Measurement of OH radical CT for inactivating Cryptosporidium parvum using photo/ferrioxalate and photo/TiO2 systems.
OBJECTIVE
This study investigates the inactivation of Cryptosporidium parvum using the OH radical and reports the OH radical CT (OH radical concentration x contact time) values for C. parvum inactivation.


RESULTS
Although a wealth of information has demonstrated the efficacy of the microbial inactivation activity of the OH radical, no studies have performed a quantitative estimation of the OH radical for C. parvum inactivation. The CT value of the OH radical required for 2 log C. parvum inactivation was measured with two OH radical-generating systems, photo/ferrioxalate and photo/TiO2. The OH radical was approx. 10(4)-10(7)-fold more effective for microbial inactivation than other popular chemical disinfectants such as ozone, chlorine dioxide and free chlorine.


CONCLUSIONS
The OH radical appears to be suitable for microbial inactivation with a calculated CT value required for 2 log C. parvum inactivation of 9.3 x 10(-5) mg min l(-1).


CONCLUSIONS
This study is the first report of an investigation on the role of the OH radical in the photo/ferrioxalate and photo/TiO2 systems and on the OH radical CT required for C. parvum inactivation.
Cho
M
M
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
Yoon
J
J
D000818:Animals; D016785:Cryptosporidium parvum / Q000187:drug effects*; D004203:Disinfection / Q000379:methods*; D017665:Hydroxyl Radical / Q000494:pharmacology*; D008027:Light; D010070:Oxalates / Q000737:chemistry; D010083:Oxidants, Photochemical / Q000494:pharmacology*; D014025:Titanium / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
D010070:Oxalates; D010083:Oxidants, Photochemical; C034942:ferrioxalate; C009495:titanium dioxide; D017665:Hydroxyl Radical; D014025:Titanium