Comparação das energias de ativação e taxas de oxidação de ligninas kraft e da bananicultura oxidadas e seu possível uso como quelantes de íons de cobre.

• Autor(a) principal: Taha, Tarik Chaves
• Data de Publicação: 2022
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/217335
• topic: Lignin; Oxidation; Biorefinery; Heavy metals; Polution; Lignina; Oxidação; Biorrefinaria; Metais pesados; Poluição

Pollution is one of the most important environmental problems to be overcome and can be defined as a change in the parameters and natural properties of the environment, which can cause damage to the health, safety or well-being of the population subject to its effects. An important type of pollution is that caused by heavy metal. These remain in the environment and can accumulate in human and animal tissues, causing environmental impacts, health problems and deaths. Therefore, a less harmful relationship is necessary from the point of view of depletion of natural resources and environmental pollution, so that minimum environmental conditions can be guaranteed to allow the survival of the current and future generations. One of the ways to achieve this goal is by adding value to new sustainable products that can be used for environmental remediation, such as lignin, through chemical modifications such as oxidation. Therefore, the objective of this work was to quantify and compare the oxidation of kraft, organosolv and acid pretreatment lignins, using 20 and 40 µL of potassium permanganate, in addition to obtaining and comparing the activation energies for the wavelengths of 360 and 400 nm using also the two concentrations of the oxidant. Through the results it can be concluded that the highest oxidation was that of organosolv lignin using 40 µL at wavelengths of 360 and 400 nm at all temperatures except 70°C, with kraft lignin having been the highest for that temperature. At 520 nm kraft lignin had the highest overall oxidation considering all temperatures. As for the activation energies, the highest was that of the organosolv lignin from the oxidized banana leaf with 20 µL of potassium permanganate at both wavelengths (43,819 J/mol for 360 nm and 20,064 J/mol for 400 nm), and the lower was that of acid pretreatment lignin using 40 µL of oxidant (7,784 J/mol and 3,447 J/mol for 360 and 400 nm respectively). In the experiment involving lignin and lignin solutions with copper, the latter presented higher oxidation, indicating the complexation of the metal molecules to the lignin molecule (acid pretreatment)