Ferrous iron oxidation rates in the pycnocline of a permanently stratified lake

Chemosphere ◽  
2007 ◽  
Vol 66 (8) ◽  
pp. 1561-1570 ◽  
Author(s):  
Sergi Díez ◽  
Gregory O. Noonan ◽  
John K. MacFarlane ◽  
Philip M. Gschwend
Keyword(s):  
Ferrous Iron ◽  
Iron Oxidation ◽  
Stratified Lake ◽  
Oxidation Rates ◽  
Ferrous Iron Oxidation

Oxygen and carbon dioxide kinetic challenges for thermophilic mineral bioleaching processes

2004 ◽  
Vol 32 (2) ◽  
pp. 273-275 ◽  
Author(s):  
S.H. de Kock ◽  
P. Barnard ◽  
C.A. du Plessis
Keyword(s):  
Ferrous Iron ◽  
Large Scale ◽  
Elevated Temperatures ◽  
Ferrous Sulphate ◽  
Iron Oxidation ◽  
Co2 Concentration ◽  
Batch Cultures ◽  
Oxidation Rates ◽  
Ferrous Iron Oxidation ◽  
Oxygen Gas

Agitated bacterial tank bioleaching reactors are currently sparged with air to satisfy both oxygen and CO2 requirements of microbial cells. Under high-sulphide loading conditions, as is the case with high-grade metal sulphide concentrates, the microbial and chemical demand for oxygen is significantly increased during the bioleaching process. Sparging with enriched oxygen gas may offer an alternative process option to increased agitation and sparged aeration, to overcome the mass transfer difficulties at elevated temperatures where thermophilic Archaea, rather than Bacteria, are used. In the case of air sparging, the DO (dissolved oxygen) concentration in tank reactors could not be increased to a point where it would become inhibitory due to the limited oxygen content of air (20.9% O2). The use of enriched oxygen in such reactors at large scale does, however, pose its own set of process risks. The first aim of this investigation was, therefore, to determine the effects of various DO concentrations, in both the limiting and inhibitory ranges, on the microbial activity of Sulfolobus sp. U40813, a typical thermophilic mineral-leaching archaeon. Secondly, the effect of CO2 concentration on the rate of ferrous iron oxidation was investigated. Both the oxygen and CO2 kinetics were examined in controlled batch cultures at 78°C, using ferrous sulphate and potassium tetrathionate as energy sources. The optimal DO concentration for iron oxidation was found to be between 1.5 and 4.1 mg·l−1. The use of elevated DO concentrations (above 4.1 mg·l−1) inhibited the ferrous oxidation rates. The optimal gas CO2 concentration for ferrous iron oxidation was found to be in the range 7–17% (v/v). The iron oxidation rates were, however, severely limited at CO2 concentrations less than 7%, indicating that the CO2 supply was limiting in this range and inhibited the microbial growth rate.

scholarly journals Kinetics of different bioreactor systems with Acidithiobacillus ferrooxidans for ferrous iron oxidation

2019 ◽  
Vol 128 (2) ◽  
pp. 611-627
Author(s):  
Mohsen Yavari ◽  
Sirous Ebrahimi ◽  
Valeh Aghazadeh ◽  
Mohammad Ghashghaee
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Iron ◽  
Iron Oxidation ◽  
Fixed Bed ◽  
Lower Sensitivity ◽  
Hydraulic Residence Time ◽  
Oxidation Rates ◽  
State Process ◽  
Ferrous Iron Oxidation ◽  
Biofilm Development

Abstract The relative performance of two biofilm-based airlift reactors using different kinds of packing materials and one fixed bed biofilm reactor with a homemade packing material of high specific area (~ 1000 m2/m3) was addressed. The bioreactors operated under ferrous iron loading rates in the range of 8–120 mol Fe(II)/m3 h. Acidithiobacillus ferrooxidans cells immobilized in the three bioreactors afforded the reactions for an extended period of 120 days of continuous operation at the dilution rates of 0.2, 0.4, 0.7, 1 and 1.2 h−1. The maximum ferrous iron oxidation rates achieved in this study at a hydraulic residence time of 1.2 h were about 91, 68 and 51 mol Fe(II)/m3 h for the fixed bed, airlift1, and airlft2 bioreactors. The performance data from the fixed-bed bioreactor offered a higher potential for ferrous iron oxidation because of fast biofilm development, the formation of a thick biofilm, and lower sensitivity to shear, which enhanced the startup time of the bioreactor and the higher reactor productivity. Proper kinetic models were also presented for both the startup period and the steady-state process.

Ferrous Iron Oxidation in Packed-Bed Reactors at Elevated Temperatures

2015 ◽  
Vol 1130 ◽  
pp. 226-229 ◽  
Author(s):  
Aleksander Bulaev
Keyword(s):  
Ferrous Iron ◽  
Elevated Temperatures ◽  
Iron Oxidation ◽  
Packed Bed ◽  
Thermophilic Microorganisms ◽  
Packed Bed Reactors ◽  
Moderately Thermophilic ◽  
Oxidation Rates ◽  
Ferrous Iron Oxidation ◽  
In Series

The ferrous iron oxidation by mixed culture of moderately thermophilic microorganisms (Sulfobacillus thermosulfidooxidansSh 10-1 andAcidiplasmaMBA-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 experiments. The first one contained (g L-1) 59 Fe2+, the second one contained (g L-1) 59 Fe2+, 16 Fe3+, 2 Cu2+, 2 Zn2+. The hydraulic retention time was 120 hours. Iron oxidation rates in the experiment with the first solution were 0.5, 0.35, and 0.2 g L-1h-1in first, second and third reactor, respectively. The oxidation rates in the experiment with the second solution were 0.3, 0.2, and 0.185 g L-1h-1in first, second and third reactor, respectively. Iron oxidation efficiencies in the experiments with the first and second solutions were 77% and 47%. Stable continuous iron oxidation at high temperature was successfully demonstrated, but further investigations are required for improving the rate and efficiencies of oxidation.

Ferrous iron oxidation in moderately thermophilic acidophile Sulfobacillus sibiricus N1T

2010 ◽  
Vol 56 (10) ◽  
pp. 803-808 ◽  
Author(s):  
Tatiana Y. Dinarieva ◽  
Anna E. Zhuravleva ◽  
Oksana A. Pavlenko ◽  
Iraida A. Tsaplina ◽  
Alexander I. Netrusov
Keyword(s):  
Ferrous Iron ◽  
High Performance ◽  
Iron Oxidation ◽  
Early Exponential Phase ◽  
Moderately Thermophilic ◽  
Terminal Oxidases ◽  
Cytochrome Bo ◽  
Ferrous Iron Oxidation ◽  
Transport Chain ◽  
Membrane Bound

The iron-oxidizing system of a moderately thermophilic, extremely acidophilic, gram-positive mixotroph, Sulfobacillus sibiricus N1T, was studied by spectroscopic, high-performance liquid chromatography and inhibitory analyses. Hemes B, A, and O were detected in membranes of S. sibiricus N1T. It is proposed that the electron transport chain from Fe2+ to O2 is terminated by 2 physiological oxidases: aa3-type cytochrome, which dominates in the early-exponential phase of growth, and bo3-type cytochrome, whose role in iron oxidation becomes more prominent upon growth of the culture. Both oxidases were sensitive to cyanide and azide. Cytochrome aa3 was more sensitive to cyanide and azide, with Ki values of 4.1 and 2.5 µmol·L–1, respectively, compared with Ki values for cytochrome bo3, which were 9.5 µmol·L–1 for cyanide and 7.0 µmol·L–1 for azide. This is the first evidence for the participation of a bo3-type oxidase in ferrous iron oxidation. The respiratory chain of the mixotroph contains, in addition to the 2 terminal oxidases, a membrane-bound cytochrome b573.

scholarly journals A kinetic model of ferrous iron oxidation by Acidithiobacillus ferrooxidans in a batch culture

2005 ◽  
Vol 11 (2) ◽  
pp. 59-62 ◽  
Author(s):  
Dragisa Savic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Miroslav Vrvic
Keyword(s):  
Kinetic Model ◽  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Iron ◽  
Bubble Column ◽  
Iron Oxidation ◽  
Yield Coefficient ◽  
Transfer Rates ◽  
Ferrous Iron Oxidation ◽  
Menten Kinetic ◽  
Kinetics Of

The batch oxidation kinetics of ferrous iron by Acidithiobacillus ferrooxidans were examined at different oxygen transfer rates and pH in an aerated stirred tank and a bubble column. The microbial growth, oxygen consumption rate and ferrous and ferric iron were monitored during the biooxidation. A kinetic model was established on the basis of the Michaelis-Menten kinetic equation for bacterial growth and the constants estimated from experimental data (maximum specific growth rate 0.069 h-1, saturation constant 2.9 g/dm3, and biomass yield coefficient based on ferrous iron 0.003 gd.w./gFe). Values calculated from the model agreed well with the experimental ones regardless of the bioreactor type and pH conditions.

Iron targeted transcriptome study draws attention to novel redox protein candidates involved in ferrous iron oxidation in “Ferrovum” sp. JA12

2018 ◽  
Vol 169 (10) ◽  
pp. 618-627 ◽  
Author(s):  
Sophie R. Ullrich ◽  
Anja Poehlein ◽  
Gloria Levicán ◽  
Martin Mühling ◽  
Michael Schlömann
Keyword(s):  
Ferrous Iron ◽  
Iron Oxidation ◽  
Redox Protein ◽  
Ferrous Iron Oxidation

scholarly journals Increasing cell concentration does not affect specific ferrous iron oxidation rate in a continuously stirred tank bioreactor

2018 ◽  
Vol 181 ◽  
pp. 189-194
Author(s):  
Naomi J. Boxall ◽  
Ka Yu Cheng ◽  
Chris A. du Plessis ◽  
David Collinson ◽  
Christina Morris ◽  
...  
Keyword(s):  
Oxidation Rate ◽  
Ferrous Iron ◽  
Cell Concentration ◽  
Iron Oxidation ◽  
Stirred Tank ◽  
Stirred Tank Bioreactor ◽  
Ferrous Iron Oxidation
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