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Research: Key findings |
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Summary of key findings, MBRCT study:
* Remove TSS to below detection limits (<10 mg/L)
* Reduce DOC at a rate of 9000 mg/(ft2*day)
* Reduce Phosphorus at a rate of 428 mg/(ft2*day)
* Nitrify Ammonia at a rate of 750 mg/(ft2*day)
* Simultaneously denitrify nitrate to nitrogen gas
Summary of key findings, NIWA study:
* Matrix with plants more effective than matrix alone for copper, suspended sediment and nutrient removal.
Approximate results for planted islands treating synthetic urban stormwater:
* 50-65% removal of total copper after 7 days, 70-85% in 14 days
* 5-30% removal of zinc in 7 days, 30-45% in 14 days
* 50-67% reduction in turbidity in 7 days and down to < 1 NTU after 14 days
* Ammonium-nitrogen (NH4-N) reduced by 50-90 % in 3 days and 65-95% after 7 days
* Dissolved Reactive Phosphorus (DRP) reduced up to 20-50% after 7 days, 50-85% after 14 days.
Note: In the conclusions section of the Tanner/Headley report, they list the range (in metric units) of removal as:
Copper: 3.8 – 6.4 mg/square meter /day
Zinc: 25 – 88 mg/square meter /day.
Converting to our standard Floating Island U.S. units yields:
Copper: 0.4 – 0 .6 mg/sf/day
Zinc: 2.3 – 8.2 mg/sf/day
Peer Reviewed articles:
 Frank Stewart et al. had their paper entitled “Floating Islands as an Alternative to Constructed Wetlands for Treatment of Excess Nutrients from Agricultural and Municipal Wastes – Results of Laboratory-Scale Tests” published in a peer-reviewed journal, Land Contamination and Reclamation. Click here to read the article in full.
NZWWA - water & wastes in New Zealand, issue 155, July 2008. Article by Dr Chris C Tanner and Dr Tom Headley Floating treatment wetlands - an innovative solution to enhance removal of fine particulates, copper and zinc
Complete Report of MBRCT grant:
Click on this link to read the Final Report
 Summary of Bisphenol-A study (Mykal Eden and Joanita Matthews):
* Floating islands are net absorbers of Bisphenol-A, an estrogen mimicker.
Using male beta fish and measuring the number of gill flares, when exposed to BPA, the gill flares ceased after 10 days. When exposed to BPA and a floating island, gill flares initially reduced but began to climb again on day 4. By day 10 they were back to normal levels.
For a summary of their research, please click on this link
and for their graph, click this link
The following bullet points highlight the research results and efforts that surround BioHaven® Floating Islands. We are very excited about the myriad solutions a seemingly simple island can provide.
 • Floating Islands reduce nutrient levels in any water system by supporting the growth of microbes and plants. Measuring only the impact of microbes, one square foot of BioHaven® floating island is sufficient to reduce nitrate by over 10 grams per day, ammonia by up to 0.7 gram per day, and phosphate by 0.5 grams per day.
• All three nutrients tested (nitrate, ammonia, and phosphate) are removed simultaneously by a single island in any water system. A few pilot studies that are currently underway include a wastewater treatment facility in Wiconisco, PA, and a public waterway in Toronto, Canada.
 • Various studies are investigating the impacts of floating islands on the removal of multiple pollutants. The National Institute of Water and Atmospheric Research (NIWA) have implemented floating islands in storm water retention ponds to mitigate heavy metals (lead, copper, etc.). Early results indicate that the islands are having significant impacts on those contaminants.
• Several groups have approached Floating Island International with interest and projects to investigate the removal of various “exotic” pollutants such as naphthenic acid, PCB, and pharmaceuticals.
• Floating islands effectively dampen wave activity and act as buffers against wind and wave erosion. Several projects are being developed to measure the efficacy of erosion prevention in marine settings and in lakes.
 • BioHaven® floating islands sequester carbon dioxide from the atmosphere. With growing concerns about greenhouse gases and their impacts on global climate, floating islands represent a unique way to sequester carbon in, on, and under islands. Measurements are currently being taken to identify how much carbon is retained within both natural floating islands and BioHaven® floating islands.
 • Floating islands provide wildlife habitat. Various organizations including Citizens for Conservation (Illinois) and Delta Waterfowl (North and South Dakota), have implemented islands as a means of restoring wetland habitat.
Summary of MBRCT Grant findings, written by Frank Stewart for the Final Report
Major Research Results
• The islands demonstrated rapid removal of ammonium, nitrate, phosphate, organic carbon and suspended solids, compared to controls and to
previous data by other researchers. Removals were calculated on a unitbasis (milligrams of nutrient removed per day per square foot of island surface.
 The best removal rates obtained by BioHaven® floating islands in outdoor test ponds during this project were as follows:
ammonium 759mg d-1 ft-2;
nitrate 759 mg d-1 ft-2;
phosphate 106 mg d-1 ft-2;
BOD 547 mgd-1 ft-2.
The best removal rates obtained by BioHaven® floating islands in test tanks under laboratory conditions during this project were as follows:
ammonium 338 mg d-1 ft-2;
nitrate 10,600 mg d-1 ft-2;
phosphate 428 mg d-1ft-2.
• The BioHaven® floating islands achieved simultaneous aerobic and anoxic removal of ammonium, nitrate, phosphate, and organic carbon within a single island in a single impoundment.
 • The BioHaven® floating islands removed phosphate via bacterial processes at approximately the same rate as suspended algae removed phosphate via plant growth. After the phosphate had been removed, water in ponds with BioHaven® floating islands was much clearer than algae-choked water in ponds without BioHaven® floating islands. Turbidity values were 26 NTUs versus 388 NTUs for the island pond and the control, respectively.
• The performance of BioHaven® floating islands can be optimized by providing proper conditions for the bacterial processes. These conditions are dependent upon the nutrient of concern: for ammonium removal,
alkalinity and aeration control are critical;
for nitrate removal, adequateorganic carbon is required. In order to maximize the efficacy of the
islands, critical parameters must be measured prior to and during the treatment process; auxiliary aeration, alkalinity and carbon should be supplied if necessary.
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