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In this experiment, we focused on influent turbidities of 5, 100 and 500 NTU on three different flocculator lengths (2796cm, 5592cm, 8388cm). We varied alum across a range from 0-90 mg/L. This was accomplished using one of two increment functions. To study low alum dosages, we used a power increment function with a base of 1.5 mg/L. For standard tests, we used a linear increment function with a slope of 10 mg/L
The alum dose was varied in process controller using the increment function shown in Figure 1:
FIGURE 1: Process Controller setpoints used to vary the alum dose.
The following are characteristic Process Controller Files were used in our experiments. We provide one example of a low alum dosage (power increment) test, and one example of standard alum dosage (linear increment) test: