@article {Petri:2009:1938-6478:318, author = "Petri, Brian and Odegaard, Conrad", title = "UV Reactor Challenges with a High Resistance Surrogate for Adenovirus Credit", journal = "Proceedings of the Water Environment Federation", volume = "2009", number = "1", year = "2009", abstract = "Adenovirus has been shown to have a high resistance to low pressure UV. For 4-log virus credit in the LT2 ESWTR, a low pressure UV dose of 186 mJ/cm2 is required. UV reactors must be bioassay validated to achieve credit per the LT2 ESWTR, but currently available challenge microorganisms are not able to demonstrate these high dose values. For example, using MS2 bacteriophage which ranges in resistance from 18-25 mJ/cm2/log, 7.4-10.3 log reductions of MS2 would be required. This is operationally very difficult to do at any reasonable scale. We set out to find a highly UV resistant microorganism that could be cultured to high titers, for doing practical demonstrations of high UV resistances. We used spores of the fungus Aspergillus niger, and characterized them with a low pressure UV collimated beam. To show the feasibility of their practical usage, we used A. niger spores to do full scale challenges of a residential scale low pressure UV reactor (up to 68 L/min flow) and a municipal drinking water scale medium pressure UV reactor (up to 2100 L/min flow). We successfully demonstrated reduction equivalent doses > 400 mJ/cm2 using the A. niger spores, making these spores a viable choice for high dose UV reactor challenges such as those required to achieve multi-log virus credit for the LT2 ESWTR.", pages = "318-321", url = "http://www.ingentaconnect.com/content/wef/wefproc/2009/00002009/00000001/art00030", doi = "doi:10.2175/193864709793847573", keyword = "Bioassay, Adenovirus, UV disinfection, validation, surrogate" }