- Ultraviolet (UV) disinfection systems contact the treated secondary wastewater with UV light bulbs that are encased in clear housings.
- The UV light kills pathogenic organisms by using a germicidal photochemical wavelength.
- Unlike chlorination, UV leaves no residual in the wastewater with which to be concerned.
- Plants that use UV must either have dual UV systems or have chlorination as a backup. Additionally, these UV systems are energy consumptive.
GPSC Prelims and Mains Notes, GPSC Test Series