DESIGNS CONSIDERED
The principals behind ecology water treatment systems involve the cultivating of biofilms and the strategic placement of plants and organisms to help consume organic matter and remove contaminants, respectively. With this in mind, our team agreed that the initial designs should at a very minimum, include a trickling filter (to cultivate biofilms), several containers holding aquatic plant life in series (to remove contaminants), and a pumping mechanism to draw water from the pond and through the trickling filter. Materials constraints were not specified during this process so as to not restrain creativity.
Each member then came up with a potential design to pursue, which are shown below.
Each member then came up with a potential design to pursue, which are shown below.
Floating 5-Cell TreatmentThe Floating 5-Cell Treatment is a simplified version of the Cement Foam Float Treatment. Both are designed to float near the surface and treat water in the same fashion. With the 5-Cell Treatment, the wooden raft which supports the system will help protect against contact with objects while providing turtles with basking areas along the edges. Another advantage of this design comes from its durability and cost. It is relatively cheap to build and implement and should easily last for years. A significant drawback of this design comes from its extremely artificial appearance, which fails to blend in with the surrounding evironment. Another is the use of PVC piping, which over time have been known to release toxic compounds.
|
Cement Foam Float TreatmentThe Cement Float is constructed of a shaped foam base, covered with chicken wire and a thin layer of cement. The closed-cell foam provides the buoyancy necessary to float the structure, while the cement provides a natural look and structural integrity. The design encompasses similar treatment steps as the Five Cell structure, with a few differences. Instead of using containers like the Five Cell design, the Cement Float uses a dug out trench (by shaping the foam), and a series of weirs to separate the trench into different treatment cells. This has the added benefit of maximizing the treatment capacity by not wasting surface area on piping, and additionally has a natural look due to the absence of PVC pipes and plastic bins. However, this structure is made mostly of closed cell foam, which is not recyclable in most municipalities, and is not biodegradable.
|
Cascading Helix Treatment
The Cascading Helix structure consists of multiple five gallon water jugs attached to a wood post. The jugs would be the standard large blue water containers with the tops cut off, and water would be gravity fed in series between the jugs. This design has the added benefit of increasing the treatment volume with larger containers over the other two designs. The structure is fairly simple to build, but it does include some challenges and concerns. A primary difficulty is securing the jugs to the post to withstand all environmental conditions, while keeping in mind that these containers weight approximately 40 lbs and are made of plastic. The height of the structure also becomes an aesthetic concern, as it would be protruding out of the middle of the pond.
|
Plant Selection
Common Cattail (Typha latifolia)
This plant would be used in the 2nd containers in any of the 3 design options above. It can be paired with small lifeforms like snails and small fish. They can remove heavy metals and organic matter.
This plant would be used in the 2nd containers in any of the 3 design options above. It can be paired with small lifeforms like snails and small fish. They can remove heavy metals and organic matter.
Common Reed (Phragmites australis)
This plant is commonly used in constructed wetlands or reed beds to remove nitrogen. This plant would be used in the 2nd or 3rd container.
This plant is commonly used in constructed wetlands or reed beds to remove nitrogen. This plant would be used in the 2nd or 3rd container.
Willows (Salix spp.)
This plant would like be used in the 3rd and/or 4th container. It is a hyper accumulator plant, which can uptake contaminants including metals like cadmium and uranium and even hydrocarbons organic solvents.
This plant would like be used in the 3rd and/or 4th container. It is a hyper accumulator plant, which can uptake contaminants including metals like cadmium and uranium and even hydrocarbons organic solvents.
Water Hyacinth (Elchhornia spp.)
This is an aquatic plant native to South America. It is a free floating and is one of the fastest growing plants known. While it is widely considered invasive, if contained, it can be extremely effective in cleaning water.
This is an aquatic plant native to South America. It is a free floating and is one of the fastest growing plants known. While it is widely considered invasive, if contained, it can be extremely effective in cleaning water.
Duckweed (Lemnoideae spp.)
This small floating and fast growing plant can be paired with different types of algae to remove nitrogen and phosphorus. It does best when bathed in sunlight.
This small floating and fast growing plant can be paired with different types of algae to remove nitrogen and phosphorus. It does best when bathed in sunlight.