The International Association of Dredging Companies (IADC) has released in its latest Terra et Aqua an article named ‘Some Proven Benefits of Polymer Use in the Treatment of Sediments in Recent Dredging Projects’.
For several decades, polymers have been used in the treatment of sediments for improving the dewatering step and reaching high solid content along with clear-water release, IADC said in the article.
In order to show the main benefits of polymer use in the dredging industry, two projects started in the last three years have been selected for presentation in this article to demonstrate the main benefits of their use in the dredging industry.
Port-La-Forêt harbor in La ForêtFouesnant, France has not had any form of maintenance dredging in over 30 years. For the harbor’s cleaning, 40,000 cubic meters of polluted sediment needed to be flocculated and pumped into geotextile tubes on a dewatering site located four kilometers away.
The turbidity of the water released has been constantly monitored and kept below the authorized level throughout the project. The benefits of polymer use in conjunction with dewatering tubes are a shorter drying time and higher quality of released water.
The Kishon River project, contaminated by chemicals from both industrial effluents and municipal wastewater, aimed at cleaning seven kilometers downstream of Haifa, Israel.
Over a period of 20 months, some 400,000 cubic meters of material are expected to be removed from the river bottom and treated. Bioremediation is used after sediment dewatering.
The benefits of polymer use in conjunction with dewatering equipment area a higher level of dryness in the final solid waste and higher quality release water.
With increasing pressure from local communities and authorities on project timeframe, worksite footprint and water quality, the use of polymers will be prevalent in dredging projects, especially those located in heavily populated areas or dealing with contaminated sediment.