Integrating water temperature in chlorine decay modelling: a case study

Temperature is one of the factors that most influences chlorine decay rates in drinking water systems. The current paper assesses and demonstrates the importance of using a temperature dependent chlorine bulk decay model for the accurate prediction of disinfectant residuals in water supply systems. Chlorine concentration in a water transmission system was modelled for two seasons using a temperature-dependent bulk decay model at a constant and variable temperature. Results show that water temperature can vary within the system and that the accurate prediction of residuals may additionally require the incorporation of a water temperature model in the simulators. In this case study such approach was developed innovatively by establishing a water-age-dependent temperature function.