Iron oxidation and precipitation in a simulated heap leaching solution in a Leptospirillum ferriphilum dominated biofilm reactor

Özkaya, Bestamin; Şahinkaya, Erkan; Nurmi, Pauliina; Kaksonen, Anna H.; Puhakka, Jaakko A.

doi:10.1016/j.hydromet.2007.02.009

Cited by 35 publications

(19 citation statements)

References 27 publications

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“…Nevertheless, both pH and temperature play a key role on iron concentration (and thus Eh values) due to ferric iron precipitation as jarosite. Although pH values below 2.0 are recommended to prevent jarosite formation (Pina et al, 2010), its precipitation is kinetic controlled, thus at high temperatures, such as those applied during leaching with moderate thermophiles the precipitation rate is increased (Daoud and Karamanev, 2006; Ozkaya et al, 2007; van Hille et al, 2010). Hence, jarosite precipitation was significant even at pH below 2.0 in the current work, thus controlling iron solubility and explaining the above-mentioned results (Figure 3B).…”

Section: Discussionmentioning

confidence: 99%

Column Bioleaching of Fluoride-Containing Secondary Copper Sulfide Ores: Experiments With Sulfobacillus thermosulfidooxidans

Rodrigues

Santos

Leôncio

et al. 2019

Front. Bioeng. Biotechnol.

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Bioleaching is a mature technology, which is widely employed commercially in the leaching of primary sources of metals (ores, concentrates, and mine residues). The current work discussed the effects of aluminum sulfate additions to the growth medium, PLS recirculation and bleeding on the column bioleaching of secondary copper sulfide ores with a significant content of fluoride-containing minerals. Fluoride is toxic to bacteria at the pH of bioleaching but its toxicity may be overcome in the presence of soluble aluminum and ferric iron. Therefore, experiments were carried out in 10 × 100 cm height aerated columns, loaded with 10 kg of crushed and agglomerated copper ore and inoculated with Sulfobacillus thermosulfidooxidans . Initially, fluoride concentrations of up to 2.5 g/L in the pregnant leach solution were observed due to the fast dissolution of fluoride-bearing minerals. Aluminum was added to the leaching solution to reduce the Al/F ratio so that the concentration of HF (the main toxic species) was decreased, but while the total fluoride concentration was higher than that of aluminum, the bacterial population as low. Therefore, the current work emphasizes that it is possible to set up conditions to enable bioleaching even at high fluoride concentrations. Following this approach, copper extractions above 90% were achieved for a H 2 SO 4 consumption ranging from 128.8 to 206.1 Kg/ton.

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Section: Discussionmentioning

confidence: 99%

Column Bioleaching of Fluoride-Containing Secondary Copper Sulfide Ores: Experiments With Sulfobacillus thermosulfidooxidans

Rodrigues

Santos

Leôncio

et al. 2019

Front. Bioeng. Biotechnol.

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“…During this period, DO sharply decreased from 2.50 to 0.25 mg/L and accordingly effluent Fe 2+ concentration increased from 800 to 9,500 mg/L. Due to the oxygen mass transfer limitation, Fe 2+ conversion was 55% during this period [13].…”

Section: Fluidized Bed Reactor Performancementioning

confidence: 93%

“…Thereafter, the FBR was operated at HRT between 1.5 and 5 h at pH 2 (Regime-3). Detailed information on the FBR and process variables has been reported by Ozkaya et al [13].…”

Section: Fluidized Bed Reactormentioning

confidence: 99%

Biologically Fe2+ oxidizing fluidized bed reactor performance and controlling of Fe3+ recycle during heap bioleaching: an artificial neural network-based model

Özkaya

Şahinkaya

Nurmi

et al. 2007

Bioprocess Biosyst Eng

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The performance of a biological Fe(2+) oxidizing fluidized bed reactor (FBR) was modeled by a popular neural network-back-propagation algorithm over a period of 220 days at 37 degrees C under different operational conditions. A method is proposed for modeling Fe(3+) production in FBR and thereby managing the regeneration of Fe(3+) for heap leaching application, based on an artificial neural network-back-propagation algorithm. Depending on output value, relevant control strategies and actions are activated, and Fe(3+) production in FBR was considered as a critical output parameter. The modeling of effluent Fe(3+) concentration was very successful, and an excellent match was obtained between the measured and the predicted concentrations.

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“…Biofilms cost the USA literally billions of dollars every year in energy losses, equipment damage, product contamination, and medical infections . But biofilms can also offer huge potential for bio‐remediating hazardous waste sites, bio‐filtering municipal and industrial water and waste water, forming bio‐barriers to protect soil and ground water from contamination, as well as heap leaching .…”

Section: Introductionmentioning

confidence: 99%

3‐D spatio–temporal structures of biofilms in a water channel

Chen

Hou

Ren

et al. 2014

Math Methods in App Sciences

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We develop a numerical predictive tool for multiphase fluid mixtures consisting of biofilms grown in a viscous fluid matrix by implementing a second-order finite difference discretization of the multiphase biofilm model developed recently on a general purpose graphic processing unit. With this numerical tool, we study a 3-D biomass-flow interaction resulting in biomass growth, structure formation, deformation, and detachment phenomena in biofilms grown in a water channel in quiescent state and subject to a shear flow condition, respectively. The numerical investigation is limited in the viscous regime of the biofilm-solvent mixture. In quiescent flows, the model predicts growth patterns consistent with experimental findings for single or multiple adjacent biofilm colonies, the so-called mushroom shape growth pattern. The simulated biomass growth both in density and thickness matches very well with the experimentally grown biofilm in a water channel. When shear is imposed at a boundary, our numerical studies reproduce wavy patterns, pinching, and streaming phenomena observed in biofilms grown in a water channel.

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Iron oxidation and precipitation in a simulated heap leaching solution in a Leptospirillum ferriphilum dominated biofilm reactor

Cited by 35 publications

References 27 publications

Column Bioleaching of Fluoride-Containing Secondary Copper Sulfide Ores: Experiments With Sulfobacillus thermosulfidooxidans

Column Bioleaching of Fluoride-Containing Secondary Copper Sulfide Ores: Experiments With Sulfobacillus thermosulfidooxidans

Biologically Fe2+ oxidizing fluidized bed reactor performance and controlling of Fe3+ recycle during heap bioleaching: an artificial neural network-based model

3‐D spatio–temporal structures of biofilms in a water channel

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