Influence of diagenetic processes and terrestrial/anthropogenic sources in the REE contents of the Cascais submarine canyon (Iberian western coast)

ABSTRACT: Temporal variations of rare earth elements (REE) and their fractionation patterns, major elements, Pb and Hg were determined in two multicores collected at 445 and 2100 m water depth (mwd) in the Cascais submarine canyon (CSC). The PAAS-normalized REE patterns suggest mixing of Tagus estuarine and marine sediments, marked by MREE (Nd‐Dy series) enrichment and by positive Eu-anomaly, with marine sediments. The positive Eu/Eu* implies incorporation of detrital feldspar minerals derived from the estuary. Ce/Ce*, (La/Yb)PAAS and (Nd/Yb)PAAS show differences between the two cores. Core 252-35 from the shallower site is enriched in HREE (Ho‐Lu series) over LREE (La‐Pr series), a pattern also found in the Tagus estuary in the vicinity of an abandoned chemical complex, where the environment is affected by the legacy of massive-sulfide ores processing. There seems to be only limited down-canyon sediment transport to the deeper reaches where core 252-32 was collected. This deeper site shows Ce/Ce* peaks coinciding with low (La/Yb)PAAS values suggesting preferential diagenetic remobilization of LREE relative to HREE. Upcore Pb/Al and Hg/Corg trends observed in both cores indicate dispersion of the anthropogenic component from the estuary through the CSC, which is less obvious from the ∑REE/Al trends particularly in the deeper site. This may suggest the influence of diagenetic processes in the REE signal, associated with relatively low sediment accumulation rates.info:eu-repo/semantics/publishedVersio

Submarine Cascais Canyon as a sediment conduit to the deep sea : comparison with adjacent slopes

Submarine canyons are known to be important conduits that trap, accumulate and deliver both natural and anthropogenic sediments from the shelf to the deep sea. Ten multi-cores from the Cascais Canyon and from the neighbour slopes (off Estremadura and Sines) were dated by 21Opb methodologies and analyzed for texture, major and trace metals to evaluate the role of submarine canyons in the transport of anthropogenic metals to the abyssal plains. Higher accumulation mass rates were determined in the upper Cascais Canyon than in the lower canyon and slopes. Enrichment factors (EF) were used to evaluate the level of metal enrichment in the studied areas. EF values exceeding natural background concentrations were obtained for Pb suggesting an anthropogenic and/or diagenetic source for Pb enrichment in the Cascais Canyon, but also, to a lesser extent, in the Estremadura and Sines slopes. Studies of provenance based on the ratio of different stable Pb isotopes can help to determinethe origin of such metal in the sediments

Alterações recentes nas razões isotópicas de Pb em sedimentos do Canhão Submarino de Cascais, Portugal

Temporal variations in lead concentrations and stable lead isotopic ratios in two sediment cores from the Cascais Canyon shows changes in sources of Pb during the last two centuries. The increase of total Pb contents wIth the evolution of Pb ratio recorded in both cores reveals the Increase of Pb from industrial sources. Nevertheless, this increase is lower in deeper core location (252-32) due to dilution and mixing with uncontaminated marine materials. An isotopic shift towards lower Pb/Pb in the shallower core (252-35) during the 1970s may reflect the increasing number of vehicles in the Lisboa area during that time

Validation et assurance qualité appliquée à la composition chimique du lait de chèvre : mesures des minéraux et éléments traces.

In the present study, quality assurance programmes were implemented to validate and control the analytical methodologies used for the characterization of minerals and trace elements in goat milk from Portuguese breeds. With the exception of chloride that was determined by potentiometric titration, all the other elements were determined by spectroscopic techniques after different sample decomposition: P was measured by ultraviolet-visible molecular absorption spectrometry, Ca, Fe, K, Mg, Mn, Na and Zn by flame atomic absorption spectrometry and Cd, Co, Cr, Cu, Mo, Ni and Pb by electrothermal atomic absorption spectrometry. The methods performance characteristics, namely specificity, limit of detection, limit of quantification, working range, precision and trueness were evaluated. Measurement uncertainty was expressed in terms of precision and trueness. Precision under intralaboratory reproducibility conditions was estimated from triplicate analysis, and the trueness component was estimated in terms of overall recovery using either skim milk powder certified reference materials or spiked samples. The results obtained are discussed on the basis of the performance criteria required by EC regulations to verify when a method is suitable for food control. The methods used for the characterization of minerals and trace elements in goat milk complied with EC requirements since there was no matrix influence, the Horrat values were $<$ 2.0, recoveries were within the interval 1.00 $\pm$ 0.10 for minerals and 1.00 $\pm$ 0.20 for trace elements and the combined uncertainty of the results were lower than the maximum standard uncertainty calculated using the uncertainty function approach. In relation to the limits of detection and quantification, the limits obtained for Pb were lower than those specified by EC regulation.Dans ce travail, des programmes d'assurance de la qualité ont été mis en œuvre afin de valider et de contrôler les méthodes d'analyse utilisées pour caractériser les minéraux et les éléments traces du lait de chèvres de race portugaise. À l'exception du chlorure, qui a été déterminé par titrage potentiométrique, tous les autres éléments ont été déterminés par différentes techniques spectroscopiques après décomposition de l'échantillon : P a été mesuré par spectrométrie d'absorption moléculaire ultraviolet-visible (UV-VIS-MAS), Ca, Fe, K, Mg, Mn, Na, et Zn par spectrométrie d'absorption atomique de flamme (FAAS) et Cd, Co, Cr, Cu, Mo, Ni et Pb par spectrométrie d'absorption atomique électrothermique (ETAAS). Les caractéristiques de performance des méthodes, à savoir la spécificité, limite de détection, limite de quantification, la plage de travail, la précision et la justesse ont été évaluées. Les incertitudes de mesure ont été exprimées en termes de précision et de justesse. La précision sous des conditions de reproductibilité intralaboratoire a été estimée à partir des analyses en triple. La justesse a été estimée en termes de récupération globale, soit en utilisant des poudres de lait matériaux de référence certifiés ou des échantillons dopés. Les résultats obtenus sont discutés sur la base des critères de performance requis par les règlements CE pour vérifier qu'une méthode est adaptée au contrôle des aliments. Les méthodes utilisées pour la caractérisation des minéraux et des éléments traces dans le lait de chèvre se conformaient aux exigences de la CE car il n'y avait pas d'influence de la matrice, les valeurs de Horrat étaient inférieures à 2,0 ; les récupérations étaient dans l'intervalle $1,00 \pm 0,10$ pour les minéraux et dans l'intervalle $1,00 \pm 0,20$ pour les éléments traces et l'incertitude combinée des résultats était inférieure à l'incertitude normalisée maximale, calculée en utilisant la fonction de l'incertitude. En ce qui concerne les limites de détection et de quantification, nos limites calculées pour le plomb étaient inférieures à celles spécifiées par le règlement CE

EVALUATION OF MEASUREMENT UNCERTAINTY FOR THE MOISTURE AND DRY MATTER MASS FRACTION IN INDUSTRIAL RESIDUES AND SLUDGES

Abstract − Moisture mass fraction, wH2O, and dry matter mass fraction, wDM,, are analytical parameters required by environmental European regulations. The metrological quality, namely measurement uncertainty, comply the fitness for purpose and enhances the comparability of analytical results. In this work, the component by component approach for measurement uncertainty estimation of w and wDM is reported and the O H 2 input quantities assessed. The measurement uncertainty of method’s precision, under within-laboratory reproducibility conditions, f(precision)Rw, was the only significant influence-1 quantity when w&gt; 0,10 g g for both ranges. In case of wH2

Behaviour and fate of metals in urban wastewater treatment plants: a review

The concerns on metals in urban wastewater treatment plants (WWTPs) are mainly related to its contents in discharges to environment, namely in the final effluent and in the sludge produced. In the near future, more restrictive limits will be imposed to final effluents, due to the recent guidelines of the European Water Framework Directive (EUWFD). Concerning the sludge, at least seven metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) have been regulated in different countries, four of which were classified by EUWFD as priority substances and two of which were also classified as hazardous substances. Although WWTPs are not designed to remove metals, the study of metals behaviour in these systems is a crucial issue to develop predictive models that can help more effectively the regulation of pre-treatment requirements and contribute to optimize the systems to get more acceptable metal concentrations in its discharges. Relevant data have been published in the literature in recent decades concerning the occurrence/fate/behaviour of metals in WWTPs. However, the information is dispersed and not standardized in terms of parameters for comparing results. This work provides a critical review on this issue through a careful systematization, in tables and graphs, of the results reported in the literature, which allows its comparison and so its analysis, in order to conclude about the state of the art in this field. A summary of the main consensus, divergences and constraints found, as well as some recommendations, is presented as conclusions, aiming to contribute to a more concerted action of future research. © 2015, Islamic Azad University (IAU)

The CONVERTE project: biomass potential for energy

ABSTRACT: Climate change caused by the excessive use of non-renewable resources as a means of supporting the current society demands is forcing the development of circular economy models and social, economic and environmental balanced solutions. In Portugal, in recent decades, important progresses have been made on waste resources management practices in line with the objectives and directives of the European Union. The urban and industrial wastes are, to a certain extent, a case of success since the effort developed has created tools for the prevention, control, recovery and recycling of a considerable percentage of the generated amounts. However, this effort has not yet reached its full potential, and there are still diverse underexplored issues, such as a systematic assessment of the waste biomass suitability for specific energy conversion technologies, and the promotion of non-food-competing energy crops on marginal lands. CONVERTE will identify and quantify the different waste biomass types generated in the Portuguese continental territory, and shall develop a biomass-driven energy matrix that correlates the biomass types with eight technological value chains for heat, power and/or advanced biofuels as main products. This is expected to impact positively on the national energy security and to reduce the overall Portuguese greenhouse gas (GHG) emissions, namely in the transport sector, contributing to increase the country sustainability score.info:eu-repo/semantics/publishedVersio