Kinetics of Ferrous Iron Oxidation by Moderately Thermophilic Microorganisms

2007 ◽  
Vol 20-21 ◽  
pp. 517-520
Author(s):  
Pablo S. Pina ◽  
V.A. Leão ◽  
C.A. Silva ◽  
S.N. Medrício ◽  
J. Frenay
Keyword(s):  
Ferrous Iron ◽  
Iron Oxidation ◽  
Thermophilic Microorganisms ◽  
Moderately Thermophilic ◽  
Ferrous Iron Oxidation ◽  
Kinetics Of

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.

The Effect of Total Iron Concentration and Iron Speciation on the Rate of Ferrous Iron Oxidation Kinetics of Leptospirillum ferriphilum in Continuous Tank Systems

2007 ◽  
Vol 20-21 ◽  
pp. 447-451 ◽  
Author(s):  
Jochen Petersen ◽  
Tunde Victor Ojumu
Keyword(s):  
Oxidation Kinetics ◽  
Ferrous Iron ◽  
Ferric Iron ◽  
Iron Oxidation ◽  
Iron Concentration ◽  
Total Iron ◽  
Ferrous Iron Oxidation ◽  
Utilisation Rate ◽  
Kinetics Of ◽  
Total Iron Concentration

In this study the results from a systematic study of the oxidation kinetics of Leptospirillum ferriphilum in continuous culture at total iron concentrations ranging from 2 to12 g/L are reported. In all experiments the steady-state concentrations of ferrous iron were small and comparable, and at least 97% of was as ferric. Surprisingly, the specific ferrous iron utilisation rate decreased with increasing total iron concentration, while yield coefficients increased. It was noted that the biomass concentration in the reactor (as measured by both CO2 uptake rate and cell counts) dramatically increased with increasing total iron concentrations, whereas it stayed more or less the same over a wide range of dilution rates at a given total iron concentration. The experimental data was re-analysed in terms of ferrous iron kinetics using Monod kinetics with a ferric inhibition term. The results confirm that the maximum specific iron utilisation rate is itself a function of ferric iron concentration, declining with increasing concentration. It thus appears that high concentrations of ferric iron stimulate microbial growth while at the same time inhibiting the rate of ferrous iron oxidation. It is postulated that these phenomena are related, i.e. that more growth occurs to reduce the load on the individual cell, possibly by sharing some metabolic functions.

Effect of Operating Conditions on the Chemical Phosphate Removal Using during Ferrous Iron Oxidation

2013 ◽  
Vol 807-809 ◽  
pp. 478-485 ◽  
Author(s):  
Ting Li ◽  
Wen Yi Dong ◽  
Hong Jie Wang ◽  
Jin Nan Lin ◽  
Feng Ouyang ◽  
...  
Keyword(s):  
Ferrous Iron ◽  
Removal Rate ◽  
Iron Oxidation ◽  
Operating Conditions ◽  
Phosphate Removal ◽  
Order Kinetic ◽  
Ferrous Iron Oxidation ◽  
Order Kinetic Model ◽  
Time Required ◽  
Kinetics Of

In this study, the effect of operating parameters and the co-existing ions on the phosphate removal during the ferrous iron oxidation was investigated. Results showed that with the increase of DO and [Fe (II)]0, the final phosphate removal rate both increased. But with increasing of pH, the final phosphate removal rate firstly increased and then decreased when the pH was higher than 8.0. The co-existing ions affected the final removal rate significantly, and the kinetics of phosphate removal followed the pseudo-first-order kinetic model. The corresponding kobs trends for the cation followed the order of Cu2+>Mn2+>Zn2+>NH4+-N. The presence of Cu2+ promoted the phosphate removal significantly. Compared with the control, , the time required to achieve 40 % phosphate removal rate, at the condition of 0.5 mg/L Cu2+, reduced from 60 min to 10 s. However, the selective anions inhibited the phosphate removal, due to the formation of Fe-anions complexes. The effect of selective anions on the phosphate removal rate constant decreased in the order of SO42->Cl-> NO3-.

Kinetics of Microbial Ferrous-Iron Oxidation by Leptospirillum Ferriphilum: Effect of Ferric-Iron on Biomass Growth

2009 ◽  
Vol 71-73 ◽  
pp. 259-262 ◽  
Author(s):  
Tunde Victor Ojumu ◽  
Jochen Petersen
Keyword(s):  
Ferrous Iron ◽  
Microbial Growth ◽  
Ferric Iron ◽  
Iron Oxidation ◽  
Iron Concentration ◽  
Biomass Concentration ◽  
Reaction Conditions ◽  
Leptospirillum Ferriphilum ◽  
Ferrous Iron Oxidation ◽  
Kinetics Of

The kinetics of microbial ferrous-iron oxidation have been well studied as it is a critical sub-process in bioleaching of sulphide minerals. Exhaustive studies in continuous culture have been carried out recently, investigating the effects of conditions relevant to heap bioleaching on the microbial ferrous-iron oxidation by Leptospirillum ferriphilum [1-3]. It was postulated that ferric-iron, which is known to be inhibitory, also acts as a stress stimulus, promoting microbial growth at higher total iron concentration. This paper investigates this phenomenon further, by comparing tests run with pure ferrous-iron feeds against those where the feed is partially oxidised to ferric at comparable concentrations. The findings clearly suggest that, contrary to reactor theory, it is indeed ferrous iron concentration in the reactor feed that determines biomass concentration and that ferric iron concentration has little effect on microbial growth. Further mathematical analysis shows that the phenomenon can be explained on the basis of the Pirt equation and the particular reaction conditions employed in the test work.

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