scholarly journals A novel approach coupling ferrous iron bio-oxidation and ferric iron chemo-reduction to promote biomineralization in simulated acidic mine drainage

RSC Advances ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 5083-5090 ◽  
Author(s):  
Ning Wang ◽  
Di Fang ◽  
Guanyu Zheng ◽  
Jianru Liang ◽  
Lixiang Zhou

Controlled addition of ZVI into Acidithiobacillus ferrooxidans-mediated biomineralization can markedly improve the formation of secondary Fe-minerals in AMD.

2013 ◽  
Vol 825 ◽  
pp. 115-119 ◽  
Author(s):  
Albert Saavedra ◽  
Beatriz Pavez ◽  
Mauricio Diaz ◽  
Juan Carlos Gentina

The ability ofAcidithiobacillus ferrooxidansto get its energy from the oxidation of ferrous iron and the inhibitory effect of high ferric iron concentrations on its growth behaviour has been extensively studied. Furthermore it is known thatA. ferrooxidansexudes organic substances called extracellular polymeric substances (EPS), which could play a role in its protection against adverse environmental conditions. In this context, the aim of this work was to study the production of EPS during adaptation ofA. ferrooxidansto high ferric ion concentrations. The experiments were performed in shake flasks of 250 mL at 30 °C, 200 rpm and at an initial pH of 1.8. In order to establish the natural tolerance of the strain, its growth behaviour was evaluated at high ferric iron concentrations by adding consecutively the equivalent of 9 g/L of ferrous iron each time it was depleted in the broth. Cell growth stopped once ferric iron concentration increased up to 38 g/L. The adaptation consisted in eight sub-cultures run in parallel at initial concentrations of ferrous iron of 18, 27 and 36 g/L. The EPS was quantified as micro volumes using confocal laser scanning microscopy (CLSM), labelling the cells with propidium iodide and EPS carbohydrates with wheat germ agglutinin (WGA). During the adaptation procedure it was observed an increase in the ferric ion volumetric productivity of subcultures run with 27 and 36 g/L, as a result of cell adaptation. The amount of EPS exuded by cells was higher along with those experimental conditions having higher ferric iron concentrations. It was not detected EPS on cells grown on 9 g/L of ferrous iron. This study found that the adapted strain showed higher production of EPS at high ferric ion concentrations and higher ferric ion tolerance than non-adapted ones.


Author(s):  
K.N. Seitkamal ◽  
◽  
Nariman Zhappar ◽  
Valerij Shaikhutdinov ◽  
Aigerim Shibaуeva ◽  
...  

Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivoransis an important process in the bioleaching of minerals and the treatment of acid mine drainage. The rate at which biooxidation reactions take place is directly related to the microorganisms’growth temperature. Decreasing the temperature of reaction causes both a decrease on the chemical reactions rates and a decrease on bacterial growth. In this study, the effects of pH and temperatures on oxidation of ferrous sulfate by a native At. ferrooxidans and At. ferrivorans strains were investigated. The biooxidation tests conducted in shake flasks at 28 °C and 8 °C and at initial pH 1.6 for 5 days. During the experiment, the mesophilic iron oxidizers were capable of growing on ferrous iron at concentrations of 4.5 g/L at low and optimum temperature. However, the rate of mesophilic biooxidation of ferrous iron was higher than that observed in the psychrophilic biooxidation. In conclusion, during the experiment the At. ferrivorans strain 535 showed high activity in oxidizing at low temperature than other strains. It means even at very low temperatures, microorganisms play an important role in the oxidation and leaching of sulphide ores.


2018 ◽  
Vol 773 ◽  
pp. 367-372
Author(s):  
Jun Hui Fan ◽  
Xing Yu Liu ◽  
Qi Yuan Gu ◽  
Ming Jiang Zhang

Acid mine drainage is detrimental to the environment, which is rich of a variety of heavy metals, and has a low pH value and high acidity. The purpose of this paper is to study the bio-oxidation of ferrous iron and the selective precipitation of ferric iron, to gain a long-term effective solution to the environmental problem. The maximum ferrous iron bio-oxidation rate (76.19mg/L·h) was obtained at a low pH value of 3.0 and culture temperature of 30°C. In addition, we found a relatively higher ferric iron removal rate (99.18%) and the lowest copper loss rate (4.59%) at a pH value of 3.2 and reaction temperature of 30°C and stirring time of 4h.


2003 ◽  
Vol 69 (10) ◽  
pp. 6165-6173 ◽  
Author(s):  
K. Duquesne ◽  
S. Lebrun ◽  
C. Casiot ◽  
O. Bruneel ◽  
J.-C. Personné ◽  
...  

ABSTRACT Weathering of the As-rich pyrite-rich tailings of the abandoned mining site of Carnoulès (southeastern France) results in the formation of acid waters heavily loaded with arsenic. Dissolved arsenic present in the seepage waters precipitates within a few meters from the bottom of the tailing dam in the presence of microorganisms. An Acidithiobacillus ferrooxidans strain, referred to as CC1, was isolated from the effluents. This strain was able to remove arsenic from a defined synthetic medium only when grown on ferrous iron. This A. ferrooxidans strain did not oxidize arsenite to arsenate directly or indirectly. Strain CC1 precipitated arsenic unexpectedly as arsenite but not arsenate, with ferric iron produced by its energy metabolism. Furthermore, arsenite was almost not found adsorbed on jarosite but associated with a poorly ordered schwertmannite. Arsenate is known to efficiently precipitate with ferric iron and sulfate in the form of more or less ordered schwertmannite, depending on the sulfur-to-arsenic ratio. Our data demonstrate that the coprecipitation of arsenite with schwertmannite also appears as a potential mechanism of arsenite removal in heavily contaminated acid waters. The removal of arsenite by coprecipitation with ferric iron appears to be a common property of the A. ferrooxidans species, as such a feature was observed with one private and three collection strains, one of which was the type strain.


2015 ◽  
Vol 1130 ◽  
pp. 97-100 ◽  
Author(s):  
Jiri Kucera ◽  
Eva Pakostova ◽  
Oldrich Janiczek ◽  
Martin Mandl

Ferric iron may act as a thermodynamically favourable electron acceptor during elemental sulfur oxidation byAcidithiobacillus ferrooxidansin extremely acidic anoxic environments. A loss of anaerobic ferric iron reduction ability has been observed in ferrous iron-grownA. ferrooxidansCCM 4253 after aerobic passaging on elemental sulfur. In this study, iron-oxidising cells aerobically adapted from ferrous iron to elemental sulfur were still able to anaerobically reduce ferric iron, however, following aerobic passage on elemental sulfur it could not. Preliminary quantitative proteomic analysis of whole cell lysates of the passage that lost anaerobic ferric iron-reducing activity resulted in 150 repressed protein spots in comparison with the antecedent culture, which retained the activity. Identification of selected protein spots by tandem mass spectrometry revealed physiologically important proteins including rusticyanin and outer-membrane cytochrome Cyc2, which are involved in iron oxidation. Other proteins were associated with sulfur metabolism such as sulfide-quinone reductase and proteins encoded by the thiosulfate dehydrogenase and heterodisulfide reductase complex operons. Furthermore, proteomic analysis identified proteins directly related to anaerobiosis. The results indicate the importance of iron-oxidising system components for anaerobic sulfur oxidation in the studied microbial strain.


2013 ◽  
Vol 825 ◽  
pp. 120-124 ◽  
Author(s):  
Albert Saavedra ◽  
Beatriz Pavez ◽  
Mauricio Diaz ◽  
Juan Carlos Gentina

The presence of extracellular polymeric substances (EPS) is important in the building of biofilms on mineral surfaces, increasing the bioleaching activity, as well as protecting the cells from adverse environmental conditions. The objective of this work was to study the effect of galactose in EPS production by Acidithiobacillus ferrooxidans. The experiences were performed in shake flask of 250 mL at 30 °C, 200 rpm and at an initial pH of 1.8. In order to establish the natural tolerance of the strain, its growth behaviour was evaluated at high ferric iron concentrations by adding consecutively the equivalent of 9 g/L of ferrous iron each time it was depleted in the broth. Cell growth stopped once ferric iron concentration increased up to 38 g/L. In order to determine the optimal conditions for EPS production, experiments were run in a chemostat of 0.5 L, operated at a constant dilution rate of 0.03 h-1. Different steady states were obtained varying feeding concentrations of galactose (0.15%; 0.25% and 0.35%) and carbon dioxide (180 ppm and 360 ppm). , Cells grown in the chemostat at optimum operation conditions were used as inoculum to determine oxidative capacity of the microorganisms overproducing EPS. The EPS was quantified using confocal laser scanning microscopy (CLSM), labelling the cells with propidium iodide and EPS carbohydrates with wheat germ agglutinin (WGA). The higher volume production of EPS was observed in cells grown using 360 ppm of CO2 and 0.35% of galactose. Also it was observed a size increment of cells, compared to cells grown in culture medium having 9 g/L of ferrous iron where presence of EPS was no detected. The results revealed that EPS overproducing A. ferrooxidans showed a tolerance to ferric iron concentration almost 9.5 g/L higher than the natural tolerance of cells grown in absence of galactose. Presence of galactose in culture medium stimulated the EPS production.


2009 ◽  
Vol 71-73 ◽  
pp. 291-294
Author(s):  
T. Vargas ◽  
P. Diáz ◽  
B. Escobar

Ferrous iron oxidation studies in the presence of activated carbon were conducted at 30 °C in basal medium at pH 1.6 with a pure strain of Acidithiobacillus ferrooxidans. Two-chamber modified shake flasks were used in these experiments, which prevented direct contact between the microorganisms and the carbon contained in the flasks. This design permitted an accurate determination of bacterial population during the experiment and enabled the involvement of ferric iron reduction with carbon to be evidenced. Notably, iron was initially added as ferric iron in a concentration of 3 g/L. It could be observed that bacteria could grow in this condition evidencing that bacteria was in fact oxidizing ferrous ion produced from reduction of ferric by carbon. From complementary experiments in which activated carbon was contacted with abiotic solutions containing ferric ion in the concentration range 0.1 – 1.2 g/l, the chemical reductive action of carbon of ferric iron was confirmed and a kinetic expression for this reaction was determined. A mathematical model was developed which incorporated expressions for the kinetic of bacterial oxidation of ferrous ion and the chemical reduction of ferric ion. This model enabled the prediction of the rate of bacterial growth and ferrous ion oxidation in a bioreactor as a function of the initial concentrations of iron, activated carbon and bacterial population. Results in this work imply that the observed variations in activity observed by other authors during bacterial oxidation of ferrous iron with A. ferrooxidans adsorbed on carbon can be in fact related to bacterial utilization of supplementary ferrous iron produced by the chemical action of carbon, phenomenon which is not explicitly accounted for.


2016 ◽  
Vol 167 (5) ◽  
pp. 357-366 ◽  
Author(s):  
Jiri Kucera ◽  
Eva Pakostova ◽  
Jan Lochman ◽  
Oldrich Janiczek ◽  
Martin Mandl

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