New solutions for contaminated harbor sediments
A problem faced by many industrial ports is what to do with contaminated marine sediment that is regularly dredged from the sea floor—sediment that often contains high levels of carcinogenic PCBs, cadmium, lead and mercury. In the past, these polluted soils were dumped further out to sea or transported to inland landfills, both fiscally and environmentally costly options.
A Swedish-Norwegian team of researchers has found a way to transform marine sediment into building material through a process that makes its pollutants inert. The soft sediments are mixed with binders, cement, and steel slag, which stabilizes the mixture and prevents pollutants from leaching out of the matrix. Since mixing is performed on-site, transportation costs are reduced or eliminated, and the cement-like construction material can be used immediately in the harbor, to build structures like buildings and loading zones.