ferrous iron oxidation

Ferrous iron oxidation under acidic conditions – The ... - Science Direct

Nov 15, 2014 ... In this study, the kinetics of Fe(II) oxidation in the presence of the iron oxyhydroxides ferrihydrite, Si-ferrihydrite, schwertmannite, lepidocrocite and goethite are investigated over the pH range 4–5.5. Despite limited sorption of Fe(II), the rate of Fe(II) oxidation is up to 70-fold faster than in the absence of any...

Read More

Ferrous Iron Oxidation - an overview | ScienceDirect Topics

Sulfolobus acidocaldarius. S. acidocaldarius is an extremely acidophilic, thermophilic, chemolithotrophic microorganism that has the ability to use ferrous iron oxidation as a source of energy (Brock et al., 1972). It closely resembles A. brierleyi morphologically and physiologically, however the two species differ genotypically.

Read More

Oxygenation of Ferrous Iron - G. Fred Lee & Associates

ferrized by oxidizing the ferrous iron with dissolved oxygen and then remov- ing the resulting ferric oxide floc by sedimentation or filtration. Ferrous iron in river water—e.g., pollution by mine drainage or iron pickling wastes—not only disturbs the oxygen balance but reduces the pH and forms suspended matter as ferric...

Read More

Oxygenation of Ferrous Iron - ACS Publications

ferrized by oxidizing the ferrous iron with dissolved oxygen and then remov- ing the resulting ferric oxide floc by sedimentation or filtration. Ferrous iron in river water--e.g.. pollution by mine drainage or iron pickling wastes-not only disturbs the oxygen balance but reduces the pH and forms suspended matter as ferric...

Read More

Air Oxidation of Ferrous Iron in Water - Semantic Scholar

Abstract: Air oxidation of ferrous iron in water was studied. It was worked at three different values of pH and concentration. Oxidation was firstly carried out at stationary atmosphere. Thereafter, the experiment was successively repeated by blowing air to the solution without and with inert packing. Lastly, the catalytic effect of...

Read More

Example 9.--Kinetic Oxidation of Dissolved Ferrous Iron with Oxygen

The time for complete oxidation of ferrous iron is a matter of minutes in an aerated solution when pH is above 7.0. However, Fe 3+ forms solute complexes with OH - and it may also precipitate as iron oxyhydroxides, so that pH decreases during oxidation. Because the rate has quadratic dependence on the activity of OH -...

Read More

ferrous iron oxidation - University of Vermont

The oxidation kinetics of ferrous iron are well known to be pH dependent, with the slow oxidation kinetics of ferrous iron at low pH being part of the early basis for considering the importance of microbial iron oxidation in the formation of acidic Mine drainage (Singer and Stumm, 1970). There are many known iron-oxidizing...

Read More

Ferrous iron oxidation by anoxygenic phototrophic bacteria | Nature

NATURAL oxidation of ferrous to ferric iron by bacteria such as Thiobacillus ferrooxidans or Gallionella ferruginea1, or by chemical oxidation2,3 has previously been thought always to involve molecular oxygen as the electron acceptor. Anoxic photochemical reactions4–6 or a photobiological process involving two...

Read More

Microbial Ferrous Iron Oxidation in Acidic Solution - jstor

ABSTRACT: Microbial ferrous iron oxidation in a dilute sul furic acid medium at low pH was investigated. Part of a study of acidic leach solution chemistry and chemical speciation the effects on metal-sulfide oxidation these studies were performed to un derstand the processes that accompany microbial extraction of.

Read More

OXYGENATION OF FERROUS IRON IN MINE DRAINAGE WATERS

as exhibiting catalytic properties in the oxidation of ferrous iron. This paper represents a quantitative evaluation of the individual factors con- trolling the oxidation of iron pyrite; the relative rates of the various consecutive reactions have been considered in order to elucidate the rate- determining reaction. The laboratory...

Read More

FERROUS IRON OXIDATION BY FERROBACILLUS FERROOXIDANS

The electron transport chain and Fe++-cytochrome c reductase of Ferrobacillus ferrooxidans were studied to elucidate the mechanism of iron oxidation by this autotrophic bacterium.The iron oxidation involved the cytochrome c and a type cytochrome of F. ferrooxidans in the electron transport system. The initial enzyme of...

Read More

Ferrous iron oxidation by denitrifying bacteria in profundal ...

Keywords: Ferrous iron; Iron oxidation; Iron cycle; Freshwater sediment; Denitri¢cation. 1. Introduction. Iron is the fourth-most abundant element in the Earth's crust and the most prevalent redox-active metal. Due to the rapid chemical oxidation of ferrous iron with oxygen and the low solubility of ferric iron minerals in water,...

Read More

Anaerobic and aerobic oxidation of ferrous iron at neutral pH by ...

Nine out of ten anaerobic enrichment cultures inoculated with sediment samples from various freshwater, brackish-water, and marine sediments exhibited ferrous iron oxidation in mineral media with...

Read More

ROLE OF FERROUS IRON OXIDATION IN THE ALTERA- TION OF ...

Artificiral weathering of biotites in the laboratory indicates that ferrous iron is oxidized to the same extent under acid, neutral and alkaline conditions, contrary to theoretical as- sumptions. Under neutral and alkaline conditions, the Ierrous iron oxidation causes a large decrease in surface charge and the expanded crystal...

Read More

amrclearinghouse.org :::AMD Basics - FERROUS, FERRIC IRON:::

Ferrous - ferric iron. Mine water with iron contamination may take on more than one chemical form. As it turns out, this can be a significant property, especially when we devise treatment strategies to remove the iron. The iron will be in one of two oxidation states: ferrous having a +2 charge, or ferric having a +3 charge.

Read More

THE MECHANISM OF IRON CATALYSIS IN CERTAIN OXIDATIONS ...

It is well known t,hat ferrous iron is comparatively stable in acid solut,ion and that it is rapidly oxidized to the ferric state by the oxygen of the air in alkaline solution. No satisfactory explanation for this has been brought forward. One difference in the condi- tion of the iron in the two solutions immediately suggests itself.

Read More

Ferrous iron oxidation under acidic conditions - The effect of ferric ...

Title: Ferrous iron oxidation under acidic conditions - The effect of ferric oxide surfaces [ Erratum: 2015GeCoA.156..241J ]. Authors: Jones, Adele M.; Griffin, Phillipa J.; Collins, Richard N.; Waite, T. David. Affiliation: AA(School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052,...

Read More

oxidation of ferrous iron. Anaerobic, nitrate-dependent ... - CiteSeerX

Iron is the most prevalent redox-active metal in the bio- sphere. In anoxic soils and sediments, ferric iron is reduced to the ferrous state mainly through the activities of various iron- reducing bacteria (15, 18). Widespread and well-studied reoxi- dation processes of iron(II) are its chemical reactions with molecular oxygen...

Read More

Kinetics of ferrous iron oxidation by Sulfobacillus thermosulfidooxidans

The biological oxidation of ferrous iron is an important sub-process in the bioleaching of metal sul- fides and other bioprocesses such as the removal of H2S from gases, the desulfurization of coal and the treatment of acid mine drainage (AMD). As a consequence, many Fe(II) oxidation kinetics studies have mostly been...

Read More

(1938) Importance of Ferrous Iron in Plants and Soils, The

been thoroughly investigated. Neither has the importance of ferrous iron in soils and its relation to soil organic matter been suf- ficiently appreciated. It was the purpose of this investigation to obtain further informa- tion along these lines. State of Oxidation of Iron in Plants. The distribution of iron in plants has been studied by...

Read More

Iron in Drinking Water - IDPH

Although present in drinking water, iron is seldom found at concentrations greater than 10 milligrams per liter (mg/L) or 10 parts per million. ... Water containing ferrous iron is clear and colorless because the iron is completely dissolved. ... This sediment is the oxidized or ferric form of iron that will not dissolve in water.

Read More

OXIDATION PATHWAYS FOR FERROUS IRON ... - USRA-Houston

OXIDATION PATHWAYS FOR FERROUS IRON SMECTITES ON MARS AND THE REDOX. EVOLUTION OF GALE CRATER. S. M. Chemtob1, V. B. Rivera-Banuchi1, J. G. Catalano2, R. D. Nickerson2,. R. V. Morris3, D. G. Agresti4, W. Liu5, and N. Yee5. 1Temple University, Philadelphia, PA (chemtob@temple.edu),.

Read More

Anaerobic Oxidation of Ferrous Iron by Purple Bacteria ... - Chemistry

Anaerobic Oxidation of Ferrous Iron by Purple Bacteria, a New Type of Phototrophic Metabolism. ARMIN EHRENREICH AND FRIEDRICH WIDDEL*. Max-Planck-Institut fuir Marine Mikrobiologie, D-28359 Bremen, Germany. Received 22 July 1994/Accepted 29 September 1994. Anoxic iron-rich sediment samples that had...

Read More

Oxygenation of Ferrous Iron - epa nepis

In the contract the scope of the work was stated as follows: Specific Aims: (1) To determine rates of air oxidation of ferrous iron in the _2 presence of SO, within the pH range 2-5; (2) To determine rate of ferric iron hydrolysis within the pH range 2-5; (3) To investigate the colloid-chemical properties of hydrolyzed iron (III)...

Read More

Electrochemical Oxidation of Ferrous Iron in Very Dilute Solutions

Abstract. Experimental results are presented for the anodic oxidation of ferrous iron in dilute ferrous sulfate‐sulfuric acid solutions. A conductive fixed‐bed, flow‐through, electrochemical reactor in which electric current flow is parallel to the direction of electrolytic solution flow was used. Steady‐state anodic polarization...

Read More

A study of the rate of oxidation of iron in aerated ... - IDEALS @ Illinois

Tj_ was used as a parameter to measure the rate of oxidation of ferrous iron. 2. This was graphically computed from the slope of the line representing the log of ferrous iron remaining plotted against time. Finally a trivariate regression analysis was made with data fromthe field experiments and the following equation was...

Read More

Potential for Microbial Oxidation of Ferrous Iron in Basaltic Glass ...

May 18, 2015 ... Basaltic glass (BG) is an amorphous ferrous iron [Fe(II)]–containing material present in basaltic rocks, which are abundant on rocky planets such as Earth and Mars. Previous research has suggested that Fe(II) in BG can serve as an energy source for chemolithotrophic microbial metabolism, which has...

Read More

Stability of ferrous-iron-rich bridgmanite under reducing midmantle ...

Jun 5, 2017 ... Significance. This paper reports an unexpected change in the oxidation state of Fe in bridgmanite, the most dominant mineral in the lower mantle. The oxidation state change resolves the discrepancy between laboratory and seismic studies on the chemical composition of the lower mantle, showing that the...

Read More

Ferrous Iron Oxidation in Packed-Bed Reactors at Elevated ...

The ferrous iron oxidation by mixed culture of moderately thermophilic microorganisms (Sulfobacillus thermosulfidooxidans Sh 10-1 and Acidiplasma MBA-1) was investigated in continuous experiments in three packed-bed reactors connected in series at temperature 55°C, and a pH of 1.0. Two solutions were used in the...

Read More

Ferrous iron oxidation and rusticyanin in halotolerant, acidophilic ...

Microbiology. 2009 Apr;155(Pt 4):1302-9. doi: 10.1099/mic.0.023192-0. Ferrous iron oxidation and rusticyanin in halotolerant, acidophilic 'Thiobacillus prosperus'. Nicolle Jle C(1), Simmons S, Bathe S, Norris PR. Author information: (1)Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.

Read More

Anaerobic oxidation of ferrous iron by purple bacteria, a new type of ...

Abstract. Anoxic iron-rich sediment samples that had been stored in the light showed development of brown, rusty patches. Subcultures in defined mineral media with ferrous iron (10 mmol/liter, mostly precipitated as FeCO3) yielded enrichments of anoxygenic phototrophic bacteria which used ferrous iron as the sole...

Read More

iron - 2 The 4 Technology Solutions

In groundwater systems iron occurs in one of two oxidation states: reduced soluble divalent ferrous iron (Fe+2) or oxidized insoluble trivalent ferric iron (Fe+3). The modern atmosphere has 21% oxygen, causing most of the iron in shallow subsurface soils to be in the oxidized ferric state. Ferric hydroxide (Fe(OH)3) is the...

Read More

Ferrous Iron Oxidation under Acidic Conditions – The Effect of Ferric ...

Dec 19, 2017 ... Request (PDF) | Ferrous Iron Oxidati... | In this study, the kinetics of Fe(II) oxidation in the presence of the iron oxyhydroxides ferrihydrite, Si-ferrihydrite, schwertmannite, lepidocrocite and goethite are investigated over the pH range 4 to 5.5. Despite limited sorption of Fe(II), the rate of Fe(II) oxidation is up to...

Read More

Ferric - Wikipedia

In water, iron forms compounds that are often insoluble, at least near neutral pH. A salt of iron hydrolyzes water and produces iron(III) oxide-hydroxides while contributing hydrogen ions to the solution, lowering the pH. In contrast, typical Na+ salts (e.g. NaCl) dissolve in water without...

Read More

Diversity of Ferrous Iron-Oxidizing, Nitrate-Reducing Bacteria and ...

In previous studies, three different strains (BrG1, BrG2, and BrG3) of ferrous iron-oxidizing, nitrate-reducing bacteria were obtained from freshwater sediments. All three strains were facultative anaerobes and utilized a variety of organic substrates and molecular hydrogen with nitrate as electron acceptor. In this study...

Read More

Anaerobic, nitrate-dependent microbial oxidation of ferrous iron.

Enrichment and pure cultures of nitrate-reducing bacteria were shown to grow anaerobically with ferrous iron as the only electron donor or as the additional electron donor in the presence of acetate. The newly observed bacterial process may significantly contribute to ferric iron formation in the suboxic zone of aquatic...

Read More

Kinetics of Ferrous Iron Oxidation by Leptospirillum Bacteria in ...

The oxidation of ferrous iron by Leptospirillum bacteria was studied in a continuous culture in the dilution rate range 0.009-0.077 h-1 and could be described with a rate equation for competitive ferric iron inhibition kinetics in terms of the ferric/ferrous iron ratio in the solution. The ferrous iron oxidation in the continuous...

Read More

Ferric and Ferrous Iron in Cell Culture | Sigma-Aldrich

Primary Functions of Iron in Cell Culture Systems: Iron is essential for cell respiration and metabolism. Without iron cells stop growing and eventually die. Iron can undergo univalent redox reactions. Its oxidized and reduced forms are referred to as ferric and ferrous iron, respectively. Hemoglobin is the quantitatively...

Read More

Bacterial oxidation of ferrous iron by Acidithiobacillus ferrooxidans in ...

The oxidation of ferrous iron by Acidithiobacillus ferrooxidans in the pH range 2.5–7.0 was characterized. In order to measure the rate of bacterial oxidation of ferrous iron with A. ferrooxidans in this high pH range, a novel experimental methodology was developed. The results showed that the inhibition of ferrous iron...

Read More
PRE Post:grinding plant diatoms
NEXT Post:sheet mirror like finish grinding machine