scholarly journals Equilibrium and Kinetic Study of Ammonium Sorption by Raphia farinifera

2019 ◽  
Vol 230 (10) ◽  
Author(s):  
Paweł Staroń ◽  
Paulina Sorys ◽  
Jarosław Chwastowski
Keyword(s):  
Chemical Nature ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Second Order ◽  
Isotherm Models ◽  
Mechanism Analysis ◽  
Order Model ◽  
Sorption Model ◽  
Pseudo Second Order ◽  
Kinetics Of

Abstract The study investigated the sorption capacity of biosorbent-raphia sp. against ammonia. Raphia fibers were used without and with the modification of its surface with NaCl, NaNO3, and K2SO4. The data was analyzed in the state of equilibrium using four isotherm models such as Langmuir, Freudlich, Temkin, and Dubinin-Radushkevich. The equilibrium of ammonia sorption for all studied systems was best described by the Freudlich isotherm model. On its basis, it can be assumed that the studied process is of chemical nature, which results from the value of the coefficient 1/n < 1. In order to confirm the sorption mechanism, analysis of the kinetics of the ammonia sorption process on raphia fibers was performed. Four kinetic models of sorption were calculated: pseudo-first-order model, pseudo-second-order model, Elovich model, and Webber-Morris intermolecular diffusion model. The sorption kinetics of the modeled ammonia waste were carried out using unmodified palm fibers and all kinds of surface modification. This process was best described by the pseudo-second-order sorption model, which can be considered as a confirmation of the chemical nature of ammonia sorption on raphia sp. fibers.

scholarly journals Equilibrium and Kinetics of U(VI)aq Adsorption on in situ Generated Fe2O3. nH2O

2019 ◽  
Vol 70 (10) ◽  
pp. 3482-3485
Author(s):  
Ioana Carmen Popescu (Hostuc) ◽  
Ligia Stoica ◽  
Carolina Constantin ◽  
Ana Maria Stanescu
Keyword(s):  
Kinetic Modelling ◽  
Sorption Process ◽  
Second Order ◽  
Chemical Component ◽  
Isotherm Models ◽  
Sorption Equilibrium ◽  
Equilibrium And Kinetics ◽  
Pseudo Second Order ◽  
Kinetics Of

The paper aims to present research results obtained at the study of equilibrium and kinetics of U(VI)aq sorption on in situ generated Fe2O3 x nH2O from model solutions. The studied systems represent U(VI) solutions with CU(VI) = 5-30 mg�L-1 for which maximum U(VI) removal efficiencies (%RU(VI) = 95.98) on in situ generated Fe2O3��nH2O were obtained in the following working conditions: pH = 8.75, tcontact = 30 min, [U(VI)] : [Fe(III)] =1:75 and stirring rate 250 RPM. The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models were used to study U(VI) sorption equilibrium. Langmuir isotherm with the correlation coefficient R2 (0.9808) suggests that it involves physical interactions. Freundlich (R2 = 0.8349) and Temkin (R2 = 0.8715) models describe well the sorption process suggesting that there also exists a chemical component, complexing and/or co-precipitation. The kinetic modelling according to the pseudo-first and pseudo-second order models, respectively has demonstrated that the U(VI) sorption equilibrium follows the pseudo-second order equation suggesting a chemical component of the process.

scholarly journals Equilibrium and Kinetics of U(VI)aq Adsorption on in situ Generated Fe2O3. nH2O

2019 ◽  
Vol 70 (10) ◽  
pp. 3482-3485
Keyword(s):  
Kinetic Modelling ◽  
Sorption Process ◽  
Second Order ◽  
Chemical Component ◽  
Isotherm Models ◽  
Sorption Equilibrium ◽  
Equilibrium And Kinetics ◽  
Pseudo Second Order ◽  
Kinetics Of

The paper aims to present research results obtained at the study of equilibrium and kinetics of U(VI)aq sorption on in situ generated Fe2O3 x nH2O from model solutions. The studied systems represent U(VI) solutions with CU(VI) = 5-30 mg·L-1 for which maximum U(VI) removal efficiencies (%RU(VI) = 95.98) on in situ generated Fe2O3’”nH2O were obtained in the following working conditions: pH = 8.75, tcontact = 30 min, : =1:75 and stirring rate 250 RPM. The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models were used to study U(VI) sorption equilibrium. Langmuir isotherm with the correlation coefficient R2 (0.9808) suggests that it involves physical interactions. Freundlich (R2 = 0.8349) and Temkin (R2 = 0.8715) models describe well the sorption process suggesting that there also exists a chemical component, complexing and/or co-precipitation. The kinetic modelling according to the pseudo-first and pseudo-second order models, respectively has demonstrated that the U(VI) sorption equilibrium follows the pseudo-second order equation suggesting a chemical component of the process. Keywords: uranium, sorption/precipitate flotation, adsorption isotherms modelling, kinetics

scholarly journals Biosorption and Diffusion Modeling of Pb(II) by Malt Bagasse

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Klaiani B. Fontana ◽  
Giane Gonçalves Lenzi ◽  
Erica R. L. R. Watanabe ◽  
Ervin Kaminski Lenzi ◽  
Juliana A. M. T. Pietrobelli ◽  
...  
Keyword(s):  
Sorption Process ◽  
Isotherm Models ◽  
Diffusion Modeling ◽  
Biosorption Capacity ◽  
Kinetic And Thermodynamic Parameters ◽  
Pseudo Second Order ◽  
Ph Optimization ◽  
Kinetics Of ◽  
And Diffusion

The removal of Pb(II) from water by biosorption processes onto malt bagasse was investigated and the kinetic and thermodynamic parameters were obtained; additionally a diffusion modeling was proposed. The characterization of malt bagasse was performed by FTIR and SEM/EDS. The experiments were conducted in batch system and an experimental design based response surface methodology was applied for agitation speed and pH optimization. The kinetics of biosorption followed pseudo-second-order model and the temperature of the process affected the biosorption capacity. Isotherm models of Langmuir, Freundlich, and Elovich were applied and the Langmuir model showed better fit and the estimated biosorption capacity was 29.1 mg g−1. The negative values obtained for ΔG° and positive values of ΔH° confirm, respectively, the spontaneous and endothermic nature of the process. The diffusion modeling was performed based on experiments in the absence of agitation to investigate the influence of the biosorbent on the sorption process of Pb(II) ions.

Adsorption Kinetics of Pb2+ Ions Using Chitosan Nanoparticles

2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu
Keyword(s):  
Adsorption Kinetics ◽  
Chitosan Nanoparticles ◽  
Second Order ◽  
Isotherm Model ◽  
Order Model ◽  
Adsorption Characteristics ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Second Order Model

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.

scholarly journals Kinetics of scandium recovery by TVEX-TBP from the solution formed after the salt chlorinator cake leaching

2020 ◽  
Vol 168 ◽  
pp. 00050
Author(s):  
Vadym Korovin ◽  
Yurii Pohorielov ◽  
Yurii Shestak ◽  
Oleksandr Valiaiev ◽  
Jose Luis Cortina
Keyword(s):  
Chemical Interaction ◽  
Extraction Process ◽  
Second Order ◽  
Order Kinetic ◽  
Order Model ◽  
Elovich Equation ◽  
Diffusion Phase ◽  
Leaching Solution ◽  
Pseudo Second Order ◽  
Kinetics Of

Kinetics of scandium recovery by TVEX containing tributyl phosphate was studied from the clarified leaching solution of salt chlorinator cake. To assess the contribution of each diffusion phase, experimental data were analyzed using a graphic method. To define the contribution of chemical interaction into the scandium extraction process, recovery kinetics was quantitatively described using pseudo-first order, pseudo-second order kinetic models and Elovich equation in linearized form. It was established that recovery kinetics was most accurately described with the pseudo-second-order model.

Removal of Pb (II) from Aqueous Solution by Blast-Furnace Slags

2013 ◽  
Vol 726-731 ◽  
pp. 2736-2741
Author(s):  
Ming Da Liu ◽  
Ge Tian ◽  
Liang Jie Zhao ◽  
Yao Sheng Wang ◽  
Lei Guo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Blast Furnace ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Sorption Process ◽  
Second Order ◽  
Order Model ◽  
Pseudo Second Order ◽  
Solution Kinetic ◽  
Second Order Model

Five blast-furnace slags were used as adsorbents to remove Pb (II) from aqueous solution. Kinetic studies showed that the sorption process was best described by pseudo-second-order model. Among Langmuir, Freundlich and Temkin isotherms, the Freundlich isotherm had a better fit with the simulation of the adsorption of Pb (II).

Removal of hazardous pharmaceutical dyes by adsorption onto papaya seeds

2014 ◽  
Vol 70 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Caroline Trevisan Weber ◽  
Gabriela Carvalho Collazzo ◽  
Marcio Antonio Mazutti ◽  
Edson Luiz Foletto ◽  
Guilherme Luiz Dotto
Keyword(s):  
Aqueous Solutions ◽  
Second Order ◽  
Isotherm Models ◽  
Order Model ◽  
Application Range ◽  
First Order ◽  
Adsorption Capacities ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
Papaya Seeds

Papaya (Carica papaya L.) seeds were used as adsorbent to remove toxic pharmaceutical dyes (tartrazine and amaranth) from aqueous solutions, in order to extend application range. The effects of pH, initial dye concentration, contact time and temperature were investigated. The kinetic data were evaluated by the pseudo first-order, pseudo second-order and Elovich models. The equilibrium was evaluated by the Langmuir, Freundlich and Temkin isotherm models. It was found that adsorption favored a pH of 2.5, temperature of 298 K and equilibrium was attained at 180–200 min. The adsorption kinetics followed the pseudo second-order model, and the equilibrium was well represented by the Langmuir model. The maximum adsorption capacities were 51.0 and 37.4 mg g−1 for tartrazine and amaranth, respectively. These results revealed that papaya seeds can be used as an alternative adsorbent to remove pharmaceutical dyes from aqueous solutions.

Adsorption Kinetics of Zn(II) from Aqueous Solutions onto Epichlorohydrin Crosslinked Chitosan

2012 ◽  
Vol 463-464 ◽  
pp. 7-11 ◽  
Author(s):  
Ming Yan Dang ◽  
Hong Min Guo ◽  
Yan Kun Tan
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Crosslinking Agent ◽  
Second Order ◽  
Order Model ◽  
Pseudo Second Order ◽  
Crosslinked Chitosan ◽  
Kinetics Of ◽  
Second Order Model

Chitosan was crosslinked using epichlorohydrin as crosslinking agent to prepare crosslinked chitosan which was used as an adsorbent for the removal of Zn(II) from aqueous solutions. The adsorption prosperities of Zn(II) on crosslinked chitosan were studied, including the influence of pH value and the adsorption kinetics. The kinetics of adsorption was discussed using two kinetic models, the pseudo first-order and the pseudo second-order model. Results reveal that the crosslinked chitosan is suitable as adsorbent to remove Zn(II) from dilute solution. The rate parameters for the Zn(II) by crosslinked chitosan were also determined. It was shown that the adsorption kinetics of Zn(II) could be best described by the pseudo second-order model and the adsorption process may involve a physical adsorption.

Study of Fluorescent Dyeing Process and Influence of Mixture Dyes on High-visibility

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000
Author(s):  
Mohamed Hamdaoui ◽  
Ahlem Lanouar ◽  
Sabri Halaoua
Keyword(s):  
Fluorescent Dyes ◽  
Second Order ◽  
Disperse Dyes ◽  
Order Model ◽  
Nernst Equation ◽  
First Order ◽  
Dyeing Process ◽  
Pseudo Second Order ◽  
Polyester Dyeing ◽  
Kinetics Of

In this paper, we present the results of an investigation and analysis of an experimental study of fluorescent disperse dyes used for dyeing polyester fabrics to high-visibility colors. This paper describes the results of spectrophotometric color measurements for yellow luminous, red luminous and orange luminous fluorescent dyes and their matching with the requirements of the EN 471 standard. The results of this study showed that the adsorption isotherms of polyester dyeing with fluorescent disperse luminous dyes follow the Nernst equation; the Nernst constants were determined and interpreted. The adsorption kinetics of fluorescent disperse dyes on polyester is studied by using the peudo-first-order model, the pseudo-second-order equation and the intraparticle diffusion equation. The results show that pseudo-second-order models fit well the experimental data with higher average regression coefficients (R2 > 0.98). They also show that high-visibility is influenced by the dye concentration, and that the dye mixtures can affect the high-visibility.

scholarly journals Tea Stem as a Sorbent for Removal of Methylene Blue from Aqueous Phase

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Tzan-Chain Lee ◽  
Shumao Wang ◽  
Zonggui Huang ◽  
Zhongxing Mo ◽  
Gangxing Wang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Ionic Strength ◽  
Aqueous Phase ◽  
Removal Efficiency ◽  
Adsorption Mechanism ◽  
Second Order ◽  
Isotherm Models ◽  
Order Model ◽  
Pseudo Second Order ◽  
Second Order Model

The potentiality of tea stem for the adsorption of methylene blue (MB) from aqueous phase was investigated. A series of operating factors, including the initial MB concentration, contact time, pH of solution, dose of tea stem, and ionic strength of solution, were conducted to understand the effect of adsorption of MB onto tea stem. Adsorption isotherm, kinetic models, thermodynamic investigation, and regenerability of tea stem were systematically investigated in this study. The experiment results revealed that the removal efficiency decreased with MB concentration and the equilibrium time of adsorption at different initial MB concentrations was approximately at 60 min. The appropriate dose of tea stem powder was found to be 4 g/L. The pHzpc of tea stem was evaluated and was observed to be 6.0 ± 0.2. The removal efficiency increased with pH ranging from 3.0 to 5.0 and remained constantly at the pH range of 5.0–11.0. The pH affected the adsorption because of the repellent power between H+ and dye cation. The ionic strength was found to have a negligible effect on the adsorption. The Langmuir and Temkin isotherm models were found to be the best isotherm models to elucidate the adsorption mechanism between MB and tea stem powder. The maximum adsorption capacity of 103.09 mg/g derived from the Langmuir model was much close to the experimental result. From the kinetic analysis, the pseudo-second-order model was found to be the suitable model to describe the adsorption behavior. The calculated adsorption capacities at different temperatures derived from the pseudo-second-order model ranging from 68.91 to 69.8 mg/g were well close to the experimental data. The intraparticle diffusion of MB molecules into pore structures of tea stem powder is the rate-limiting step for the adsorption process in this study. Evaluation of thermodynamic parameters including changes in enthalpy, entropy, and Gibb’s free energy indicated the adsorption mechanism between MB and tea stem powder was a spontaneous and exothermic process. The regeneration/adsorption experiments indicated that the tea stem powder efficiently remained more than 97% after five cycles using NaOH as a desorbing agent and thus be used for many times. On the basis of experimental results obtained, it is concluded that the tea stem has a considerable potential as a low-cost sorbent for removing MB from the aqueous phase.

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