Interaction dynamics between a contaminated dredged sediment and extracting solutions of different nature

Abstract

The purpose of this work is to study the dynamics between the matrix of a contaminated marine sediment, its contaminants and various desorbing solutions by means of equilibrium tests, sedimentation trials and zeta potential, with the focus on assessing optimum enhancing solutions for decontamination purposes. Materials and methods The sediment samples were analysed to determine their physico-chemical characteristics: particle size distribution, solids concentration, total organic carbon (TOC), content of heavy metals, organic contaminants, mineralogical phases, zeta potential and buffer capacity. Twelve extracting solutions of different nature were used for equilibrium tests, in which the dynamic behaviour of the sediment was evaluated. Elemental analysis was carried out for the sediment samples and the solutions before and after the tests. Results and discussionThe sediment was mainly composed of clay and lime, with a high content of iron, which has a strong influence on sorption-desorption processes. The sediment had a considerable buffer capacity at low and high pH values. The desorption of the metals was not proportional to pH. The highest decrease in the concentration of metals from the sediment was obtained with 0.2 M ethylenediaminetetra-acetic acid (EDTA) and 1 M nitric acid, while the lowest degree of metal extraction occurred in pure water and potassium iodide (KI). Conclusions The most important parameters for contaminant release were complexation ability of the solution for the sediment components and pH of the solution. A promising design for the remediation treatment for the investigated sediment includes complexation and strong acid agents.

High-capacity adsorbents from stainless steel slag for the control of dye pollutants in water

“…One of the approaches to convert slag into a product with new potentialities is focused on exploring the effect of accelerated carbonation for storing point-source emissions of CO 2 (Baciocchi et al 2010 ; Bonenfant et al 2008 ; Huijgen et al 2005 ; Johnson 2000 ; Kodama et al 2008 ; Lekakh et al 2008 ; Santos et al 2013 ). This conversion is accompanied by improving the mechanical properties, significant reduction in basicity, and stabilization of heavy metal leaching (Garcia-Blas et al 2019 ; Johnson et al 2003 ; Van Gerven et al 2005 ). Black furnace slags (BFS) are used widely as supplementary materials in cements, having the cements type CEM V/B until a 49% of substitution of clinker by slags (Roy 1982 ), increasing in a big deal its durability (Castellote and Andrade 2006 ; Osborne 1999 ).…”

Surfactants in electrokinetic remediation of sediments to enhance the removal of metals

“…Sediment samples were dredged from a European marine harbour in the south-east coast of Spain. Sampling and storage conditions and characterisation of the sediment are described in detail in (Garcia-Blas et al 2020b). These included size particle distribution (67% of the sediment was ≤ 63 μm and around 30% was ≤ 2 μm); total organic carbon, following the ISO 10694 standard (2.1%); carbonate content according to NEN-EN-ISO 10693 (10.2 g kg −1 ); organotin compounds as specified by NEN-EN-ISO 23161 (tributyltin 57 µg kg −1 ); total petroleum hydrocarbons using gas chromatography-flame ionisation detection (TPH C10-C40:70 mg kg −1 ); polycyclic aromatic hydrocarbons (PAH-VROM, 10 < 0.30 mg kg −1 ), (total PAH (EPA, 16) < 0.48 mg kg −1 ); and polychlorinated biphenyls (PCB < 0.007 mg kg −1 ) by gas chromatography-mass spectrometry.…”

Sediment as a dynamic natural resource—from catchment to open sea

“…The results in the different sites showed different degrees of metals' bioaccumulation by fungi mainly due to environmental conditions, the physical characteristics of sediments, and the different fungal species used. Garcia-Blas et al (2020a) explored the dynamics between the matrix of polluted marine sediments, type of contaminants and various desorbing solutions considering equilibrium tests, sedimentation trials, and zeta potential with the focus on assessing optimum enhancing solutions for decontamination purposes. The sediment, mainly composed of clay and lime and containing high concentrations of iron, demonstrated a strong influence on sorption-desorption processes.…”