Artificial Floating Island System as a Sustainable Solution for
Addressing Nutrient Pollution and Harmful Algal Blooms (HABs) in Ohio
Abstract
Nutrient pollution is considered one of America’s most widespread,
costly, and challenging environmental problems. Artificial Floating
Islands (AFIs), a phytoremediation technology, has been proven as an
efficient, environmental-friendly, and cost-effective strategy to
address this issue. However, most previous studies of AFIs were done in
controlled conditions at mesocosm experiments. In addition, limited
information exists on the use of AFIs as a nutrient
remediation/prevention strategy in Ohio. This study aims to fill these
gaps. We are currently undertaking a combination of mesocosm and natural
experiment to assess the nutrient-removal efficiency of AFI systems in
the Milliron Research Wetlands (at the Ohio State University Mansfield
campus), and establish a performance baseline for two native aquatic
plant species, Carex comosa and Eleocharis palustris. In this study, 18
AFIs, 6 planted with Carex comosa, 6 with Eleocharis palustris, and 6
have no plants, were deployed in a section of the Milliron Research
Wetlands. Physical and chemical parameters are being monitored
bi-weekly. The AFI systems are constructed using PVC pipes to provide
buoyance, EVA foam mats as platforms, and nylon nets to cover the
system. Each AFI unit has nine luffa sponges, inserted in the foam mat,
to hold aquatic plant seedlings, keep the moisture of roots, and enlarge
the surface area for bacterial biofilm development. Since nutrient
removal from the wetland is affected by numerous natural processes, a
mesocosm experiment was set up to assist the quantification of nutrient
removal due specifically to the presence of AFIs. The mesocosm
experiment mimics the natural experiment at the wetland and contain 12
equal-size tanks containing water pumped directly from the wetland, 3 of
which have AFIs with Carex comosa, 3 have Eleocharis palustris, 3 have
no plants, and 3 contain just water from the wetland. Physical and
chemical measurements (as well as sample collections) are performed
weekly in the tanks. Water in the tanks are exchanged bi-weekly.
Preliminary results show that the AFI systems quickly developed large
root systems and extensive bacterial biofilms. The effects of the
associations between plant biomass, biofilm development, and changing
chemical and physical conditions will be investigated as the experiment
progresses.