What is tertiary treatment in wastewater management?

Tertiary treatment in wastewater management refers to advanced treatment processes that follow secondary treatment. This stage is designed to further improve the quality of the effluent before it is discharged or reused. After the secondary treatment stage, which typically focuses on removing biodegradable organic matter and suspended solids, tertiary treatment involves additional processes aimed at specific contaminants that may remain.

These advanced processes can include filtration, chemical treatment, disinfection (such as chlorination or ozonation), and nutrient removal (such as phosphorus and nitrogen). The goal of tertiary treatment is to produce effluent that meets higher standards of purity, making it suitable for surface water discharge or for reuse in irrigation, industrial processes, or even safe drinking water after appropriate treatment.

The other options represent different stages or aspects of wastewater treatment. Preliminary screening is about removing large solids at the beginning, sludge management refers to the treatment of solids collected during the process, and basic treatment focuses on settling solids, which is a more fundamental level of treatment than what tertiary treatment encompasses.