The Effect of Upstream Treatment Processes on UV Disinfection Effectiveness

The purpose of this manuscript is to present discussions on how UV light penetrates into wastewater particles and how subsequent UV inactivation of coliform bacteria can be modeled. Impacts that result from particle size distribution, activated sludge mean cell residence time, and process type are explored. Discussion is presented as to how microorganisms other than coliform bacteria may be affected by interactions with particles. The manuscript concludes with recommendations pertaining to the operation of upstream treatment processes to maximize the effectiveness of UV disinfection when attempting to comply with very stringent regulatory criteria (e.g., unrestricted reuse criteria).