitrification cycle is characterized by the conversion of ammonia to nitrite and then to nitrate. The process begins with ammonia, which is derived from organic matter decomposition. Specialized bacteria known as ammonium-oxidizers convert ammonia (NH3) into nitrite (NO2-). This is an essential step because it transforms ammonia, which can be toxic at higher concentrations, into a less harmful form.

Subsequently, another group of bacteria, called nitrite-oxidizers, further oxidizes nitrite into nitrate (NO3-). Nitrate is a more stable form of nitrogen that can be utilized by plants and is often found in soil and aquatic environments.

Thus, the step-by-step process in nitrification is: firstly, ammonia is oxidized to nitrite, followed by the oxidation of nitrite to nitrate. Recognizing this sequence helps in understanding nutrient cycling in ecosystems and potential implications for wastewater treatment processes, as nitrogen compounds can affect water quality if not properly managed.