What does the term 'nutrient removal' refer to in wastewater treatment?

The term 'nutrient removal' in wastewater treatment specifically refers to the process of removing nitrogen and phosphorus from the wastewater. These nutrients, while essential for plant growth in appropriate amounts, can cause significant environmental issues like algal blooms when they are present in excess in water bodies. These blooms can deplete oxygen in the water, leading to dead zones that are harmful to aquatic life.

Techniques used for nutrient removal often include biological processes, where bacteria convert nitrogen compounds into harmless nitrogen gas, as well as chemical processes for treating phosphorus. The goal of nutrient removal is to protect water quality and ensure that treated wastewater can be safely released into the environment or reused, thereby providing both ecological and sanitary benefits.