What does "pathogen removal" refer to in sewage treatment?

Pathogen removal in sewage treatment specifically refers to the process of eliminating harmful microorganisms, such as bacteria, viruses, and parasites, from wastewater before it is discharged or reused. This is crucial for public health, as these pathogens can pose significant health risks if the treated water is not properly sanitized. The successful removal of pathogens ensures that the effluent is safe for either discharge into the environment or further treatment processes.

While reducing nutrient levels in effluent is an important aspect of sewage treatment, it does not directly address the elimination of harmful microorganisms. Techniques for separating solids from liquids and removing large debris are also vital for the treatment process, but these actions are focused on physical separation and do not specifically involve the destruction or inactivation of pathogens. Hence, the focus of pathogen removal emphasizes the biological aspect of improving the safety and quality of treated wastewater.