Which process is used to destroy pathogens in sewage?

The process used to destroy pathogens in sewage is disinfection. Disinfection is specifically designed to eliminate or inactivate harmful microorganisms, including bacteria, viruses, and protozoa, that may be present in wastewater. This is particularly important in sewage treatment because untreated sewage can pose significant public health risks.

Disinfection can occur through various methods, such as chlorination, ultraviolet (UV) radiation, or ozonation. Each of these methods effectively targets and neutralizes pathogens, ensuring that the treated water meets safety standards before being released into the environment or reused.

In contrast, filtration primarily physically removes solids and larger particles from the water but does not effectively kill pathogens. Decomposition refers to the natural breakdown of organic matter by microorganisms, which can help reduce some levels of contaminants but is not guaranteed to destroy all pathogens. Evaporation is a process in which liquid turns into vapor, but it does not address the presence of pathogens in sewage, as they would remain in the solid residues or untreated effluent. Thus, disinfection is the most effective and appropriate method to ensure the safety of wastewater treatment.