Estudo da concentração e recuperação de íons lantânio e neodímio por biossorção em coluna com a biomassa Sargassum sp
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Data
2007-03-26
Autores
Oliveira, Robson Caldas de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O processo de biossorção tem sido reconhecido como alternativa potencial na concentração de metais pesados e radioisótopos a partir de corpos d'água que recebem ação antropogênica (indústria, mineração, etc.). A biossorção é um processo que se baseia na remoção de íons metálicos de uma solução, a partir de interações entre o metal e determinados sítios ativos presentes em revestimentos celulares, provenientes de biomassas como algas, bactérias e fungos. Em geral utiliza-se a biomassa inativa (morta), pois se eliminam problemas de toxicidade dos metais na biomassa viva e custos com nutrientes. Há também na literatura crescente interesse na concentração, recuperação e separação de metais de grande interesse tecnológico, como as terras-raras (TR). Os metais de elementos TR são essenciais para fabricação de produtos de alta tecnologia tais como laseres, supercondutores, catalisadores para craqueamento de petróleo, equipamentos miniaturizados, lâmpadas fluorescentes, satélites, fósforos,absorvedores de radiação ultravioleta, magnetos permanentes e armazenadores de informação. Apesar de apresentarem maior disponibilidade na natureza que metais como zinco e cobre, possuem alto valor agregado devido aos dispendiosos e complexos processos de separação e purificação de misturas de TR, resultado da alta similaridade química entre os elementos do grupo, envolvendo inúmeros passos de extração com solventes e/ou resinas de troca-iônica. Poucos países detêm processos de separação de TR e, dessa forma, o domínio dessa tecnologia determina uma importância considerável nos aspectos geopolíticos, estratégicos e econômicos, visto a extensão de investimentos em P&D envolvidos e as descobertas geológicas das últimas décadas das jazidas chinesas, grande mercado a ser explorado, que abrangem 80% das reservas mundiais. O objetivo deste trabalho foi...
The biosorption process has been recognized as a potential alternative for heavy metals and radioisotopes uptake from wastewaters produced by anthropogenic (industry, mining, etc.). The biosorption is a process based on metallic ions removal of aqueous solutions due to interactions between the metals and several active sites present on cellular envelope (walls and membranes) from algae, bacterial, or fungal biomasses. Generally the inactive biomass (dead) is utilized, to avoid heavy metals toxicity problems with live biomass and nutrients costs. There is a crescent interest in concentration, recovery, and separation of high technological relevance metals, such as rare earth metals (RE). The RE are essentials for manufacturing of lasers, superconductors, cracking catalysts for petroleum, miniaturized equipment, fluorescents lamps, satellites, phosphorus ultraviolet radiation absorbers, permanent magnets, and electronic information storage. Although RE metals are more available than other metals as zinc and copper, they present high market values due to expensive and complexes processes of separation and purification from mixtures due to its chemical similarities; the processes involve several steps of solvent extraction and/or ion-exchange resins. Only a few countries have the technology for separation process of the RE, which present a considerable importance, in both geopolitic and economic aspects due to the extensive R&D investments and the significant geological discoveries of RE ores deposits on last decades in China, which has 80% of the global reserves. The aim of this work was to evaluate the biosorption process in RE removal and separation from synthetic solutions. The results obtained in the work for lanthanum and neodymium biosorption in columns with Sargassum sp. biomass were satisfactory on the experimental conditions utilized. The results showed that: (a) the maximum biosorption...(Complete abstract click electronic access below)
The biosorption process has been recognized as a potential alternative for heavy metals and radioisotopes uptake from wastewaters produced by anthropogenic (industry, mining, etc.). The biosorption is a process based on metallic ions removal of aqueous solutions due to interactions between the metals and several active sites present on cellular envelope (walls and membranes) from algae, bacterial, or fungal biomasses. Generally the inactive biomass (dead) is utilized, to avoid heavy metals toxicity problems with live biomass and nutrients costs. There is a crescent interest in concentration, recovery, and separation of high technological relevance metals, such as rare earth metals (RE). The RE are essentials for manufacturing of lasers, superconductors, cracking catalysts for petroleum, miniaturized equipment, fluorescents lamps, satellites, phosphorus ultraviolet radiation absorbers, permanent magnets, and electronic information storage. Although RE metals are more available than other metals as zinc and copper, they present high market values due to expensive and complexes processes of separation and purification from mixtures due to its chemical similarities; the processes involve several steps of solvent extraction and/or ion-exchange resins. Only a few countries have the technology for separation process of the RE, which present a considerable importance, in both geopolitic and economic aspects due to the extensive R&D investments and the significant geological discoveries of RE ores deposits on last decades in China, which has 80% of the global reserves. The aim of this work was to evaluate the biosorption process in RE removal and separation from synthetic solutions. The results obtained in the work for lanthanum and neodymium biosorption in columns with Sargassum sp. biomass were satisfactory on the experimental conditions utilized. The results showed that: (a) the maximum biosorption...(Complete abstract click electronic access below)
Descrição
Palavras-chave
Biotecnologia, Metais de terras raras, Biossorção de metais
Como citar
OLIVEIRA, Robson Caldas de. Estudo da concentração e recuperação de íons lantânio e neodímio por biossorção em coluna com a biomassa Sargassum sp. 2007. 61 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 2007.