What process describes the conversion of nitrate to nitrogen gas?

The process that describes the conversion of nitrate to nitrogen gas is denitrification. This biological process involves the reduction of nitrates (NO3-) and nitrites (NO2-) to nitrogen gas (N2) or, in some cases, to nitrous oxide (N2O). Denitrification typically occurs under anaerobic conditions, where specialized bacteria utilize nitrates and nitrites as electron acceptors instead of oxygen during respiration.

Denitrification plays a critical role in the nitrogen cycle, helping to reduce excessive nitrates in environments such as water bodies, thereby preventing problems like eutrophication. This process contributes to balancing nitrogen levels in ecosystems by returning nitrogen to the atmosphere, making it available again for uptake by plants and microorganisms.

Nitrification, on the other hand, is the process of converting ammonia into nitrates, not the conversion of nitrates to nitrogen gas. Autotriphication is not a recognized term in the context of wastewater treatment processes. Anaerobic decomposition involves the breakdown of organic matter without oxygen, which can lead to methane production, but it does not specifically refer to the conversion of nitrates to gaseous nitrogen.