Emiss?o de ?xido nitroso e metano proveniente da vinha?a em lagoas e canais de distribui??o e ap?s ferti-irriga??o

• Autor(a) principal: Paredes, D?bora da Silva
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/2684
• topic: Etanol; Gases de efeito estufa; Vinhoto; Aduba??o; Cana-de-a??car; Ethanol; Greenhouse gases; Stillage; Fertilization; Sugarcane; Agronomia

The vinasse, the main residue from ethanol production, has chemical characteristics that can lead to production of N2O and CH4. This study aimed to evaluate the potential emission of N2O and CH4 from vinasse lagoons and distribution channels, and the emissions resulting from the application of vinasse in soil. Emissions of greenhouse gases (GHG) from the lagoons and channels were quantified in a sugar mill plant of S?o Paulo, being evaluated from the release of the plant until a point farther, at approximately 10 km far. Three lagoons and four channel sections were considered. Static chambers used to gas sampling were placed at five different points in each lagoon, whilst four chambers spaced every 40 meters were used for each channel section. The amount of dissolved CH4 in vinasse was measured at a plant in Campos dos Goytacazes - RJ. The vinasse of this plant was also used to evaluate the contribution of accumulated mud at the bottom of the channels and lagoons on the emissions of CH4, which was done in a greenhouse at Embrapa Agrobiologia. For the evaluation of N2O emissions from the application of vinasse to soil, two experiments, one in a greenhouse and another in the field were carried out, both in the experimental area of Embrapa Agrobiologia. In these experiments, the direct N2O emissions were assessed along with losses through NH3 volatilization, which are used for calculations of indirect emissions of N2O. For the greenhouse, the treatments applied were fresh and old vinasse, filter cake, urea and control. In a second step, at the greenhouse and at field conditions, the treatments were vinasse, urea, urea with a subsequent application of vinasse, vinasse with a subsequent application of urea and control. The largest N2O and CH4 emissions were obtained in the vinasse channels; on average, 4.23 ? 0.14 mg N2O-N m-2 h-1 and 515.1 g CH4 m-2 h-1. The amount of dissolved CH4 present in samples of vinasse was an average of 2.55 ?g CH4 mL-1 vinasse. The addition of mud to the vinasse increased 4 folds CH4 fluxes. With the application of vinasse to soil, the highest percentages of N emissions as N2O were found for the vinasse treatment, which represented 15% under greenhouse conditions, and 0.6% and 2.5% for the first and second phases of the field experiment, respectively. Only the urea treatment showed significant N losses through NH3 volatilization, the highest under greenhouse (32%) and in the first phase of the field experiment (28.6% of applied N), and the lowest (2.5%) in the second phase of the field experiment. The storage of vinasse in lagoons and its distribution by channels are important sources of CH4 to the atmosphere, whilst its application to soil favors N2O emissions, restricted to the first 3 days after application. The volatilization of NH3 did not exceed 6% of N existing in the vinasse.