Enhancing the activity of iron-oxidising bacteria: A case study with process liquors from heap bioleaching of a complex sulphide ore
| Autor: | Minna Peltola, Sarita Ahoranta, Aino-Maija Lakaniemi, Jaakko A. Puhakka |
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| Rok vydání: | 2017 |
| Předmět: |
Cadmium
biology Nitrogen deficiency Microorganism Metallurgy Metals and Alloys chemistry.chemical_element Vanadium 02 engineering and technology Acidithiobacillus 010501 environmental sciences biology.organism_classification 01 natural sciences Industrial and Manufacturing Engineering 020501 mining & metallurgy Ferrous Nutrient 0205 materials engineering chemistry Bioleaching Environmental chemistry Materials Chemistry 0105 earth and related environmental sciences |
| Zdroj: | Hydrometallurgy. 167:163-172 |
| ISSN: | 0304-386X |
| DOI: | 10.1016/j.hydromet.2016.11.010 |
| Popis: | In the present study, six process liquors (PL1 - PL6) originating from heap bioleaching of a complex sulphide ore were examined to reveal factors limiting microbial activity in the bioheaps. PL4 had the lowest iron oxidation activity even though its indigenous iron-oxidising community was diverse (Acidithiobacillus, Leptospirillum, Acidiferrobacter, and Sulfobacillus species). Shake flask experiments at 27 °C revealed that ferrous iron (Fe2+) and aluminium (Al3+) concentrations up to 16 and 12 g/L, respectively, were not inhibitory for the iron-oxidising microorganisms in PL4. In addition, Al3+ concentrations of ≤ 6 g/L were shown to enhance iron oxidation rates. High correlation between increased concentrations of cadmium (Cd), sulphate (SO42−), and vanadium (V) and decreased iron oxidation rates was detected when comparing process liquors 1–6. Moreover, possible nutrient limitation in PL4 was delineated by selectively supplementing it with macro- and micronutrients. Supplementation of 320 mg/L of nitrogen (as NH4+) to PL4 significantly increased iron oxidation rates from 20 mg/L/h (no nutrient supplementation) to 160 mg/L/h and would likely also enhance the heap bioleaching process. Additionally, microorganisms growing in high inhibitory ion concentrations (e.g. Cd2+) were shown to be more sensitive to nitrogen deficiency than microorganisms growing in more dilute liquors. |
| Databáze: | OpenAIRE |
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