الملخص الإنجليزي
Ensuring clean water that is micropathogens-free is of vital importance for achieving the
sixth goal of the Sustainable Development Goals (SDGs). This can be achieved by
introducing disinfection as a final process in drinking water treatment. As chlorination is
often used synonymously with disinfection, this research focused on identifying the effect
of temperature, chlorine source, and initial chlorine concentration on chlorine bulk decay.
By a pilot scale system, the dissipation of chlorine resulting from wall decay-related
factors like pipe size and the flow rate was studied. Empirical models were developed of
the disinfectant concentration over time based on pilot scale systems. To relate laboratory
work with actual drinking water systems, EPANET program was utilized to simulate free
chlorine dissipation along a section of the water distribution network in Al Seeb area,
Muscat, Oman. The last part of this research was an investigation into the dissipation of
chlorine in similar systems as households’ water storage tanks and evaluating household
drinking water facilities by conducting a survey and water quality analysis. The results
indicated that temperature had the most effect on the dissipation of chlorine in the bulk
water and there was no significant difference in its dissipation with regard to chlorine
source and initial concentration. For the pipe loop system, as the difference in the tested
sizes of pipes was too small, the obtained decay rates among them were not significant.
Moreover, increasing the flow rate increased the dissipation rate insignificantly.
Regarding EPANET simulation model, no significant difference was observed between
the actual and EPANET model predicted chlorine concentrations when bulk and wall
decay coefficients obtained from laboratory work and the pilot scale system were applied.
For the household water storage tanks, the disinfectant dissipated in the opened-lid tank
faster than in the closed-lid tank and chlorine dissipated completely in less than two days
in both tanks. This research will provide better visualization for stakeholders about some
of the factors that affect chlorine dissipation in drinking water systems. Moreover, the
outcomes will provide an indication of the locations to boost residual chlorine in the
distribution network and whether to center the attention on the drinking water supply
network or storage tanks.
