PROTOTYPE CONSTRUCTION
The decision matrix revealed that the floating 5-cell treatment system was our best option to pursue based on weights of the factors we chose, and our team agreed to pursue this design. The 5-cell treatment system will operate by having a pump draw water from the pond and feeding it through the trickling filter. A dome placed above the trickling filter will help disperse water for maximum treatment effectiveness. Water will then be transferred through a series of four containers, each containing a different species of plant to help remove targeted contaminants. Water will then be discharged back into the pond and the cycle repeats.
Below are construction details of the three main components which comprise of our treatment system: the frame, raft, and trickling filter.
Click here to view the exact materials used for the prototype along with their costs.
Below are construction details of the three main components which comprise of our treatment system: the frame, raft, and trickling filter.
Click here to view the exact materials used for the prototype along with their costs.
THE FRAME
Construction of our prototype began during Week 5 with the assembly of our frame. We chose to use 3/4" schedule 40 PVC as the material due to its versatility and low cost. Eight pieces of both 12 1/4" and 7 1/4" pipes were cut and joined together with PVC 90-degree elbows and pressure crosses (see below left). 1" holes were then bored on both sides (see below second from left) of all four containers. A combination of PVC bushings, couplings, and rubber o-rings were then installed to provide leakproof seals at inflow and outflows for each container.
Construction of our prototype began during Week 5 with the assembly of our frame. We chose to use 3/4" schedule 40 PVC as the material due to its versatility and low cost. Eight pieces of both 12 1/4" and 7 1/4" pipes were cut and joined together with PVC 90-degree elbows and pressure crosses (see below left). 1" holes were then bored on both sides (see below second from left) of all four containers. A combination of PVC bushings, couplings, and rubber o-rings were then installed to provide leakproof seals at inflow and outflows for each container.
Click here to see the test results for the PVC frame.
THE RAFT
Construction of the wooden raft began during Week 9. Cedar dog ear pickets were selected for the wood due to their strength and low cost. Following our design (see below top left), we cut boards of the following dimensions:
- 34" x 5 1/2" x 5/8" (Qty 8)
- 11" x 5 1/2" x 5/8" (Qty 8)
- 12 1/8" x 7 1/2" x 5/8" (Qty 3)
- 10 7/8" x 7 1/2" x 5/8" (Qty 2)
- 12 1/8" x 4 3/4" x 5/8" (Qty 1)
Click here to see the test results for the raft.
THE TRICKLING FILTER
Construction of the trickling filter began during Week 9. Air conditioning air filters were selected as media for promoting biofilm growth due to their light weight. Three layers of varying media thickness were cut to size and held together with poultry netting (see below bottom left). A common bucket of 12" diameter was then drilled with holes along the sides (to provide oxygen circulation) and used to hold the three sections of media. Oyster shells were placed on the very top to provide additional surface area for biofilm growth. A mixing bowl drilled with holes also substituted as our "dome", which is intended to disperse water evenly throughout the trickling filter for maximum effectiveness. A 40" section of 1/2" PVC pipe through which water will be pumped was then inserted through the dome, bucket, and raft. Rubber grommets were used to prevent water leakage.
Click here to see the test results for the trickling filter.