Multiple stressors in an estuarine system: Effects of nutrients, trace elements, and trophic complexity on benthic photosynthesis and respiration

Estuaries ◽  
2002 ◽  
Vol 25 (1) ◽  
pp. 57-69 ◽  
Author(s):  
Andrew E. Laursen ◽  
Sybil P. Seitzinger ◽  
Robert Dekorsey ◽  
James G. Sanders ◽  
Denise L. Breitburg ◽  
...  
Keyword(s):  
Trace Elements ◽  
Multiple Stressors ◽  
Estuarine System ◽  
Photosynthesis And Respiration

The effects of multiple stressors on the balance between autotrophic and heterotrophic processes in an estuarine system

Estuaries ◽  
2003 ◽  
Vol 26 (2) ◽  
pp. 352-364 ◽  
Author(s):  
Tracy N. Wiegner ◽  
Sybil P. Seitzinger ◽  
Denise L. Breitburg ◽  
James G. Sanders
Keyword(s):  
Multiple Stressors ◽  
Estuarine System

scholarly journals Influence of the “Great Acceleration” of the Anthropocene on the fluxes of trace elements in sediments of the Santos and São Vicente estuarine system, southeastern Brazil

2021 ◽  
Author(s):  
José Lourenço Friedmann Angeli ◽  
Julie Sartoretto ◽  
Bianca Kim ◽  
Paulo Ferreira ◽  
Michel Mahiques ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Trace Elements ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Enrichment Factors ◽  
Southeastern Brazil ◽  
Adjacent Area ◽  
Estuarine System ◽  
Shelf Sediment ◽  
Great Acceleration

Abstract The worldwide evidence of human activities on the environment led the scientific community to recognize a new geologic time unit known as the Anthropocene. Since the twentieth century, the estuaries have been largely impacted by urbanization and industrialization needs driven by population and economic growth. To assess the contamination, provenance, and fluxes of trace elements (As, Cr, Cu, Ni, Pb, Sc, V and Zn) over the last century, a geochemical and chemometric technique was employed in sediment cores of the Santos and São Vicente Estuarine System (SSVES), an industrial and port region of international importance. The results indicated low contamination, with the highest enrichment factors (EF) for Cu (EF = 3.1), Pb (EF = 2.7), Zn (EF = 2.4) and As (EF = 2.3) found next to the harbor area. The Pre-industrial records confirm the relatively high concentrations of As and its naturally enriched occurrence on the Brazilian shelf. Sediment accumulation rates and trace element fluxes showed a general increase over the years, since the early 1960s, associated with the “Great Acceleration” of the mid-twentieth century. These alterations are human-induced and include urbanization and industrialization. Nonetheless, as the contents and enrichment of trace elements indicate that the region is not severely polluted, we hypothesize that the contamination in the SSVES is likely related to the drainage and erosion of the urbanized adjacent area, rather than direct disposal of inorganic contaminants from the industrial activity.

scholarly journals Distribution, Mobility and Fate of Trace Elements in an Estuarine System Under Anthropogenic Pressure: the Case of the Karstic Timavo River (Northern Adriatic Sea, Italy)

2021 ◽  
Author(s):  
Elena Pavoni ◽  
Matteo Crosera ◽  
Elisa Petranich ◽  
Jadran Faganeli ◽  
Katja Klun ◽  
...  
Keyword(s):  
Trace Elements ◽  
Surface Sediments ◽  
Suspended Particles ◽  
Critical Conditions ◽  
Residual Fraction ◽  
Secondary Source ◽  
Estuarine System ◽  
Anthropogenic Pressure ◽  
Water Interface ◽  
Northern Adriatic

AbstractThe accumulation of contaminants and their potential mobility represent two of the main environmental issues facing coastal environments. Sediments often act as “reservoirs” of contaminants, including potentially toxic trace elements, but they can also be considered a secondary source of contamination due to remobilisation processes at the sediment-water interface which may affect the quality of the coastal water and aquatic biota. This research aims to provide a geochemical characterisation of the estuarine system of the Timavo/Reka River, focusing on the occurrence of trace elements in different environmental matrices with the purpose of highlighting potential critical conditions in terms of environmental quality. The surface sediments were found to be enriched in several trace elements especially in the innermost sector of the area. There, sulphate-reductive conditions in the bottom saltwater testify to potential anoxia at the sediment-water interface, driving trace element accumulation in the residual fraction of the sediments. However, Fe and Mn redox behaviour appears to play a crucial role in the recycling of dissolved trace elements in the water column. With the lone exception of the saltwater in the innermost sector, trace elements were found to be mainly associated with suspended particles due to oxidation and precipitation processes, whereas a common lithogenic origin was identified for Cr, Ni, and Co, which are significantly correlated both in the surface sediments and in the suspended particles.

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.

Trace Elements and Iron in Human Metabolism

1979 ◽  
Vol 7 (6) ◽  
pp. 1330-1331
Author(s):  
E. D. WILLS
Keyword(s):  
Trace Elements ◽  
Human Metabolism

Meat and Meat Products Consumption in Italy: Contribution to Trace Elements, Heme Iron and selected B Vitamins supply

2004 ◽  
Vol 74 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Lombardi-Boccia ◽  
Lanzi ◽  
Lucarini ◽  
Di Lullo
Keyword(s):  
Trace Elements ◽  
Daily Intake ◽  
Meat Products ◽  
Heme Iron ◽  
B Vitamins ◽  
Zinc Intake ◽  
Consumption Frequency ◽  
Iron And Zinc ◽  
Iron Heme ◽  
Daily Intakes

This study was undertaken to estimate the contribution of meat and meat products consumption to the daily intakes of trace elements (Fe, Zn, Cu, Se), heme iron, and selected B vitamins (thiamine, riboflavin, niacin) in Italy. Meat and meat products were selected on the basis of their consumption frequency reported by the most recent nationwide dietary individual survey carried out in Italy (INN-CA study). The daily intakes of total iron and heme iron were 1.65 and 1.13 mg/person/day. Zinc intake was 3.65 mg/person/day. Beef made the main contribution to iron, heme iron, and zinc daily intakes. Copper daily intake was 107.3 mug/person/day, with meat products provided the highest contribution (40 mug/person/day). Daily intake of selenium (7.14 mug/person/day) was provided mainly by poultry consumption. Thiamine intake was 228 mug/person/day, and meat products were the main source (110 mug/person/day). Riboflavin intake was 136 mug/person/day, with both beef and meat products as the main contributors (40 mug/person/day). Niacin intake was 7.53 mg/person/day, and poultry was the main source (2.28 mg/person/day). Meat and meat products were a valuable source of micronutrients, supplying 47, 48, and 24% of zinc, niacin, and thiamin daily requirements, respectively, and over 10% of iron, copper, selenium, and riboflavin daily average requirement values of the italian RDAs calculated for the population involved in the survey (INN-CA study).

Pre-concentration of selected trace elements from seawater by co-precipitation on Mg(OH)2

2003 ◽  
Vol 107 ◽  
pp. 945-948 ◽  
Author(s):  
P. M. Nicolaysen ◽  
E. Steinnes ◽  
T. E. Sjobakk
Keyword(s):  
Trace Elements ◽  
Co Precipitation
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