Which of the following methods can be used for sewage disinfection?

Chlorination is a widely accepted method for sewage disinfection because it effectively kills harmful pathogens present in wastewater. The process involves adding chlorine or chlorine compounds to the sewage, which acts as a strong oxidant, disrupting the cellular structure of bacteria, viruses, and other microorganisms. This method is favored for its ability to maintain a residual level of disinfectant in the effluent, providing ongoing protection against recontamination as the treated sewage is discharged.

Chlorination is also relatively easy to implement in various wastewater treatment systems and is cost-effective when considering operational expenses. It plays a crucial role in ensuring that treated wastewater meets health and safety standards before being reused or released into the environment.

While mechanical filtration, heating, and biological treatment are methods related to wastewater treatment, they do not primarily serve the role of disinfection in the same way chlorination does. Mechanical filtration may remove larger solids but does not effectively eliminate pathogens. Heating can kill bacteria but is not a standard method for large-scale sewage treatment due to energy costs. Biological treatment helps in reducing organic content but may leave pathogens in the effluent, which necessitates disinfection.