Large Market for Dewatering Sediment

Belt filter presses, recessed chamber filter presses, geo tubes and centrifuges are all used to dewater sediment removed from lakes, harbors and waterways. This large market is identified in two McIlvaine reports, Liquid Filtration and Media World Markets and Sedimentation and Centrifugation World Markets. (www.mcilovainecompany.com)

The opportunities fall into two categories:

• Sediment removed to deepen harbors and waterways

• Sediment removed to reduce contamination

The sediment is very likely to be contaminated. So the separation processes must not only dewater sediment for disposal, but must treat effluent to remove contaminants.

U.S. waterways contain more than one billion tons of contaminated sediments, according to EPA. Every major harbor bed is polluted. Many other countries around the world are facing even more serious contamination issues.

EPA has announced a massive $1.7 billion cleanup plan, the largest in EPA history, for the lower eight miles of the Passaic River in New Jersey, running from Belleville to Newark.

That stretch is the most severely contaminated part of the river. It is polluted with high levels of dioxin, polychlorinated biphenyls (PCBs) and other contaminants resulting from a century of industrial activity. The river will be dredged from bank to bank. More than four million cubic yards of toxic sediment will be removed from the river bed. Cleanup of the Passaic has been under study for 25 years.

EPA says that sediment removal will be accompanied by capping of the river bottom. The contaminated sediment will be pressed, dried and shipped out of state for disposal. EPA says it is the largest cleanup in EPA history.

The effluent will undergo a series of additional filtration steps which may also include additional presses or centrifuges. Alternatively cartridges, bag filters and cross-flow membranes may be used. The final flow schematics for Passaic have not yet been determined.