scholarly journals The Kinetics, Mechanism and Effect of Contact Time on the Adsorption of Cadmium and Glyphosate to Alfisol

2020 ◽  
pp. 23-29
Author(s):  
F. B. Okanlawon ◽  
O. A. Okon- Akan ◽  
O. A. Adegoke ◽  
O. A. Olatunji
Keyword(s):  
Organic Contaminants ◽  
Environmental Remediation ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Intraparticle Diffusion Model ◽  
Standard Procedures ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Linear Plot ◽  
Pass Through

This study was carried out using Alfisol as an adsorbent to adsorb Cadmium and Glyphosate both of which are common inorganic and organic contaminants. The soil samples were air-dried and allowed to pass through 2mm sieve before use while its analysis was done following the standard procedures. The kinetic data were tested with pseudo-first-order and pseudo-second-order models, and it was concluded that both adsorbates adsorption followed the pseudo-second-order kinetics, while the nature and the mechanism of adsorption processes were studied by using an intraparticle diffusion model. A complete linear plot of intraparticle diffusion was obtained for glyphosate which suggests that intraparticle diffusion was the rate-controlling step in its adsorption but the opposite is the case for cadmium adsorption. The peak removal of cadmium occurred after 50 minutes with equilibrium attained over 250 minutes while peak glyphosate removal was achieved after 30 minutes. It can be concluded that Alfisol can be effectively used for the adsorption of both Cadmium and Glyphosate thus showcasing a potential environmental remediation process.

scholarly journals Dye removal abilities of the mesophilic and thermophilic biomass: a kinetics study

2018 ◽  
Vol 20 (2) ◽  
pp. 408-416
Keyword(s):  
Intraparticle Diffusion ◽  
Second Order ◽  
Intraparticle Diffusion Model ◽  
First Order Kinetics ◽  
Different Types ◽  
Pseudo Second Order ◽  
Acidic Conditions ◽  
Red Dye ◽  
Experimental Kinetics ◽  
Kinetics Of

Mesophilic biomass and thermophilic biomass samples were isolated and used to remove Dorasyn Red dye from aqueous solutions. The biosorption kinetics of dye uptake by four different types of biomass at three temperatures (20, 30, and 40 °C) were investigated using pseudo-first order kinetics, pseudo-second order kinetics, intraparticle diffusion, Elovich, and Bangham models. The pseudo-second-order kinetics model and the first stage of the intraparticle diffusion model were effective in describing the experimental kinetics data. The biosorption results showed that the mesophilic biomass samples could be useful for removing dye under acidic conditions.

scholarly journals Study on isotherm, kinetics, and thermodynamics of adsorption of crystal violet dye by calcium oxide modified fly ash

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Sagnik Chakraborty ◽  
Anupam Mukherjee ◽  
Subhabrata Das ◽  
Naga Raju Maddela ◽  
Saima Iram ◽  
...  
Keyword(s):  
Fly Ash ◽  
Diffusion Model ◽  
Calcium Oxide ◽  
Crystal Violet ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Solution Ph ◽  
Symbiotic Associations ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order

The natural Fly ash modified with calcium oxide has been employed to eliminate the crystal violet dyestuff from the simulated solution. Herein, the effect of different physicochemical factors like primary dye concentration, sorption contact time, the quantity of the adsorbent, temperature, along with initial simulated solution pH, evaluated for illustrating the mechanism of adsorption. Furthermore, the equilibrium study was conducted, and equilibrium models like Langmuir, Freundlich, and Dubinin- Raduskevich (D-R) were fitted to obtain analytical results to endow with more insight into the process. The results acknowledged that the Langmuir model is well apt and suggests that the adsorption mechanism happens in a monolayer on the fly ash surface. Pseudo-first order, Pseudo-second order, and the intraparticle diffusion model evaluated, and the interpretation suggests the sorption method is obeying the Pseudo-second order and intraparticle diffusion model. The ascertained negative values of Gibbs free energy affirmed the unconstrained process for all symbiotic associations, and the obtained data 78.70 kJ mol<sup>–1</sup> enthalpy values manifested that exothermic mechanism was governing the reaction. The above assessment confirms the application of Calcium oxide pre-treated fly ash as a cheap adsorbent to eliminate the crystal violet dyestuff from the simulated solution.

scholarly journals Endüstriyel Sızıntı Suyundan Pb(II) Giderimi İçin Genleştirilmiş Perlit Kullanımı: Kinetik Çalışmalar

2018 ◽  
Vol 6 (3) ◽  
pp. 360
Author(s):  
Fulya Aydın Temel
Keyword(s):  
Kinetic Models ◽  
Diffusion Processes ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Expanded Perlite ◽  
Film Diffusion ◽  
Intraparticle Diffusion Model ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
One Step

In this study, the removal efficiency of Pb(II) from industrial leachate was investigated by using expanded perlite by adsorption. The effects of pH, contact time, and adsorbent dosage were examined on the Pb(II) removal. The adsorption kinetics were tested to understand the adsorption mechanism using three kinetic models, i.e., Elovich, intraparticle diffusion, and the pseudo second order reaction kinetic models. As the result, the best conformity kinetic model for Pb(II) adsorption on expanded perlite was described as the pseudo second-order (R2>0.99). It is indicated that chemisorption is the determining step of adsorption process rather than mass transfer from industrial leachate. According to the data obtained from intraparticle diffusion model, the adsorption is composed of more than one step. This can be attributed to the fact that the adsorption in the final portion was the intraparticle diffusion while the adsorption in the first portion was the film diffusion. Both film diffusion and intraparticle diffusion processes in the adsorption of Pb(II) on expanded perlite are significant. This study indicated that expanded perlite was an influential alternative adsorbent for the removal of Pb(II) by adsorption from industrial leachate.

scholarly journals Removal of Lead Ions from Waste Water Using Modified Jordanian Zeolite

2020 ◽  
pp. 19-30
Author(s):  
Hutaf M. Baker
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Sodium Dodecyl ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Lead Ions ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Intraparticle Diffusion Model ◽  
Dodecyl Sulfate ◽  
Pseudo Second Order

In this study a Jordanian Zeolite was modified using anionic surfactant which is sodium dodecyl sulfate (sodium dodecyl sulfate). The sorption of Pb(II) from synthetic wastewater by surfactant modified  Zeolite (SMZ) was investigated as a function of temperature. The experimental data was analysed using isotherm models namely Langmuir, Freundlich, Redlich-Peterson and Temkin and kinetic models such as the pseudo- second-order, intraparticle diffusion and the Elovich models in order to understand the mechanism of the interaction between this SMZ and the lead ions. All the isotherm models showed good correlation with the experimental results but Freundlich was the best. The calculated DH was obtained using Langmuir constant (aL), its value of 8.29kJ/mol revealed that the type of sorption is physical oneThe values of RL at all temperatures reflect the favorability of this interaction. The calculated activation energy was 21.126 kJ/mol using the pseudo-second order constant (k2), which indicates that the sorption is physisorption. The intraparticle diffusion model showed multilinearity which means multiple stages there occurred to achieve the removal of lead ions, the first linear curve is due to the boundary layer diffusion and the second linear curve isfor the intraparticle diffusion effect. The adsorption kinetics data fitted also Elovich model.

scholarly journals Removal of Disperse Blue 56 and Disperse Red 135 dyes from aqueous dispersions by modified montmorillonite nanoclay

2017 ◽  
Vol 23 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Javad Ahmadishoar ◽  
Hajir Bahrami ◽  
Barahman Movassagh ◽  
Hosein Amirshahi ◽  
Mokhtar Arami
Keyword(s):  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Isotherm Models ◽  
Disperse Dyes ◽  
Order Kinetic ◽  
Intraparticle Diffusion Model ◽  
Modified Montmorillonite ◽  
Pseudo Second Order

In this study modified montmorillonite was used as an adsorbent for the removal of two selected disperse dyes i.e., Disperse Blue 56 (DB) and Disperse Red 135 (DR) from dye dispersions. The adsorption equilibrium data of dyes adsorption were investigated by using Nernst, Freundlich and Langmuir isotherm models. The adsorption kinetics was analyzed by using different models including pseudo-first-order, pseudo-second-order, Elovich and Intraparticle diffusion model. The Freundlich isotherm was found to be the most appropriate model for describing the sorption of the dyes on modified nanoclay. The best fit to the experimental results was obtained by using the pseudo-second-order kinetic equation, which satisfactorily described the process of dye adsorption. Although different kinetic models may control the rate of the adsorption process, the results indicated that the main rate limiting step was the intraparticle diffusion. The results showed that the proposed modified montmorillonite could be used as an effective adsorbent for the removal of disperse dyes even from highly concentrated dispersions.

scholarly journals Kinetic model for the sorption of copper ions onto sugar beet shreds

2014 ◽  
Vol 68 (6) ◽  
pp. 793-799 ◽  
Author(s):  
Mirjana Brdar ◽  
Marina Sciban ◽  
Dragana Kukic ◽  
Tatjana Dosenovic
Keyword(s):  
Sugar Beet ◽  
Diffusion Model ◽  
Copper Ions ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Least Square ◽  
Coefficient Of Determination ◽  
Order Kinetic ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order

Adsorption kinetics is of great significance to evaluate the performance of adsorption process. The kinetics of copper ions adsorption onto different sized sugar beet shreds has been considered. Sugar beet shreds are very promising adsorbents due to their convenient chemical composition and availability in relatively large quantities in many countries. Experimental data were fitted with pseudo-first and pseudo-second-order kinetic models. Also, we used the intraparticle diffusion model for further analysis of kinetics. The coefficient of determination indicates that, the pseudo-second-order equation obtained by using non-linear least square method, was the most appropriate model for the description of copper ions adsorption onto sugar beet shreds. The adsorption capacities at equilibrium, for a particle size of 224 - 400 ?m, 400 - 750 ?m and 750 - 1000 ?m, are 10 mg/g, 9 mg/g and 8.6 mg/g, respectively. By using intraparticle diffusion model proposed by Weber and Morris, it was obtained that there exist two different stages in adsorption: fast initial adsorption which is further limited by intraparticle diffusion.

scholarly journals Adsorption of cationic dye onto Moroccan natural rock

2019 ◽  
Vol 9 (1) ◽  
pp. 37-44
Author(s):  
Amira AM ◽  
Fatima Ouzidan ◽  
Tarik Ainane ◽  
Mohamed Talbi ◽  
M'hammed El Kouali
Keyword(s):  
Adsorption Kinetics ◽  
Diffusion Mechanism ◽  
Elimination Rate ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Order Model ◽  
Intraparticle Diffusion Model ◽  
Natural Rock ◽  
Pseudo Second Order ◽  
Second Order Model

This paper evaluates the ability of a natural rock found in Morocco to remove the pollutant properties of methylene blue (MB) dye. In this regard, the experiments were conceived to test the hypothesis that the rock native of the country’s region of Khenifra can be used as a new abundant adsorbent to remove cationic dyes from water through the adsorption technique in order to avoid extra cost and contribute to the valorization of this material. For this, several factors such as pH of the solution, granulometry, mass of adsorbent, initial dye concentration and stirring rate were tested. The adsorption kinetics process was tested through three models, namely, the pseudo-first-order model, pseudo-second-order model and the intraparticle diffusion model, to predict which type of adsorption is best suited in the removal of dye pollution. The batch study proves that only the granulometry (G ≤ 63µm = 91%, G ≤ 80µm = 88.4% and G ≤ 100µm=70.7%) and the adsorbent mass (the more the mass of the adsorbent increases the more the elimination is achieved) can influence the elimination rate of our rock. Meanwhile, the data of the adsorption kinetics test show that the experimental adsorption could be described by the mechanism of the pseudo-second-order model (correlation coefficients near the unit ‘R 2 = 0.99’ ), confirming chemical sorption as a rate-limiting step of the intraparticle diffusion mechanism. According to the results of this study, the rock collected from the area of Khenifra can be used as a new and efficient adsorbent in the field of wastewater treatment.

scholarly journals Guidelines for general adsorption kinetics modeling

2020 ◽  
Vol 74 (1) ◽  
pp. 65-70
Author(s):  
Bojana Obradovic
Keyword(s):  
Adsorption Kinetics ◽  
Scale Up ◽  
Second Order ◽  
Particle Diffusion ◽  
Analysis And Evaluation ◽  
Inappropriate Use ◽  
Adsorption Processes ◽  
Intra Particle Diffusion ◽  
Elovich Equation ◽  
Pseudo Second Order

Adsorption processes are widely used in different technological areas and industry sectors, thus continuously attracting attention in the scientific research and publications. Design and scale-up of these processes are essentially based on the knowledge and understanding of the adsorption kinetics and mechanism. Adsorption kinetics is usually modeled by using several well-known models including the pseudo-first and pseudo-second order models, the Elovich equation, and the intra-particle diffusion based models. However, in the scientific literature there are a significant number of cases with the inappropriate use of these models, utilization of erroneous expressions, and incorrect interpretation of the obtained results. This paper is especially focused on applications of the pseudo-second order, intra-particle diffusion and the Weber-Morris models, which are illustrated with typical examples. Finally, general recommendations for selection of the appropriate kinetic model and model assumptions, data regression analysis, and evaluation and presentation of the obtained results are outlined.

scholarly journals Synthesis of New Cyclodextrin-Based Adsorbents to Remove Direct Red 83:1

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1880
Author(s):  
José A. Pellicer ◽  
María Isabel Rodríguez-López ◽  
María Isabel Fortea ◽  
Vicente M. Gómez-López ◽  
David Auñón ◽  
...  
Keyword(s):  
Room Temperature ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Freundlich Isotherm ◽  
Intraparticle Diffusion ◽  
Isotherm Models ◽  
Intraparticle Diffusion Model ◽  
Pseudo Second Order ◽  
Physical Interactions ◽  
Resonance Particle

Two cyclodextrins (CDs), γ– and hydroxypropyl (HP)–γ–CDs were used to synthesize new adsorbents by using epichlorohydrin (EPI) as cross-linking agent in order to remove Direct Red 83:1 (DR) from water. Both polymers were characterized in terms of Fourier spectroscopy, nuclear magnetic resonance, particle size distribution and thermogravimetric analysis. Experimental data for both polymers were well fitted to the pseudo-second order and intraparticle diffusion model, indicating that in the adsorption both chemical and physical interactions are essential in the removal of DR. Three different isotherm models were analyzed, concluding that γ–CDs–EPI followed the Temkin isotherm and HP–γ–CDs-EPI the Freundlich isotherm, these results suggested that the adsorption was happening onto heterogeneous surfaces. The results of the Gibbs free energy showed that the adsorption was spontaneous at room temperature. In order to eliminate the remaining dye after the polymer treatment, and advanced oxidation process (AOP) was considered, achieving more than 90% of removal combining both mechanisms.

scholarly journals Characterization and Evaluation of Zeolite A/Fe3O4 Nanocomposite as a Potential Adsorbent for Removal of Organic Molecules from Wastewater

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Emmanuel Nyankson ◽  
Jonas Adjasoo ◽  
Johnson Kwame Efavi ◽  
Reuben Amedalor ◽  
Abu Yaya ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Isotherm Models ◽  
Adsorption Efficiency ◽  
Ferrous Chloride ◽  
X Ray ◽  
Intraparticle Diffusion Model ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Chloride Salts

In this work, zeolite (Z) and Z-Fe3O4 nanocomposite (Z-Fe3O4 NC) have been synthesized. The Fe3O4 nanoparticles were synthesized using the extract from maize leaves and ferric and ferrous chloride salts and encapsulated into the zeolite framework. The nanocomposite (Z-Fe3O4 NC) was characterized using X-ray diffractometer (XRD), Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). The potential of Z-Fe3O4 NC as an adsorbent for removing methylene blue molecules (MB) from solution was examined using UV-Vis and kinetic and equilibrium isotherm models. The adsorption data fitted best with the pseudo-second-order model and Weber and Morris model, indicating that the adsorption process was chemisorption, while the Weber and Morris described the rate-controlling steps. The intraparticle diffusion model suggests that the adsorption processes were pore and surface diffusion controlled. The Langmuir isotherm model best describes the adsorption process indicating homogeneous monolayer coverage of MB molecules onto the surface of the Z-Fe3O4 NC. The maximum Langmuir adsorption capacity was 2.57 mg/g at 25°C. The maximum adsorption efficiency was 97.5%. After regeneration, the maximum adsorption efficiency achieved at a pH of 7 was 82.6%.

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