Each year millions of tonnes of sediment are dredged worldwide as part of harbour maintenance. Oxidation of dredged sediment leads to CO2 emissions and the release of contaminants. The sediment is currently either transported out to sea or contained due to high levels of toxic compounds and heavy metals. This makes dredging costly, but this could be avoidable if the sediment became a resource.

Dredged sediment a potential building material

Dredged sediment is a potential building material but must be modified to prevent negative environmental impacts. Using different grades of sediment dredged from Europe’s largest sea port – Port of Rotterdam, the project will test the feasibility of transforming harbour sediment into a building material with neutral or negative CO2 footprint. 

Reactive silicate minerals participate in natural carbon sequestration

The researchers will assess how the addition of reactive silicate minerals, particularly olivine, which is known to participate in natural carbon sequestration, can transform dredged sediment from waste to resource.

“The project aims to be transformational in our understanding of the challenges, and particularly the possibilities associated with reusing harbour sediment,” says Prof Jasper Griffioen from the Copernicus Institute of Sustainable Development and TNO. 

“In this project, we will establish whether simple natural amendments can reduce or maybe even reverse the environmental impact of dredging activities. Furthermore, the innovations that we propose could boost the reuse of harbor sediment and thereby help alleviate the global shortages of sediment as building material, also for ecological engineering projects", says NIOZ project leader Peter Kraal.