Since the 60's, geotextile tubes and bags are used as a geocontainment technology in marine structure applications. More recently, geotextile tubes technology also has been used all over the world to dewater many kinds of sludge and dredged sediments with success regarding safety, volume reduction, efficiency and economy. This process starts with pumping the polymeric coagulates and or flocculated slurry straight to the bags, where the solid part is retained inside and the liquid part flows through the pores of the woven engineered filtration textile. In some cases, depending on chemical and biological analysis, the effluent can return to the original process, be used for agricultural irrigation or even to be discharged in nearby waterways. For a long time it was usual, as a preliminary analysis, to perform a HBT (HBT) to predict the behavior of the engineered filtration textile regarding retention and filtration in a given amount of time. Using time as an important parameter to evaluate the dewatering efficiency, the HBT through the effluent quality and dry mass of the material within the bag provides good and conservative results in comparison to the full scale unit. However, the HBT presents some downside points, such as the manual filling process, the broken flock during filling, and the different position of the hanging bag in comparison to the dewatering tube. These factors imply that the test can be improved and modified to better evaluate the dewatering and filtration performance. This paper presents a comparison between the Hanging Bag Test (HBT) and a Simulated Dewatering Test (SDT) tubes test results using actual samples of contaminated sediments. These results are used to determine the design for full scale dewatering tube designs.
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