Caracterização físico-química de biochars provenientes de lodo de esgoto : influência de diferentes temperaturas de pirólise e atmosferas

• Ano de defesa: 2024
• Autor(a) principal: Pires, Keyla Bendia
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Agroquímica; Centro de Ciências Exatas, Naturais e da Saúde; UFES; Programa de Pós-Graduação em Agroquímica
• Palavras-chave em Português: Lama de depuração; Agronomia
• Link de acesso: http://repositorio.ufes.br/handle/10/17938

This research study, driven by population growth and the ensuing environmental challenges, is dedicated to exploring sustainable solutions for the treatment of sewage sludge (SS). The principal objective was to generate biochar derived from SS at three distinct locations within the southern region of Espírito Santo, Brazil. The pyrolysis process was conducted at temperatures of 350, 550, and 750°C in the presence or absence of argon flow. Atomic absorption spectroscopy (AAS) was utilized to assess the biochar's elemental composition, employing three distinct acid extraction methodologies for the nutritional analysis. The results obtained by AAS indicated significant data for the pseudo-total availability of potassium in Cachoeiro, at 550 °C under an argon atmosphere, reaching 15 g/kg, and calcium in Itaoca at 750 °C under an oxygen atmosphere, reaching 30 g/kg. In Pacotuba, the percentage availability of calcium reached 47% at 750 °C in an oxygen atmosphere. The percentage availability of manganese in Pacotuba also exhibited a significant result, reaching 25% at three treatment temperatures in an argon atmosphere. The second phase entailed a qualitative analysis employing scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction, and Fourier transform infrared spectroscopy (FT-IR). X-ray diffraction analysis revealed the formation of turbostratic carbon structures and the formation of crystalline structures of inorganic compounds. Scanning electron microscopy (SEM) images demonstrated that the particle's interior consisted of a dark core indicative of carbon, while lighter inorganic oxides adhered to the surface. Fourier transform infrared (FT-IR) analysis revealed the presence of structures such as hydroxyl groups and C-H stretches at wavelengths between 4000 and 3500 cm-1 . The present study significantly advances our understanding of environmental stewardship in a context of sustainable agricultural practices. Biochar has been proven to be an efficacious conditioning agent for potassium and calcium, as evidenced by this study