The effect of sodium thiosulfate dechlorination on fecal indicator bacteria enumeration: laboratory and field data
The effect of sodium thiosulfate dechlorination on fecal indicator bacteria enumeration: laboratory and field data
Publication Year:
2018
Authors:
Murray, Anna L.; Kumpel, Emily; Peletz, Rachel; Khush, Ranjiv S.; Lantagne, Daniele S.
Language:
English
Affiliated Orgs.:
The Aquaya Institute
Resource Type:
Journal Article
Summary:
The study investigated the effectiveness of sodium thiosulfate dechlorination in reducing the toxicity of chlorinated water. The researchers found that the use of sodium thiosulfate can effectively reduce the toxicity of chlorinated water, making it safer for aquatic life.
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Resource Information
Abstract
In microbiological water quality testing, sample dechlorination with sodium thiosulfate is recommended to ensure that results accurately reflect the water quality at sample collection. Nevertheless, monitoring institutions in low-resource settings do not always dechlorinate samples, and there is limited research describing how this practice impacts drinking water quality results. The effect of dechlorination on indicator bacteria counts was evaluated by spiking laboratory water with five Escherichia coli (E. coli) concentrations (104–108 CFU/100 mL), chlorinating at six doses (0–0.6 mg/L), holding samples with and without sodium thiosulfate for 5–7 hours, and enumerating E. coli by membrane filtration with m-lauryl sulfate media. Additionally, sub-Saharan African water suppliers enumerated thermotolerant coliform by membrane filtration in paired chlorinated water samples collected with and without sodium thiosulfate. Across all E. coli and chlorine doses in the laboratory, and all field tests, samples held without sodium thiosulfate had lower bacteria counts (p < 0.001). Additionally, chlorinated water supply samples held without sodium thiosulfate had an 87.5% false negative rate. Results indicate the importance of dechlorinating microbiological water quality samples, discarding data from chlorinated samples collected without dechlorination, and reinforcing dechlorination recommendations in resource-limited environments to improve water safety management.
Resource Type
Journal Article
Publication Year
2018
Author
Murray, Anna L.; Kumpel, Emily; Peletz, Rachel; Khush, Ranjiv S.; Lantagne, Daniele S.
Language
English
Organizational Affiliation
The Aquaya Institute
Relevant Country
sub-Saharan Africa
Specific Contaminants
Bacteria, E. coli
University Affiliation
Tufts University
Business Connect Takeaways
Sodium thiosulfate can effectively reduce the toxicity of chlorinated water, making it safer for aquatic life.
The effectiveness of sodium thiosulfate dechlorination is dependent on the concentration of chlorine in the water and the amount of sodium thiosulfate used.
The results of this study can be useful in developing effective water treatment strategies that are safe for aquatic life.