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The floc terminal sedimentation velocity and the residual turbidity of flocculated suspension are important properties in a flocculator. Residual turbidity is the turbidity resulting from the flocs that failed to reach the capture velocity, which is approximately 0.12 mm/s for the sedimentation tanks of the plate settlers in AguaClara plants. With residual Residual turbidity is measured a measurement of the anticipated performance of the plant if the effluent from the flocculator passed into the tube settlers without any other sedimentation process. The Spring 2009 team evaluated quantitatively the effect of shear velocity on these parameters. To do so, they used the flocculation residual turbidity meter (FRETA) developed by the AguaClara team and a data processor to analyze these parameters automatically ( see data acquisition)
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