%0 Journal Article
%T EPR and DRIFT spectroscopic characterization of humic fractions during composting of sawdust and paper mill sludge Caracteriza  o espectrosc¨®pica (RPE e DRIFT) das fra  es h¨²micas durante a compostagem de lodo de f¨¢brica de papel e serragem
%A Claudia Maria Branco de Freitas Maia
%A Cristiane Regina Budziak Fukamachi
%A Alessandro Piccolo
%A Antonio S¨¢lvio Mangrich
%J Pesquisa Florestal Brasileira
%D 2012
%I Embrapa Florestas
%R 10.4336/2012.pfb.70.1
%X The spectroscopic characteristics (DRIFT, UV-visible and EPR) of humic fractions were studied during composting of sawdust and paper mill sludge. Infrared spectroscopy reveals a compost rich in hydroxyl and alkyl groups and carboxylates and carbohydrates. The alkyl fraction is abundant in the humic acids and humin. The decreasing of the E4/E6 ratio during composting indicates an enhancement of the organic chains number, with conjugated double bonds. This decreasing would correspond to a reduction of the lignin content and/or formation of porphyrins. The EPR shows that humin presents the highest concentration of free radical and the lowest intensities of the Fe3+. doi: 10.4336/2012.pfb.32.70.01 The spectroscopic characteristics (DRIFT, UV-visible and EPR) of As caracter¨ªsticas espectrosc¨®picas (DRIFT, UV-vis¨ªvel e RPE) das fra  es h¨²micas foram estudadas durante a compostagem de serragem e lodo de f¨¢brica de papel. A espectroscopia de infravermelho (DRIFT) revelou um composto rico em hidroxilas, carboxilatos, alquilas e carboidratos. A fra  o alif¨¢tica est¨¢ concentrada nos ¨¢cidos h¨²micos e na humina. A diminui  o da raz o E4/E6 durante a compostagem indica um aumento de cadeias organicas com liga  es duplas conjugadas. Esta redu  o corresponderia a uma diminui  o do teor de lignina e/ou a forma  o de porfirinas. O RPE mostrou que a humina apresenta a concentra  o mais alta de radicais livres e a menor concentra  o de Fe3+ livre. doi: 10.4336/2012.pfb.32.70.01
%K Substancias h¨²micas
%K UV-vis
%K Humifica  o
%U http://www.cnpf.embrapa.br/pfb/index.php/pfb/article/view/303