Historical eutrophication and pollution records off Bandar Abbas coast (North of Strait of Hormuz) using benthic foraminiferal ecology and geochemistry of trace elements from a sediment core

2021 ◽  
pp. 101929
Author(s):  
Mohammad Ali Hamzeh ◽  
Emad Koochaknejad ◽  
Samad Hamzei
Keyword(s):  
Trace Elements ◽  
Sediment Core ◽  
Strait Of Hormuz ◽  
Bandar Abbas

Contamination assessment and prediction of 27 trace elements in sediment core from an urban lake associated with land use

2019 ◽  
Vol 191 (4) ◽  
Author(s):  
Luciane Maria Vieira ◽  
Daniel Macedo Neto ◽  
Edivando Vitor do Couto ◽  
Guilherme Bertuzzo Lima ◽  
Ana Paula Peron ◽  
...  
Keyword(s):  
Land Use ◽  
Trace Elements ◽  
Sediment Core ◽  
Urban Lake ◽  
Contamination Assessment

Temporal variation of trace elements, rare earth elements and Pb isotope ratios in sediment core from Kiel Bay, western Baltic Sea

2020 ◽  
Vol 17 (8) ◽  
pp. 579
Author(s):  
Anna Maria Orani ◽  
Emilia Vassileva ◽  
Sabine Schmidt ◽  
Sylvain Berail ◽  
Julien P. G. Barre
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Baltic Sea ◽  
Sediment Core ◽  
Sediment Cores ◽  
Isotope Ratios ◽  
Anthropogenic Contamination ◽  
Historical Sources ◽  
Coal Burning

Environmental contextTrace elements in coastal environments represent an environmental concern and their monitoring in sediment cores provides insight into their historical sources. A well-dated core from Kiel Bay, western Baltic Sea, provided trace element data, including lead, cadmium, rare earth elements, mercury and methyl mercury. Lead and mercury isotope ratios were useful for the apportionment of pollution sources, indicating that coal burning was a major contributor. AbstractWe present a comprehensive study on the variation of trace elements (TEs) and rare earth elements (REEs) in a well-dated sediment core from Kiel Bay, western Baltic Sea. Mass fractions of 34 elements (major and trace) together with other relevant parameters, such as organic carbon and grain size, were determined in a 20-cm core that covers the last century. Enrichment factors and geoaccumulation indices were determined to assess the possible influence of anthropogenic inputs on element distribution. The obtained results show that the highest enrichment of TEs occurred in the period 1917–1970 especially for the priority elements as Hg, Cd and Pb. Determination of methylmercury (MeHg) was also performed, as it showed the highest content in surface samples. The MeHg percentages ranged from 0.02 to 1.2% of the total Hg. REEs, which are nowadays considered as new emerging contaminants, did not reveal high enrichment attributable to anthropogenic influences, but provided useful baseline information for future monitoring of the area. The study of the Pb isotopic composition proved to be a valuable tool in determining the Pb pollution source, and revealed Pb in the layers that showed the highest enrichment came mainly from coal burning. Mercury isotopic signatures in the sediment core were used as a tool to identify the sources of Hg pollution. An isotope mixing model based on mass-dependent (MDF) and mass-independent fractionations (MIF) identified coal burning as the most probable dominant source for Hg anthropogenic contamination in the area.

Depth Profile Of Trace Elements In a Sediment Core Of a High-Altitude Lake Deposit At The Pyrenees, Spain

2006 ◽  
Vol 172 (1-4) ◽  
pp. 273-293 ◽  
Author(s):  
Isela Lavilla ◽  
A. V. Filgueiras ◽  
F. Valverde ◽  
J. Millos ◽  
A. Palanca ◽  
...  
Keyword(s):  
Trace Elements ◽  
High Altitude ◽  
Sediment Core ◽  
Depth Profile ◽  
High Altitude Lake

Postglacial sedimentation in the White Sea (northwestern Russia) reconstructed by integrated microfossil and geochemical data

2019 ◽  
Vol 93 ◽  
pp. 110-123 ◽  
Author(s):  
Dmitry F. Budko ◽  
Liudmila L. Demina ◽  
Ekaterina A. Novichkova ◽  
Yelena I. Polyakova ◽  
Marina D. Kravchishina ◽  
...  
Keyword(s):  
Trace Elements ◽  
Sediment Core ◽  
Barents Sea ◽  
White Sea ◽  
Metal Speciation ◽  
Active Phase ◽  
The Arctic ◽  
Geochemical Data ◽  
The White Sea ◽  
Biogenic Components

AbstractThe White Sea being connected with the Arctic Ocean via the Barents Sea has an influence on its water temperature/salinity structures and biological processes and thus has an indirect impact on the Eurasian climate system. In this work, we have managed to find a correspondence between the climate fluctuation in the Holocene and changes in the geochemical and microfossil properties in the sediment core of the White Sea. For the first time, the element speciation in the sediment core covering about 10,000 cal yr BP period was investigated. The cooling periods (the early Holocene and the Subboreal stage) were characterized by a trend of increase in Si, Al, and Ti contents and Ti/Al ratios, which reflect lithogenous contribution, and decrease in geochemically labile forms of trace elements. A significant increase in the content of organic-bound trace elements and biogenic components (Сorg, BSi, and chlorin) was observed during periods of Holocene climatic optimums. The evident relationship between the metal speciation and indicators of the sedimentation paleoenvironment is observed at the stage of the active phase of early diagenesis after the slowing down of the biogeochemical processes. Down-core decrease in the Mn oxyhydroxide content exhibited a weakening of diagenesis processes at the ~130–150 cm depth.

Microanalytical Identification of a New Zr-Nb-Fe Phase

1990 ◽  
Vol 48 (2) ◽  
pp. 132-133
Author(s):  
O.T. Woo ◽  
G.J.C. Carpenter
Keyword(s):  
Trace Elements ◽  
Cold Rolling ◽  
Proportionality Factor ◽  
Tube Material ◽  
X Ray ◽  
Metal Foils ◽  
Arc Melting ◽  
Intermetallic Particles ◽  
Intermetallic Precipitates ◽  
Cold Worked

To study the influence of trace elements on the corrosion and hydrogen ingress in Zr-2.5 Nb pressure tube material, buttons of this alloy containing up to 0.83 at% Fe were made by arc-melting. The buttons were then annealed at 973 K for three days, furnace cooled, followed by ≈80% cold-rolling. The microstructure of cold-worked Zr-2.5 at% Nb-0.83 at% Fe (Fig. 1) contained both β-Zr and intermetallic precipitates in the α-Zr grains. The particles were 0.1 to 0.7 μm in size, with shapes ranging from spherical to ellipsoidal and often contained faults. β-Zr appeared either roughly spherical or as irregular elongated patches, often extending to several micrometres.The composition of the intermetallic particles seen in Fig. 1 was determined using Van Cappellen’s extrapolation technique for energy dispersive X-ray analysis of thin metal foils. The method was employed to avoid corrections for absorption and fluorescence via the Cliff-Lorimer equation: CA/CB = kAB · IA/IB, where CA and CB are the concentrations by weight of the elements A and B, and IA and IB are the X-ray intensities; kAB is a proportionality factor.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

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