What typically happens to nitrogen compounds in wastewater without the denitrification process?

Nitrogen compounds in wastewater, when not subjected to the denitrification process, primarily contribute to nutrient pollution. This occurs because nitrogen, often present in forms like ammonia and nitrates, can persist in the ecosystem and, when discharged into water bodies, can lead to excessive growth of algae—known as algal blooms. These blooms can deplete oxygen levels in the water, harm aquatic life, and cause deterioration of water quality, highlighting the significance of nitrogen as a nutrient pollutant.

The denitrification process helps to convert these nitrogen compounds into nitrogen gas, which can be released harmlessly into the atmosphere. Without this process, the nitrogen remains in the water, exacerbating pollution issues. Other choices such as complete removal, conversion to organic matter, or evaporation do not accurately reflect the fate of nitrogen compounds in the absence of denitrification.