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Biosorption of lead from simulated industrial wastewaters by aquatic bryophytes

Martins, Ramiro; Boaventura, Rui
Fonte: Dr. Ronaldo Santos Herrero Publicador: Dr. Ronaldo Santos Herrero
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.52%
Aquatic bryophytes are frequently used as biomonitors for trace metals in aquatic ecosystems. Nevertheless, their special characteristics also allow using them as biosorbents to clean industrial wastewaters. As biosorption is a low cost and effective method for treating metal-bearing wastewaters, understanding the kinetics process is relevant for design purposes. In this study, the performance of the aquatic bryophyte Fontinalis antipyretica for removing lead from simulated wastewaters has been evaluated. Three kinetic models (pseudo-first order, pseudo-second order and Elovich) were fitted to the experimental data and compared using a Test-F. Previously, the effect of parameters such as the initial solution pH, contact time and initial metal ion concentration, on biosorption was investigated. The initial pH of the solution was found to have an optimum value is in the range 4.0-6.0. The equilibrium sorption capacity of lead by Fontinalis antipyretica increased with the initial metal concentration. For an initial metal concentration of 10 mg L-1, the uptake capacity of the moss, at equilibrium, is 4.8 mg g-1. Nevertheless, when the initial concentration increases up to 100 mg L-1, the uptake of lead is 10 times higher. The pseudo-second order biosorption kinetics provided the better correlation with the experimental data . The applicability of the Langmuir and Freundlich adsorption isotherms for the present system was tested. The maximum sorption capacity of mosses was 68 mg g-1.

Biosorption of lead from simulated industrial wastewaters by aquatic bryophytes

Martins, Ramiro
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
37.52%
Aquatic bryophytes are frequently used as biomonitors for trace metals in aquatic ecosystems. Nevertheless, their special characteristics also allow using them as biosorbents to clean industrial wastewaters. As biosorption is a low cost and effective method for treating metal-bearing wastewaters, understanding the kinetics process is relevant for design purposes. In this study, the performance of the aquatic bryophyte Fontinalis antipyretica for removing lead from simulated wastewaters has been evaluated. Three kinetic models (pseudo-first order, pseudo-second order and Elovich) were fitted to the experimental data and compared using a Test-F. Previously, the effect of parameters such as the initial solution pH, contact time and initial metal ion concentration, on biosorption was investigated. The initial pH of the solution was found to have an optimum value is in the range 4.0-6.0. The equilibrium sorption capacity of lead by Fontinalis antipyretica increased with the initial metal concentration. For an initial metal concentration of 10 mg L-1, the uptake capacity of the moss, at equilibrium, is 4.8 mg g-1. Nevertheless, when the initial concentration increases up to 100 mg L-1, the uptake of lead is 10 times higher. The pseudo-second order biosorption kinetics provided the better correlation with the experimental data . The applicability of the Langmuir and Freundlich adsorption isotherms for the present system was tested. The maximum sorption capacity of mosses was 68 mg g-1.

Biosorption and desorption of lanthanum(III) and neodymium(III) in fixed-bed columns with Sargassum sp.: Perspectives for separation of rare earth metals

Oliveira, Robson C.; Guibal, Eric; Garcia, Oswaldo
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 715-722
ENG
Relevância na Pesquisa
37.61%
Rare earth (RE) metals are essentials for the manufacturing of high-technology products. The separation of RE is complex and expensive; biosorption is an alternative to conventional processes. This work focuses on the biosorption of monocomponent and bicomponent solutions of lanthanum(III) and neodymium(III) in fixed-bed columns using Sargassum sp. biomass. The desorption of metals with HCl 0.10 mol L-1 from loaded biomass is also carried out with the objective of increasing the efficiency of metal separation. Simple models have been successfully used to model breakthrough curves (i.e., Thomas, Bohart-Adams, and Yoon-Nelson equations) for the biosorption of monocomponent solutions. From biosorption and desorption experiments in both monocomponent and bicomponent solutions, a slight selectivity of the biomass for Nd(III) over La(III) is observed. The experiments did not find an effective separation of the RE studied, but their results indicate a possible partition between the metals, which is the fundamental condition for separation perspectives. (C) 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012

Samarium(III) and praseodymium(III) biosorption on Sargassum sp.: Batch study

Oliveira, Robson C.; Jouannin, Claire; Guibal, Eric; Garcia, Oswaldo
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 736-744
ENG
Relevância na Pesquisa
37.52%
This work evaluates the potential of a Sargassum biomass for the biosorption of Sm(III) and Pr(III) using synthetic solutions. Under selected experimental conditions (excess of sorbent), the biosorption kinetics were fast: 30-40 min were sufficient for the complete recovery of the metals. The kinetic profiles were modeled using the pseudo-second order rate equation. The second objective of this study was to evaluate the possibility to separate these metals. Biosorption isotherms and uptake kinetics for the two metals (in binary component solutions) were almost overlapped. The biomass did not show significant selectivity for any of these two metals, in batch reactor. (C) 2010 Elsevier Ltd. All rights reserved.

Study of biosorption of rare earth metals (La, Nd, Eu, Gd) by Sargassum sp. biomass in batch systems: Physicochemical evaluation of kinetics and adsorption models

Oliveira, R. C.; Garcia, O.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 605-608
ENG
Relevância na Pesquisa
37.52%
This work evaluated kinetic and adsorption physicochemical models for the biosorption process of lanthanum, neodymium, europium, and gadolinium by Sargassum sp. in batch systems. The results showed: (a) the pseudo-second order kinetic model was the best approximation for the experimental data with the metal adsorption initial velocity parameter in 0.042-0.055 mmol.g -1.min-1 (La < Nd < Gd < Eu); (b) the Langmuir adsorption model presented adequate correlation with maximum metal uptake at 0.60-0.70 mmol g-1 (Eu < La < Gd < Nd) and the metal-biomass affinity parameter showed distinct values (Gd < Nd < Eu < La: 183.1, 192.5, 678.3, and 837.3 L g-1, respectively); and (c) preliminarily, the kinetics and adsorption evaluation did not reveal a well-defined metal selectivity behavior for the RE biosorption in Sargassum sp., but they indicate a possible partition among RE studied. © (2009) Trans Tech Publications.

Characterization of metal-biomass interactions in the lanthanum(III) biosorption on Sargassum sp using SEM/EDX, FTIR, and XPS: Preliminary studies

Oliveira, Robson C.; Hammer, Peter; Guibal, Eric; Taulemesse, Jean-Marie; Garcia, Oswaldo
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 381-391
ENG
Relevância na Pesquisa
37.67%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); This work investigates the mechanisms involved in the biosorption of lanthanum (La(III)) on Sargassum sp. biomass using scanning electron microscopy (SEM), SEM coupled to energy dispersive X-ray spectroscopy (SEM/EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The biosorbent is characterized by a large heterogeneity of chemical groups constituting different biomass biopolymers and sea compounds. SEM revealed the colonization of Sargassum sp. surface by diatoms. SEM/EDX and XPS showed the presence of different chemical groups related to macroalgae, diatoms, and elements of marine environment. FTIR revealed the bidentate complexation of La(III) by alginate carboxylate groups. XPS confirmed that La(III) biosorption occurs via oxygenated compounds: O 1s spectra presented a new phase after metal biosorption; La 3d(5/2) spectra confirmed the cooperative action of the Sargassum sp. biopolymers in the biosorption; and Si 2p spectra confirmed that the diatoms did not contribute to the biosorption, at least under selected experimental conditions. (C) 2013 Elsevier B.V. All rights reserved.

Comparative study between natural and artificial zeolites as supports for biosorption systems

Tavares, M. T.; Quintelas, C.; Figueiredo, Hugo; Neves, Isabel C.
Fonte: Trans Tech Publications Inc. Publicador: Trans Tech Publications Inc.
Tipo: Artigo de Revista Científica
Publicado em //2006 ENG
Relevância na Pesquisa
37.52%
This study aims the definition of a new material that may act as a robust and yet cost effective biosorbent for treatment of wastewater with low concentration of heavy metals. A comparative study was made between two biosorption systems composed of an Arthrobacter viscosus biofilm supported on Cuban natural zeolites and on prepared NaY and NaX, in terms of their ability to retain ionic chromium. The bacterium is able to reduce Cr(VI) to Cr(III) and, only then, this smaller and positive ion may be entrapped in the zeolite cages by ion exchange. The first support was tested in a continuous flow semipacked bed column. The highest removal ratio, 42%, was achieved for initial chromium concentration of 10 mg/L, but the best up-take, 5.5 mg/gzeolite, was obtained for initial concentration of 70 mg/L. Biosorbents prepared with the same biofilm supported in NaY and NaX zeolites were also considered in batch studies, with a typical kinetics of biosorption processes, reaching 20% of initial chromium removal within an initial range of Cr(VI) concentration between 50 and 250 mg/L. These last structures were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (DRX) and thermal analysis (TGA). All these techniques indicated that the biosorption process does not modify the morphology and structure of the FAU-zeolites.; Departamento de Ciências da Terra da Universidade do Minho; La Habana University; Fundação para a Ciência e Tecnologia...

Comparative study between natural and artificial zeolites as supports for biosorption systems

Tavares, M. T.; Quintelas, C.; Figueiredo, Hugo; Neves, Isabel C.
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Conferência ou Objeto de Conferência
Publicado em //2005 ENG
Relevância na Pesquisa
37.52%
This study aims the definition of a new material that may act as a robust and yet cost effective biosorbent for treatment of wastewater with low concentration of heavy metals. A comparative study was made between two biosorption systems composed of an Arthrobacter viscosus biofilm supported on Cuban natural zeolites and on prepared NaY and NaX, in terms of their ability to retain ionic chromium. The bacterium is able to reduce Cr(VI) to Cr(III) and, only then, this smaller and positive ion may be entrapped in the zeolite cages by ion exchange. The first support was tested in a continuous flow semi-packed bed column. The highest removal ratio, 42%, was achieved for initial chromium concentration of 10 mg/L, but the best up-take, 5.5 mg/gzeolite, was obtained for initial concentration of 70 mg/L. Biosorbents prepared with the same biofilm supported in NaY and NaX zeolites were also considered in batch studies, with a typical kinetics of biosorption processes, reaching 20% of initial chromium removal within an initial range of Cr(VI) concentration between 50 and 250 mg/L. These last structures were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (DRX) and thermal analysis (TGA). All these techniques indicated that the biosorption process does not modify the morphology and structure of the FAU-zeolites.; Fundação para a Ciência e a Tecnologia (FCT) - POCTI/EQU/12017/2001...

Experimental analysis and mathematical prediction of Cd(II) removal by biosorption using support vector machines and genetic algorithms

Hlihor, R. M.; Diaconu, M.; Leon, Florin; Curteanu, Silvia; Tavares, T.; Gavrilescu, M.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica
Publicado em 25/05/2015 ENG
Relevância na Pesquisa
37.67%
We investigated the bioremoval of Cd(II) in batch mode, using dead and living biomass of Trichoderma viride. Kinetic studies revealed three distinct stages of the biosorption process. The pseudo-second order model and the Langmuir model described well the kinetics and equilibrium of the biosorption process, with a determination coefficient, R2 > 0.99. The value of the mean free energy of adsorption, E, is less than 16 kJ/mol at 25°C, suggesting that, at low temperature, the dominant process involved in Cd(II) biosorption by dead T. viride is the chemical ion-exchange. With the temperature increasing to 4050°C, E values are above 16 kJ/mol, showing that the particle diffusion mechanism could play an important role in Cd(II) biosorption. The studies on T. viride growth in Cd(II) solutions and its bioaccumulation performance showed that the living biomass was able to bioaccumulate 100% Cd(II) from a 50 mg/L solution at pH 6.0. The influence of pH, biomass dosage, metal concentration, contact time and temperature on the bioremoval efficiency was evaluated to further assess the biosorption capability of the dead biosorbent. These complex influences were correlated by means of a modeling procedure consisting in data driven approach in which the principles of artificial intelligence were applied with the help of support vector machines (SVM)...

Biosorption of cadmium using the fungus Aspergillus niger

Barros Júnior,L.M.; Macedo,G.R.; Duarte,M.M.L.; Silva,E.P.; Lobato,A.K.C.L.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2003 EN
Relevância na Pesquisa
37.67%
Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. An experimental design was also used to determine the values of the under study variables that provided the greatest biosorption efficiency. A technique for biomass recovery was also developed with the objective of determining the capacity of the regenerated biomass to biosorb the metals in solution. This research proved that with a pH of 4.75, a biomass concentration of 0.7 g/L, and a heavy metal concentration varying between 5 and 10 mg/L a biosorption process of biosorption with Aspergillus niger could be successfully used for heavy metal removal from oil field water in the oil industry.

Biosorption kinetics of Cd (II), Cr (III) and Pb (II) in aqueous solutions by olive stone

Calero,M.; Hernáinz,F.; Blázquez,G.; Martín-Lara,M. A.; Tenorio,G.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
37.67%
A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II), Cr (III) and Pb (II) from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is the one that best describes the biosorption of the three metal ions for all the range of experimental conditions investigated. For the three metal ions, the maximum biosoption capacity and the initial biosorption rate increase when the initial metal concentration rises. However, the kinetic constant decreases when the initial metal concentration increases. The temperature effect on biosorption capacity for Cd (II) and Cr (III) is less significant; however, for Pb (II) the effect of temperature is more important, especially when temperature rises from 25 to 40ºC. The biosorption capacity at mmol/g of olive stone changes in the following order: Cr>Cd>Pb. Thus, for an initial concentration of 220 mg/ℓ, a maximum sorption capacity of 0.079 mmol/g for Cr (III)...

Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

Dotto,G. L.; Vieira,M. L. G.; Esquerdo,V. M.; Pinto,L. A. A.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2013 EN
Relevância na Pesquisa
37.72%
The equilibrium and thermodynamics of azo dye (tartrazine and allura red) biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS) were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0%) and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

Kinetic studies on the biosorption of phenol by nanoparticles from Spirulina sp. LEB 18

Dotto, Guilherme Luiz; Costa, Jorge Alberto Vieira; Pinto, Luiz Antonio de Almeida
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.67%
A kinetic study on the biosorption of phenol by nanoparticles from Spirulina sp. LEB 18 was carried out. The Spirulina sp. nanoparticles were prepared and characterized. Kinetic curves of phenol biosorption were obtained in batch system, being verified the effects of initial concentration (50, 150, 250 and 450 mg L 1) and stirring rate (50, 200 and 400 rpm). The models of pseudo-first order, pseudo-second order, Elovich, Bangham, general order and Weber–Morris were used for the kinetic interpretations. Spirulina sp. nanoparticles were stable, monodisperse, spherical with mean diameter of 230 nm. The phenol biosorption was a relatively fast process, being favored at higher values of initial concentration and stirring rate. Pseudo-second order and general order models showed satisfactory fit with the experimental data and the maximum biosorption capacity was around 101 mg g 1. From the Weber– Morris analysis, it was found that external mass transfer and intraparticle diffusion occurred during the phenol biosorption on Spirulina sp. nanoparticles. The externalmass transfer was faster at higher values of initial concentration and stirring rate, and the intraparticle diffusion was favored at high initial concentrations.

Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

Dotto, Guilherme Luiz; Vieira, Mery Luiza Garcia; Esquerdo, Vanessa Mendonça; Pinto, Luiz Antonio Almeida
Fonte: Abeq Publicador: Abeq
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.72%
The equilibrium and thermodynamics of azo dye (tartrazine and allura red) biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS) were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R2>0.99 and ARE<5.0%) and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

Biosorption kinetics of Cd(II), Cr(III) and Pb(II) in aqueous solutions by olive stone

Calero de Hoces, M??nica; Hern??inz Berm??dez de Castro, Francisco; Bl??zquez Garc??a, Gabriel; Mart??n-Lara, Mar??a de los ??ngeles; Tenorio Rivas, Germ??n
Fonte: Associa????o Brasileira de Engenharia Qu??mica Publicador: Associa????o Brasileira de Engenharia Qu??mica
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.67%
A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II), Cr (III) and Pb (II) from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is the one that best describes the biosorption of the three metal ions for all the range of experimental conditions investigated. For the three metal ions, the maximum biosoption capacity and the initial biosorption rate increase when the initial metal concentration rises. However, the kinetic constant decreases when the initial metal concentration increases. The temperature effect on biosorption capacity for Cd (II) and Cr (III) is less significant; however, for Pb (II) the effect of temperature is more important, especially when temperature rises from 25 to 40??C. The biosorption capacity at mmol/g of olive stone changes in the following order: Cr>Cd>Pb. Thus, for an initial concentration of 220 mg/???, a maximum sorption capacity of 0.079 mmol/g for Cr (III)...

Physicochemical studies of cadmium (II) biosorption by the invasive alga in Europe Sargassum muticum

Lodeiro Fernández, Pablo; Cordero Pérez, Bruno; Grille Cancela, Zulaika; Herrero Rodríguez, Roberto; Sastre de Vicente, Manuel E.
Fonte: Wiley Interscience Publicador: Wiley Interscience
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.67%
In recent years, there has been a significant increase in the studies concerning brown seaweed as biosorbents for metal removal owing to their high binding ability and low cost. This work reports the results of a study regarding the cadmium binding equilibria of dead biomass from the seaweed Sargassum muticum; this alga is a pest fouling organism that competes with the local fucalean species and may also interfere with the “sea industry”; therefore, it would constitute an ideal material to be used as biosorbent. Seven different treatments were tested in order to obtain a stable biomass that could be suitable for industrial use under a broad range of operational conditions. The treatments employed were protonation, chemical crosslinking with formaldehyde, KOH, Ca(OH)2 and CaCl2 or physical treatments with acetone and methanol. The equilibrium adsorption isotherms of Langmuir, Freundlich and Langmuir-Freundlich, were obtained for the quantitative description of the cadmium uptake. The effect of pH on biosorption equilibrium was studied at values ranging from 1 to 6, demonstrating the importance of this parameter for an accurate evaluation of the biosorption process. Maximum biosorption was found for pH higher than 4.5. The 1 maximum biosorption uptake for the raw biomass was 65 mg⋅g-1...

Biosorption of fluoroquinolones by activated sludge and aerobic granules sludge

Ferreira, Vanessa R. A.; Amorim, Catarina L.; Cravo, Sara M.; Tiritan, Maria E.; Castro, Paula M. L.; Afonso, Carlos M. M.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em 13/05/2015 ENG
Relevância na Pesquisa
37.67%
Oral communication; Antibiotic residues have been detected in various environmental matrices, such as surface water and even drinking water. Although present at low levels (μg/L, ng/L), many antibiotics are bioaccumulative, pseudo-persistent and can promote resistance/alterations in bacterial populations [1]. Recent studies on antibiotics removal by activated sludge (AS) and aerobic granules (AGS) show biosorption as the dominant process, determining the fate of these micropollutants [2-3]. In this work the biosorption of three widely used fluoroquinolones (FQ) - ofloxacin (OFL), norfloxacin (NOR) and ciprofloxacin (CPF) - to AS and AGS was evaluated. A High Performance Liquid Chromatography with Fluorescence Detection (HPLC-FD) method was validated and used to follow the biosorption of the target FQ. Data obtained in this study contribute to a better comprehension of FQ biosorption behavior in AS and AGS. At pH 7 AS showed better performance to biosorb OFL, NOR and CPF than AGS. The higher biosortion capacity of AS was probably due to the negative charge on its surface, evaluated by a zeta potential of -25.65 mV, at pH 7. OFL was the less biosorbed, both onto AS and AGS, because this FQ at pH 7 is mainly present in its anionic form. The equilibrium data for AS showed a better fit to the Langmuir model...

Recent advances in biosorption of heavy metals: support tools for biosorption equilibrium, kinetics and mechanism

Hlihor, Raluca Maria; Bulgariu, Laura; Sobariu, Dana Luminita; Diaconu, Mariana; Tavares, T.; Gavrilescu, Maria
Fonte: Editura Academiei Romane/Publishing House of the Romanian Academy Publicador: Editura Academiei Romane/Publishing House of the Romanian Academy
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
37.67%
Heavy metals are increasingly present in industrial wastes and effluents, which can generate serious concerns for environmental quality and human health. Consequently, there is a continuous expansion of researches for new approaches and developments to guarantee environmental cleaning-up. Although there are some physico-chemical established methods for the removal of heavy metals from various environmental compartments, biosorption gains further confidence as a reliable alternative compared to classical technologies, which are expensive and sometimes unreliable. This paper aims to analyze the biosorption as a biotechnological strategy for the decontamination of aqueous effluents containing heavy metal ions, in terms of its potential for metal immobilization and uptake. The paper also focuses on the most important parameters affecting the removal of heavy metals by various categories of biosorbents both living and non-living forms of biomass and provides new alternatives for modeling and optimization of process equilibrium and kinetics. A special attention was paid to biosorption mechanism, as a factual challenge for process optimization and scale-up. The potential benefits and problems associated to metal removal by biosorption are highlighted.; Roumanian National Authority for Scientific Research...

Evaluation of copper resistant bacteria from vineyard soils and mining waste for copper biosorption

Andreazza,R; Pieniz,S; Okeke,B.C; Camargo,F.A.O
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2011 EN
Relevância na Pesquisa
37.61%
Vineyard soils are frequently polluted with high concentrations of copper due application of copper sulfate in order to control fungal diseases. Bioremediation is an efficient process for the treatment of contaminated sites. Efficient copper sorption bacteria can be used for bioremoval of copper from contaminated sites. In this study, a total of 106 copper resistant bacteria were examined for resistance to copper toxicity and biosorption of copper. Eighty isolates (45 from vineyard Mollisol, 35 from Inceptisol) were obtained from EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) experimental station, Bento Gonçalves, RS, Brazil (29º09'53.92''S and 51º31'39.40''W) and 26 were obtained from copper mining waste from Caçapava do Sul, RS, Brazil (30º29'43.48''S and 53'32'37.87W). Based on resistance to copper toxicity and biosorption, 15 isolates were identified by 16S rRNA gene sequencing. Maximal copper resistance and biosorption at high copper concentration were observed with isolate N2 which removed 80 mg L-1 in 24 h. Contrarily isolate N11 (Bacillus pumilus) displayed the highest specific copper biosorption (121.82 mg/L/OD unit in 24 h). GenBank MEGABLAST analysis revealed that isolate N2 is 99% similar to Staphylococcus pasteuri. Results indicate that several of our isolates have potential use for bioremediation treatment of vineyards soils and mining waste contaminated with high copper concentration.

Effect of the fluidized bed drying on the sturcture and biosorption capability of Pb+2 of agave epidermis

Hernández-Botello,M.T.; Chanona-Pérez,J.J.; Mendoza-Pérez,J.A.; Trejo-Valdez,M.; Calderón-Domínguez,G.; Barriada Pereira,J.L.; Sastre de Vicente,M.E.; Perea-Flores,M.J.; Terres-Rojas,E.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
Relevância na Pesquisa
37.67%
A fluidized bed drying study of agave epidermis obtained from wastes of the "pulque" manufacture was made. Drying kinetics modeling and the influence of the operation conditions on the shrinkage, micro structure and biosorption capability of Pb+2 were studied. Drying kinetics was carried out at 50, 60, 70 and 80 °C. Six semi-empirical models were tested and diffusion approach model provided the best fits. Effective diffusivity varied from 3.73xl0-9 to 6.99x10-9 m²s-1, for untreated slabs (UT) and from 3.65x 10-9 to 7.74x10-9 m²s-1 for treated samples (T) with hydrochloric acid. Activation energy was found to be 21.22 and 23.89 kJ/mol for UT and T samples respectively. Shrinkage and the microstructure changes of T slabs were larger than UT samples. T samples dried at 70 and 80 °C showed a reduction in their Pb+2 biosorption capability, caused by a large shrinkage and severe microstructural changes. For UT samples their biosorption capability was increased in relation with increase of the shrinkage and drying temperature. T samples dried at 50 and 60 °C improved their biosorption capability of Pb+2, while UT samples dried at 70 and 80 °C showed a better biosorption capability. These results can be useful for preparation of biosorbents.