New Approach to Treating the Soft Clay/Silt Fraction of Dreged Material

Maintenance and capital dredging is absolutely necessary to keep shipping lanes open and harbors accessible. Since the early 1970s the ecological impact of dredging processes and disposal techniques has been studied carefully. Facing strict environmental regulations, ports worldwide are currently changing their dredged material management plans to stay economically viable. Restrictions and exclusion of traditional disposal techniques require a multifaceted approach to dispose of, recycle, decontaminate and reuse the material. For clean dredged material several strategies of beneficial use have been established successfully throughout the last decades. However, contaminated sediments are more difficult to place. Especially the productive use of the soft clay / silt fraction poses many unsolved problems because it tends to attract the pollutants. Existing technologies are often energy-consuming and expensive, treat only certain fractions of dredged material, raise issues of secondary pollution, or lack community acceptance.