The nature of soil particles particularly those reacting with arsenate in a series of chemically treated samples

Soil Research ◽  
1983 ◽  
Vol 21 (4) ◽  
pp. 455 ◽  
Author(s):  
AW Fordham ◽  
K Norrish
Keyword(s):  
Iron Oxides ◽  
Ammonium Oxalate ◽  
Titanium Oxides ◽  
Iron Oxide Particles ◽  
Chemical Treatments ◽  
Organic Complexes ◽  
Oxide Particles ◽  
Soil Components ◽  
Diffraction Patterns ◽  
High Degree

Arsenate uptake by a surface sample of a lateritic podzol was controlled mainly by iron oxide particles in a very finely divided state of about 50 A in diameter. Despite their size, these particles had some crystalline characteristics - they had semi-regular appearance; had limited solubility in ammonium oxalate (in darkness) and in sodium pyrophosphate; and sometimes gave ring-type electron diffraction patterns identifiable as goethite. The particles contained a high degree of substitution of aluminium for iron. They associated with other soil components, for example, forming surface deposits upon larger kaolin flakes or else microaggregates with smaller ones. They reacted with soil organic matter, which caused marked inhibition of arsenate uptake. Titanium oxides competed with iron oxides for arsenate, and were able to dominate uptake when iron oxides were removed chemically. The behaviour of other components towards arsenate was described, together with their appearance, composition and stability during a series of successive chemical treatments. No iron-organic complexes nor poorly crystalline aluminosilicates appeared to be present. Some reputedly selective reagents extracted excess aluminium, most of it coming from chloritized vermiculite. Small kaolin particles were also dissolved and, in some cases,. this caused fresh precipitation of iron oxides from iron previously held within the clay lattice.

scholarly journals INVESTIGATION OF SURFACES OF NOVEL IRON OXIDES WITH GRAIN AND GRAIN BOUNDARY

2018 ◽  
Vol 56 (1A) ◽  
pp. 226
Author(s):  
Nguyet Viet Long
Keyword(s):  
Heat Treatment ◽  
Iron Oxide ◽  
Grain Boundary ◽  
Iron Oxides ◽  
Particle System ◽  
Oxide Particle ◽  
Oxide System ◽  
Iron Oxide Particle ◽  
Iron Oxide Particles ◽  
Oxide Particles

Hierarchical nano/microscale α-Fe2O3 iron oxide particle system was prepared by an improved and modified polyol method with the use of NaBH4 agent with high heat treatment at 900 °C in air. Here, α-Fe2O3 iron oxide particles with different shapes were analyzed. The morphologies of the surfaces of α-Fe2O3 iron oxide particles show the oxide structures with the different nano/microscale ranges of grain sizes. In this research, we have found that grain and grain boundary growth limits can be determined in α-Fe2O3 iron oxide structure. This leads to the possibility of producing new iron oxide structures with distribution of desirable size grain and grain boundary. With α-Fe2O3 structure obtained, the magnetic properties of the α-Fe2O3 iron oxide system are different from those of previously reported studies. in national and international studies.Keywords: Iron iron oxides, α-Fe2O3, chemical polyol methods, heat treatment.

scholarly journals Accelerated dissolution of iron oxides in ice

2012 ◽  
Vol 12 (8) ◽  
pp. 20113-20134 ◽  
Author(s):  
D. Jeong ◽  
K. Kim ◽  
W. Choi
Keyword(s):  
Iron Oxide ◽  
Grain Boundary ◽  
Iron Oxides ◽  
Boundary Region ◽  
Dust Particles ◽  
Iron Oxide Particles ◽  
Iron Dissolution ◽  
Dissolved Iron ◽  
Enhanced Dissolution ◽  
Oxide Particles

Abstract. Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a~new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4), the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the type of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid-like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 °C to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

scholarly journals Accelerated dissolution of iron oxides in ice

2012 ◽  
Vol 12 (22) ◽  
pp. 11125-11133 ◽  
Author(s):  
D. Jeong ◽  
K. Kim ◽  
W. Choi
Keyword(s):  
Iron Oxide ◽  
Grain Boundary ◽  
Surface Area ◽  
Iron Oxides ◽  
Boundary Region ◽  
Iron Oxide Particles ◽  
Iron Dissolution ◽  
Dissolved Iron ◽  
Enhanced Dissolution ◽  
Oxide Particles

Abstract. Iron dissolution from mineral dusts and soil particles is vital as a source of bioavailable iron in various environmental media. In this work, the dissolution of iron oxide particles trapped in ice was investigated as a new pathway of iron supply. The dissolution experiments were carried out in the absence and presence of various organic complexing ligands under dark condition. In acidic pH conditions (pH 2, 3, and 4), the dissolution of iron oxides was greatly enhanced in the ice phase compared to that in water. The dissolved iron was mainly in the ferric form, which indicates that the dissolution is not a reductive process. The extent of dissolved iron was greatly affected by the kind of organic complexing ligands and the surface area of iron oxides. The iron dissolution was most pronounced with high surface area iron oxides and in the presence of strong iron binding ligands. The enhanced dissolution of iron oxides in ice is mainly ascribed to the "freeze concentration effect", which concentrates iron oxide particles, organic ligands, and protons in the liquid like ice grain boundary region and accelerates the dissolution of iron oxides. The ice-enhanced dissolution effect gradually decreased when decreasing the freezing temperature from −10 to −196 °C, which implies that the presence and formation of the liquid-like ice grain boundary region play a critical role. The proposed phenomenon of enhanced dissolution of iron oxides in ice may provide a new pathway of bioavailable iron production. The frozen atmospheric ice with iron-containing dust particles in the upper atmosphere thaws upon descending and may provide bioavailable iron upon deposition onto the ocean surface.

scholarly journals Aqueous one-pot synthesis of well-defined zwitterionic diblock copolymers by RAFT polymerization: an efficient and environmentally-friendly route to a useful dispersant for aqueous pigments

2021 ◽  
Vol 23 (3) ◽  
pp. 1248-1258
Author(s):  
Shannon M. North ◽  
Steven P. Armes
Keyword(s):  
Iron Oxide ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Environmentally Friendly ◽  
Iron Oxide Particles ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Effective ◽  
Oxide Particles

An atom-efficient, wholly aqueous one-pot synthesis of zwitterionic diblock copolymers has been devised. Such copolymers can serve as highly effective aqueous dispersants for nano-sized transparent yellow iron oxide particles.

scholarly journals Imaging of the Vulnerable Carotid Plaque: Biological Targeting of Inflammation in Atherosclerosis Using Iron Oxide Particles and MRI

2014 ◽  
Vol 59 (5) ◽  
pp. 1472
Author(s):  
J.M.S. Chan ◽  
C. Monaco ◽  
M. Wylezinska-Arridge ◽  
J.L. Tremoleda ◽  
R.G.J. Gibbs
Keyword(s):  
Iron Oxide ◽  
Carotid Plaque ◽  
Iron Oxide Particles ◽  
Oxide Particles

scholarly journals Internalization of annexin A5-functionalized iron oxide particles by apoptotic Jurkat cells

2009 ◽  
Vol 4 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Geralda A. F. van Tilborg ◽  
Tessa Geelen ◽  
Hans Duimel ◽  
Paul H. H. Bomans ◽  
Peter M. Frederik ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Jurkat Cells ◽  
Annexin A5 ◽  
Iron Oxide Particles ◽  
Oxide Particles

Effect of Zeolite on the Dispersion Stability of Iron Oxide Particles

1986 ◽  
Vol 56 (5) ◽  
pp. 309-316 ◽  
Author(s):  
Michiko Kimura ◽  
Motoko Komaki ◽  
Akihiko Yabe
Keyword(s):  
Iron Oxide ◽  
Dispersion Stability ◽  
Iron Oxide Particles ◽  
Oxide Particles
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