Which methods are commonly used for disinfection in wastewater treatment?

Disinfection in wastewater treatment is a critical process aimed at eliminating pathogenic microorganisms to safeguard public health and the environment. The correct choice highlights three widely accepted methods: chlorination, ultraviolet (UV) light, and ozonation.

Chlorination involves adding chlorine or chlorine compounds to the wastewater, effectively killing or inactivating bacteria, viruses, and other pathogens. It is one of the most traditional and prevalent methods used due to its efficiency and effectiveness.

Ultraviolet (UV) light disinfection utilizes ultraviolet radiation to target and destroy the DNA of microorganisms, rendering them unable to reproduce. This method is increasingly favored due to its ability to avoid chlorine by-products, which can be harmful to aquatic ecosystems.

Ozonation involves injecting ozone gas into the wastewater, which acts as a strong oxidizer, disrupting the cellular structure of microorganisms and inactivating them. Ozone decomposes back into oxygen, leaving no harmful residual chemicals in the treated water.

The other methods listed do not serve the primary function of disinfection. Filtration and sedimentation are primarily used for the physical removal of solids and particles from wastewater but do not specifically target pathogens. Similarly, centrifugation and chemical mixing are typically associated with the separation of solids or enhancing the interactions of various substances