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| Titel |
Biochemical stability of sewage sludge chars and their impact on soil organic matter of a Mediterranean Cambisol |
| VerfasserIn |
Marina Paneque, José María De la Rosa, Carlos Aragón, Jürgen Kern, Heike Knicker |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250121785
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| Publikation (Nr.) |
 EGU/EGU2016-632.pdf |
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| Zusammenfassung |
| Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is
necessary prior its application into agricultural soils. The pyrolysis of SS increases its
stability in a degree which depends on the thermal treatment used. Thus, chars produced by
using hydrothermal carbonization are typically more stable than normal soil organic matter
(SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of
highly-recalcitrant SS-chars to soil will likely increase its carbon sequestration potential;
however the fertilizing properties of SS may be compromised due to its alteration during the
pyrolysis.
The main goal of this work was to investigate the biochemical recalcitrance of two
13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their
impact on the SOM quality and carbon stability.
Thus, we studied the distribution of 13C between plants and soil after the addition of the
13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation
experiment, using a Mediterranean Cambisol as matrix and tested the following
treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was
produced in a pilot-scale waste-water plant and enriched with 13C by the addition of
13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of
the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of
Lolium perenne were sowed and incubated under controlled conditions. The biomass
production as well as the concentration of 13C in leaves and roots was determined
after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its
transformation into bioavailable forms were monitored by stable isotopic mass
spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR
spectroscopy as a means for the detection of chemical alterations of the chars during their
aging.
Libra J., Ro K., Kammann C., Funke A., Berge N., Neubauer Y., Titirici M., Fuhner C.,
Bens O., Kern J., Emmerich K. (2011) Hydrothermal carbonization of biomass residuals: a
comparative review of the chemistry, processes and applications of wet and dry pyrolysis.
Biofuels, 2 (1), 89-124. |
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