What is the purpose of tertiary treatment of sewage? - Leaving Cert Chemistry - Question i - 2008

The primary purpose of tertiary treatment of sewage is to remove lower levels of nitrogen and phosphorus compounds from wastewater. This process is crucial in reducing the nutrient loading in aquatic ecosystems, which helps prevent eutrophication. Eutrophication can lead to excessive growth of algae, depletion of oxygen in water, and subsequent harm to aquatic life. By targeting the reduction of nitrates and phosphates, tertiary treatment plays a vital role in maintaining water quality and promoting a healthier environment.