| Autor: |
Mofidi, Alexander A., Baribeau, Hélène, Rochelle, Paul A., De Leon, Ricardo, Coffey, Bradley M., Green, James F. |
| Zdroj: |
Journal - American Water Works Association; June 2001, Vol. 93 Issue: 6 p95-109, 15p |
| Abstrakt: |
Bench‐scale experiments determined the germicidal effects of varying dosages of polychromatic ultraviolet (UV) radiation on oocysts of Cryptosporidium parvum. C. parvumoocysts suspended in treated surface water were irradiated with polychromatic light emitted by either a medium‐pressure, continuous‐wave UV lamp or a pulsed‐UV lamp then assayed with human cell culture techniques. Experiments conducted using pulsed‐UV doses of ≥ 16 mJ/cm2provided > 2‐log inactivation of suspended oocysts of C. parvum.Experiments at lower UV dosages established a dose‐response relationship with both the medium‐pressure and pulsed‐UV lamps. When disinfection results from both light sources were compared on an equivalent dosage basis, no statistical difference in disinfection power was found between the medium‐pressure and pulsed‐UV lamps. Results from both lamps showed that UV doses as low as 7.5 and 11 mJ/cm2provided inactivation of infectious oocysts of C. parvumat rates of 1 log (90%) and 2 log (99%), respectively. The authors also examined UV disinfection of heterotrophic bacteria and Escherichia coli.They found the response of heterotrophic bacteria to be statistically different from that of C. parvum, whereas E. coli's response to UV light did not statistically differ from that of C. parvum.This suggests that E. colimay be a surrogate organism for C. parvumdisinfection provided by UV technologies. |
| Databáze: |
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