Newsletter and Technical Publications
<Sourcebook
of Alternative Technologies for Freshwater Augumentation in East and
Central Europe>
3.16 Recycling of Water In the Power Generation Industry
Technical Description
The technology comprises a number of water savings opportunities which
can be realized through the application of alternative technical
approaches to the use of water in the power generation industry. For
example, the Riga, Latvia, Thermal Power Plant Number 1 uses a large
volume of surface water for cooling, and, after passing this freshwater
once through the cooling process, discharges this entire volume of
chemically and thermally polluted water to Lake Kiezers, situated in
the City of Riga. Based upon the reconstruction experience obtained at the
Riga Thermal Power Plant Number 2, it is proposed that this once through
system be replaced with a treatment and recycling system that should
consume significantly less water. After cooling, the cooling water used at
the Number 2 Plant is biologically treated in ponds and recycled. This
system is largely closed, with only small volumes of supplemental water
being withdrawn from Lake Kiezers.
Extent of Use
Similar projects are under construction, or have been completed, in a
few thermoelectric power plants in Poland, Ukraine, and Hungary.
Operation and Maintenance
Use of the treatment and recycling technology is fully compatible with
standard operation and maintenance procedures in thermoelectric power
plants. However, the recycling system does require some additional
maintenance in order to recirculate the treated cooling water and to
operate the biological treatment ponds.
Level of Involvement
This technology is generally implemented at the company level.
Costs
Costs are difficult to identify, and depend on scale of the project.
Effectiveness of the Technology
At Riga, it is anticipated that the introduction of recycling of cooling
water will reduce water consumption at the power plant by 9.5 times.
Recycling the treated cooling water for other purposes at the plant should
increase reuse by up to 25 times. Specifically, the use of water for
industrial purposes prior to reconstruction of the plant consumed 30 x
106m3/year. This volume is expected to be reduced to 3.1 x 106m³/year,
or about 10% of the previously consumed volume. Use of recycled water is
expected to increase from about 43 x 106m³/year to almost 71 x 106m³/year,
or a 1 650% increase.
Suitability
This reuse technology is suitable for use at thermoelectric power
plants.
Advantages
All of the cooling water, process water, and wash water used in the
power plant is treated and reused. The greatest benefit of this technology
is the prevention of thermal pollution in the lake.
Disadvantages
No disadvantages have been identified. Some modification of the
wastewater collection and circulation systems must be undertaken, which
has a cost impact.
Cultural Acceptability
This technology is accepted as a profitable and efficient environmental
technology.
Further Development of the Technology
The technologies used in the Riga Project were designed by the Latvian
State Enterprise "Siltumprojekts", which is main design
authority for power production and supply in Latvia and the Baltic States.
Information Sources
Rolands Bebris, Ministry of Environmental Protection and
Regional Development, 25 Peldu Str., 1494 Riga, Latvia, Tel. (371-7)
227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.
Anna Egle, V/U "Meliorprojects", 11 Novembra
Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.
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