Radiochemical study of the sorption of trace elements. VII. Adsorption of yttrium on polyethylene and the effect of low concentrations of iron

1971 ◽  
Vol 36 (5) ◽  
pp. 1913-1922 ◽  
Author(s):  
P. Beneš ◽  
J. Kučera
Keyword(s):  
Trace Elements ◽  
Low Concentrations ◽  
Radiochemical Study

Distribution of metallic trace elements (ETM) in surface soils around the Mediouna discharge (southern of Casablanca)

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Samples ◽  
The Other ◽  
Surface Soils ◽  
Other Hand ◽  
Metallic Trace Elements ◽  
Low Concentrations ◽  
Uncontrolled Landfill

The objective of present research was to characterize the surface soils located at 300, 600 and 1000 m of an uncontrolled landfill. The work also aims to evaluate the levels and spatial distribution of metallic trace elements (Cd, Pb, Cu, Ni, Zn, Cr, Co and As) in these soils. Soil samples were collected in 36 points around the landfill. Results showed that Cd, Pb, Zn are concentrated in the soils rich in clay and carbonates, and in organic matter, located at 300 m from the landfill. The basic pH of all soils enhances the retention of these metals. On the other hand, As present in soils at 300, 600 and 1000 m at concentrations slightly higher than those of referenced soils were apparently mobilized by water from the solid/water interfaces. The other metals Cu, Ni, Co, Cr are present at very low concentrations.

Controls on the trace element composition of crustal melts

1996 ◽  
Vol 87 (1-2) ◽  
pp. 33-41 ◽  
Author(s):  
F. Bea
Keyword(s):  
Trace Elements ◽  
Trace Element ◽  
Trace Element Composition ◽  
Element Composition ◽  
A Value ◽  
Low Concentrations ◽  
Mode Of Occurrence ◽  
Trace Constituents ◽  
Solution Kinetics ◽  
Significant Mass

ABSTRACT:The behaviour of trace elements during partial melting depends primarily on their mode of occurrence. For elements occurring as trace constituents of major phases (e.g. Li, Rb, Cs, Eu, Sr, Ba, Ga, etc.), slow intracrystalline diffusion (D ≍ 10−16 cm2 s−1) at the temperature range of crustal anatexis causes all effective crystal-melt partition coefficients to have a value close to unity and impedes further melt-restite re-equilibration. Usually, therefore, the trace element composition of crustal melts simply depends on the mass balance between the proportion and composition of phases that melt and the proportion and composition of newly formed phases. The behaviour of trace elements occurring as essential structural components in accessory phases (e.g. P, La-Sm, Gd-Lu, Y, Th, U, Zr, Hf, etc.) depends on the solubility, solution kinetics, grain size and the textural position of accessory phases. In common crustal protoliths a significant mass fraction of monazite, zircon, xenotime, Th-orthosilicates, uraninite; etc.—but not apatite—is included within other major and accessory phases. During low melt fraction anatexis the amount of accessory phases available for the melt is not sufficient for saturation, thus producing leucosomes with concentrations of La-Sm, Gd-Lu, Y, Th, U and Zr lower than expected from solubility equations. Low concentrations of these elements may also occur if the melt is prevented from reaching equilibrium with the accessories due to fast segregation. However, the first mechanism seems more feasible as leucosomes that are undersaturated with respect to monazite and zircon are frequently saturated, even oversaturated, with respect to apatite.

Sign in / Sign up

Export Citation Format

Share Document