In this work, humic substances were extracted from water samples collected monthly from the Negro River basin in the Amazon state (Brazil) to study their properties in the Amazonian environment and interactions with the mercury ion considering the influence of seasonalness in this formation. The C/H, C/N and C/O atomic ratio parameters, functional groups, concentration of semiquinone-type free radicals, pH, plu...
Dependendo das condições do sistema, os ácidos húmicos podem atuar como oxidantes ou redutores. Nos sistemas naturais, o fluxo de elétrons está diretamente associado à quantidade e à qualidade do húmus. O potencial do eletrodo e a capacidade de oxidação informam sobre os fatores intensidade e capacidade dos sistemas redox, respectivamente. Estudos prévios têm aventado a hipótese de que radicais livres nos ácido...
The understanding of soil carbon stabilization processes can be very useful in the development of mitigation techniques for CO2 emissions and global warming. The greater the hydrophobicity of soil organic matter the more stabilized soil organic carbon. Therefore, hydrophobicity can be a sensitive index to characterize the ‘quality’ of soil organic matter. In this context, the present work aimed to characterize...