We first began be experimenting with 30ppi polyurethane foam. Our experimental setup consisted of a column consisting of 10 layers of 2.54cm foam. We then ran 5, 20, and 50NTU water with a residual alum concentration of 1.5 mg/L through the filter for 24 hours.
_Figure 1: 30ppi foam, 50 NTU influent