What is the main reason for disinfecting treated sewage before discharge?

Disinfecting treated sewage before discharge primarily aims to kill pathogens. Treated sewage can contain various microorganisms, including bacteria, viruses, and protozoa, which can pose health risks to humans and the environment if released untreated. By employing methods such as chlorination, ultraviolet (UV) light, or ozonation, the disinfection process effectively neutralizes these harmful pathogens, significantly reducing the potential for disease transmission and ensuring that the effluent meets regulatory standards for safe discharge into water bodies.

While improving aesthetic qualities, removing heavy metals, and eliminating odors are important aspects of sewage treatment and help enhance the overall quality of treated effluent, they do not address the critical public health concern of pathogen presence. Therefore, the primary objective of disinfection is to ensure that the treated sewage is safe for discharge and minimizes health risks associated with pollutants.