FIA Technology
Floating Wetlands provide a natural method for purifying water
in contaminated water bodies

Floating Wetlands

Water Quality Issues

High nutrient levels in natural water bodies contribute to algal blooms and uncontrolled aquatic plant growth that eventually rots and robs the water of its dissolved oxygen.  If a water body reaches a state known as eutrophic, it is devoid of oxygen and no living creatures can survive. Clean and healthy water bodies provide habitat for fauna such as frogs, fish and yabbies, as well as beneficial uses such as water recycling and recreational use.

Floating Wetland Principles

Floating vegetation provides a biological filtration system for the removal of nutrients and other pollutants from water bodies.

The combination of plants and bacteria provide the means of converting contaminants to forms that are benign in terms of water quality effects. This is achieved by plant absorption and the action of various types of bacteria that inhabit the panel and plant structure. The floating structure itself and the root mass in the water column provide the range of micro-environments that allow these processes to operate.

A square metre of Floating Wetland has the capacity to process about 5 kg on Nitrogen(N) and 2 kg of Phosphorus (P) based nutrients per year. This is a typical nutrient loading in one megalitre of polluted water. In practical situations about 3-5% coverage of the water surface is normally recommended.

 

Benefits of Floating Wetlands

Suppression of algal blooms and eutrophication through high efficiency stripping of nutrients.

 

How do Floating Wetlands work?

water quality comparison

Floating Wetlands are a micro eco-system where plants and bacteria form a symbiotic relationship supported by our unique filler material and the plant roots themselves. Some nutrients and heavy metals will be absorbed in the plant biomass but the majority of nitrogen, phosphorus and organic nutrients are converted by bacteria to chemical forms that escape as gases, or metabolites that are removed from the nutrient cycle. Bacteria also bind suspended particles together so they become heavy enough to sink, in a process called flocculation.

The result is a very clear and clean water body generally free from algal blooms and excessive aquatic plant growth that can cause the ecosystem to die.

Plant Growth

underwater root mass

Wetland macrophytes will rapidly grow through the porous panel and develop a large root mass within the water column. This forms an important part of the biosphere of a Floating Wetland Island. The photograph shows root development for sedge after four months. FIA can provide a list of wetland plants and recommendations on species selection.