Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal
Leaching experiments of solid matrices (bitumen and cement pastes) have been first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface (see the paper of Bertron et al.). Of course, as might be suspected, the cement matrix impo...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2013-07-01
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| Series: | EPJ Web of Conferences |
| Online Access: | http://dx.doi.org/10.1051/epjconf/20135601003 |
| _version_ | 1818789554675515392 |
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| author | Albrecht A. Rafrafi Y. Sablayrolles C. Bertron A. Kassim C. Alquier M. Erable B. |
| author_facet | Albrecht A. Rafrafi Y. Sablayrolles C. Bertron A. Kassim C. Alquier M. Erable B. |
| author_sort | Albrecht A. |
| collection | DOAJ |
| description | Leaching experiments of solid matrices (bitumen and cement pastes) have been first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface (see the paper of Bertron et al.). Of course, as might be suspected, the cement matrix imposes highly alkaline pH conditions (10 <pH <11). The screening of a range of anaerobic denitrifying bacterial strains led us to select Halomonas desiderata as a model bacterium capable of catalyzing the reaction of nitrate reduction in these extreme conditions of pH. The denitrifying activity of Halomonas desiderata was quantified in batch bioreactor in the presence of solid matrices and / or leachate from bitumen and cement matrices. Denitrification was relatively fast in the presence of cement matrix (<100 hours) and 2 to 3 times slower in the presence of bituminous matrix. Overall, the presence of solid cement promoted the kinetics of denitrification. The observation of solid surfaces at the end of the experiment revealed the presence of a biofilm of Halomonas desiderata on the cement paste surface. These attached bacteria showed a denitrifying activity comparable to planktonic bacterial culture. On the other side, no colonization of bitumen could be highlighted as either by SEM or epifluorescence microscopy. Now, we are currently developing a continuous experimental bioreactor which should allow us a more rational understanding of the bitumen-cement-microbe interactions. |
| first_indexed | 2024-12-18T14:41:25Z |
| format | Article |
| id | doaj.art-14aaedc6a2444aa5b19edeaf0337316b |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-12-18T14:41:25Z |
| publishDate | 2013-07-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-14aaedc6a2444aa5b19edeaf0337316b2022-12-21T21:04:23ZengEDP SciencesEPJ Web of Conferences2100-014X2013-07-01560100310.1051/epjconf/20135601003Nitrate reducing bacterial activity in concrete cells of nuclear waste disposalAlbrecht A.Rafrafi Y.Sablayrolles C.Bertron A.Kassim C.Alquier M.Erable B.Leaching experiments of solid matrices (bitumen and cement pastes) have been first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface (see the paper of Bertron et al.). Of course, as might be suspected, the cement matrix imposes highly alkaline pH conditions (10 <pH <11). The screening of a range of anaerobic denitrifying bacterial strains led us to select Halomonas desiderata as a model bacterium capable of catalyzing the reaction of nitrate reduction in these extreme conditions of pH. The denitrifying activity of Halomonas desiderata was quantified in batch bioreactor in the presence of solid matrices and / or leachate from bitumen and cement matrices. Denitrification was relatively fast in the presence of cement matrix (<100 hours) and 2 to 3 times slower in the presence of bituminous matrix. Overall, the presence of solid cement promoted the kinetics of denitrification. The observation of solid surfaces at the end of the experiment revealed the presence of a biofilm of Halomonas desiderata on the cement paste surface. These attached bacteria showed a denitrifying activity comparable to planktonic bacterial culture. On the other side, no colonization of bitumen could be highlighted as either by SEM or epifluorescence microscopy. Now, we are currently developing a continuous experimental bioreactor which should allow us a more rational understanding of the bitumen-cement-microbe interactions.http://dx.doi.org/10.1051/epjconf/20135601003 |
| spellingShingle | Albrecht A. Rafrafi Y. Sablayrolles C. Bertron A. Kassim C. Alquier M. Erable B. Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal EPJ Web of Conferences |
| title | Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal |
| title_full | Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal |
| title_fullStr | Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal |
| title_full_unstemmed | Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal |
| title_short | Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal |
| title_sort | nitrate reducing bacterial activity in concrete cells of nuclear waste disposal |
| url | http://dx.doi.org/10.1051/epjconf/20135601003 |
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