02100nam a2200253 a 450000100080000000500110000800800410001910000220006024501340008226001930021630000080040952012110041765000120162865000250164065300230166565300160168865300300170470000140173470000130174870000210176170000190178270000250180170000200182619794692015-02-04       2013    bl uuuu     u00u1 u    #d1 aALHO, C. F. B. V.  aBiochar stable fraction quantification by thermochemical oxidation and assessement by 13C-NMR spectrocopy.h[electronic resource]  aIn: ENCONTRO BRASILEIRO DE SUBSTÂNCIAS HÚMICAS, 10., Santo Antônio de Goiás, GO, 2013. Anais... Porto Alegre: Grupo Brasileiro da Sociedade Internacional de substâncias húmicasc2013  a4p.  aAlthough biochar is often regarded lized into carbon dioxide. However, it is unclear how much of this material is rapidly oxidized, that is, how much remain in the soil for NQPIGTRGTKQFU'ƑQTVUJCXGDGGPWPFGTVCMGP to develop methodologies to quantify the stable fraction present in biochar, quickly, easily reproducible, and that somehow represents TGCN?GNFEQPFKVKQPU6JGTGHQTGVJGCKOQHVJKU UVWF[YCUVQGXCNWCVGVJGGƑGEVQHFKƑGTGPV R[TQN[UKU?PCNVGORGTCVWTGUQPVJGUVCDKNKV[QH biochar produced from Eucalyptus dunnii wood by analyzing biochar samples before and after a thermo-chemical oxidation using 13 C NMR spec- troscopy. Stable-C fraction increased as higher R[TQN[UKU?PCNVGORGTCVWTGYCU6JGTOQEJGOical oxidation was responsible for removing labile structures still present as well as aromatic structures less resistant to degradation. Thermo-chemical oxidation was also responsible for the functionalization of biochars, being this ef- HGEVOKNFGTCUJKIJGTR[TQN[UKU?PCNVGORGTCVWTG was. The balance between C storage (Stable-C HTCEVKQPCPFCITQPQOKEDGPG?VU HWPEVKQPCNK\Ction) of biochar should be carefully evaluated, as its characteristics can vary depending on the conditions by which it was produced.  abiochar  acarbon sequestration  aFunctionalizatio n  aSta- bility  aThermo-chemical oxidation1 aCROSS, A.1 aSOHI, S.1 aRODRIGUES, R. C.1 aNOVOTNY, E. H.1 aMAIA, C. M. B. de F.1 aLELIS, R. C. C.