Carvão hidrotérmico: avaliação das características húmicas e do efeito no desenvolvimento de plantas
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2019-07-12
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Universidade Estadual Paulista (Unesp)
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O Brasil é um dos maiores produtores de cana-de-açúcar do mundo. A produção de açúcar e etanol a partir da cana gera subprodutos, como a vinhaça e o bagaço de cana. A vinhaça vem sendo empregada na fertirrigação de culturas, e o bagaço de cana na cogeração de energia. Problemas como salinização do solo, contaminação de lençol freático, com a mosca do estábulo (dificultado o ganho de peso do gado e provocando diminuição na produção de leite) são relatados. O emprego destes na carbonização hidrotérmica (CHT) é uma alternativa, ambientalmente adequada, para sua disposição. A CHT é um processo de conversão termoquímica de biomassa, o qual produz um material sólido rico em carbono (carvão hidrotérmico), e uma fração líquida (água de processo). As características do carvão hidrotérmico mostram potencial para sua utilização como condicionantes de solos. Já a água de processo poderia ser utilizada como fertilizante líquido. Assim, o objetivo deste trabalho foi caracterizar o carvão hidrotérmico quanto as suas características húmicas, comparando-as com as de solos Terrra Mulata; avaliar os efeitos da aplicação de carvão hidrotérmico como fertilizante na cultura de milho para diferentes solos e taxas de aplicação. Ainda, foram avaliados os efeitos no desenvolvimento inicial de milho, alface e tomate, na presença da água de processo; a toxicidade da água de processo para Artemia salina; e o efeito do carvão hidrotérmico no desenvolvimento inicial de milho e tomate, por meio de extratos obtidos em água e solução ácida. A caracterização húmica mostrou que compostos resultantes de degradação biológica, assim como diferentes estruturas de lignina estavam presentes da composição dos ácidos húmicos de solos Terra Mulata, porém não foram observados na composição do material tipo-húmico. Entre as culturas analisadas, a água de processo melhor estimulou o desenvolvimento das sementes de milho, especialmente na concentração de 250 mg C L-1. A água de processo foi classificada como praticamente não tóxica para Artemia salina. O extrato aquoso de carvão hidrotérmico melhor estimulou o desenvolvimento tanto de milho quanto de tomate, cujas melhores concentrações foram 100 e 50 mg C L-1 respectivamente. Para a aplicação em solo, não foram observadas diferenças na produção de biomassa entre as taxas de aplicação avaliadas, indicando que o mesmo não atuou negativamente no desenvolvimento de milho.
Brazil is the largest producer of sugarcane in the world. The production of sugar and ethanol from sugarcane generates by-products such as vinasse and sugarcane bagasse. Vinasse has been used in crop fertigation, and sugarcane bagasse is used in energy cogeneration. Although their applications are known, there is a surplus of these materials that are stocked at the industries. Problems linked to soil salinization, groundwater contamination, problems with the stable fly (decrease at cattle gain weight and decrease in milk production) are reported. Their use in hydrothermal carbonization (CHT) is an environmentally friendly alternative for their disposal. CHT is a biomass thermochemical conversion process, which produce a solid material rich in carbon (hydrochar), and liquid fraction (process water). The hydrochar characteristics showed potential for its use as soil conditioners. Further, the process water could be used as liquid fertilizer. Thus, the aim of this work was the hydrochar characterization regarding its humic characteristics, comparing them with those from Terra Mulata soils; the evaluation of hydrochar as fertilizer in maize crop with different application rates using different soils. Further, it was evaluated the effects of maize, lettuce and tomato in the inicial development by the use of process water; the process water toxicity to Artemia salina organisms; the effects of hydrochar in the inicial development of maize and lettuce by acid and water extracts obtained from hydrochar. The humic characterization showed that compounds from microbiological degradation as different lignin derivatives were present in the humic acid from Terra Mulata soils, however these compounds were not observed in the humic-like material. Among the crops evaluated, the process water better stimulated the development of maize seeds, specially at concentration of 250 mg C L-1. The process water was classified as practically non-toxic to Artemia salina. The aqueous extract from hydrochar better stimulated the development for maize at 100 mg C L-1 and for tomato at 50 mg C L-1. For soil application it was not observed differences in biomass production among the applications rates studied. This suggests that the hydrochar did not affected negatively the maize development.
Brazil is the largest producer of sugarcane in the world. The production of sugar and ethanol from sugarcane generates by-products such as vinasse and sugarcane bagasse. Vinasse has been used in crop fertigation, and sugarcane bagasse is used in energy cogeneration. Although their applications are known, there is a surplus of these materials that are stocked at the industries. Problems linked to soil salinization, groundwater contamination, problems with the stable fly (decrease at cattle gain weight and decrease in milk production) are reported. Their use in hydrothermal carbonization (CHT) is an environmentally friendly alternative for their disposal. CHT is a biomass thermochemical conversion process, which produce a solid material rich in carbon (hydrochar), and liquid fraction (process water). The hydrochar characteristics showed potential for its use as soil conditioners. Further, the process water could be used as liquid fertilizer. Thus, the aim of this work was the hydrochar characterization regarding its humic characteristics, comparing them with those from Terra Mulata soils; the evaluation of hydrochar as fertilizer in maize crop with different application rates using different soils. Further, it was evaluated the effects of maize, lettuce and tomato in the inicial development by the use of process water; the process water toxicity to Artemia salina organisms; the effects of hydrochar in the inicial development of maize and lettuce by acid and water extracts obtained from hydrochar. The humic characterization showed that compounds from microbiological degradation as different lignin derivatives were present in the humic acid from Terra Mulata soils, however these compounds were not observed in the humic-like material. Among the crops evaluated, the process water better stimulated the development of maize seeds, specially at concentration of 250 mg C L-1. The process water was classified as practically non-toxic to Artemia salina. The aqueous extract from hydrochar better stimulated the development for maize at 100 mg C L-1 and for tomato at 50 mg C L-1. For soil application it was not observed differences in biomass production among the applications rates studied. This suggests that the hydrochar did not affected negatively the maize development.
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Solos, Fertilizante, Germinação, Crescimento, Carbonização, Soil, Fertilizer, Germination, Growth, Carbonization