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篇目详细内容 |
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【篇名】 |
Features of ferric sulfate precipitates formed by different cultivations of Acidithiobacillus ferrooxidans |
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【刊名】 |
Frontiers of Earth Science in China |
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【刊名缩写】 |
Front. Earth Sci. China |
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【ISSN】 |
1673-7385 |
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【EISSN】 |
1673-7490 |
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【DOI】 |
10.1007/s11707-010-0018-4 |
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【出版社】 |
Higher Education Press and Springer-Verlag Berlin
Heidelberg |
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【出版年】 |
2010 |
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【卷期】 |
4
卷2期 |
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【页码】 |
152-159
页,共
8
页 |
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【作者】 |
Xin WANG;
Yan LI;
Anhuai LU;
Changqiu WANG;
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【关键词】 |
Acidithiobacillus ferrooxidans; electrochemical cultivation; schwertmannite; jarosite |
【摘要】 |
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This study focused on the ferric sulfate precipitates formed during the culture of Acidithiobacillus ferrooxidans (A. ferrooxidans) in a modified 9K medium by applying a potential control on the electrode. X-ray diffraction (XRD), environmental scanning electron microscope (ESEM), Raman spectroscopy (Raman) and Fourier Transform Infrared spectroscopy (FTIR) were carried out to characterize and identify the precipitates which were formed, respectively, in the electrochemical cultivation with a fixed cathode potential (bias-experiment) and in the conventional batch cultivation without cathode potential control (no-bias-experiment). The results indicated that K-jarosite presented in both experiments while NH4-jarosite and schwertmannite were only found in the no-bias-experiment. The formation of different precipitates could be attributed to the different growth statuses and rates of A. ferrooxidans and the different concentrations of Fe3+. In the bias-experiment, external electrons reproduced Fe2+ and promoted the growth of A. ferrooxidans, thus resulting in the low Fe3+ concentration and the rapid depletion of NH4+ as the nitrogen source, in which K-jarosite was preferentially formed. In the no-bias- experiment, the lower concentration of A. ferrooxidans was observed, which was due to the continuous consumption of Fe2+ by bacteria, thus resulting in the relatively higher Fe3+ and the NH4+ concentration in culture. The high concentration of Fe3+ favored the precipitation of the solid solution of K-NH4-H3O jarosite, and led to the formation of schwertmannite after K+ and NH4+ were depleted. |
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