The primary method of nitrogen removal in constructed wetland treatment systems is __________.

The primary method of nitrogen removal in constructed wetland treatment systems is through nitrification/denitrification. This process involves two key stages: nitrification, where ammonia is converted to nitrates by bacteria, and denitrification, where nitrates are reduced to nitrogen gas, which is then released into the atmosphere. Constructed wetlands facilitate these biological processes by providing a suitable environment where microorganisms can thrive, enabling effective nitrogen removal from wastewater.

Although volatilization, which involves the conversion of ammonium to ammonia gas that escapes into the atmosphere, can occur under certain conditions, it is not the primary mechanism in constructed wetlands. Precipitation-adsorption in soils and plant or algal uptake are also relevant processes; however, they play a secondary role compared to the combined action of nitrification and denitrification in promoting nitrogen removal from wastewater in these systems.

Understanding the significance of nitrification/denitrification is crucial as it highlights the essential microbial processes and environmental conditions that are optimized in constructed wetland designs to achieve effective nitrogen removal.