Thermal Decomposition Kinetics of Humic Substances Extracted from Mid-Rio Negro (Amazon Basin) Soil Samples
نویسندگان
چکیده
Neste trabalho substâncias húmicas (SH) extraídas de solos não alagáveis (Araçá) e alagáveis (Iara) foram caracterizadas com cálculos de estabilidade e energias de ativação associadas com a desidratação e decomposição térmica de SH utilizando TGA and DTA, ressonância paramagnética eletrônica (EPR) e razões atômicas C/H, C/N e C/O. Para SH extraídas de solos alagáveis, existe evidências da influência da umidade sobre o processo de humificação da matéria orgânica. Observações do comportamento térmico, com análise elementar, indicaram a presença de fósseis de carbono orgânico nas partículas de argila, o que só decompõe acima de 800 oC. Essa característica pode explicar as diferentes estabilidades térmicas e energias de ativação requeridas na pirólise para amostra Iara comparada a amostra Araçá.
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Podzolisation and exportation of organic matter in black waters of the Rio Negro (upper Amazon basin, Brazil)
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REFERENCIAS Y ENLACES [1] F. J. Stevenson, Humus Chemistry: Genesis, Composition, Reactions, Wiley Interscience, New York (1994). [2] G. R. Aiken, “Isolation and concentration technique for aquatic humic substances”, p. 363−385 in Humic Substances in Soil, Sediment and Water, G. R. Aiken, D. M. McKnight, R. L. Wershaw, P. MacCarthy, Edts., Wiley, New York (1985). [3] Y. Inbar, Y. Chen, Y. Hadar...
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