| Title |
Mathematical Model Simulations Assessing the Effects of Temperature on Residual Chlorine Concentrations in Water Storage Tanks |
| Authors |
노유래 ( Yoorae Noh ) ; 박준홍 ( Joonhong Park ) |
| DOI |
https://doi.org/10.15681/KSWE.2017.33.2.187 |
| Keywords |
Bulk decomposition; Evaporation; Residual chlorine; Sorption; Temperature; Water storage tank |
| Abstract |
To ensure the hygienic safety of drinking water in a water storage tank, the concentrations of residual chlorine should be above a certain regulated level. In this study, we conducted model simulations to investigate the effects of temperature on residual chlorine under water storage tank conditions typical for use in Seoul. To this effect, model parameter values (decomposition rate constant, sorption coefficient, and evaporation mass transfer coefficient) were determined in laboratory experiments. The model simulations under continuous flow conditions showed that the residual chlorine concentrations satisfied the Korea ministry of environment`s water quality standard level (0.1 mg/L) at all temperature conditions (5°C, 10°C, 15°C, 20°C, and 25°C). When the tanks were in a no-flow condition (i,e., no tap-water influent due to a sudden shut-down), the concentrations lowered relative to the water quality regulatory level. The findings of simulating Seoul`s water storage tanks also suggested that the disappearance rate of residual chlorine could be reduced by the tanks` design optimization with maintenance of low water temperature, minimization of air flow and volume, suppression of water dispersion, and the use of wall materials with low sorption ability. |