In 2005, when BioHaven Floating Islands came to the attention of eminent wetland scientist Dr. Chris Tanner, he heralded them as the “new generation” of floating treatment wetlands. Tanner immediately began a research program to measure their ability to remove nutrients and heavy metals from stormwater. His success sparked over a decade of BioHaven research at leading universities and institutes around the world.
What Makes BioHavens Different?
- Their matrix structure is a perfect plant-growing platform, allowing perennial plants to fully mature and be effective over many years without reaching a performance plateau.
- They are a quasi-hydroponic system that uses a growing medium to supply plants with nutrition that does not leach into the water.
- Oxygen is allowed to permeate the upper layers to benefit plant growth, while below the waterline, biofilm covers every fiber.
- The permeable matrix, even when coated in biofilm, does not plug up.
- Plants, plant roots and BioHaven matrix combine to perform a vast surface area for biofilms to attach to as the optimal pathway for removal.
- Their internal buoyancy provides depth and rigidity, making them extremely robust.
- They are scalable in length, width and depth to meet the demands for small and large system sizing, suitable for use in any waterbody.
Nature’s Wetland Effect is a term we use to describe why BioHavens are so effective: they biomimic the processes of a natural wetland – hence “Nature’s Wetland Effect.” We break these processes down to two primary components – surface area and circulation.
Floating Islands – or Floating Treatment Wetlands (FTWs) as they are also called – provide a massive amount of surface area. First, the BioHaven matrix has a high surface-area to footprint ratio. Second, the plants contribute an enormous amount of surface area, within the island and below it.
Surface area is important because it promotes the growth of biofilm communities which are composed of massive numbers of the different microbes responsible for cleaning water. Biofilms are more resilient and reproduce faster than free-swimming microbes. And, en masse, they excrete a sticky substance called EPS (Extra-cellular Polymeric Substance) that traps fine particles and promotes water clarity and digestion. We would go so far as to say this EPS traps microplastics, which is being researched at present.
“Concentrated Wetland Effect” is related. It reflects the fact that a BioHaven Floating Island has all its surface area in the water column, as opposed to other types of constructed wetland where the plants are rooted into the ground or sediments.
Circulation can be natural – the path that water takes from inflow to outflow in a pond or lake provides natural circulation – or forced, helped along by a mechanical system, which might also provide aeration. The BioHaven StreamBed is an example of a BioHaven that provides both surface area and circulation in a single unit.
Floating Island International has partnered with biofilm engineers and plant scientists to bring a best-in-class approach to nutrient management and water resource recovery. Our engineers are graduates and associates of Montana State University’s world-class Center for Biofilm Engineering and fully understand the water remediation and recovery environment. Our plant specialists are experts in choosing hyper-accumulator plants and microbes for the best possible phytoremediation results in aquatic settings.
Water Resource Recovery Pathways
For a full discussion on the removal mechanisms of floating treatment wetlands, please call us to request our Pathways Reports