Physico-chemical and environmental characterisation of sediments from Cantabrian estuaries (Northern Spain)

Abstract

Previous studies show that sediments of the Cantabrian estuaries (Northern Spain) contain significant concentrations of heavy metals and organic pollutants derived from intensive industrial, agricultural and urban activities. In the most polluted sediments of two estuaries (the bay of Santander and estuary of Suances), physico-chemical and environmental characterisation has been carried out. Water content, density, pH, specific surface, porosity and particle diameter distribution have been evaluated as physical parameters. Total metal contents have been analysed as inorganic parameters. Loss of ignition (LOI), phenol index and extractable organic halogens (EOX) have been determined as organic parameters. Two leachate assays have been carried out in order to evaluate the environmental behaviour of the sediments. Total availability has been analysed using the NEN 7341 test and the mobility of the pollutants has been determined using the EN 12457 leaching test at two liquid/solid ratios. The obtained results have been compared with European Union regulations. The physical parameters and inorganic compounds are very similar in the studied sediments. However, the sediments from Suances have high concentrations of LOI and EOX. The obtained correlation of the physical parameters with the particle size distribution is useful in the study of the sediment addition to ceramic process as a sediment management option. A comparison of the results obtained from the total, availability and mobility analysis of the inorganic pollutant concentrations of As, Ba, Ni, Pb and Zn present in sediments has been made, giving knowledge for the development of regulations and tools that would contribute to the integral management of the estuarine areas.

Stabilization/solidification of an alkyd paint waste by carbonation of waste-lime based formulations

“…1). The leaching tests used were previously described by Coz et al [34]. The chemical analytes regulated in the EU landfill Directive [33] and present in the paint waste, namely As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se, Zn, the total dissolved solids (TDS) and the anions F − , Cl − and SO 4 2− , were analyzed in the leachates obtained from the different lixiviation test previously described.…”

CO2 seawater acidification by CCS-simulated leakage: Kinetic modelling of Zn, Pb, Cd, Ni, Cr, Cu and As release from contaminated estuarine sediment using pH-static leaching tests

“…The pH is one of the variables that most influences the mobility and availability of inorganic contaminants from solid matrices (Coz et al, 2007), and thus, pH-dependent leaching tests seem to be an appropriate assay for assessing its influence. Standard or modified pH-dependent leaching tests with continuous pH control such as CEN/TS 14997 (2015) have been widely used to evaluate the release of contaminants from soil and sediments (Cappuyns and Swennen, 2005;Cappuyns et al, 2004a,b;Centioli et al, 2008;Horckmans et al, 2007;Shtiza et al, 2009;Van Herreweghe et al, 2002).…”

Influence of sediment acidification on the bioaccumulation of metals in Ruditapes philippinarum

“…As H + competes with metals for aquatic ligands, at low pH values, metals tend to be found as free ionic forms, which are increasingly available to biota (Rensing and Maier 2003). Coz et al (2007) predicted enhanced mobility of metals in sediment pore water and the overlying water column as a direct result of decreases in the pH of surface sediments. Two types of coastal sediments are usually reported as exhibiting low pH values: organically enriched sediments, like salt marshes, where the release of protons during oxidation reactions reduces pH (Caçador et al 2000), and sediments influenced by acid discharges from mining activities (López-González et al 2006).…”