Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Canna can: Ornamental eliminates pollutants from stormwater runoff

14.12.2009
Perennials, wetland plants compared for ability to remove harmful nitrogen, phosphorous

Rapid population growth and urbanization have raised concerns over stormwater runoff contamination. Studies on watersheds indicate that excess nutrients, specifically nitrate–nitrogen and soluble reactive phosphorus are found in stormwater runoff in many new urban areas.

These pollutants degrade water quality and have an impact on the downstream ecosystem by contributing to the growth and decomposition of oxygen-depleting microorganisms.

A research team recently used a nutrient recirculation system (NRS) to assess the ability of four ornamental and three wetland plant species to remove nitrogen and phosphorous from stormwater runoff. The study showed that canna is a promising ornamental species for stormwater mitigation, and harvesting the aboveground biomass of canna can effectively remove nitrogen and phosphorous from the treatment system.

A variety of stormwater treatment technologies such as constructed wetlands and retention ponds have been developed in response to increasing regulatory pressures, but water quality issues are still found in many stormwater treatment structures. To meet increasingly rigorous EPA regulations, significant nitrogen and phosphorous reductions are necessary to improve water quality before it is discharged into the ecosystem from stormwater retention structures.

A relatively new technique using floating wetlands (also called "floating islands") for stormwater improvement has been tested in a wastewater treatment pond and a laboratory-scale constructed wetland; the results have suggested that the use of floating systems can increase mitigation capacity and provide efficient nitrogen and phosphorous removal in small treatment structures in urban areas. When ornamental plants are added to floating wetland systems, the benefits can be both aesthetic and environmental.

In a study published in a recent issue of the journal HortScience, a research team headed by Yan Chen of Louisiana State University's Hammond Research Station, analyzed the nutrient removal abilities of herbaceous perennial ornamentals (canna, iris, calla lily, and dwarf papyrus) compared with those of wetland plants (arrow arum, pickerelweed, and bulltongue arrowhead) in three experiments. The nutrient recirculation system (NRS) was filled with a nutrient solution with total nitrogen (N) and phosphorous (P) concentrations of 11.3 and 3.1 mg/liter, respectively, to simulate high levels of nutrient contaminations in stormwater.

The results showed that 'Australia' canna had the greatest water consumption, total biomass production, and aboveground nitrogen and phosphorous content, followed by pickerelweed. 'Golden Fleece' iris had higher tissue nitrogen concentrations than canna, but much lower biomass production. Dwarf papyrus had similar total biomass as pickerelweed, but less shoot biomass. Nitrogen and phosphorous removed from the NRS units planted with canna (98.7% N and 91.8% P) were higher than those planted with iris and arrow arum (31.6% and 31.5% N, and 38.5% and 26.3% P, respectively). NRS units planted with dwarf papyrus had similar nutrient recovery rate as pickerelweed, but much less total N and P were removed as a result of less water consumption. The NRS units planted with calla lily had lower nutrient removal than canna and pickerelweed.

Results from the study suggest that ornamental canna has the potential to be used as mitigation plants in urban stormwater floating biofiltration treatment. Because canna is a perennial plant and allocates the majority of its biomass to shoots, it can be harvested regularly, offering consistent removal of biomass from the treatment system. Chen noted that more research needs to be done to evaluate factors that might affect its application, such as "nitrogen and phosphorous loading and hydraulic conditions, planting densities, poly culture, harvesting frequency, and growth maintenance techniques."

The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/cgi/content/abstract/44/6/1704

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application.

Michael W. Neff | EurekAlert!
Further information:
http://www.ashs.org

More articles from Agricultural and Forestry Science:

nachricht Food for the city – from the city
03.09.2018 | Fraunhofer-Institut für Arbeitswirtschaft und Organisation IAO

nachricht How the forest copes with the summer heat
29.08.2018 | Universität Basel

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

Im Focus: Graphene enables clock rates in the terahertz range

Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.

Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

 
Latest News

Making better use of enzymes: a new research project at Jacobs University

19.09.2018 | Life Sciences

Light provides spin

19.09.2018 | Physics and Astronomy

Enjoying virtual-reality-entertainment without headache or motion sickness

19.09.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>