Natural Dewatering of Marine Dredged Sediments

Abstract

The aim of this study is to explore the water content decrease in dredged sediment by natural evaporation and/or drainage. This operation constitutes, in several fields, a preliminary operation to insure a reliable beneficial use of this material. Firstly, a methodology is proposed to assess the relative efficiency of drainage and evaporation in the process of water content reduction in the dredged sediment. Secondly, comparisons of measured evaporation rates are compared to predictions of an available model in the literature. Thirdly, the observed stages during drying are explained in the light of standard parameters measured on the sediment. Finally, a relationship between water content decrease and increase of shear strength of the sediment is discussed. These results will allow a better management of beneficial use of the sediment and enhance scheduling of the drying operation and its transport.

Keywords:

• Atterberg limits
• Drainage
• Evaporation
• Marine dredged sediments
• Natural dewatering
• Shear strength

ACKNOWLEDGMENTS

The authors thank the Harbour of Dunkerque for providing the studied materials and the European Commission for their support throughout SETARMS projects.