TY - JOUR
T1 - Photocatalytic inactivation of Cryptosporidium parvum with TiO2 and low-pressure ultraviolet irradiation
AU - Ryu, Hodon
AU - Gerrity, Daniel
AU - Crittenden, John C.
AU - Abbaszadegan, Morteza
N1 - Funding Information:
This research was supported by the National Science Foundation (NSF) Water Quality Center at Arizona State University. This work was performed while Daniel Gerrity was an appointed United States Department of Homeland Security (DHS) Fellow under the DHS Scholarship and Fellowship Program. All opinions expressed in this paper are the authors’ and do not necessarily reflect the policies and views of NSF and DHS.
PY - 2008/3
Y1 - 2008/3
N2 - This study investigated the efficacy of low-pressure ultraviolet (UV) irradiation and the synergistic effect of UV/titanium dioxide (TiO2) photocatalysis on Cryptosporidium parvum oocyst inactivation. At UV doses of 2.7, 8.0, and 40 mJ/cm2, oocyst inactivation was 1.3, 2.6, and 3.3 log10, respectively. Reactive oxygen species (ROS) generated by longwave UV radiation (>315 nm) and TiO2 achieved less than 0.28-log inactivation. However, the synergistic effect of germicidal (254 nm) UV and TiO2 resulted in 2-log and 3-log oocyst inactivation with 4.0 and 11.0 mJ/cm2, respectively. Therefore, using TiO2 in combination with UV reduced the dose requirement for 3-log inactivation by 56%. An approximate 1-log decrease in inactivation of oocysts was observed with nanopure water in comparison to buffered water, whereas changes in pH from 6 to 8 had little effect on the photocatalytic inactivation of oocysts in either matrix (P>0.1).
AB - This study investigated the efficacy of low-pressure ultraviolet (UV) irradiation and the synergistic effect of UV/titanium dioxide (TiO2) photocatalysis on Cryptosporidium parvum oocyst inactivation. At UV doses of 2.7, 8.0, and 40 mJ/cm2, oocyst inactivation was 1.3, 2.6, and 3.3 log10, respectively. Reactive oxygen species (ROS) generated by longwave UV radiation (>315 nm) and TiO2 achieved less than 0.28-log inactivation. However, the synergistic effect of germicidal (254 nm) UV and TiO2 resulted in 2-log and 3-log oocyst inactivation with 4.0 and 11.0 mJ/cm2, respectively. Therefore, using TiO2 in combination with UV reduced the dose requirement for 3-log inactivation by 56%. An approximate 1-log decrease in inactivation of oocysts was observed with nanopure water in comparison to buffered water, whereas changes in pH from 6 to 8 had little effect on the photocatalytic inactivation of oocysts in either matrix (P>0.1).
KW - Cryptosporidium inactivation
KW - Integrated cell culture quantitative PCR
KW - UV/TiO photocatalysis
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U2 - 10.1016/j.watres.2007.10.037
DO - 10.1016/j.watres.2007.10.037
M3 - Article
C2 - 18037465
AN - SCOPUS:40749126814
SN - 0043-1354
VL - 42
SP - 1523
EP - 1530
JO - Water Research
JF - Water Research
IS - 6-7
ER -