Influence of zinc on ferrous iron bio-oxidation: Biological or physical nature?

Mazuelos, Alfonso; Iglesias, N.; Romero, R.; Mejías, Miguel Ángel; Carranza, Francisco

doi:10.1016/j.bej.2009.12.018

Cited by 5 publications

(6 citation statements)

References 35 publications

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“…Fe 2+ concentration was determined with K 2 Cr 2 O 7 0.05 N (accuracy ±3 mg L −1 ) by potentiometric titration (Radiometer‐Copenhagen). [Cu] and [Fe] were determined by atomic absorption spectroscopy (Perkin Elmer 2380) at 324.8 nm (Cu) and 248.3 nm (Fe) in air‐acetylene flame.…”

Section: Methodsmentioning

confidence: 99%

“…Bio‐oxidation can be improved using reactors designed specifically for this purpose. Among the tested designs, the one which has shown the greatest Fe 3+ productivities is the flooded packed bed reactor . In these reactors, cells adhere to the particles of the packed bed forming a bio‐film, and they are fed with liquors containing Fe 2+ and air, which are introduced through the bottom of the reactor and flow upward.…”

Section: Introductionmentioning

confidence: 99%

“…This paper shows the results obtained from studying the effect of Cu 2+ on Fe 2+ bio‐oxidation, with the novelty of experiments being conducted in continuous operation of a packed bed bioreactor with immobilised cells. Using this type of bioreactor, as well as obtaining results about the influence of Cu 2+ on bio‐oxidation in a device closer to industrial reality, it is possible to attain steady state conditions for the microbial population that it holds . Like this, it is possible to maintain cells' response to variations in [Cu 2+ ] in the feed through time.…”

Section: Introductionmentioning

confidence: 99%

“…Using this type of bioreactor, as well as obtaining results about the influence of Cu 2+ on bio-oxidation in a device closer to industrial reality, it is possible to attain steady state conditions for the microbial population that it holds. 18,19 Like this, it is possible to maintain cells' response to variations in [Cu 2+ ] in the feed through time. Special attention will be paid to cell oxygenation in the aim of testing whether the negative effect of Cu 2+ on Fe 2+ is exclusively biotic, as stated in the literature, or, on the contrary, it bears some relation to oxygen solubility reduction as a result of the salting-out effect.…”

Section: Introductionmentioning

confidence: 99%

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Causes of inhibition of bioleaching by Cu are also thermodynamic

Mazuelos

García-Tinajero

Romero

et al. 2018

J of Chemical Tech & Biotech

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BACKGROUND Cu is an indispensable natural resource for society, as its use is widespread and essential for many technologies. Consequently, worldwide production is around 18×106 tn year−1, and close to 25% is produced by bioleaching. Bioleaching enables Cu extraction from minerals in atmospheric conditions by virtue of the catalytic activity of microorganisms. Microbial catalysis is mainly based on Fe3+ production as a leaching agent, a process known as Fe2+ bio‐oxidation. However, bio‐oxidation is inhibited by Cu2+ which limits the use of bioleaching with Cu mineral ores. RESULTS This paper, for the first time, examines the effect of Cu2+ on continuous Fe2+ bio‐oxidation using a packed bed bioreactor with supported cells. Bio‐oxidation was possible in the presence of 20 g L−1 Cu2+, with a less than 25% reduction in rate. About 15% of this drop in rate is due to biological inhibition and the rest to a reduction in oxygen solubility because of salting‐out. The biotic effect is reversed when Cu2+ is removed from the input, and the salting‐out effect can be overcome by improving aeration conditions. CONCLUSION These results, apart from having important ramifications for designing Cu ore bioleaching facilities, contribute to a more versatile and competitive idea of this clean technology. © 2018 Society of Chemical Industry

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Causes of inhibition of bioleaching by Cu are also thermodynamic

Mazuelos

García-Tinajero

Romero

et al. 2018

J of Chemical Tech & Biotech

Self Cite

View full text Add to dashboard Cite

show abstract

“…Like natural acid mine drainage (AMD) systems, low-pH Fe(II)-oxidizing (FeOX) reactors typically exhibit such low taxonomic diversity and have been used for cost-effective removal of iron from AMD. Like many microbial reactors, these systems can suffer from process instability that arises due to changes in influent pH (Mousavi et al, 2007;Mazuelos et al, 2010a), Fe(II) concentrations (Mazuelos et al, 2001;Mousavi et al, 2007;Ojumu et al, 2008;Ojumu et al, 2009;Mazuelos et al, 2010a;Mazuelos et al, 2010b;Mazuelos et al, 2012;Fernandez-Rojo et al, 2017), aeration rates (Mazuelos et al, 2001;Mazuelos et al, 2010b;Fernandez-Rojo et al, 2017), temperature and salinity (Ojumu et al, 2008;Ojumu et al, 2009). In previous work, Sheng et al (2016) operated lab-scale stirred reactors in chemostatic mode at a variety of pH and [Fe(II)] setpoints in order to establish a generalized rate law for microbial Fe(II) oxidation (Sheng et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Functional redundancy imparts process stability to acidic Fe(II)‐oxidizing microbial reactors

Ayala

Simister

Crowe

et al. 2020

Environmental Microbiology

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In previous work, lab-scale reactors designed to study microbial Fe(II) oxidation rates at low pH were found to have stable rates under a wide range of pH and Fe(II) concentrations. Since the stirred reactor environment eliminates many of the temporal and spatial variations that promote high diversity among microbial populations in nature, we were surprised that the reactors supported multiple taxa presumed to be autotrophic Fe(II) oxidizers based on their phylogeny. Metagenomic analyses of the reactor communities revealed differences in the metabolic potential of these taxa with respect to Fe(II) oxidation and carbon fixation pathways, acquisition of potentially growth-limiting substrates and the ability to form biofilms. Our findings support the hypothesis that the long-term co-existence of multiple autotrophic Fe(II)oxidizing populations in the reactors are due to distinct metabolic potential that supports differential growth in response to limiting resources such as nitrogen, phosphorus and oxygen. Our data also highlight the role of biofilms in creating spatially distinct geochemical niches that enable the coexistence of multiple taxa that occupy the same apparent metabolic niche when the system is viewed in bulk. The distribution of key metabolic functions across different co-existing taxa supported functional redundancy and imparted process stability to these reactors.

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Biotic factor does not limit operational pH in packed-bed bioreactor for ferrous iron biooxidation

Mazuelos

Moreno

Carranza

et al. 2012

Journal of Industrial Microbiology and Biotechnology

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Ferrous ion biooxidation is a process with many promising industrial applications: mainly regeneration of ferric ion as an oxidizing reagent in bioleaching processes and depuration of acid mine drainage. The flooded packed-bed bioreactor (FPB) is the design that leads to the highest biooxidation rate. In this bioreactor, biomass is immobilized in a biofilm that consists of an inorganic matrix, formed by precipitated ferric compounds, in the pores of which cells are attached. This biofilm covers the surface of particles (siliceous stone) that form the bed. The chemical stability of this inorganic matrix defines the widest possible pH range in FPBs. At pH below 1, ferric matrix is dissolved and cells are washed out. At pH higher than 2, ferric ion precipitates massively, greatly hindering mass transfer to cells. Thus, among other parameters, pH is recognised as a key factor for operational control in FPBs. This paper aims to explain the effect of pH on FPB operation, with an emphasis on microbial population behaviour. FPBs seeded with mixed inocula were assayed in the pH range from 2.3 to 0.8 and the microbial population was characterised. The microbial consortium in the bioreactor is modified by pH; at pH above 1.3 Acidithiobacillus ferrooxidans is the dominant microorganism, whereas at pH below 1.3 Leptospirillum ferrooxidans dominates. Inoculum can be adapted to acidity during continuous operation by progressively decreasing the pH of the inlet solution. Thus, in the pH range from 2.3 to 1, the biotic factor does not compromise the bioreactor performance.

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Influence of zinc on ferrous iron bio-oxidation: Biological or physical nature?

Cited by 5 publications

References 35 publications

Causes of inhibition of bioleaching by Cu are also thermodynamic

Causes of inhibition of bioleaching by Cu are also thermodynamic

Functional redundancy imparts process stability to acidic Fe(II)‐oxidizing microbial reactors

Biotic factor does not limit operational pH in packed-bed bioreactor for ferrous iron biooxidation

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