Master the PE Civil: WRE Exam 2025 – Dive Into Your Engineering Success!

The process referred to is denitrification, which is a crucial part of the nitrogen cycle. During denitrification, nitrates (NO₃⁻) or nitrites (NO₂⁻) are reduced to nitrogen gas (N₂) by specific bacteria under anaerobic conditions (absence of oxygen). This process not only removes excess nitrogen from the environment, thereby preventing potential water pollution and eutrophication but also contributes to the release of nitrogen gas back into the atmosphere.

Denitrification is essential in wastewater treatment, as it helps in managing nitrogen levels, especially in effluent before it enters larger water bodies. The conversion of nitrates into nitrogen gas effectively decreases nutrient loading in aquatic systems, promoting balanced ecosystems.

In contrast, nitrification refers to the oxidation of ammonia to nitrates, while ammonification involves the breakdown of organic nitrogen into ammonia. Oxidation generally pertains to any chemical reaction involving the loss of electrons, which does not specifically address the deoxidization of nitrogen. Thus, denitrification is the accurate term for the reduction of nitrogen compounds to release nitrogen gas.