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- Bjornbom, E., et al.
(författare)
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Reduction of NOx with NH3 in presence of pyrolysed macro-cycle catalyst
- 1991
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Reduction of NOx with NH3 in the presence of pyrolyzed cobalt-tetraphenylporphyrin, CoTPP 'macro-cycle black', was studied. Active carbon, Norit RBXS 1, was used as a carrier. The experimental conditions were varied as follows: temperature from 95 to 140°C, space velocity of the gas mixture 1000-5000 h-1 and catalyst content 0-1%. The results showed that, in the experimental range studied, the temperature has no significant effect on the conversion of NOx. The conversion of NOx at low space velocity of the gas (1000 h-1) was high (approx. 90%), both in the presence and absence of CoTPP black. This was explained by the fact that the active carbon used as a catalyst support also has a catalytic effect on the reduction of NOx. At low space velocity this effect is sufficient to achieve high conversion of NOx in the presence of active carbon only. The conversion decreased at higher space velocity, however. The presence of CoTPP black counteracted the negative effect of the increased space velocity. The effect of the 'macro-cycle black' on the conversion of NOx was significant at higher space velocitites.
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| 2. |
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| 3. |
- Logue, Jürg Brendan, et al.
(författare)
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Experimental insights into the importance of aquatic bacterial community composition to the degradation of dissolved organic matter
- 2016
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Ingår i: The ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 10:3, s. 533-545
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Tidskriftsartikel (refereegranskat)abstract
- Bacteria play a central role in the cycling of carbon, yet our understanding of the relationship between the taxonomic composition and the degradation of dissolved organic matter (DOM) is still poor. In this experimental study, we were able to demonstrate a direct link between community composition and ecosystem functioning in that differently structured aquatic bacterial communities differed in their degradation of terrestrially derived DOM. Although the same amount of carbon was processed, both the temporal pattern of degradation and the compounds degraded differed among communities. We, moreover, uncovered that low-molecular-weight carbon was available to all communities for utilisation, whereas the ability to degrade carbon of greater molecular weight was a trait less widely distributed. Finally, whereas the degradation of either low-or high-molecular-weight carbon was not restricted to a single phylogenetic clade, our results illustrate that bacterial taxa of similar phylogenetic classification differed substantially in their association with the degradation of DOM compounds. Applying techniques that capture the diversity and complexity of both bacterial communities and DOM, our study provides new insight into how the structure of bacterial communities may affect processes of biogeochemical significance.
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