The effect of temperature on the efficacy of ozonation for inactivating Cryptosporidium parvum oocysts
| Autor: | Tsuyoshi Hirata, A. Shimura, Takeo Moniwa, Hoshikawa Hiroshi, N. Motoyama, M. Suzuki, Shigemitsu Morita, M. Kaneko |
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| Rok vydání: | 2001 |
| Předmět: |
Environmental Engineering
Ozone Contact time Population Dynamics Microbiology Water Purification symbols.namesake chemistry.chemical_compound Oxidants Photochemical Water Supply Animals Water Science and Technology Log10 reduction Infectivity Arrhenius equation Cryptosporidium parvum Chromatography biology Temperature Atmospheric temperature range Models Theoretical biology.organism_classification chemistry Water temperature symbols |
| Zdroj: | Water science and technology : a journal of the International Association on Water Pollution Research. 43(12) |
| ISSN: | 0273-1223 |
| Popis: | Examination of the effects of water temperature on the inactivation of Cryptosporidium parvum oocysts with ozone, ozonation experiments were conducted in a semi-batch mode with a wide temperature range of 3-30 degrees C. Inactivation was assessed in terms of mice infectivity and in vitro excystation. The temperature dependency of the CT products by a reduction in infectivity of 2 log10 could be described successfully by the Arrhenius equation, 1/CT = 1.086 x 10(18)e-12520/K where CT is the integrated ozone concentration over the contact time (mg/min/L) and K is the Kelvin temperature of water. As for the reduction in viability assessed by the excystation assay, protocol B, the obtained regression equation, 1/CT = 1.802 x 10(18)e-12640/K, was almost identical to that observed for the infectivity. Thus, the CT products required for a 2 log10 reduction in both infectivity and viability increased by an average factor of 4.2 for every 10 degrees C decrease in water temperature. Additionally, our findings suggested that the viability, as determined by protocol B, could substitute for animal infectivity in evaluating the effects of environmental factors on the efficacy of ozonation. |
| Databáze: | OpenAIRE |
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