1. uV Drinking Water Treatment
Emerging Technologies

2. NSF/ANSI Standard 55
Evaluation of Microbiological Reduction Performance Capability
Low Pressure uV Lamps
254nm Wavelength
Performance Equated to Delivered Dose
Class A 40 mJ/cm2 With Sensor Technology – Unknown Water Supply
Class B 16 mJ/cm2 Without Sensing Technology – Known Water Supply
Test Organisms
Bacteriophage MS2 – Class A
S. cerevisiae/Bacteriophage T1 – Class B

3. How does UV inactivate micro-organisms?
Well Accepted Mechanism of UV Inactivation
253.7nm
UVC Absorbance of DNA
At a wavelength of 254nm, UV will break the molecular bonds within micro-organismal DNA, producing thymine dimers and thereby destroying them or prohibiting growth and reproduction

4. Emerging Technologies
Alternate uV Technologies Are Under Active Development
LED
DBD
Excimer
MP CFL
Halogen
uV Emissions May Be Monochromatic or Polychromatic at Wavelengths Other Than 254 nm

5. Market Trends

6. The Issue (Opportunity)
Standard 55 Performance Based Upon Dose…..
Dose Equated to Anticipated Log Reduction at 254 nm Wavelength
Relationship of Dose to Log Reduction Based Upon Established Research and Scientific Findings
The Question (s)
Does the Dose/Log Reduction Relationship Hold For Alternate Technologies Emitting as Wavelength (s) Other than 254 nm?
Is There a Need for the Development of Alternative Measuring Tools?
Can These Alternate Technologies Be Built Into Standard 55?

7. Summary of Previous Wavelength Works
(nm)
Polychromatic
Monochromatic
Organisms
Main Findings
Ref
210, 220, 230, 240, 260, 270, 280, 290
Adenovirus
More DNA damage was observed at >260nm
Loss of viral infectivity was due to the UV damage to a viral component at <240nm
S. Beck et al., Environ. Sci. & Technol., 2014
214, 230, 240, 254, 265, 280, 293
Bacillus / spores
MS2 coliphage
MS2 was 3 times more sensitive to near 214nm compared to the 254 nm
B. subtilis spores were most sensitive to 265nm
H. Mamane-Gravetz et al., Environ. Sci. & Technol., 2005
216, 230, 242, 255, 263, 271, 281, 290
Cryptosporidium parvum oocysts
C. Parvum oocyst was most sensitive to 271nm
Oocyst can be appreciably inactivated at low UV dose
K. Linden et al., Water Sci. & Technol., 2001
222, 228, 239, 260, 280, 289
Other wavelength emitted by the polychromatic UV lamps are more effective than the 254nm emitted by LP UV.
K. Linden et al., Appl. Environ. Microbio., 2007

8. Motion
The motion is that the uV Task Group be requested to evaluate the available research associated with alternate uV technologies related to the germicidal treatment of water and report back to the Joint Committee their findings and recommendations for accommodating these technologies within the NSF/ANSI standards framework.

12. How Emerging Technologies Inactivate
How UV inactivates
254nm comparison to other wavelengths
MS2 Surrogate potential
E Coli
S Typhimurium LT2
Bacillus Subtilis Spores

13. How does 253.7nm compare to other wavelength?
Mamane-Gravetz et al., Environ. Sci. & Technol., 2005
Linden et al., Water Sci. & Technol., 2001
Beck et al., Environ. Sci. & Technol., 2014
Linden et al., Appl. Environ. Microbiol., 2007

14. How does MS2/254nm Inactivation compare to bacteria / waterborne pathogens?
Bowker et al., Water Research., 2011
Ren Zhuo Chen et al., Water Research., 2009

15. How does MS2/254nm Inactivation compare to bacteria / waterborne pathogens?
Ren Zhuo Chen et al., Water Research., 2009
Mamane-Gravetz et al., Envirron. Sci. Technology., 2005

16. Testing Protocol Opportunities
Revision to NSF/ANSI Standard 55
MS2 as surrogate
Development of new NSF Certification
Alternative Surrogate