Floating Islands Australasia
natural, efficient and economic purification of contaminated water bodies
Floating Island Technology
Water quality and water conservation are key issues for Australia and the World.
Vast quantities of water are wasted and natural water courses are damaged due to contamination from excess nutrients such as nitrogen and phosphorus and from heavy metals.
Vegetation can provide a natural and environmentally friendly means of controlling these excess nutrients and pollutants.
The nutrients and pollutants are absorbed by a bio film (mainly bacterial) that develops on the plant roots and support structures.
High surface area is needed to maximise the growth of the bio film
Floating vegetation on suitable floating structures can offer an efficient means of providing the required surface area in reduced space. Such structures are called Floating Biosphere Islands of Floating Vegetated Islands.
Floating structures also offer options to reduce evaporation in channels and reservoirs and can be designed to reduce wave damage.
Benefits of Floating Biosphere Islands
- Assists removal of N, P and some heavy metals etc, including faecal contamination
- Accelerated process – due to high surface area on roots and island structures
- Largely independent of water depth (min 1 m) – permits smaller/deeper ponds
- Can move islands for easier sediment collection
- Flexibility to control water flow, residence time and manage turbulence
- Reduces smell, improves visuals
- Can reduce evaporation
- Can reduce wave damage
- Allows creation of habitat for wild-life & protection for fish
- Potential to harvest plants as biomaterial
Performance Criteria for Floating Biosphere Islands
- Stability in wind, good anchorage
- Stability in flowing & turbulent water
- Flexibility in design & size
- Allow plant roots access to water
- High surface area to optimise pollution control
- Sufficient bulk to ensure plant stability
- Effective for up to 10 years in harsh environment
- Allow air. rain & dust to pass into water body
- Low cost
- Non-polluting