Experimental determination of efficiency of capping materials during consolidation of metal-contaminated dredged material

A review of the in-situ capping amendments and modeling approaches for the remediation of contaminated marine sediments

“…Unfortunately, the goodness of fitting between the observed and the modeled values was not always computed. Bortone et al (2020) chose the mean absolute errors * Highest value obtained calculated as: %Eff = 1 − ⁄ (Eek et al, 2007) with C = concentration in water.…”

Potential consolidation-induced NAPL migration from coal tar impacted river sediment under a remedial sand cap

“…However, to assure the efficacy of such a remedial strategy, the long-term dynamic processes that determine the chemical profiles within the cap and the shorter term physical processes that directly result from overburdening the sediment with cap materials (i.e., consolidation) need to be considered [6][7][8]. The latter processes may include significant sediment consolidation that in turn will result in changes in hydraulic conductivity as the pore fluids are squeezed from the submerged sediments to the new cap [9,10]. The potential also exists for fine sediment particles, coal tar, and dissolved aromatic hydrocarbons to be transported with this water, effectively reducing the effective thickness of the new sand layer [5,11,12].…”

“…The consolidation of high water content dredged sediments and sludges due to capping have been investigated by several researchers [10][11][12][13][14], however few studies have focused on the behavior of in-place coal tar impacted sediments under such remedial measures. Because of the unique nature of coal tar, its presence within sediment may affect the initial plasticity of the sediment before consolidation, and may affect the magnitude and rate of consolidation due to placement of a sand-based cap where effective stress is increased.…”

Mercury remobilization in Saguenay Fjord (Quebec, Canada) sediments: Insights following a mass-flow event and its capping efficiency

“…In lacustrine and estuarine sediments, remediation of mercurycontaminated sediments usually include dredging (Hosokawa, 1993; Barbosa and de Almaida, 2001;Wang et al, 2004;Randall and Chattopadhyay, 2013), in-situ and ex-situ capping (Jacobs and Förstner, 2001;Eek et al, 2007;Johnson et al, 2010), binding to sorbent materials (Knox et al, 2008;Bower et al, 2008;Gosh et al, 2011;Chavez et al, 2013), (co)-precipitation (Piao and Bishop, 2006), and phytoremediation (Chattopadhyay et al, 2012). When the sediments are to be isolated from the overlying water column, it is critical to have detailed knowledge of the speciation and distribution of mercury in the sediments as well as to continuously monitor their evolution after isolation to detect remobilization of the mercury (Johnson et al, 2010).…”