Reduction of photoreactivation with the combined UV/peracetic acid process or by delayed exposure to visible light
Photoreactivation of microorganisms following UV inactivation is a well-known, but complex, phenomenon. It is affected by several factors, including UV fluence, wavelength, light intensity, and exposure time to photoreactivating light. The effect on photoreactivation of a combined peracetic acid (PA...
| Veröffentlicht in: | Water environment research : a research publication of the Water Environment Federation. - 1998. - 79(2007), 9 vom: 15. Sept., Seite 991-9 |
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| Format: | Aufsatz |
| Sprache: | English |
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2007
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| Zugriff auf das übergeordnete Werk: | Water environment research : a research publication of the Water Environment Federation |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Disinfectants Oxidants, Photochemical Peracetic Acid I6KPI2E1HD |
| Zusammenfassung: | Photoreactivation of microorganisms following UV inactivation is a well-known, but complex, phenomenon. It is affected by several factors, including UV fluence, wavelength, light intensity, and exposure time to photoreactivating light. The effect on photoreactivation of a combined peracetic acid (PAA)/UV process has not been investigated. Accordingly, this study compared the degree of photoreactivation, under both sunlight and artificial lights, following UV and combined PAA/UV inactivation of fecal coliforms. Effluent samples from the Montreal Wastewater Treatment Plant (MWTP) (Quebec, Canada) were exposed, for 3 hours, to both low- and high-intensity artificial lights and sunlight. All resulted in similar photoreactivation levels. However, average photoreactivation for UV-treated wastewater samples was 1.2 logs, compared with 0.1 log for the combined PAA/UV treatment. Hence, the use of PAA in combination with UV can significantly reduce the potential for photoreactivation. To simulate the photoreactivation conditions of the MWTP effluent (which passes through a 4-km outfall tunnel with approximately 3 hours detention time), UV-treated samples were kept in the dark for 3 hours before photoreactivating light exposure. After this period, photoreactivation levels were close to zero. Hence, the effects of photoreactivation may be diminished by use of a combined disinfection scheme and/or by delaying exposure of the disinfected wastewater to light |
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| Beschreibung: | Date Completed 04.01.2008 Date Revised 23.09.2019 published: Print Citation Status MEDLINE |
| ISSN: | 1554-7531 |