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Widner, R. C.; Sousa, Maria F.B.; Bertazzoli, Rodnei

doi:10.1023/a:1003286810393

Cited by 47 publications

(33 citation statements)

References 16 publications

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“…Figure 4 shows that the decrease of the normalized Pb 2+ concentration [C/C 0 ] as a function of time is not exponential, as one would expect for a mass-controlled reaction. 13 Nevertheless, the values of X Pb 2+ and F e are significantly higher than those reported in the literature 1,3,7,12,13 for the experimental parameter range used in the present study. By comparing the results obtained in the present work with those that we previously reported for a membranecompartmentalized flow-through cell with a SSW cathode for Pb 2+ removal 12,13 (see Table 2), one can clearly see that the membrane-less flow-through cell with SSW cathodes and anode here reported is much more efficient.…”

Section: Optimization Of Pb 2+ Removalcontrasting

confidence: 72%

“…This occurs because competitive parallel reactions, such as the oxygen, water and nitrate reduction reactions (O 2 + 4H + + 4e -→ 2H 2 O, 2H 2 O + 2e -→ H 2 + 2OH -and NO 3 -+ H 2 O + 2e -→ NO 2 -+ 2OH -, respectively), and the water oxidation reaction (2H 2 O → O 2 + 4H + + 4e -), become important as I is increased.…”

Section: Optimization Of Pb 2+ Removalmentioning

confidence: 99%

“…Electrochemical techniques have been extensively used for the treatment of aqueous effluents because they offer an environmentally and friendly way of removing toxic metallic ions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and/or organic species [16][17][18][19][20][21][22] via redox reactions. The environmental compatibility is the main advantage of electrochemical methods, as the reagent, the electron, is a "clean reagent".…”

Section: Introductionmentioning

confidence: 99%

“…It is clear from equation 7, that Q has no significant influence on X Pb 2+ (see also Figure 3a), although several other studies showed that the rate of electrochemical reactions under mass transport conditions is dependent on Q. 2,3,6,12 According to Koene and Janssen, 32 increases in Q enhance the electrochemical-reaction rate as a consequence of the diffuse layer becoming thinner. In the present case, lower Q values possibly promoted insignificant changes in the mass transport coefficient, while higher ones led to the formation of preferential streaming channels and/or dead zones.…”

mentioning

confidence: 98%

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Galvanostatic removal of Pb2+ ions from diluted solutions by the use of a membrane-less flow-through cell with stainless steel wool electrodes

Almeida

Bocchi

Rocha‐Filho

et al. 2011

J. Braz. Chem. Soc.

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A remoção de íons Pb 2+ a partir de soluções diluídas foi estudada, em condições galvanostáticas, usando uma célula de fluxo sem membrana com eletrodos de esponja de aço inoxidável (SSW). A metodologia de superfície de resposta (variáveis independentes: corrente elétrica e vazão) foi usada para obter as condições ótimas para a remoção de Pb 2+ a partir de 2 L de uma solução de Pb(NO 3 ) 2 50 mg L -1 em NaNO 3 0,10 mol L -1 + H 3 BO 3 0,10 mol L -1 (pH 4,8). A partir das superfícies de respostas, concluiu-se que a vazão (59-341 L h -1 ) não influencia significativamente no processo de remoção de Pb 2+ . Por outro lado, o aumento da corrente elétrica leva a uma maior remoção de Pb 2+ , com valores significantemente melhores de consumo de energia específica e eficiência de corrente quando comparados àqueles relatados na literatura. Para um experimento realizado na região de condições ótimas (70 mA e 200 L h -1 ), uma conversão de Pb 2+ de 99,6% foi atingida depois de 90 min de eletrólise. A utilização da célula de fluxo sem membrana com eletrodos de SSW, além de ser energeticamente mais eficiente, levou à remoção de Pb 2+ em ambos os eletrodos, mais predominantemente no anodo, sobre o qual 95% dos íons Pb 2+ foram convertidos a PbO 2 .The removal of Pb 2+ ions from dilute solutions was investigated under galvanostatic conditions using a membrane-less flow-through cell with stainless steel wool (SSW) electrodes. The response surface methodology (independent variables: electric current and volumetric flow rate) was used to find the optimal conditions for Pb 2+ removal from 2 L of an aqueous solution of 50 mg L -1 Pb(NO 3 ) 2 in 0.10 mol L -1 NaNO 3 + 0.10 mol L -1 H 3 BO 3 (pH 4.8). The obtained response surfaces revealed that the volumetric flow rate (59-341 L h -1 ) does not substantially affect the Pb 2+ removal process. On the other hand, the electric current increase led to higher Pb 2+ removal, with significantly improved values of specific energy consumption and current efficiency when compared with those reported in the literature. For an experiment carried out in the optimum-condition region (70 mA and 200 L h -1 ), a Pb 2+ conversion of 99.6% was attained after 90 min of electrolysis. The use of the membrane-less flow-through cell with SSW electrodes, besides being significantly more energy efficient, led to Pb 2+ removal on both electrodes, but predominantly in the SSW anode, on which more than 95% of the Pb 2+ ions were converted to PbO 2 .Keywords: electrolytic removal of Pb 2+ ions, electrochemical treatment, Pb 2+ wastewater, simultaneous cathodic/anodic Pb 2+ removal, factorial design, response surface methodology IntroductionNowadays, environmental agencies of many countries require the treatment of aqueous effluents containing toxic metallic ions, such as Cd 2+ , Cr 6+ and Pb 2+ , to decrease their concentrations to lower values than those permitted for discharge into sewers (few mg L -1 down to zero, depending on the country). The treatment of these effluents is usually done adjusting their pH or a...

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Section: Optimization Of Pb 2+ Removalcontrasting

confidence: 72%

Section: Optimization Of Pb 2+ Removalmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 98%

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Galvanostatic removal of Pb2+ ions from diluted solutions by the use of a membrane-less flow-through cell with stainless steel wool electrodes

Almeida

Bocchi

Rocha‐Filho

et al. 2011

J. Braz. Chem. Soc.

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“…x y3 ry4 for the species Fe CN . Considering that 6 lead deposition electrolyte solutions are free from ferricyanide, the reversible couple observed in Figs. w Ž .…”

Section: Lead Deposition Onto Fvcmentioning

confidence: 99%

Lead deposition onto fractured vitreous carbon: influence of electrochemical pretreated electrode

Sosa¹,

Carreño²,

Ponce-de-León³

et al. 2000

Applied Surface Science

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Ž .Ž . We evaluated the electrochemical deposition of Pb II onto Fractured Vitreous Carbon FVC electrodes from solutions Ž . containing very low concentrations of lead in different electrolytes sulfate or chloride . To examine how the FVC surface state influences the lead deposition efficiency, the electrodes were subjected to different electrochemical pretreatments prior Ž . to the actual deposition process. The FVC electrode was used as a representative model of the vitreous carbon VC bulk, avoiding the polishing procedure that could change the surface. Electrochemical pretreatment was carried out by cyclic voltammetry in electrolytes containing chloride or nitrate anions and in some cases, ferrocyanide. Before and after the Ž . electrochemical pretreatment, the electrode surface morphology was assessed using Atomic Force Microscopy AFM Ž . imaging. The quantity of lead deposited on the FVC electrode surface lead deposition efficiency in each experiment was estimated from the charge under the lead anodic, dissolution peak. Electrochemical pretreatment of electrodes in chloride or nitrate electrolytic baths consistently reduced the lead deposition efficiency. A detailed analysis, correlating lead deposition efficiencies to surface roughness and fractal dimension of the freshly prepared and electrochemically pretreated FVC electrodes, indicated that the decrease in efficiency corresponded to the change in electrode surface geometry. The greater efficiency of lead deposition observed in the chloride-containing electrolyte was due to the interaction between chloride and deposited lead rather than a chloride interaction with the FVC substrate. q

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Adsorption of Pb(II) Using Magnetic Titanate Nanotubes Prepared via Two‐Step Hydrothermal Method

Zhang

Wang

Chen

et al. 2013

CLEAN Soil Air Water

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Magnetic titanate nanotubes (MTNTs) have been prepared by a two‐step hydrothermal method and used as adsorbents for the removal of Pb(II) from aqueous solution. The MTNTs are characterized by N2 adsorption–desorption analysis, transmission electron microscopy, powder X‐ray diffraction, vibrating sample magnetometer, zeta potentials analysis, X‐ray photoelectron spectra (XPS), and Fourier transform infrared (FT‐IR) spectroscopy. The results indicate that CoFe2O4 is formed in the hydrothermal process and implanted into the entangled network of nanotubes. The saturation magnetization of MTNTs is 9.20 emu g−1, which makes MTNTs can be readily recovered in an external magnetic field. The adsorption of Pb(II) over MTNTs is very fast and follows the pseudo‐second‐order kinetic model. Additionally, Pb(II) adsorption is strongly pH dependent and the maximum adsorption capacity of MTNTs for Pb(II) reaches 442.5 mg g−1 at pH 5.0. FT‐IR and XPS analysis suggest that the adsorption mechanism of MTNTs is ionic exchange between Pb(II) and Na+/H+ in the interlayer of nanotubes. Furthermore, Pb(II)‐loaded MTNTs can be regenerated by saturated EDTA‐2Na solution at pH 2.5 and the adsorbents can be used repeatedly.

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Untitled

Cited by 47 publications

References 16 publications

Galvanostatic removal of Pb2+ ions from diluted solutions by the use of a membrane-less flow-through cell with stainless steel wool electrodes

Galvanostatic removal of Pb2+ ions from diluted solutions by the use of a membrane-less flow-through cell with stainless steel wool electrodes

Lead deposition onto fractured vitreous carbon: influence of electrochemical pretreated electrode

Adsorption of Pb(II) Using Magnetic Titanate Nanotubes Prepared via Two‐Step Hydrothermal Method

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