scholarly journals Application ofGlycyrrhiza glabraRoot as a Novel Adsorbent in the Removal of Toluene Vapors: Equilibrium, Kinetic, and Thermodynamic Study

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Fazel Mohammadi-Moghadam ◽  
Mohammad Mehdi Amin ◽  
Mehdi Khiadani (Hajian) ◽  
Fariborz Momenbeik ◽  
Heshmatollah Nourmoradi ◽  
...  
Keyword(s):  
Contact Time ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Adsorbate Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Study ◽  
Better Than

The aim of this paper is to investigate the removal of toluene from gaseous solution throughGlycyrrhiza glabraroot (GGR) as a waste material. The batch adsorption experiments were conducted at various conditions including contact time, adsorbate concentration, humidity, and temperature. The adsorption capacity was increased by raising the sorbent humidity up to 50 percent. The adsorption of toluene was also increased over contact time by 12 h when the sorbent was saturated. The pseudo-second-order kinetic model and Freundlich model fitted the adsorption data better than other kinetic and isotherm models, respectively. The Dubinin-Radushkevich (D-R) isotherm also showed that the sorption by GGR was physical in nature. The results of the thermodynamic analysis illustrated that the adsorption process is exothermic. GGR as a novel adsorbent has not previously been used for the adsorption of pollutants.

Adsorption of enrofloxacin from aqueous solution by bentonite

Clay Minerals ◽  
2013 ◽  
Vol 48 (4) ◽  
pp. 627-637 ◽  
Author(s):  
J. X. Zhang ◽  
Q. X. Zhou ◽  
W. Li
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Batch Experiments ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Better Than

AbstractThe removal of enrofloxacin, a fluoroquinolone antibiotic, from aqueous solution by adsorption onto bentonite was investigated in this study. The effects of initial concentrations, contact time and temperature on the adsorption of enrofloxacin were studied via batch experiments. The adsorption equilibrium was achieved within 60 min for all studied concentrations. The adsorption capacity increased with the increase of initial concentration within a concentration range. Higher temperatures were favourable for the adsorption. The change of Gibbs free energy (ΔG°), change of enthalpy (ΔH°) and change of entropy (ΔS°) were evaluated and the results indicate that the adsorption should be an endothermic and spontaneous process. The Langmuir isotherm model fitted to the experimental data better than the Freundlich model. The adsorption follows the pseudo-second order kinetic model.

scholarly journals Removal of Cu(II) Ions byLeucaena Leucocephala(Subabul) Seed Pods from Aqueous Solutions

2010 ◽  
Vol 7 (s1) ◽  
pp. S377-S385 ◽  
Author(s):  
A. K. Patil ◽  
V. S. Shrivastava
Keyword(s):  
Leucaena Leucocephala ◽  
Contact Time ◽  
Unit Weight ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Isotherm Equations ◽  
Adsorbent Dose

In this method,Leucaena leucocephalaseed pods (LLSP) have been used for removal of Cu(II) ions from aqueous solution. Batch adsorption experiments were conducted to study the effect of process parameters like pH, contact time initial Cu(II) ions concentration and adsorbent dose. The maximum adsorption of Cu(II) ions onLeucaena leucocephalaseed pods was 94.17% at pH 5. The amount of metal adsorbed per unit weight of adsorbent increases with time and reach equilibrium after 30 minutes of shaking time for the different initial metal concentrations. The Freundlich and Langmuir isotherm equations were applied for the equilibrium adsorption data and the various isotherm parameters were evaluated. The obtained plots were linear as evident fromR2values close to unity. The data agreed very well with the pseudo second-order kinetic model.

scholarly journals Study of the Digestate as an Innovative and Low-Cost Adsorbent for the Removal of Dyes in Wastewater

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 852
Author(s):  
Sicong Yao ◽  
Massimiliano Fabbricino ◽  
Marco Race ◽  
Alberto Ferraro ◽  
Ludovico Pontoni ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Removal Rate ◽  
Low Cost ◽  
Second Order ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Diffusion Kinetic ◽  
Pseudo Second Order

Digestate, as an urban solid waste, was considered as an innovative adsorbent for colorant polluted wastewater. Batch adsorption experiments were carried out using digestate as an adsorbent material to remove various dyes belonging to different categories. The removal rate and adsorption capacity of dyes were evaluated and the dose of digestate, contact time, and initial dye concentration were studied. The maximum removal rate was approximately 96% for Methylene Blue. The equilibrium time for the Methylene Blue was 4 h, while for other dyes, a longer contact time was required to reach the equilibrium. The suspicion of colloidal matter release into the solution from solid fraction of the digestate led to the investigation of the consequence of a washing step of the digestate adsorbent upstream the adsorption experiment. Washed and not washed adsorbents were tested and the differences between them in terms of dye removal were compared. Moreover, experimental data were fitted by pseudo-first order, pseudo-second order, and intra-partial diffusion kinetic models as well as Langmuir, Freundlich, and Sips isotherm models. The results from fitted models showed that the adsorption of various dyes onto the digestate was mostly well fitted by the Langmuir isotherm and pseudo-second-order kinetic model.

scholarly journals Cr(VI) adsorption from aqueous streams on eggshell membranes of different birds used as biosorbents

2020 ◽  
Vol 38 (9-10) ◽  
pp. 413-434
Author(s):  
Jessica Badillo-Camacho ◽  
Eulogio Orozco-Guareño ◽  
Gregorio G Carbajal-Arizaga ◽  
Ricardo Manríquez-Gonzalez ◽  
Icela D Barcelo-Quintal ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Membrane Surfaces ◽  
Adsorption Isotherm Models ◽  
Before And After ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Efficient Option

The discharges enriched with heavy metals, particularly Cr(VI), are a serious environmental problem. In this work, it is presented the use of biosorbents from eggshells membranes of ostrich, quail, duck and chicken; the membranes were easily prepared and studied for the removal of Cr(VI) from aqueous solutions. Maximum uptake of 1.41 mmol g−1 membrane permitted the identification of ostrich membrane as the material with the highest Cr(VI) uptake. N2 adsorption experiments permitted to classify ostrich membranes as mesoporous materials, since they had pore size of 14.8 nm. This represented an advantage on the nature of these membranes to be used as biosorbents with respect to other membranes. The adsorption isotherm models such as Langmuir and Freundlich were verified using experimental data. Langmuir model described the adsorption process satisfactorily at pH 1 and 2 whereas Freundlich model fitted data better at pH 3 and 5. The adsorption kinetic data were adjusted to a pseudo-second order kinetic model. TGA results permitted demonstrating a low thermal stability of ostrich membrane, since it starts decomposing at around 50°C due to the fact that membranes have about 60% protein. Through SEM microscopy was possible to observe the morphology of the membrane surfaces before and after Cr(VI) uptake which reflects the textural characteristics of the biosorbent. FTIR and XPS analyses suggested that Cr was adsorbed on ostrich membranes through the amine groups of proteins conforming the fibers of membranes. Despite the oxygen shows higher electronegativity than N, Cr shows more preference toward N due to fact that pH conditions favor the positive charges on the surface of the membrane. Our results make evident that this waste material is a novel and efficient option for the removal of Cr(VI) from aqueous solutions.

scholarly journals Kinetics and adsorption studies of lead (II) onto activated carbon using low cost adsorbents

2018 ◽  
Vol 20 (2) ◽  
pp. 381-388 ◽  
Keyword(s):  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Rate Limiting Step ◽  
Bambusa Vulgaris ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Fagopyrum Esculentum Moench

The removal of Lead (II) from aqueous solutions using Fagopyrum esculentum Moench (Buckwheat) and Bambusa vulgaris (common bamboo) as adsorbents was investigated. The effects of various experimental parameters such as initial concentration, contact time and pH have been studied using batch adsorption technique. All the Adsorption isotherm models fitted well with the adsorption data. However, Freundlich isotherm displayed a better fitting model than the other two isotherm models due to high correlation coefficient (R2). This indicates the applicability of multilayer coverage of the Pb (II) on the surface of adsorbent. The adsorption kinetics was studied using four simplified models and it was found to follow the pseudo-second-order kinetic model which confirmed the applicability of the model. The adsorption mechanism was found to be chemisorption and the rate-limiting step was mainly surface adsorption.

scholarly journals Adsorption and Kinetics Studies of Cu (II) ions Removal from Aqueous Solution by Untreated and Treated Sugarcane Bagasse

2015 ◽  
Vol 17 (3) ◽  
pp. 583-593 ◽  
Keyword(s):  
Sugarcane Bagasse ◽  
Contact Time ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Adsorption Affinity ◽  
Optimum Ph ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Better Than

<div> <p>Adsorption of Cu (II) ions by untreated sugarcane bagasse (USCB) and treated sugarcane bagasse (TSCB) was investigated. Sugarcane bagasse was treated with 0.1M oxalic acid prior to TSCB adsorption studies. Dependence of Cu (II) adsorption on pH, contact time, temperature and initial concentration of adsorbate solution were also investigated. Optimum pH 2 and contact time of 100 minutes were observed for both USCB and TSCB, while Cu II sorption increased with temperature. Under optimum condition, TSCB adsorbed Cu (II) ions better than USCB (1.854mgg<sup>-1</sup>and 0.556mgg<sup>-1</sup>respectively). Thermodynamic investigations showed that Cu (II) adsorption was feasible, spontaneous and endothermic. Kinetic data was adequately described by Ho&rsquo;s pseudo-second-order kinetic model while intra-particle diffusion model described a slow adsorption affinity. It was concluded that Cu (II) adsorption by sugarcane bagasse is a favourable chemisorption process and was well explained by both Langmuir and Freundlich isotherms.</p> </div> <p>&nbsp;</p>

scholarly journals Kinetics of adsorption of methylene blue onto activated kolanut pod

2021 ◽  
Vol 12 (2) ◽  
pp. 156-162
Author(s):  
A.S. Muhammad ◽  
M.A. Abdurrahman
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Kinetics Of Adsorption ◽  
Initial Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Calculated Amount

A batch adsorption process was carried out by optimizing, the effect of contact time (10min to 180min) and initial concentration (5mg/l to150mg/l). The adsorbent was characterized using FTIR spectra and SEM, and the result obtained showed shifting and disappearance of peaks after adsorption. The results of the adsorption kinetics, which includes the correlation coefficient 0.9771 and the agreement between the amount adsorbed experimentally (1.472mg/g) and the calculated amount absorbed(1.196mg/g) revealed that MB was adsorbed satisfactory according to the pseudo second-order kinetic model.

scholarly journals Synthesis and Characterisation of Graphene Oxide-Silica-Chitosan for Eliminating the Pb(II) from Aqueous Solution

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1922
Author(s):  
Sepehr Azizkhani ◽  
Ebrahim Mahmoudi ◽  
Norhafizah Abdullah ◽  
Mohd Halim Shah Ismail ◽  
Abdul Wahab Mohammad ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Contact Time ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Removal Capacity ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Heavy metal ions have a toxic and negative influences on the environment and human health even at low concentrations and need to be removed from wastewater. Chitosan and graphene oxide are suitable nano plate adsorbents with high adsorption potential because of their π-π interaction, and they are available functional groups that interact with other elements. In this study, graphene oxide was coated with silica to enhance the hydrophilicity of the adsorbent. Subsequently, the adsorbent was functionalised by various amounts of chitosan to improve the Pb(II) removal. The adsorbent was analysed using transmission electron microscopy (TEM), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and mapping analysis techniques. An investigation of the influences of the initial concentration of Pb(II), pH and contact time were included to obtain the optimum amount of adsorption. The range of the initial Pb(II) concentration studied was from 10 to 120 mg/L. The pH factor ranged from 3 to 8 with contact time from 0 to 140 min. Freundlich, Temkin and Langmuir isotherm models were fit to the results, and a pseudo-second-order kinetic model was found to provide a good fit as well. The maximum Pb(II) removal capacity achieved was 256.41 (+/− 4%) mg/g based on Langmuir isotherms.

scholarly journals Adsorptive removal of catechol and resorcinol by orange flavedo (citrus sinensis): mechanisms based on the flavedo com-ponents d-limonene, carotenoids, ascorbates, flavonoids and hydroxycinnamic acids

2017 ◽  
Vol 6 (1) ◽  
pp. 7
Author(s):  
Kamgaing Theophile ◽  
Doungmo Giscard ◽  
Ngouoko Kouonang Jimmy Julio ◽  
Tchieno Melataguia Francis Merlin ◽  
Ketcha MBadkam Joseph
Keyword(s):  
Contact Time ◽  
Low Cost ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Batch Mode ◽  
X Ray ◽  
Adsorbate Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Phenomena

Orange flavedo and its adsorption behavior towards catechol (Ctc) and resorcinol (Res) were studied. Adsorption experiments were conducted in batch mode at room temperature. X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Brunauer−Emmett−Teller (BET) and Fourier transform infrared (FTIR) data were used to characterize the biosorbent. The Effects of various parameters including equilibrium pH, sorbent dosage, initial adsorbate concentration and contact time were investigated. The optimum contact time and pH for the removal of Ctc and Res were 35 min and pH 2 respectively. The adsorption isotherms fitted well with Freundlich model, the adsorption of Ctc and Res being multilayer and the surface of orange flavedo heterogeneous; the pseudo-second order kinetic model better reflects the adsorption phenomena. An adsorption mechanism based on the molecules grafted to the surface of the orange flavedo is proposed in this study. 0.2 gram of the biosorbent was sufficient to completely eliminate 2.2 milligrams of resorcinol and catechol from solution. Therefore, non-modified orange flavedo is a promising candidate, as a low-cost biosorbent, for the removal of Ctc and Res from aqueous solution.

scholarly journals Modified Cenospheres as an Adsorbent for the Removal of Disperse Dyes

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Markandeya Tiwari ◽  
S. P. Shukla ◽  
D. Mohan ◽  
D. S. Bhargava ◽  
G. C. Kisku
Keyword(s):  
Adsorption Process ◽  
Low Cost ◽  
Agitation Speed ◽  
Disperse Dyes ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorbate Concentration ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorbent Dose

The main objective of this investigation was to use modified cenospheres for the removal of disperse blue 79:1 (DB) and disperse orange 25 (DO) dyes from aqueous solution by batch adsorption process under different conditions (pH, adsorbent dose, adsorbate concentration, agitation speed, contact time, and temperature). Modified cenosphere was capable of removing up to 78% of DB and 81% of DO dyes from aqueous solutions of 40 mg/L dyes concentration. The investigated data was explained by the Langmuir isotherm. The experimental data were found to follow the pseudo-second-order kinetic model. The results of this study suggested that modified cenospheres could be used as a low-cost alternative to expensive adsorbents like activated carbon in wastewater treatment for the removal of disperse dyes.

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