The dredging concept which will be tested is highly innovative as it is mobile, cost effective, environmentally friendly and easy to use. The system is also highly automated, which makes it cost-effective.
If successful it will allow for other sites across Europe to consider substituting state of the art treatment alternatives with a more environmentally sound and cost effective solution.
The new dredging system that has been developed by TechMarket uses an unmanned, totally automated, dredging unit. The system consists of a surface raft that pulls an underwater unit on which the dredging nozzles are placed. The underwater unit consists of 18 specially designed nozzles pumping sediments from the seabed. The system moves slowly over the seabed (1 cm/s) and does therefore not cause any re-suspension of sediments (i.e. it allows the sediments to be brought up layer by layer in a way that minimizes the turbidity and thereby minimizes the spreading of hazardous substances and the impact on biological life).
The cone-shaped nozzles only retrieve light organic fractions, leaving sand and heavier fractions on the seabed. On top of that the way of bringing up the sediments layer by layer offers an opportunity to treat the layers in different ways depending on their content of hazardous substances and nutrients.
The capacity of each under water unit is 15 m3/hour. Three underwater units will work in parallel, giving a total capacity of 45 m3/hour. This is a suitable capacity for the subsequent steps of the process. Furthermore, the surface raft is in turn controlled by four automated wires, placed in the corners of the dredging area (on shore, or at anchored platforms) through a predetermined dredging path, using GPS input. The system can be operated 24-hours, and can be supervised locally or remotely using built in sensors. The technology can be handled by a non-professional and can be used at any place where there is a need for taking up sediments.