Floating Treatment Wetlands:
A Deeper Understanding
BioHaven® floating islands are biomimetic, self-sustaining floating treatment wetlands that are designed to remove excess nutrients and other contaminants from lakes, streams and wastewater lagoons. The islands typically use a combination of microbial (bacteria and algae) and plant growth to effectively take up, precipitate and/or filter nutrients and other pollutants from water. FII has patented both Leviathan™ (forced circulation) and BioHaven® (natural flow) treatment systems.
BioHaven floating islands have been described as a hybrid wetland: hydraulically, they behave like a stormwater detention pond, while their treatment processes is that of a wetland. The floating matrix, plus the plant roots hang beneath it, provide a large surface area for biofilm growth which forms an important part of the treatment “reactor.”
The microbes and macrophytes uptake nutrients and move them into and through the food chain. Suspended organic particles stick to the biofilm and become periphyton, food for scuds, nymphs and ultimately fish. Suspended inorganic solids, such as heavy metals in particulate form, slough off and settle in the benthic zone beneath the island. The island is a sink for carbon dioxide and it enables nitrates and ammonia to be removed from the water and safely converted back to Nitrogen gas. This process prevents or slows down eutrophication and keeps the aquatic system in balance.
However, as with all life forms, microbes are limited by certain primary variables, which, in this case, are surface area and circulation.
“The Wetland Effect” = surface area + circulation
Forced circulation of water through the floating island matrix to gain maximum contact with biofilm has been shown to increase the effectiveness of the floating island up to 500 percent.
BioHaven floating islands have been demonstrated to remove all the typical wastewater parameters of concern – ammonium, nitrate, phosphorus, organic carbon and suspended solids — within a single island body.
When it comes to water treatment, stewarding towards nature’s process of microbial remediation represents a viable alternative to chemical solutions.
BioHaven floating islands can be installed in nearly any waterway and launched with a minimum of disturbance.