Investigation of natural dewatering of dredged sediments incorporating evaporation and drainage

Abstract

Whether driven by the need to dispose of contaminated sediment, a reduction in the size of confined disposal areas, or a lack of land adjacent to dredge sites, dewatering practices have gained prominence over the past few years. It is necessary to dewater these dredged sediments so that they can be used for beneficial purposes, such as industrial or construction backfill material. This study explores the natural dewatering method that reduces the water content of dredged sediment through evaporation and drainage. This research implemented two types of dredged sediments from different origins to determine the effects of sediment type on both evaporations as well as dredging. First, the effects of diameter on the rate of evaporation (ROE) and the potential of evaporation (POE) were investigated. The measured POE was then compared to the predicted POE using Rohwer’s and Penman’s models. In order to improve the handling of these dredged sediments prior to beginning the valorization process, a correlation between the decrease in water content and the increase in shear strength is discussed. This research will improve the handling of these sediments for transportation and indirect management of dredged sediment valorization.