Metallic trace elements

Top PDF Metallic trace elements:

BioRefine Project: Detection of bioavailability of Metallic Trace Elements in soils by the use of microbial biosensors

BioRefine Project: Detection of bioavailability of Metallic Trace Elements in soils by the use of microbial biosensors

Acknowledgements Methodology of the work Zinc, lead and cadmium are the main Metallic Trace Elements (MTEs) found in soils contaminated by the mining industry in Europe. MTEs are spread in the environment because of the disruption of biogeochemical cycles caused by human activities. Due to their low mobility and biodegradability, they accumulate in soils where they are strongly bound to particles. It has become necessary to understand interactions between MTEs and the environment and to implement remediation actions. This work is focused on remediation monitoring techniques by using whole cell microbial biosensors able to detect zinc, lead and cadmium. Biosensors provide a signal in response to the bio-available concentration in MTEs, which are valuable for the design of efficient techniques involving bioremediation. Whole cell biosensors used in this work are based on Escherichia coli strains carrying a fluorescent reporter system. The reporter element contains a promoter sensitive to MTEs and a gene coding for the Green Fluorescent Protein (GFP). MTEs activate the synthesis of GFP, which is a very stable protein, causing the accumulation of GFP inside the cells. Then, fluorescence can be measured by flow cytometry. In this study, two biosensors were investigated: E. coli pP zraP gfp and E. coli pP zntA gfp. The last strain provided a linear response to zinc up to 20 mg/l and a curvilinear
En savoir plus

1 En savoir plus

Characterization of metallic trace elements in soils by portable X-ray fluorescence spectrometry

Characterization of metallic trace elements in soils by portable X-ray fluorescence spectrometry

Accuracy ● XRF à Interesting tool and easy to use for the prediction of metallic trace elements content in soils at a low cost. à To predict reference values (aqua regia digestion-AAS method) with sufficient accuracy, direct measurements are not suitable and a specific XRF calibration is recommended. A simple linear regression is adequate to improve the accuracy of the measured values in some cases, depending on the wanted future application.

1 En savoir plus

Arsenic and metallic trace elements cycling in the surface water-groundwater-soil continuum down-gradient from a reclaimed mine area: Isotopic imprints

Arsenic and metallic trace elements cycling in the surface water-groundwater-soil continuum down-gradient from a reclaimed mine area: Isotopic imprints

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignemen[r]

16 En savoir plus

Biorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes

Biorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes

Manure – Slurry Sewage sludge Digestate Inventory Digestate Ashes Wastewater Household wastes Industrial wastes Other(s). Inventory based on.[r]

14 En savoir plus

Spatial distribution of metallic trace elements in soils contaminated by atmospheric fallouts. Case study: Sclaigneaux (Belgium)

Spatial distribution of metallic trace elements in soils contaminated by atmospheric fallouts. Case study: Sclaigneaux (Belgium)

Impact of land uses, soil types, wind directions and distance from contaminants source on the MTE content.. Risk assessment for agricultural soil utilisations.3[r]

21 En savoir plus

Trace Elements and Fatty Acid Profile of Argyrosomus regius (Asso, 1801) from Mediterranean Aquaculture

Trace Elements and Fatty Acid Profile of Argyrosomus regius (Asso, 1801) from Mediterranean Aquaculture

Considering the trophic level, the diet, and the spatial dis- tribution of the meager, it is important to mention its potential exposure to the trace elements including mercury (Hg) (not analyzed in this study). Mercury is one of the most persistent metal contaminant [ 47 ]. Due to its high affinity for thiol groups (present in key peptides and proteins), Hg accumula- tion can cause deleterious effect [ 48 ] and ultimate mortality [ 49 ]. The mean Hg concentrations in meager muscle deter- mined by [ 50 , 51 ] correspond to 0.255 mg kg −1 and 0.251 mg kg −1 , respectively. They are above recommended regulatory standards for human health. However, in contrast to previous data that showed high concentrations of Hg in A. regius muscles, a recent study by [ 52 ] revealed that under heat stress, meager would be weakly concentrated in mercury, which would induce a relatively moderate effect of the con- taminant on human health. The fact that meager is a very resilient species that adapts easily to environmental changes [ 53 ] may explain these lower effects following exposure.
En savoir plus

11 En savoir plus

Origin and Accumulation of Trace Elements in Sediments of the Northwestern Mediterranean Margin

Origin and Accumulation of Trace Elements in Sediments of the Northwestern Mediterranean Margin

3.5. Trace element composition of the cores (Ag, Cd, Co, Cr, Mn, Ni, V, Zn) Summary statistics are given in Table S5. Concentrations of these TEs in CdC Canyon sediments were in the range of continental crust concentrations (Table 4). The distributions of V, Ni, Cr, Cd, and Zn were strongly linked to those of Li and Al, with highly significant correlation coefficients between these five elements ranging from 0.70 to 0.97 (p<0.001) (Table S2). Vanadium, Cr, Zn and Pb displayed Li or Al-like vertical profiles (Figs. 3 and S1c) suggesting their association with clay minerals. In addition, TEs mean concentrations were systematically lower (p<0.001, T-test) in cores I and L than in core G and H (Table S5), with the notable exception of Ag, which exhibited the largest and lowest concentrations for core I and L respectively (Fig. 3). Manganese distribution in the 4 cores showed background concentrations between 550 and 700 µg g -1 , and large amplitude maxima at various depths depending on the core (Fig. S2), a characteristic feature of Mn oxihydroxides authigenic formation. The presence of multiple Mn peaks in cores G, H and L suggests a temporal variation in the oxygen penetration, which could have resulted from pulses in C org sedimentation.
En savoir plus

42 En savoir plus

The use of stable isotopes and trace elements as ecological tracers in atlantic leatherback turtles

The use of stable isotopes and trace elements as ecological tracers in atlantic leatherback turtles

Coupling isotopic and trace element analysis have first highlighted low δ 15 N values and low trace element concentrations reflecting the low trophic level of leatherback and a weak exposure to pollutants. Then, using isotopic ratios and Cd data to make inferences about the feeding ecology of leatherback females have been useful in determiningdifferences in feeding grounds.

1 En savoir plus

Analysis of trace elements in liquids using LIBS combined with Laser-Induced Fluorescence

Analysis of trace elements in liquids using LIBS combined with Laser-Induced Fluorescence

Analysis of liquids by existing analytical techniques is well established, and does not call for the laborious preparatory steps often needed for solids. However, the reliable on-line analysis of liquids required to meet demands for improved control of industrial processes that are often difficult to achieve by conventional techniques. LIBS has been proposed for monitor- ing various elements in liquids, during industrial processing, as an alterna- tive to sampling for subsequent laboratory analysis. In this work, the combination of the Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Induced Fluorescence (LIF) techniques was investigated to improve the limit of detection (LoD) of trace elements (iron, lead and gold) in liquid in order to meet industrial and environmental requirements. The plasma was produced by a 266 nm frequency-quadrupled Q-switched Nd:YAG laser and then re-excited by a nanosecond Optical Parametric Oscillator (OPO) laser. To improve the reproducibility of the measurements, we built and used a cell that enables the laser to sample a fresh surface while preventing problems associated with the laser liquid interaction such as splashing, aerosols, bubbles etc. The influence of the main experimental parameters on the LIF signal, namely the ablation fluence, the excitation energy, and the inter-pulse delay, was studied. We will also discuss about the importance of the selected excitation-fluorescence scheme. Using the LIBS-LIFS tech- nique, we demonstrated LoDs for Fe and Pb of a few tens of ppb after accumulating over 100 laser shots while its value was about a few hundreds of ppb for Au. These values represent an improvement of about two orders of magnitude with respect to LIBS.
En savoir plus

3 En savoir plus

Marine sponges as a powerful tool for trace elements biomonitoring studies in coastal environment

Marine sponges as a powerful tool for trace elements biomonitoring studies in coastal environment

1. Introduction The occurrence of trace elements (TEs) in aquatic environments is related to natural sources, but also to anthropogenic inputs from in- dustrial activities. TE contaminations in the marine environment occur worldwide and the assessment of the pollution status is required, leading to the publication of several studies on this subject ( Li et al., 2000 ; Caccia et al., 2003 ; Fang et al., 2014 ; Parra et al., 2015 ; Cabrita et al., 2017 ; Ashraf et al., 2017 ). Environmental surveys are often performed on water samples but, in marine ecosystems, the very low TEs concentrations and the high salinity of seawater cause severe lim- itations in the measurements ( Søndergaard et al., 2015 ). Monitoring studies on TEs contamination are often focused on sediments and biota. Indeed, sediments act as sink and reservoirs of contaminants thus dis- playing higher TEs contents and not presenting problems related to short residence time such as for water ( Varol, 2011 ; Liu et al., 2015 ). Marine organisms find also application as tools for characterizing the state of a marine ecosystem as some of them are recognized to accu- mulate TEs. They represent a good alternative especially in rocky shores where sediments are not easily found. Sessile and active filter feeding invertebrates are often used to determine temporal and spatial variation of TE in aquatic systems ( Weis and Weis, 1999 ; Denton et al., 2006 ;
En savoir plus

14 En savoir plus

Effect Of Soil Moisture On Trace Elements Concentrations Using Portable X-ray Fluorescence Spectrometer

Effect Of Soil Moisture On Trace Elements Concentrations Using Portable X-ray Fluorescence Spectrometer

For determining trace elements concentration in situ, the samples were scanned with PXRF under field moisture conditions. For laboratory analyses, all scannings were performed with PXRF on pressed pellets (Ø: 3cm). A portable Bruker S1 Titan 600 with calibration range of 37 elements, including light elements Mg, Al and Si was used for determining trace elements concentrations in soil samples. The analyser is characterized by fast SDD ® detector and Shield TM detector protecting the sensor window from being punctured by sharp objects under analysis. The analyser was equipped with X-ray tube Rh target operating at a maximum of 50 kV and five position motorized filter changer.
En savoir plus

17 En savoir plus

Effects of Posidonia oceanica (L.) Delile (1813) Flowering on elemental components and on trace elements concentrations

Effects of Posidonia oceanica (L.) Delile (1813) Flowering on elemental components and on trace elements concentrations

Effects of Posidonia oceanica (L.) Delile (1813) Flowering on elemental components and on trace elements.. concentrations.[r]

1 En savoir plus

Assessment of Mytilus galloprovincialis to monitor 19 trace elements in the Calvi Bay

Assessment of Mytilus galloprovincialis to monitor 19 trace elements in the Calvi Bay

showing little spatial variations either at 100m or 1km scales. Filter feeders are only influenced by their relatively homogeneous pelagic environment (dissolved trace elements and suspended particulate matters), in contrast to organisms which inhabit typically heterogeneous benthic habitats. This bioindicator, a convincing candidate for the monitoring of the 12 little studied trace elements, effectively accumulates the 19 studied elements to 10 5 seawater concentrations. Mytilus galloprovincialis rapidly equilibrates (within days) with its environment, and is therefore a good indicator of chronic and stable chemical pollutions. Tissue speciation shows that the most relevant organ to monitor trace elements is the hepatopancreas. However, the important variability induced by the reproductive cycle of mussels requires using this bioindicator during its sexual dormancy.
En savoir plus

1 En savoir plus

Changes in trace elements during lactation in a marine top predator, the grey seal

Changes in trace elements during lactation in a marine top predator, the grey seal

During lactation, adult females fast and depend entirely on their body fat, mainly from the blubber, to maintain their metabolism and to produce milk. Concentrations of all elements in the maternal blubber increased throughout lactation with the reduction of blub- ber thickness ( Table 5 ), suggesting a less efficient mobilization of elements from blubber than triglycerides, the dominant lipid type ( Henderson et al., 1994 ). However, elements potentially associated to lipid reserves seem to be not mobilized all in the same way. At the beginning of lactation, elements were distributed homoge- neously across the full depth of the blubber layer (no difference between inner and outer layers). During lactation, concentrations of Ca, Fe, Zn, and Cu increased more in the inner blubber and became significantly greater in inner than in outer blubber in late lacta- tion ( Table 6 ). In contrast, concentrations of V, Cr, Ni, and Pb also increased during lactation but remained similar between inner and outer blubber. Fatty acids are mainly mobilized from the inner blub- ber layer during this period, while the outer part remains more stable ( Strandberg et al., 2008 ). Indeed, for the grey seals of the present study, inner blubber lost 18% of its lipid content, while outer blubber lost 9% during lactation (analyses in Vanden Berghe et al., 2012 ). It seems that V, Cr, Ni, and Pb would be less retained into the inner blubber than Ca, Fe, Zn, and Cu. Moreover, significant rela- tionships between V, Cr, Ni, and Pb levels were observed both in blubber and milk suggesting that these 4 elements were mobilized through similar dynamics from the blubber to the milk.
En savoir plus

12 En savoir plus

Trace elements deficiencies in the pathogenesis of respiratory distress syndrome in the mature newborn calf

Trace elements deficiencies in the pathogenesis of respiratory distress syndrome in the mature newborn calf

Introduction In Belgium, respiratory distress syndrome (RDS) is one of the leading causes of neonatal death in mature hypermuscled Belgian Blue calf (BB) but also in other cattle breeds (1). Major clinical signs (tachypnea, tachycardia and sometimes depression) develop in the first hours after birth and are due to insufficiency of functional surfactant (2). Males are more susceptible to RDS because of the inhibitor effect of testosterone on surfactant production (3). Necropsy findings reveal atelectasia, congestion, interstitial edema and emphysema. Often, intestinal lesions are also observed (1). Knowing that trace elements deficiencies can slow pulmonary maturation, the aim of this study was to investigate trace elements status in RDS affected herds in comparison with reference herds without any evidence of RDS.
En savoir plus

1 En savoir plus

Trace elements behaviour in direct- and indirect-iron metallurgy : the case of Pays de Bray (France)

Trace elements behaviour in direct- and indirect-iron metallurgy : the case of Pays de Bray (France)

KEYWORDS: trace elements, bloomery process, indirect process, slag inclusions, provenance INTRODUCTION Major and trace element analysis of non metallic inclusions in iron archaeological objects are for about 10 years the topic of numerous studies dedicated to the distinguishing of ironmaking processes [1] but also to the determining of the artefact provenance [2-9]. These latter studies mainly focus on the link between objects and ores or archaeological sites. However, to our knowledge, despite of the fact that the behaviour of major elements initially present in the ores is relatively well known, none of published studies describes in detail the one from ore to the final artefact of the trace elements in the two ironmaking chains. Yet, the comprehension of trace element behaviour is crucial before any provenance studies. Indeed, it will be shown in the following that, for different reasons, some elements could not be chosen for determining a chemical signature.
En savoir plus

20 En savoir plus

Trace Elements in Marine Environments : Occurrence, Threats and Monitoring with Special Focus on the Costal Mediterranean

Trace Elements in Marine Environments : Occurrence, Threats and Monitoring with Special Focus on the Costal Mediterranean

Mytilus spp. as bioindicator species Quality indicators: It is the unique combination of biomonitoring features Mytilus spp. exhibit that make them particularly well suited as indicator species [101,168]. They have a broad geographical distribution, ranging from temperate to subarctic regions, and colonize, as euryhalin, estuarine to fully marine waters. Because they are keystone species, it is likely that a pollutant that affects a mussel population will also exhibit a negative impact for the entire ecosystem. As long- living sessile organisms they can integrate the contaminations of their environment over long time periods. Mussels are relatively large, easy to handle, and can be used under laboratory and field conditions. They accumulate chemicals both from their diet (via the gastro-intestinal tract) and from the ambient water (via the tissue membranes in contact with water), exhibit only a limited ability to eliminate pollutants and reach higher bioaccumulation factors than other systematic groupings for many toxicants. Consequently, pollutants might exhibit negative Figure 3: Trace element (TE) cycling between the different components of a P.
En savoir plus

19 En savoir plus

Trace elements and organochlorines in sperm whales stranded on the coast of Schleswig Holstein in 2016

Trace elements and organochlorines in sperm whales stranded on the coast of Schleswig Holstein in 2016

3 Laboratory of Animal Ecology and Ecotoxicology, CART, University of Liège, B6C, 4000, Liège, Belgium. Several strandings of sperm whales occurred in the North Sea during January and February 2016. Twelve animals were necropsied and sampled after their discovery on German coasts of Schleswig Holstein. Muscle, liver, kidney and blubber samples were taken from all specimens for toxicological analyses. The concentrations of lipophilic organic pollutants such as polychlorinated biphenyl (PCB) and pesticides such as DDT were determined in adipose tissue. Metals and trace elements such as cadmium, selenium and mercury were measured in the liver, kidney and muscle. Polychlorinated biphenyls (PCBs) and pesticides such as DDTs were determined in adipose tissue at levels of 0.9 and 1.3 mg.kg -1 lipid weight respectively. Cadmium,
En savoir plus

1 En savoir plus

How are trace elements managed in the cells of Chaoborus larvae to avoid ill-effects?

How are trace elements managed in the cells of Chaoborus larvae to avoid ill-effects?

INTRODUCTION a Institut National de la Recherche Scientifique, Center Eau Terre Environnement (INRS-ETE), Université de Québec, 490 de la Couronne, Québec City, QC, Canada G1K 9A9 b CNRS/UPPA, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, UMR 5254, Hélioparc, 2. Av. Pr. Angot, Pau, 64 053, France How are trace elements managed in the cells of Chaoborus larvae to avoid ill-effects?

1 En savoir plus

"Speciation" of three Trace Elements Mercury, Lead, Cadmium in Sediments of the Lebanese Coastal Zones

"Speciation" of three Trace Elements Mercury, Lead, Cadmium in Sediments of the Lebanese Coastal Zones

Même les mesures du 137 Cs, n‘ont pas pu situer historiquement les couches sédimentaires à cause de l‘absence des quantités détectables de cet isotope radioactif. Les analyses minéralogiques montrent que 40-45% des sédiments d‘Akkar sont constitués de dolomite et d‘ankérite, 20-25% de calcite et 10-20% de quartz. Alors que les sédiments de Dora ont montré une forte abondance de quartz (70-80%) avec une présence marquée de calcite (10-20%). Quant aux caractéristiques minéralogiques des sédiments de Selaata riches en fluorine 25-55% (produit originaire du phosphate tricalcique utilisé comme matière primaire dans l‘usine des engrais chimiques avoisinante) et en quartz 25-55% et où la présence de fluoroapatite a été également démontrée, elles sont architypiques de l‘impact des rejets de l‘usine de phosphogypse. La représentation schématique globale par ACP de l‘ensemble des données correspondant aux éléments majeurs et trace des sédiments des trois sites Akkar, Dora et Selaata a permis de classifier les sédiments en trois groupes sédimentaires selon leur origine géographique mettant en évidence la spécificité chimique de chaque site; Akkar riche en Ca, Mg et Corg, Dora riche en Si et en ETM et Selaata S6 riche en Cd, Ni et Mn. Notons aussi que la projection des sédiments dans un diagramme ternaire ayant comme sommets les pourcentages en masse en CaCO 3 +MgCO 3 , SiO 2 et Al 2 O 3 +Fe 2 O 3 a permis
En savoir plus

314 En savoir plus

Show all 1426 documents...