Wastewater Operator Level 1 Practice Test

What is the main purpose of denitrification?

Convert nitrate to nitrogen gas Convert ammonia to nitrate Remove grit from wastewater Increase dissolved oxygen levels

Correct Answer:

Convert nitrate to nitrogen gas

Explanation:

Denitrification is the biological removal of nitrogen from wastewater by microorganisms that convert nitrate into nitrogen gas under low-oxygen conditions, using organic carbon as an electron donor. This is the main purpose because it directly lowers nitrate levels in the effluent, helping meet discharge limits and protect downstream water quality. It typically occurs in anoxic zones or dedicated denitrification reactors after nitrification. The nitrogen gas produced is released to the atmosphere, effectively removing nitrogen from the treatment system. Converting ammonia to nitrate is nitrification, not denitrification. Removing grit is a physical solids process, and increasing dissolved oxygen levels comes from aeration, not from denitrification.

Access more questions from this quiz

Continue to Wastewater Operator Level 1 Practice Test for more practice questions and the full quiz experience.

Access More Questions