Skip to Main Content

The correlation between the measured and modeled residual Cl2 concentrations was evaluated (Figure 11(b) and Table 1). The model tends to overestimate the residual Cl2 concentrations in 67% of the cases, compared to the measured concentrations in the real DWDS. Considering the root mean square error (Table 1), half the results showed a high error value (>0.100). This result can be due to the fact that the pipe wall effect was not evaluated in the simulation, because of the difficulty in simulating this effect at laboratory scale, while in the real system the additional reactions at pipe walls could influence water quality and, therefore, the disinfectant consumption. For instance, pipe material and biofilm in pipes could affect the water quality, determining a high ClO2 consumption. Moreover, it is possible that in the real system, a residual contaminant in water (e.g., NOM) can react with the disinfectant, determining a higher ClO2 consumption and, consequently, lower Cl2 residual concentrations. These aspects, which were not evaluated in the model, should be further investigated in future studies.

Table 1

Comparison between measured and modeled residual Cl2 concentrations, mean absolute error, and root mean square error, at 10 a.m. after one month from the start of the disinfectant dosing in both the DWTPs

Junction numberResidual Cl2 (mg L1)
Mean absoluteRoot mean
(sampling point)MeasuredModelederrorsquare error
79 0.035 0.08 0.040 0.041 
61 0.02 0.03 0.017 0.020 
145 0.03 0.02 0.011 0.011 
137 0.04 0.40 0.357 0.357 
125 0.04 0.40 0.359 0.359 
70 0.035 0.02 0.011 0.015 
124 0.05 0.29 0.241 0.241 
121 0.03 0.01 0.016 0.016 
148 0.03 0.02 0.014 0.014 
19 0.05 0.41 0.365 0.365 
116 0.05 0.40 0.354 0.354 
53 0.03 0.35 0.322 0.322 
Junction numberResidual Cl2 (mg L1)
Mean absoluteRoot mean
(sampling point)MeasuredModelederrorsquare error
79 0.035 0.08 0.040 0.041 
61 0.02 0.03 0.017 0.020 
145 0.03 0.02 0.011 0.011 
137 0.04 0.40 0.357 0.357 
125 0.04 0.40 0.359 0.359 
70 0.035 0.02 0.011 0.015 
124 0.05 0.29 0.241 0.241 
121 0.03 0.01 0.016 0.016 
148 0.03 0.02 0.014 0.014 
19 0.05 0.41 0.365 0.365 
116 0.05 0.40 0.354 0.354 
53 0.03 0.35 0.322 0.322 

Close Modal

or Create an Account

Close Modal
Close Modal