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WEBAP
Wave Energized
Baltic Aeration Pump
Picture: WEBAP pilot plant as tested in Hanöbukten
OXYGEN PUMPS
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Short version of the WEBAP project’s final report (December 2013)
How we can use nature to restore marine
environments before it is too late
More information/contact
PROJECT HOMEPAGE: www.webap.ivl.se
PROJECT LEADER: Christian Baresel, [email protected]
With the contribution of the LIFE financial instrument of the European Community and the Foundation IVL.
About the WEBAP project
Good intensions, a good approach and the willingness to change
• The main objective of the project was the demonstration of a cost-effective wave powered
device that could help to mitigate the problem of oxygen depletion (hypoxia) in the Baltic Sea.
• By aeration of oxygen depleted bottom water layers with oxygen rich water from upper water
layers, the WEBAP project aimed to reduce problems with dead bottoms and algae blooms in
the Baltic Sea.
• The core WEBAP-approach consists of a pump that exclusively uses the natural resources of
oxygen rich surface water and wave-energy to accomplish an imitation of natural oxygenation
processes that help to restore or improve the ecosystem of dead bottoms.
• Together with measures to reduce nutrient loads from the mainland, aeration/oxygenation by
WEBAP-pumps will enhance the restoration of the self-purifying bio-geochemical processes of
the Baltic Sea.
• Phosphorus that has been released from the sea sediments because of the lack of oxygen
will be bound to the bottom sediment, and hence reduce the algal blooms.
• Reducing the problem of oxygen depletion will generate several favourable effects on species
that are dependent on a balanced oxygen situation during some phase of their life cycle.
• An improved oxygen situation in the Baltic Sea will also have positive effects for the tourism
and fishery.
The problem: Eutrophication of our seas has many effects
Society has put marine ecosystems under pressure. Especially wastewater effluent
(treated and untreated), use of fertilizers in agriculture and other human impacts
have destroyed the ecosystem in large areas of the Baltic Sea.
The input of nutrients (nitrogen and phosphorus) to our seas causes algae blooming and the
consumption of the oxygen in the deep water when the algae is decomposed. This in turn leads
to a vicious circle of nutrient release from the sea sediments and more algae blooming. Besides
the death of the ecosystem and huge ecological and biological problems, tourism and fishery
in coastal regions face large future economic problems.
Dead bottoms (waters without oxygen and thus no life) are extending from year to year and
covering large parts of the Baltic Sea. However, similar problems are observed all over the world.
Source: www.smhi.se
Solution ideas and difficulties
In theory, feasible solutions exits but require the allocation of enormous amounts
of resources. The challenge is to provide realistic solutions.
Nature has shown that oxygenation of dead bottoms improves the conditions in the deep water
layers of the Baltic Sea tremendously. By mixing water with oxygen-rich water from the North Sea,
a decrease in phosphorus concentration in the water is observed in the Baltic Sea. Unfortunately,
climate change will decrease such natural events as driving parameters change.
To restore the Baltic Sea ecosystem and its self-cleaning processes before it is too late different
actions are required.
• Anthropogenic nutrient loads to the environment must be reduced because these are the
main cause for dead bottoms.
• The destroyed ecosystem of the Baltic Sea needs some help to restore and to take care of
itself.
Oxygenation is one of the most interesting approaches that have been discussed in recent years.
However, the challenge is to provide in some way those millions of tonnes of oxygen that would
be needed. For this, enormous amounts of pump energy would be needed because the depths
were the oxygen is needed is up to 120 metre deep.
So the question is: Mission
impossible?
WEBAP – Wave Energized Baltic Aeration Pump
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• The basic WEBAP approach is simple; use of natural resources to mimic a natural process
that helps to restore the Baltic Sea ecosystem.
More specifically this means:
• Waves is the source of energy needed to pump oxygen down to deep-water layers.
• The source of oxygen provided to deep-water layers is oxygen-rich surface water.
Wind direction
Oxygen-saturated
surface water
Anchorage
Advantages:
• Oxygenation & mixing
• Simple and robust design with no moving parts
and no need for electricity
Effect:
Oxygenation
and mixing.
Results of the WEBAP project
Tested at different sites in the Baltic Sea, realistic technical and economic solutions
were developed.
Within the project, two oxygen-pumps were operated during in total three years.
Comprehensive monitoring, tests, analyses and modelling using received data during this
period gave the following main results:
• The proposed pumping technologies are functional to pump oxygen-rich surface water to
deep water.
• Various technical solutions for all marine environments have been developed and tested.
• No adverse toxic or other harmful effects of oxygenation of dead bottoms could be
observed.
• Stratification of water layers, that is important for example cod reproduction, is not
disturbed even after many years of pumping.
• The project quantified the phosphorus pool in sediments that may be under different
redox conditions.
• The measurements performed provide no support for the hypothesis that the reduced
sediments in the Baltic represents a latent phosphorus bomb.
• The calculations carried out in the project indicates that it would be a step in the right
direction to oxygenate areas of the Baltic Proper with the tested method.
Developed WEBAP-systems
Realistic and affordable technological solutions for various conditions.
Solutions for pumping at different scales and if waves are not sufficient (especially in
the archipelago and close to shores).
1) Wave powered for large-scale application at sea, optionally in combination with
other offshore installations.
2) Biofuel-powered for coastal applications
in the absence of wind or waves.
3) Wave powered for both
inshore and offshore applications.
Benefits
Since using/imitating/supporting nature, the WEBAP approach has a direct positive
environmental impact and generates environmental and socio-economic benefits.
The WEBAP project provides cost-effective technical solutions that may be used for the
aeration of oxygen depleted “dead bottoms” to mitigate the problem of oxygen depletion
(hypoxia) in the Baltic Sea. This would not only produce favourable effects on the ecosystem
but an improved oxygen situation in the Baltic Sea would also have positive effects on tourism
and the fishery.
It is difficult to do something more environmentally friendly than using the power of nature
to imitate nature. Environmental impact and total cost assessment indicates that the WEBAP
approach is one of the most sustainable and cost-efficient alternatives.
Further, the results and technologies of the project are (partly with modification) transferable
to other marine environments in the world. The awareness about this severe environmental
problem is just increasing.
What next?
The project has created information that is useful for making
decisions about further actions. The question is how the various
problem owners and decision makers such as the municipalities
around the Baltic Sea, Environmental Protection Agencies, etcetera
will manage to agree on actions before it is too late.
The project partners are also driving a number of other activities
aiming at minimizing the negative impact of society on the
aquatic environment.
OXYGEN PUMPS
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