Optimization of kinetics and operating parameters for the bioleaching of heavy metals from sewage sludge, using co-inoculation of two Acidithiobacillus species
This study explores the potential for synchronous extraction of Cu, Cr, Ni and Zn during sewage sludge bioleaching processes, using three types of bacterial cultures: a pure culture of Acidithiobacillus ferrooxidans (A. ferrooxidans); a pure culture of Acidithiobacillus thiooxidans (A. thiooxidans);...
| Veröffentlicht in: | Water science and technology : a journal of the International Association on Water Pollution Research. - 1986. - 2017(2018), 2 vom: 31. Mai, Seite 390-403 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2018
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| Zugriff auf das übergeordnete Werk: | Water science and technology : a journal of the International Association on Water Pollution Research |
| Schlagworte: | Journal Article Ferrous Compounds Metals, Heavy Sewage Water Pollutants Sulfur 70FD1KFU70 |
| Zusammenfassung: | This study explores the potential for synchronous extraction of Cu, Cr, Ni and Zn during sewage sludge bioleaching processes, using three types of bacterial cultures: a pure culture of Acidithiobacillus ferrooxidans (A. ferrooxidans); a pure culture of Acidithiobacillus thiooxidans (A. thiooxidans); and a mixed culture of A. ferrooxidans and A. thiooxidans. Variable operating parameters included initial pH, solids concentration, sulfur concentration and ferrous iron concentration, with optimization via Box-Behnken design of response surface methodology. Results indicate that the mixed culture of A. ferrooxidans and A. thiooxidans, was the most effective at bioleaching heavy metals from sewage sludge. The optimal operating conditions were as follows: an initial pH of 2.0, with concentrations of 3% solids, 6.14 g L-1 sulfur and 4.55 g L-1 ferrous iron. Maximum extraction efficiencies obtained after 14 days of bioleaching under optimal conditions, were 98.54% Cu, 57.99% Cr, 60.06% Ni and 95.60% Zn. Bioleaching kinetics were effectively simulated using a shrinking core model to explain the leaching reaction, with modelling results suggesting that the rate was determined by the diffusion step |
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| Beschreibung: | Date Completed 03.08.2018 Date Revised 02.12.2018 published: Print Citation Status MEDLINE |
| ISSN: | 0273-1223 |
| DOI: | 10.2166/wst.2018.167 |