*** This version of Confluence is for testing only and contains a copy of content from June 29th 2026. No changes will be preserved. ***
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The data processor retrieves mean sedimentation velocities of the particles at each alum dose during an experiment from our data. Since the mean sedimentation velocities are calculated when we fit the data, the mean sedimentation velocities given for a 5 NTU influent water are not accurate. Indeed, even if the data processor tries to fit the data, the shape of the evolution of turbidity as a function of sedimentation velocity does not look like the fit function.
For 100 NTU and 500 NTU, the fitted data seem accurate enough that we can trust the mean sedimentation velocities or the coefficient of variation retrieved. Figure 18 below shows a plot of the raw data and the fitted data for 500 NTU water and an alum concentration of 70 mg/L.