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| Titel |
Characterisation of the bacterial populations in a saline heat storage aquifer in the North German Basin |
| VerfasserIn |
M. Alawi, S. Lerm, A. Vetter, A. Vieth, K. Mangelsdorf, A. Seibt, M. Wolfgramm, H. Würdemann |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029391
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| Zusammenfassung |
| The colonization and the ecology of microorganisms in the deep biosphere arouse
increasing interest of scientists because of utilizing the subsurface for e.g. energy
storage and recovery. The research project AquiScreen investigates the operational
reliability of eight geothermally used groundwater systems in Germany under microbial,
geochemical, mineralogical, and petrological aspects. This study shows the results of the
heat storage in Neubrandenburg (depth: 1250 m), a typical site for saline fluids in
the North German Basin. The seasonal alternation in charge and discharge mode
enabled sampling the warm (75Ë C) and the cold (45Ë C) side of the geothermal
doublet.
The analyses focus on microbially induced corrosion on plant components and
scaling resulting in filter and/or formation clogging. Microbiological analyses were
carried out with fluid and solid phase samples by 16S rDNA based Single Strand
Conformation Polymorphism (SSCP) fingerprinting. The analyses are utilized to evaluate
the impact of microbial populations on such systems. The genetic fingerprinting
revealed significant differences in the bacterial community structure between the
warm and cold side of the heat storage. Since the geochemical analyses revealed no
remarkable differences, the temperature might be crucial for the different community
structures. At the warm side of the aquifer the identified bacteria are closely related to
Variovorax and Sphingomonas. At the cold side of the heat storage sulphate reducing
and fermentative bacteria were detected. These results correspond with locally
observed iron sulphide precipitation and corrosion processes on plant components.
Particularly the bacterial population of the cold side was studied over a period of
two years. Thereby seasonal changes in the abundance of the identified bacteria,
depending on the operational mode of the geothermal plant, were observed. After a
malfunction in the pump system of the cold side of the heat storage changes in the
bacterial population structure were recognized by SSCP fingerprinting techniques. |
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