Which method is typically used for the disinfection of wastewater before it is released into the environment?

Chlorination is the most widely used method for disinfecting wastewater before it is released into the environment. This process involves adding chlorine or chlorine compounds to the water, which effectively kills bacteria, viruses, and other pathogens present in the wastewater. The primary aim of chlorination is to ensure that harmful microorganisms are eliminated, thereby reducing the risk of waterborne diseases and protecting public health.

Chlorination is favored because it is relatively cost-effective, easy to apply, and can be adjusted to meet the specific needs of a given wastewater treatment facility. Additionally, it can provide a residual effect, meaning that some chlorine remains in the water after treatment, offering continued protection as water is transported through the distribution system.

Other methods mentioned, while useful in different contexts, are not typically employed for primary disinfection in wastewater treatment. Pressure cooking and boiling are methods of sterilization commonly applied to food preparation and laboratory settings but are impractical for the large volumes of wastewater handled in treatment facilities. Filtration may remove some particles and pathogens but does not necessarily kill them or provide comprehensive disinfection. Consequently, chlorination remains the standard practice for disinfection in wastewater management before environmental discharge.