AWWA JAW69827

For systems considering ultraviolet (UV) disinfection and requiring virus inactivation of 3 to 4 logs, adenovirus appears likely to be the limiting organism in determining reactor design and UV dose. In its Long Term 2 Enhanced Surface Water Treatment Rule regulations, the U.S. Environmental Protection Agency reported that inactivation of adenoviruses to a level of 4 logs requires a UV dose of 186 mJ/cm². Recent bench-scale studies indicate that full-scale medium-pressure (MP) UV systems may be capable of achieving significant inactivation of adenovirus at lower UV doses than are possible with low-pressure systems. In this study, a protocol for field-scale testing and validation of adenovirus disinfection by MP UV light was developed and used to perform a live adenovirus challenge test showing the level of adenovirus inactivation possible in a field-scale UV disinfection system. The reactor studied here demonstrated that MP UV irradiation technology can achieve > 4-log reduction at economically viable UV doses lower than 100 mJ/cm². Includes 16 references, tables, figures.