Peer-Reviewed Journal Details
Mandatory Fields
Hayes, J.C., Garvey, M., Fogarty, A.M., Clifford, E., Rowan, N.J.
Water Science And Technology-Water Supply
Inactivation of recalcitrant protozoan oocysts and bacterial endospores in drinking water using high-intensity pulsed UV light irradiation
Optional Fields
Cryptosporidium parvum oocysts indicator species novel water treatment pulsed UV light recalcitrant bacterial endospores FOOD DECONTAMINATION CRYPTOSPORIDIUM SURFACES DIOXIDE
This constitutes the first study to compare the use of high-intensity pulsed UV light (PUV) irradiation for the novel destruction of harmful protozoan (Cryptosporidium parvum Iowa isolate) oocysts and bacterial (Clostridium perfringens ATCC 13124 and Bacillus cereus ATCC 11178) endospores in artificially-spiked water where these organisms are resistant to conventional chlorination. Experimental results revealed that all three test organisms in their dormant recalcitrant state required extended levels of pulsing to achieve significant reductions in numbers compared to other similarly PUV-treated Escherichia coli ATCC 25922 that is a non-spore forming indicator of faecal pollution in water. 120 pulses at 900 V or 16.2 J per pulse (equivalent to a UV dose of 8.39 mu J cm(-2)) were required to achieve ca. 2 log C. perfringens spore numbers, whereas a similar level of PUV irradiation reduced both C. parvum oocysts and B. cereus endospores by ca. 5 log orders. A comparative ca. 5 log reduction of E. coil cell numbers was achieved after only 25 pulses at 900 V (equivalent to a UV dose of 1.74 mu J cm(-2)).A clear trend emerged where the order of resistance to PUV-irradiation observed was C. perfringens endospores > C. parvum oocysts, B. cereus endospores > E. coil cells. This study suggests disinfection kinetic data for the more resistant C. perfringens endospores can be used as a measure of estimating disinfection efficacy of PUV treatments for C. parvum oocysts in water, avoiding the need to use complex animal or cell culture infectivity models that are only available in specialised laboratories with highly trained technicians. This study will inform future studies exploring scale-up of PUV at waste-water treatment plants.
DOI 10.2166/ws.2012.017
Grant Details
Environmental Protection Agency (EPA)
Technological Research Sector Strand I Programme, Ireland (No. A28_2008) & Environmental Protection Agency Strive Programme (2011-W-MS-5)
Publication Themes
Environment, Marine and Energy