Inactivation of indigenous coliform bacteria in unfiltered surface water by ultraviolet light.
Water Res
; 42(10-11): 2729-35, 2008 May.
Article
em En
| MEDLINE
| ID: mdl-18316110
ABSTRACT
This study examined the potential for naturally occurring particles to protect indigenous coliform from ultraviolet (UV) disinfection in four surface waters. Tailing in the UV dose-response curve of the bacteria was observed in 3 of the 4 water samples after 1.3-2.6-log of log-linear inactivation, implying particle-related protection. The impact of particles was confirmed by comparing coliform UV inactivation data for parallel filtered (11 microm pore-size nylon filters) and unfiltered surface water. In samples from the Grand River (UVT 65%/cm; 5.4 nephelometric turbidity units (NTU)) and the Rideau Canal (UVT 60%/cm; 0.84 NTU), a limit of approximately 2.5 log inactivation was achieved in the unfiltered samples for a UV dose of 20 mJ/cm2 while both the filtered samples exhibited >3.4-log inactivation of indigenous coliform bacteria. The results suggest that particles as small as 11 microm, naturally found in surface water with low turbidity (<3NTU), are able to harbor indigenous coliform bacteria and offer protection from low-pressure UV light.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Raios Ultravioleta
/
Microbiologia da Água
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Enterobacteriaceae
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article