Using Algal Virus Chlorella Virus as a Human Adenovirus Surrogate for Validation of UV Treatment Systems.

Adenovirus is among the most UV-resistant waterborne human pathogens. There is a need to identify nonpathogenic surrogates for adenovirus for the water treatment industry. In this study, the feasibility of using the algal virus chlorella virus (PBCV-1) as an adenovirus surrogate for validation of UV reactors was evaluated. The UV dose-response behavior of PBCV-1 to monochromatic UV radiation at 254 nm and action spectrum for wavelengths ranging from 214 to 289 nm were measured. A culture-based infectivity assay was used to evaluate viral inactivation, and a quantitative PCR assay was used to quantify DNA damage. A UV dose of 150 mJ/cm resulted in roughly 5-log units of reduction of PBCV-1, which is similar to that of adenovirus. Furthermore, the inactivation action spectrum of PBCV-1 was similar to that of adenovirus between 214 and 289 nm. A simplified and inexpensive prepurification method was also developed to prepare PBCV-1 viral suspensions with similar inactivation behavior to purified PBCV-1. Overall, PBCV-1 appears to represent an appropriate adenovirus surrogate for UV system performance evaluation and illustrates the potential of using algal viruses as nonpathogenic, easy to culture, and readily available surrogates for human pathogens.