Uso de carvão de osso bovino na defluoretação de água para uso em abastecimento público

• Ano de defesa: 2011
• Autor(a) principal: Marcos Vinicius Ribeiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Precipitação; Carvão de osso; Flúor; Defluoretação; Adsorção; Engenharia metalúrgica; Tecnologia mineral; Fluoretos
• Link de acesso: http://hdl.handle.net/1843/CMBC-8RZPRF

Fluoride is a chemical element which can be found in small quantities in natural waters (0,1 to 2,0 mg/L) and its occurrence is mainly due to weathering of some minerals such as fluorite (CaF2). The increasing pollution of surface waters has hindered its use for drinking, leading to the interest and needings to use groundwater. The fluoride concentration in drinking water up to 2,0mg/L causes problems such as bone and dental fluorosis in the population. This work reports an alternative method for the removal of the excess of fluoride in water using bone charcoal supplied by Bonechar®. The bonechar was characterized by XRD, FTIR, SEM/EDS, ASE methodology for BET, TG/DTG and determination of CHN. The results indicated that hydroxyapatite [Ca10(PO4)6(OH)2] is the main crystalline phase on bonechar. Minor amounts of calcite (CaCO3) was detected. The specific surface area determined was 119 m2/g as well as it was observed high porosity (macropores). The fluoride removal capacity of charcoal has been evaluated in t batch adsorption tests. The concentration of fluoride was determined by specific ion electrode. The isotherms were constructed using granular bone charcoal "in natura", granular coal washed with HCL 0,1mol/L and coal "fresh" ground at room temperature. The classical models of Langmuir and Freundluich were both suitable to represent the results. Adsorption capacities of 2,96mg/g for granular coal "in nature" and 3,44mg/g for granular coal washed were obtained. The Lagergren kinetic equation of 2nd order represented well the results, thus indicating the important chemical contribution of adsorption mechanism. This result was corroborated by the observation of the surface of the loaded coal bearing high amounts of fluoride and calcium, which indicated the presence of calcium fluoride on the surface of the adsorbent. The results is important to design the system for water defluoridation in domestic and industrial scales.