Understanding MP Low Wavelength Disinfection: Guidance for Operating and Future UV Facilities

摘要

The EPA UV Disinfection Guidance Manual (LJVDGM) was released in 2001 and 2003 and a final version released in 2006. During its development, the LJVDGM was challenged by limited experience with full scale UV system validation and operation. Recent validation testing and computational fluid dynamics (CFD) modeling raises the possibility that the validation process used for some medium pressure UV systems may not account for disinfection from low wavelength (i.e., less than 240 nm) UV light. This is because some test surrogates (e.g., MS2 phage) are inactivated more easily than target pathogens (e.g., Cryptosporidium) at these low wavelengths. There has been considerable evolution in the understanding of UV disinfection in the last decade and this communication describes factors not fully addressed by the UVDGM that impact some medium pressure UV applications.