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Previous issue date: 2014-09-11 / CNPq / Soils have the capacity to retain metals due to the occurrence of the phenomenon of sorption, which is the accumulation of ions or molecules on the surface of organic and mineral colloids. For their high organic matter content, therefore large amount of organic colloids, the Histosols have high adsorptive capacity. Sorption can be described by means of different models, which consist in equations that seek to describe the phenomenon with minimal loss of information. Because each model is based on different assumptions, it is essential to select the best suited to the conditions to be analyzed, thus avoiding possible contamination of the environment caused by errors in predicting the adsorption capacity of the soil. This study aimed to select the models that best describe the sorption of Zn, Cd, Cu and Pb on Histosols. The study was conducted by an adaptation of the Batch of Lab Batch, with increasing concentrations of ZnCl2, CdCl2, Pb(NO3)2 and CuCl2. After determination of the concentration of adsorbed metals, the metal levels involved in complex internal and external sphere were evalueted through by desorption studies. The parameters of the sorption isotherms were determined by the ISOFIT program. To compare the fit of the models, the correlation coefficient, determination coefficient, the Akaike Information Criterion Corrected (AICc), AICc Range (?AICc) and the Weighting of AICc (AICcw) were analyzed. It was observed that the linear model was the best to describe the sorption of Zn, while Langmuir was the best to describe the sorption of Cd and Pb and the Freundlich showed better adjustment to the sorption of Cu. In general, the concentrations of N and fulvic acids were the most important factors that influences the sorption of metals. Most of Zn, Cd and Pb is sorbed in electrostatics bonds, easily reversible. However, Cu in strong and almost irreversible bonds. / Os solos possuem a capacidade de reter metais devido ? ocorr?ncia do fen?meno da sor??o, que consiste no ac?mulo de ?ons ou mol?culas na superf?cie dos col?ides org?nicos e minerais. Por apresentarem alto teor de mat?ria org?nica, portanto grande quantidade de col?ides org?nicos, os Organossolos possuem elevada capacidade adsortiva. A sor??o pode ser descrita por meio de diferentes modelos, que s?o equa??es que buscam descrever o fen?meno com o m?nimo de perda de informa??es. Como cada modelo se baseia em diferentes pressupostos, ? fundamental selecionar o que melhor se adequa ?s condi??es que se pretende analisar, evitando, assim, poss?veis contamina??es do ambiente causadas por erros na previs?o da capacidade adsortiva do solo. Este estudo teve como objetivos selecionar os modelos que melhor descrevem a sor??o de Zn, Cd, Cu e Pb em Organossolos. O estudo foi conduzido atrav?s de uma adapta??o do M?todo Batch de Laborat?rio, com concentra??es crescentes de ZnCl2, CdCl2, Pb(NO3)2 e CuCl2. Ap?s a determina??o dos teores de metais adsorvidos, os teores de metais envolvidos em complexos de esfera interna e externa foram avaliados atrav?s de estudos de dessor??o. Os par?metros das isotermas de sor??o foram determinados pelo programa IsoFit. Para compara??o do ajuste dos modelos, foram analisados o Coeficiente de Correla??o, Coeficiente de Determina??o, o Crit?rio de Informa??o de Akaike Corrigido (AICc), Varia??o de AICc (?AICc) e a Pondera??o de AICc (AICcw). Observou-se que o modelo Linear foi o que melhor descreveu a sor??o de Zn, enquanto Langmuir foi o que melhor descreveu a sor??o de Cd e Pb e o de Freundlich apresentou melhor ajuste ? sor??o de Cu. Em geral, os teores de N e ?cidos f?lvicos foram os fatores que mais influenciaram a sor??o dos metais. A maior parte de Zn, Cd e Pb sorvidas encontra-se em liga??es eletrost?ticas, facilmente revers?veis. Entretanto, o Cu encontra-se em liga??es fortes e quase irrevers?veis.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:jspui/1798 |
| Date | 11 September 2014 |
| Creators | COUTINHO, Izabella Bezerra |
| Contributors | AMARAL SOBRINHO, Nelson Moura Brasil do, Pereira, Marcos Gervasio, Amaral Sobrinho, Nelson Moura Brasil do, P?rez, Daniel Vidal, Fontana, Ademir |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Curso de P?s-Gradua??o em Agronomia - Ci?ncia do Solo, UFRRJ, Brasil, Instituto de Agronomia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
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