Denitrifikáció

Denitrifikáció is a biological process that converts nitrate (NO3-) into nitrogen gas (N2). This process is carried out by a group of bacteria known as denitrifying bacteria, which are facultative anaerobes. These bacteria use nitrate as an electron acceptor in their respiration when oxygen is not available. Denitrification is a crucial part of the nitrogen cycle, as it returns nitrogen from biologically available forms back into the atmosphere.

The process typically occurs in environments with low oxygen concentrations, such as waterlogged soils, sediments, and the anoxic zones of aquatic ecosystems. Denitrifying bacteria obtain energy by reducing nitrate in a series of steps, ultimately producing nitrogen gas. This gas is then released into the atmosphere, completing the cycle. Without denitrification, nitrogen would accumulate in aquatic and terrestrial systems, potentially leading to eutrophication and other environmental problems.

Denitrification can be both beneficial and detrimental depending on the context. In wastewater treatment plants, it is intentionally promoted to remove excess nitrogen from effluent, preventing pollution of receiving waters. However, in agricultural soils, denitrification can lead to the loss of valuable nitrogen fertilizer, reducing crop yields and contributing to greenhouse gas emissions (nitrous oxide, N2O, is an intermediate product). Understanding and managing denitrification is therefore important for both environmental protection and agricultural sustainability.