We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Case Study of Particle-Related UV Shielding of Microorganisms When Disinfecting Unfiltered Surface Water.
- Authors
Cantwell, Raymond E.; Hofmann, Ron; Rand, Jennie L.; Devine, Patrick M.; VanderMarck, Monique
- Abstract
The goal of this case study was to provide pilot-scale information about the ability of ultraviolet (UV) light to disinfect unfiltered surface water. A pilot-scale (0.25 L/s) UV reactor with low-pressure UV lamps was installed on raw water entering an aqueduct from the Pardee Reservoir at the East Bay Municipal District, California. A pilot monitoring system also collected hourly particle count (2 to 100 m), turbidity, and ultraviolet transmittance (UVT) measurements for 14 months. Grab microbial samples were collected and analyzed for indigenous total coliforms and total aerobic spores (TAS) both before and after UV disinfection, to correlate survival of the organisms across the UV reactor to water quality characteristics. Concentrations of indigenous coliforms and TAS ranged up to 163 and 1,383 per 100 mL respectively, before UV exposure. The data showed that the ability of UV to disinfect coliforms was essentially unaffected by the presence of particles (up to 703>10 m per mL and 1.3 nephelometric turbidity unit [NTU]) in the unfiltered surface water. In 13 of 14 samples, no coliforms were detected in the UV treated water. Log-linear inactivation of TAS up to 2.5-log suggests that at least 99.6% of the TAS were not protected from UV disinfection by particles.
- Subjects
CALIFORNIA; ULTRAVIOLET water treatment; WATER disinfection; RADIATION shielding; ULTRAVIOLET radiation; MICROORGANISMS; WATER quality; CASE studies; PARDEE Reservoir (Calif.)
- Publication
Water Quality Research Journal of Canada (Canadian Association on Water Quality), 2010, Vol 45, Issue 3, p343
- ISSN
1201-3080
- Publication type
Article
- DOI
10.2166/wqrj.2010.030