Journal article
Lack of Influence of Extracellular Polymeric Substances (EPS) Level on Hydroxyl Radical Mediated Disinfection of Escherichia coli
Environmental science & technology, Vol.46(1), pp.241-249
01/03/2012
DOI: 10.1021/es202541r
PMID: 22082030
Abstract
Photolysis of nitrate, a prevalent constituent in agriculturally impacted waters, may influence pathogen attenuation in such systems through production of hydroxyl radical (•OH). This study focuses on the efficacy of •OH generated during nitrate photolysis in promoting E. coli die-off as a function of extracellular polymeric substances (EPS) coverage. EPS levels of four E. coli isolates were systematically altered through a sonication extraction method and photochemical batch experiments with a solar simulator examined isolate viability loss as a function of time in nitrate solutions. E. coli viability loss over time exhibited two regimes: an initial induction time, t s, with little decay was followed by rapid exponential decay characterized by a first-order disinfection rate constant, k. Increasing steady-state •OH concentrations enhanced E. coli viability loss, increasing values of k and decreasing t s values, both of which were quantified with a multitarget bacterial disinfection model. Notably, at a given steady-state •OH concentration, values of t s and k were independent of EPS levels, nor did they vary among the different E. coli strains considered. Results herein show that while •OH generated via nitrate photolysis enhances rates of disinfection in surface water, the mechanism by which •OH kills E. coli is relatively insensitive to common bacterial variables.
Details
- Title: Subtitle
- Lack of Influence of Extracellular Polymeric Substances (EPS) Level on Hydroxyl Radical Mediated Disinfection of Escherichia coli
- Creators
- Amy S GongCaylyn A LanzlDavid M CwiertnySharon L Walker
- Resource Type
- Journal article
- Publication Details
- Environmental science & technology, Vol.46(1), pp.241-249
- Publisher
- American Chemical Society
- DOI
- 10.1021/es202541r
- PMID
- 22082030
- ISSN
- 0013-936X
- eISSN
- 1520-5851
- Language
- English
- Date published
- 01/03/2012
- Academic Unit
- Center for Health Effects of Environmental Contamination; Civil and Environmental Engineering; Public Policy Center (Archive); Chemical and Biochemical Engineering
- Record Identifier
- 9983991941802771
Metrics
10 Record Views