Bottom sediment deposits removal from the Veľké Kozmálovce water reservoir

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Carried out in: 2008 – 2011
Project duration: 470 working days
Sediment volume in situ: 130,000 m³
Pumped hydromixture: 580,000 m³
Processed sediment: 105,000 tons
Sediment: 50% organic, 50% inorganic, a lot of waste and branches

Popis

Veľké Kozmálovce water reservoir is situated in the lower reaches of river Hron. Its main purpose is to provide enough service water for Mochovce nuclear power plant. However it also serves for irrigation in agriculture, industry and recreation. Moreover there is a small hydro power plant at the water reservoir weir.

The main goal of this project was to eliminate the negative impact of sedimentation on the quality of water intended to cool down reactors and furthermore restore the original capacity of the reservoir.

To dredge the sediments we used suction dredger which then transported it to the DESET PG02 technology line via floating pipeline. We separated grains bigger than 3 mm on vibrating screens. After homogenisation of the remaining fine material, we added a Praestol 855BS-type flocculant. We used Decanters Flottweg Z73 and Z92 to dewater the sediments.  The insulating properties of clay in the sediment allowed us to reuse the produced material to revitalize municipal landfill as well as construct flood protection barriers.