Modelling the chlorine decay process in a distribution network using a pilot system

Chlorine is one of the many disinfectants used to ensure bacteriological safety of drinking water. Usually residual chlorine is maintained within the distribution network to combat any probable re-contamination of the distributed water. This residual free chlorine, however, decays in water due to it...

Full description

Saved in:
Bibliographic Details
Published in:Water practice and technology 2014-12, Vol.9 (4), p.534-550
Main Authors: Buamah, R, Akodwaa-Boadi, K, Paintsil, M, Baah-Ennumh, E K, Adjaottor, A A
Format: Article
Language:English
Subjects:
Asbestos
Batch reactors
Cast iron
Chlorine
Coefficients
Concrete pipes
Contamination
Decay
Disinfectants
Distribution
Distribution management
Drinking water
Hydraulic models
Iron
Mathematical models
Modelling
Networks
Nuclear engineering
Nuclear safety
Pipes
Polyvinyl chloride
Residual chlorine
Water distribution
Water distribution systems
Water engineering
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Chlorine is one of the many disinfectants used to ensure bacteriological safety of drinking water. Usually residual chlorine is maintained within the distribution network to combat any probable re-contamination of the distributed water. This residual free chlorine, however, decays in water due to its reaction with the bulk water and the pipe material or deposits on the pipe walls. This study aimed at determining and modelling chlorine decay in the Kumasi water distribution network (KWDN) and determined locations where residual chlorine boosting is necessary. A double-jacketed batch reactor and a constructed pilot distribution system (PDS) were used to determine the bulk and wall decay coefficients. The PDS was run using aged PVC pipes (15–20 years), asbestos concrete pipes (40–50 years) and cast iron pipes (84 years) that have been in use in the KWDN. The SynerGEE® hydraulic model was used to identify the ‘zero chlorine’ points and predict top-up quantities. The bulk decay coefficient was found to be 0.053 h−1 within 8 hours at 26 °C and the residual chlorine decayed within the bulk fluid by 32–34% of its initial dose. Under the conditions tested, the cast iron pipes had the highest overall decay coefficients (K). Five locations within the network were identified as probable chlorine boosting points).
ISSN:1751-231X
1751-231X
DOI:10.2166/wpt.2014.060