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Estatística
Título: TREATMENT OF AQUEOUS SOLUTIONS CONTAINING ZINC, COPPER AND CADMIUM BY COMBINED BIOSORPTION/BIOFLOTATION PROCESS
Autor: DIEGO MACEDO VENEU
Colaborador(es): MAURICIO LEONARDO TOREM - Orientador
GABRIELA ALEJANDRA HUAMAN PINO - Coorientador
Catalogação: 10/JAN/2011 Língua(s): PORTUGUESE - BRAZIL
Tipo: TEXT Subtipo: THESIS
Notas: [pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
[en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio.
Referência(s): [pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=16718&idi=1
[en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=16718&idi=2
DOI: https://doi.org/10.17771/PUCRio.acad.16718
Resumo:
This study evaluated the potential of the microorganism Streptomyces lunalinharesii as biosorbent for removal of Zn(II), Cu(II) and Cd(II) from aqueous solutions by biosorption/bioflotation process through experimental batch. Operating parameters investigated in the stage of biosorption was solution pH, initial concentration of biomass, agitation speed, initial metal concentration, contact time and temperature. The adsorption equilibrium data were evaluated using Langmuir and Freundlich adsorption isotherm models. The kinetics sorption for metal ions were modeled using the kinetic model of zero order, first and second order models and the pseudo first and pseudo second order. The biomass separation was performed using the dissolved air flotation technique, evaluating the influence of saturation pressure, coagulant concentration and recycle ratio on removal efficiency of biomass loaded with metal ions. The surface characteristics of the microorganism and the possible interaction mechanisms involved in sorption of metal ions by biomass were evaluated based on measurements of zeta potential, analysis by infrared spectroscopy and analysis of images obtained by scanning electron microscopy (SEM/EDS). The initial value of the solution pH affected the sorption of metals, pH values appropriated in the stage of biosorption and bioflotation were 6,0 for Zn(II) and 5,0 for Cu(II) and Cd(II). The initial concentrations of biomass used in the trials were 3 g.L-1 for Zn(II) and Cu(II), and 2 g.L-1 for Cd(II), with removals of 57,5%, 35% and 63%, respectively. The agitation speed of 120rpm employed showed the best removals, 60% for Zn(II), 41% for Cu(II), and 62% for Cd(II). The data corresponding to the uptake capacity of S. lunalinharesii depending on the concentration of metal ions were tested and the Langmuir isotherm model fits well for the ions Zn(II) and Cd(II) and the Freundlich model for Cu(II). The maximum uptake capacities obtained with the Langmuir model for Zn(II), Cu(II) and Cd(II) were: 13,6; 11,53; and 24,87 mg.g-1, respectively. The tests on the biosorption kinetics showed that the process is very fast in the first 5 min of contact between biomass and metal solutions, removals above 90% were achieved for 100 min Zn(II) and Cd(II), and 50 min for Cu(II). Sorption kinetics for the ions Zn(II), Cu(II) and Cd(II) have adjusted well to the pseudo second order model. The process of removal of ions Zn(II), Cu(II) and Cd(II) was negatively affected by increasing temperature, suggesting that the process is exothermic. The values of activation energy obtained were: 40,11; 59,27 and 55,51 kJ.mol-1, respectively. The spectra obtained by IR-FT suggest that the functional groups are carboxyl, amine, amide, phosphate and hydroxyl present in cell wall biomass S. lunalinharesii are potentially responsible for biosorption of metal ions. In bioflotation employing the dissolved air flotation (DAF) technique, there is a need of adding a coagulant for improved efficiency of the flotation process. Were obtained results for biomass removal loaded with ions Zn(II), Cu(II) and Cd(II) of 94%; 95,5% and 92,1% respectively. The results presented correspond to an actual removal by biosorption and bioflotation process integrated of 9,1 mg.L-1 of Zn(II), 8,6 mg.L-1 of Cu(II) and 8,4 mg.L-1 Cd(II), starting from a saturation pressure of 5 kgf.cm-2, coagulant concentration of 45 mg.L-1 and recycle ratio of 50%.
Descrição: Arquivo:   
COVER, ACKNOWLEDGEMENTS, RESUMO, ABSTRACT, PRESENTATION, SUMMARY AND LISTS PDF    
CHAPTER 1 PDF    
CHAPTER 2 PDF    
CHAPTER 3 PDF    
CHAPTER 4 PDF    
CHAPTER 5 PDF    
CHAPTER 6 PDF    
REFERENCES PDF