Roles of natural iron oxides in the promoted sequestration of chromate using calcium polysulfide: pH effect and mechanisms

2020 ◽  
Vol 237 ◽  
pp. 116350 ◽  
Author(s):  
Tao Wang ◽  
Wanyu Wang ◽  
Yuanyuan Liu ◽  
Wei Li ◽  
Yunyi Li ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Ph Effect ◽  
Natural Iron ◽  
Calcium Polysulfide

Reduction and stabilization of Cr(VI) in soil by using calcium polysulfide: Catalysis of natural iron oxides

2020 ◽  
Vol 190 ◽  
pp. 109992
Author(s):  
Tong Zhang ◽  
Tao Wang ◽  
Wanyu Wang ◽  
Bin Liu ◽  
Wei Li ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Natural Iron ◽  
Calcium Polysulfide

scholarly journals Reactive Properties of Bioengineered and Natural Iron Oxides: A Multi-Scale Approach from First Principles

2020 ◽  
Author(s):  
Inna Kurganskaya ◽  
Malte Schuler ◽  
Carolina Santiago ◽  
Tim Wehling ◽  
Andreas Luttge
Keyword(s):  
Iron Oxides ◽  
First Principles ◽  
Multi Scale ◽  
Natural Iron ◽  
Reactive Properties

Composites prepared from natural iron oxides and sucrose: A highly reactive system for the oxidation of organic contaminants in water

2011 ◽  
Vol 166 (3) ◽  
pp. 962-969 ◽  
Author(s):  
Márcio C. Pereira ◽  
Luis C.D. Cavalcante ◽  
Fabiano Magalhães ◽  
José D. Fabris ◽  
Joseph W. Stucki ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Organic Contaminants ◽  
Reactive System ◽  
Natural Iron

Interaction of dilute fluoride solutions with hydrous iron oxides

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 201 ◽  
Author(s):  
H Farrah ◽  
WF Pickering
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Langmuir Isotherm ◽  
Ph Effect ◽  
Structural Form ◽  
Acid Media ◽  
Soluble Iron ◽  
Hydrous Oxides ◽  
Hydrous Iron Oxide ◽  
Decreasing Ph

The amount of F- retained by hydrous iron oxide suspensions was found to be a function of F- concentration (2-100 mg L-1), pH, and structural form of the iron oxide. Uptake was minimal at pH >7, and increased with decreasing pH (e.g, with 10 mg L-1 NaF in solution, the amount sorbed by freshly precipitated hydrous iron oxide varied between 7 mg/g at pH 6 and 35.5 mg/g at pH 4.5). With fixed pH (between 4.5 and 6) the amount sorbed varied with concentration in accordance with a Langmuir isotherm relationship. The pH effect was countered at lower values by solid dissolution, hence each F- concentration studied exhibited a pH (between 3.5 and 4.5) where uptake was a maximum. Solid dissolution was accompanied by the formation of soluble iron(III) fluoro complexes. In acid media, the amount of F sorbed by hydrous iron oxide >> goethite > limonite >> hematite. In environmental systems, F interaction and retention should thus be most pronounced in acid media, containing recently precipitated hydrous oxides.

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