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The following Process Controller Files were used for the 100 NTU and 500 NTU tests.
100 NTU Test File
500 NTU Test File

Results and Discussion

To find the ideal alum dosage for a certain influent turbidity, there are several qualities that must be considered. First, the resulting floc size should be large enough so that by the time it reaches the sedimentation tank, it will weigh enough to sink and settle out. Second, the resulting NTU must be small indicating an efficient flocculation/sedimentation process and clean water, and third, the alum dosage should preferably be low to save cost. (This is something minor, but we should also consider how the particle size distribution will affect the formation of a floc blanket as well. Producing very large flocs may The goal of this experiment is to study the effects of different alum doses and flocculator lengths in order to discover the most effective way to improve the design of the actual AguaClara flocculator. However, before beginning any analysis, we must first be aware of the characteristics of a good flocculator. What defines a good flocculator? A good flocculator must: first, have large enough resulting flocs at the end of the flocculator so that they will weigh down, sink, and settle out in the sedimentation tank; second, have this floc size under control to an optimal size-too large flocs will not facilitate floc blanket formation as they will settle out before the floc particles could ever become fluidized); and third, have a low resulting turbidity indicating the production of clean water. The use of alum facilitates this process; however, too much alum can create oversize flocs that settle out before reaching the sedimentation tank. In addition, the over use of alum will be expensive; cost efficiency is an important factor in building the AguaClara flocculator. To find an ideal alum dosage for a particular influent turbidity, we have varied the alum doses at a certain range and are going to see which dosage works best for each situation. The same goes to the different flocculator lengths; overly long flocculators will cause flocs to settle out before reaching the sedimentation tank and in addition will not be cost efficient. To find an ideal length, we have set up three different apparatuses with varying tube lengths: 2796 cm, 5600 cm, and 8800 cm. For each alum dosage range, we will change the length of the flocculator in order to find the ideal combination of flocculator length and alum dose.

For the first experiment, the alum dose ranged from 20 to 60 mg/L varying with an increment of 5 mg/L and the influent turbidity was around 100 NTU. The data given from this experiment was processed through Mathcad for a simplified overview of the result in graphic form.

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