Filter Foam Sheet Experiments with Coagulated Particles
In order to obtain conditions that better resemble those of an AguaClara plant, an alum dosing system and a rapid mix tube were added to our experimental setup. Ideally, these slightly larger and "stickier" particles are more likely to be trapped in the foam resulting, in a lower effluent turbidity. 
Figure 1: Experimental Setup with Alum Dose
Experiments
Experiment Set 1: Alum Dose
Preliminary experiments were run to determine if better filtration performance could be achieved after dosing 5 NTU raw water with alum.
Experiment Set 2: Depth Filtration
A series of experiments were run at a constant flow rate with a low, realistic alum dose of 1.5 mg/L in order to determine whether foam filtration acted as either a function of depth, or a function surface area.
Experiment Set 3: Horizontal Filtration
In order to optimize the plan area required for a filtration unit, we would like to be able to utilize horizontal filtration, in which raw water would flow horizontally through a vertically positioned filter. A series of experiments were run to determine if this would be possible.
Raw Water Turbidity Process
The 5 NTU raw water turbidity level was achieved using the raw water turbidity process.