Infravermelho na caracterização de ácidos húmicos de latossolo sob efeito de uso contínuo de lodo de esgoto

Abstract

RESUMOObjetivou-se caracterizar, por meio de espectroscopia no infravermelho com transformada de Fourier (IVTF), possíveis mudanças na natureza química de ácidos húmicos (AHs) extraídos de amostras de Latossolo (0-10 cm) do Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna (SP). Os dados foram obtidos após seis cultivos de milho e a aplicação de doses variáveis de lodo de esgoto de Barueri (LB) (base seca), conforme os tratamentos avaliados: LB0, LB1, LB2, LB4 e LB8, sendo 0, 1, 2, 4 e 8 vezes a necessidade de N para o milho. Como referência, foi amostrada uma área sob mata. Foram obtidos espectros de ácidos húmicos e do lodo de esgoto utilizado no experimento, e calculados os índices de hidrofobicidade (IH) e de condensação (IC) nas amostras de ácidos húmicos. Foram notadas pequenas alterações na natureza química de AHs de áreas tratadas com lodo de esgoto, em relação à testemunha. Os AHs apresentam grupos aromáticos, -OH fenólicos, -COOH, estruturas alifáticas, carboidratos e impurezas minerais. O uso contínuo de elevadas doses de LB reduziu a concentração de C-alifático e o grau de condensação dos ácidos húmicos, o que sinaliza que há frações orgânicas

Effects on the composition and structural properties of the humified organic matter of soil in sugarcane strawburning: A chronosequence study in the Brazilian Cerrado of Goiás State

“…The spectral bands did not indicate visible differences associated with specific functional groups for any of the studied conditions. However, the spectral range was similar to that reported in a number of studies (Dick et al, 2008;Czycza, 2009;Dias et al, 2009;Dobbss et al, 2009;Fontana et al, 2010;Crespo, 2011). Wide bands, typical of HA spectra, were observed in the 3440-3380 cm À1 range and correspond to OÀ ÀH stretching of the phenolic groups, the contribution of aliphatic OH groups and NH from several functional groups (Vergnoux et al, 2011).…”

Microbiological and biochemical properties of an agricultural Mexican soil amended with sewage sludge

“…It suggests that the aliphatic character of DOM of SS is higher than of unamended soil (Jackson, 1975). The aliphatic character of sewage sludge was reported by Dias et al (2009). The FTIR of the DOM of S-230, SL-230 and SH-230 samples were qualitatively similar to one another (Figure 1).…”

“…The addition of sewage sludge to the soil increased the OM and P contents (p < 0.05) in SS-treated soil, and the N contents by 1.54 times for SH-230 (p < 0.05). There are reports in the literature that sewage sludge added to soil raised the OM, P and N contents (Vaca et al, 2006;Dias et al, 2009).…”

Impact of HNO3 Solution Treatment of South Brazil Coal Matrices on Their Chemical Composition and Humic Acids Yield

“…The presence of the band in 1526 cm -1 shows that during treatment with 25% HNO 3 solution, the incorporation of NO 2 in the coal structure occurred in the HA fraction as already seen in other coals from Southern Brazil. 31,32 The values of relative intensities of HA were, in general, similar between samples R-FOR and RBC ( Table 8), indicating that after treatment with HNO 3 solution the HA of these samples showed a similar chemical composition. These results corroborate the C/N data ( Table 7).…”