Download References

УДК 504:75:581.5
M.Zakharchenko
Ukrainian Scientific and Research Institute of Ecological Problems (USRIEO, Kharkiv, Ukraine
V. Magmedov
Project Geoscientist, Environment в GENIVAR, Toronto, Canada
BACKGROUND ON CONSTRUCTED WETLAND DEVELOPMENT
Introduction. The use of higher aquatic plants for the treatment of polluted water and
wastewater began to develop on an industrial scale only within the last 35-45 years. In the 1960s,
the Max Planck Institute in Germany began to study the treatment properties of higher aquatic
plants. In the 1970s, a system using these plants for wastewater treatment, named the “Lelystad
process”, was developed in the Netherlands. In the 1970s and 1980s, this research was continued
in the USA, Denmark, the UK, Canada and Ukraine, and in the 1990s, research and
implementation of constructed wetlands continued in many European countries and the rest of
the world. In the Canada, most of these purifying systems were called “constructed wetlands”, in
the UK they were known as “reed beds” and in Ukraine they were most commonly referred to as
“bioengineering systems”.
Currently, more and more countries are adopting this technology and modifying it to suit their
own climatic, geological and botanical conditions.
Today constructed wetlands are used in many countries not only to treat run-off, agricultural
wastewater, landfill leachate or mine waters, but also as an alternative to the conventional system
of sewage treatment for single households and small communities and for industrial wastewater
tertiary treatment. Their environmental benefits are widely recognized not only because they
improve water quality, but also because they create habitat for wildlife.
Building sequence Сonstructed wetlands (CW) in Canada brought around to photos.
Geomembrane installation in CW. April 2011.
CW filled topsoil. May 2011.
Extraction of higher aquatic plants (YAP) from the donor site
Transporting the clumps of HAP from the donor site
Planting HAP in CW. May 2011.
Five weeks after planting. Juli 2011.
CW. May 2012.
Treatment process
Physical, chemical, and biological processes combine within the CW to remove
contaminants from wastewater. Treatment of wastewater within the CW occurs as the
wastewater passes through the CW sand medium and the plant rhizosphere. A thin aerobic film
around each root hair is aerobic due to the leakage of oxygen from the rhizomes, roots, and
rootlets of the cattail plants. Decomposition of organic matter is facilitated by aerobic and
anaerobic micro-organisms present. Microbial nitrification and subsequent denitrification
releases nitrogen as gas to the atmosphere. Phosphorus is coprecipitated with iron, aluminum,
and calcium compounds located in the rootbed medium Suspended solids are filtered out by the
sand medium of the CW and subsequently decomposed. Harmful bacteria and viruses are
reduced by filtration and adsorption by biological films on the sand media.
Treatment of wastewater within the AWS occurs as the wastewater passes through the AWS
sand medium and the plant rhizosphere. A thin aerobic film around each root hair is aerobic due
to the leakage of oxygen from the rhizomes, roots, and rootlets of the cattail plants.
Decomposition of organic matter is facilitated by aerobic and anaerobic micro-organisms
present. Microbial nitrification and subsequent denitrification releases nitrogen as gas to the
atmosphere. Phosphorus is coprecipitated with iron, aluminum, and calcium compounds located
in the rootbed medium Suspended solids are filtered out by the sand medium of the AWS and
subsequently decomposed. Harmful bacteria and viruses are reduced by filtration and adsorption
by biological films on the sand media.
Filtration and adsorption by biological films
Cleaning efficiency in Сonstructed wetlands (Canada) driven to the table
Parameter (mg/L)
BOD5
TSS
Phosphorus
TKN
Ammonia (NH4)
Total nitrogen
E.Coli
Total Coliform
Parameter Сonstructed wetlands (Canada)
Wetland influent (n=12)
Wetland effluent (n=23)
802.18
4.91
358.18
5.65
11.36
5.14
54.78
9.15
41.45
0.2
56.01
21.06
539.500
52
4983333
2702
Сonstructed wetlands has been proven to provide on-site treatment of wastewater year-round.
We are currently working on obtaining CW on many installation for treatment of sanitaru
sewage, abattoir wastewater and landfill leachate in Ontario, Canada.
Ecosystem studies of numerous large-scale constructed treatment wetlands throughout the
Canada have helped to inform regulatory agencies of the potential benefits of wetland creation
for successful water treatment. Permitting of discharges from constructed treatment systems is
based on well-thought-out plans for design, operation, and monitoring, as well as discharge
chemistry and receiving water body quality.
References
Berezowsky, M. 1997. Constructed Wetlands for Remediation of Urban Waste Waters. In Eyles,
N. (Ed.). Environmental Geology of Urban Areas. Geological Association of Canada. 203-213.
Magmedov, V. 2002. Constructed wetlands for low cost treatment. . Available at
http://www.constructedwetlands.org/cw/index.cfm .
Vymazal, J. (2005). Horizontal sub-surface flow and hybrid constructed wetlands systems for
wastewater treatment. Ecological Engineering, 25(5), 478-490.