What types of pollutants are typically removed during tertiary treatment?

Tertiary treatment is an advanced stage of wastewater treatment, primarily designed to further remove specific pollutants that may still be present after primary and secondary treatment processes. This level of treatment focuses on improving water quality by targeting particular contaminants.

The correct answer encompasses the removal of suspended solids, nutrients (such as nitrogen and phosphorus), and pathogens. Tertiary treatment often employs methods such as filtration, nutrient removal processes, and disinfection technologies to achieve these goals.

Suspended solids are removed to enhance the clarity and quality of the effluent, preventing them from causing pollution in receiving waters. Nutrient removal is crucial because excessive nitrogen and phosphorus can lead to eutrophication, resulting in harmful algal blooms and oxygen depletion in aquatic ecosystems. Pathogens are addressed through advanced disinfection processes, ensuring that the treated water is safe for potential reuse or discharge.

In contrast, focusing solely on pathogens overlooks the importance of nutrient and solids removal, which are critical in mitigating environmental impacts. While organic matter and heavy metals are of concern, they are typically addressed in secondary treatment or through specialized processes rather than being the primary goals of tertiary treatment. Additionally, solids and odors may be managed in earlier stages or through other operational practices but do not encompass the full spectrum of pollutants targeted during