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The efficiency value assumed at the beginning of Spring 2008 was 0.5. This means that we assumed it would take only two collisions for a particle of clay to stick to a particle of aluminum sulfate. Using the MathCAD program, we determined that this efficiency value was inaccurately high by inputting the dimensions of the Fall 2007 Demo Plant, and comparing the MathCAD output for horizontal length of maximum floc size with the actual horizontal length of maximum floc size we observed. We found that assuming an efficiency of 0.5, the program reported an optimal horizontal length about 2 times smaller than what we observed.

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We observed flocculation in the demo plant in order to determine at what point in the length of the flocculator the flocs reached a maximum size before beginning to break up. These flocs were also measured in order to be able to more accurately represent in the flocculation model the maximum floc size that it is possible to achieve in the plant. Using the location of the largest flocs as an estimate of the optimum plant length, we set the maximum floc size to the size of the measured flocs and changed the value of the efficiency factor in the flocculation model until the design length of the plant model created by the Demo Plant Spring 2008 Flocculator Design and ConstructionSP08 Flocculator D&C program was consistent with the observed occurrence of maximum floc size.

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