Síntese e caracterização de biocarvões ativados a partir de resíduos de biomassa aplicados na remoção do herbicida 2,4-D em água

• Autor(a) principal: Brito, Gilberto Maia de
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/10892
• topic: Agricultural Biomass Residues; Activated Carbon; 2,4-D Herbicide; Adsorption Isotherms; Intermolecular Interaction; Computational Molecular Modeling; Isotermas de adsorção; Interação intermolecular; Modelagem molecular computacional; Resíduos de Biomassa Agrícola; Carvão Ativado; Herbicida 2,4-D; Engenharia Sanitária; Biomassa - Resíduos; Carbono ativado; Herbicidas; Adsorção; Cinética química; Termodinâmica; Simulação (Computadores); 628

In this work, porous and applied carbonaceous materials were synthesized and characterized in the removal of the 2,4-D herbicide present in contaminated water samples by adsorption. Activated carbons (ACs) were prepared using three different types of precursors of renewable origin and very common in Brazil: sugarcane bagasse, coconut shell and endocarp of babassu coconut. The activated charcoal production process was conducted by simultaneous carbonization and physical (steam) activation in a horizontal furnace with a heating ramp of 5.0 ° C min-1 to 800.0 °C, with a water injection of 200.0 ºC and with residence time of 1 hour at 800.0 ºC. Carbonized materials with the same types of precursors were also produced under the same conditions, but without physical activation for comparison purposes. The ACs and carbonized samples were characterized by the following techniques: specific surface area, thermogravimetry, X-ray diffraction, infrared, scanning electron microscopy, nuclear magnetic resonance and elemental analysis of oxygen content. The samples of the ACs produced were compared with commercial samples produced by the companies Bahia Carbon and Merck, in addition to other studies reported in the literature, in terms of specific surface area using the model proposed by BrunauerEmmett-Teller by adsorption of N2 gas at 77 K. The specific surface area values found for the carbon samples from sugarcane bagasse, coconut husk and endocarp of babassu coconut were equal to 547, 991 and 1068 m2 g -1 , respectively. The kinetic adsorption process of 2,4-D in aqueous solutions in the ACs was studied according to the Langmuir, Freundlich and other models and compared to each other. In the study of the intermolecular interaction Herbicide-Activated Charcoal, considering two types of herbicides, the (N- (phosphonomethyl) glycine (glyphosate) and 2,4-D, was carried out in the light of Computational Molecular Modeling by the semi empirical method and the thermodynamic parameters were obtained and evaluated.