Since there is less and less space available for the storage of dredged sludge, and because regulations are becoming more strict, Ghent Dredging is fully cooperating in developing new techniques for dewatering and processing dredging sludge.
A well-known and simple approach is the mechanical technique of lagooning. Depending on the initial state of the sludge and the intended result, the sludge is dried in lagoon fields for a certain period of time. During drying, the sludge is turned several times and placed in drying rows. After a few weeks to months, the sludge has then become solid soil.
Another technique is dewatering using geocontainers. Highly diluted dredging sludge is injected with polymers and then sprayed into geocontainers. The polymers separate the water from the soil particles and the water leaves the containers through the meshes of the geotextile. After a few days to weeks, the sludge has also become solid soil, and the geocontainers can be emptied.
With both techniques, the soil is then tested and classified in accordance with the applicable regulations and taken to a recognized processing centre (biological or physico-chemical cleaning) or applied in a project with an OVAM reuse-certificate.
Ghent Dredging has a soil and sludge processing centre in the port of Ghent. The centre is located at the Rodenhuizedok near the Ghent-Terneuzen canal and has its own loading and unloading quay. In this way, dredging sludge and excavated soil from all over Flanders, Brussels, Wallonia and Northern France can be quickly delivered and removed by ship.
As a result, Ghent Dredging has realized the ideal vertical integration and everything is in its own hands. On behalf of our customers, we can carry out the dredging work ourselves, dry and treat the spoil in the soil and sludge processing centre and then reuse the raw material in water, earth or road works.
The soil and sludge processing centre is located on a site of over 6 hectares and comprises five lagooning basins with a surface area of 35,000 m² and a paved storage area of approximately 7,000 m². The centre has a processing capacity of 100,000 m³ of sludge per year. The supplied sludge is first dried and then, if necessary, biologically cleaned or undergoes another treatment.
The soil and sludge processing centre is also licensed as TOP and CGR. This allows it to accept and process surpluses from its own yards, but also from third parties. Soils contaminated with biodegradable contaminants are biologically cleaned. Batches for other types of cleaning or treatment are cleaned on the GSC or passed through for external processing.
All this is done in accordance with VLAREBO legislation under the supervision of the soil management organization Grondbank and OVAM.
View our projects with the processing of dredged material here: