Characterization of harbor sediments from the English Channel: assessment of heavy metal enrichment, biological effect and mobility

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.For a full assessment of the environmental risk posed by dredged sediments not only the anthropogenic enrichment of contaminants, but also their mobility and biological impact should be considered. This study reports on the enrichment factor (EF), mobility, and Adverse Effect Index (AEI) of metals and metalloids in nine dredged sediments. Significant enrichment of As, Cd, Pb and Zn with respect to background values is detected, and calculated AEI values for these elements suggest that it is possible that a corresponding biological effect may be observed. Correlation coefficients also reveal a link between mobility in HCl and enrichment for Cd, Cr, Ni, Pb and Zn, however As and Cu do not display such a link, possibly suggesting that the source of contamination for these elements is less recent. Mobility and enrichment are two parameters which are often studied separately; however this paper shows that in some cases strong correlations occur

Influence of soil type and natural Zn chelates on flax response, tensile properties and soil Zn availability

A greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the relative efficiencies of three natural Zn chelates [Zn-aminelignosulphonate (Zn-AML), Zn-polyhydroxyphenylcarboxylate (Zn-PHP) and Zn-S,S-ethylenediaminedisuccinate (Zn-S,S-EDDS)] applied to a crop textile flax (Linum ussitatisimum L.) at application rates of 0, 5 and 10 mg Zn kg−1. In the flax plant, the following parameters were determined: dry matter yield, soluble and total Zn concentrations in leaf and stem, chlorophyll, crude fibre, and tensile properties. For the different soil samples, the following parameters were determined: available Zn (DTPA-AB and Mehlich-3 extractable Zn), easily leachable Zn (BaCl2-extractable Zn), the distribution of Zn fractions, pH and redox potential. On the basis of the use of added Zn by flax, or Zn utilization, it would seem recommendable to apply Zn-S,S-EDDS at the low Zn rate in both soils. In contrast, adding the high Zn rate of this chelate to the weakly acidic soil produced an excessive Zn concentration in the plant, which caused a significant decrease in both dry matter yield and chlorophyll content. Furthermore, assessing available Zn with the DTPA-AB method proved the best way of estimating the level of excess Zn in flax plants. The soluble Zn concentration, which was established with 2-(N-morpholino)ethanesulfonic acid reagent (MES), of plant fresh and dry matter could be used as an alternative way of diagnosing the nutritional status of Zn in flax plants. In this experiment, the highest soil pHs were associated with the lowest redox potentials, which coincided with the smallest amounts of available Zn and water soluble Zn in soil, and the lowest levels of Zn uptake by flax plants

Cathodic protection by zinc sacrificial anodes: Impact on marine sediment metallic contamination

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Kaolinite influence on calcareous deposit formation

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Calcareous deposit formed under cathodic protection in the presence of natural marine sediments: A 12 month experiment

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Efficiency of five scale inhibitors on calcium carbonate precipitation from hard water: Effect of temperature and concentration

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The impact of aluminium sacrificial anodes on the marine environment: A case study

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Mise au point d'une méthodologie visant à la caractérisation du dépôt calco-magnésien formé sur de l'acier au carbone immergé en eau de mer naturelle

Les résultats présentés entrent dans le cadre de l'étude du complexe biofilm / dépôt calco-magnésien formé à la surface de coupons en acier au carbone (E24) immergés en eau de mer naturelle et placés sous protection cathodique. Les premiers essais ont porté sur la caractérisation chimique du dépôt calco-magnésien formé aux potentiels de –800, –900 et –1000 mV/ECS, après 4 semaines d'immersion. Plusieurs techniques d'extraction par voie chimique et mécanique ont été testées. Les extractions par voie mécanique permettant le décollement des dépôts à sec ont été préférées aux extractions chimiques conduisant à une dissolution de l'acier par les solutions acides testées. Les analyses par ICP-AES et par EDS ont démontré leur complémentarité. Elles ont révélé la présence significative de Ca et Mg et à un degré moindre de P, S et Sr. Les calculs des rapports Ca/Mg et des coefficients de distribution des éléments dans l'eau de mer) et le dépôt ont mis en évidence une présence plus importante de Mg, P et S dans les dépôts formés à –800 mV/ECS, du Ca et Sr à –900 et –1000 mV/ECS

Characterization of harbor sediments from the English Channel: assessment of heavy metal enrichment, biological effect and mobility

International audienc

Odgovorni turizem in globalizacija

International audienc