scholarly journals Synthesis ofα-MnO2Nanomaterial from a Precursorγ-MnO2: Characterization and Comparative Adsorption of Pb(II) and Fe(III)

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Van-Phuc Dinh ◽  
Ngoc-Chung Le ◽  
Thi-Phuong-Tu Nguyen ◽  
Ngoc-Tuan Nguyen
Keyword(s):  
Kinetic Studies ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Structure Morphology ◽  
Pseudo Second Order ◽  
Three Stages ◽  
Thermal Analysis Result ◽  
Two Stages ◽  
Adsorptive Properties

α-MnO2nanostructure was successfully synthesized via hydrothermal treatment of a precursorγ-MnO2. Structure, morphology, and BET surface area were characterized using X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller nitrogen adsorption (BET-N2adsorption). Thermal analysis result showed thatα-MnO2nanorods were formed fromγ-MnO2at 600°C. In addition, Pb(II) and Fe(III) adsorptive properties were investigated in an optimal condition. Results showed that equilibrium adsorption was obtained after 60 minutes for Pb(II) at pH = 4.0 and 80 minutes for Fe(III) at pH = 3.5 with 240 rpm of shaking speed overall. Experimental data was analyzed using three models: Langmuir, Freundlich, and Sips. Adsorption capacities (qm) from the Langmuir isotherm models are 124.87 mg/g for Pb(II) and 30.83 mg/g for Fe(III). Along with the highest corelation coefficients, it is clear that the adsorption of Pb(II) and Fe(III) ions onα-MnO2surface followed Sips model. Kinetic studies indicated that the uptake of Pb(II) and Fe(III) occurred in the pseudo-second-order model with two stages for Pb(II) and three stages for Fe(III).

scholarly journals Effective Removal of Malachite Green from Aqueous Solutions Using Magnetic Nanocomposite: Synthesis, Characterization, and Equilibrium Study

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ali Q. Alorabi
Keyword(s):  
Surface Area ◽  
Malachite Green ◽  
Chemical Activation ◽  
Aqueous Media ◽  
Kinetic Studies ◽  
Cost Effective ◽  
Magnetic Nanocomposite ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Order Kinetic

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.

scholarly journals ADSORPTION AND KINETIC STUDIES OF A NATURAL DYE FROM CURCUMA LONGA L., ONTO BAMBOO YARN

2017 ◽  
Vol 2 (1) ◽  
pp. 13-26
Author(s):  
Tengku Khamanur Azma Tg. Mohd Zamri ◽  
Mimi Sakinah Abd Munaim ◽  
Zularisam Ab Wahid
Keyword(s):  
Adsorption Process ◽  
Regression Coefficient ◽  
Curcuma Longa ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Natural Dye ◽  
Isotherm Models ◽  
Order Model ◽  
Dyeing Process ◽  
Pseudo Second Order

Natural dye extracted from the rhizome of Curcuma longa L. were applied to bamboo yarns using exhaustion dyeing process. This study investigates the dyeing behaviour of Curcumin; the major color component isolated from rhizomes of Curcuma longa L.on bamboo yarn. Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich isotherm models were used to test the adsorption process of curcumin on bamboo yarn. Comparison of regression coefficient value indicated that the Freundlich isotherm most fitted to the adsorption of curcumin onto bamboo yarn. Furthermore, the kinetics study on this research fitted the pseudo-second order model which indicates that the basis of interaction was chemical adsorption.

scholarly journals Parametric, equilibrium and kinetic studies on the removal of mercury using ion exchange resin

2017 ◽  
Vol 12 (2) ◽  
pp. 305-313 ◽  
Author(s):  
N. Rajamohan ◽  
M. Rajasimman
Keyword(s):  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Strong Acid ◽  
Ion Exchange Resin ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Acid Cation ◽  
Pseudo Second Order ◽  
Langmuir Constants

This experimental research was an investigation into removal of mercury by using a strong acid cation resin, 001 × 7. Parametric experiments were conducted to determine the optimum pH, resin dosage, agitation speed and the effect of change in concentration in the range of 50–200 mg/L. High resin dosages favoured better removal efficiency but resulted in lower uptakes. Equilibrium experiments were performed and fitted to Langmuir and Freundlich isotherm models. Langmuir model suited well to this study confirming the homogeneity of the resin surface. The Langmuir constants were estimated as qmax = 110.619 mg/g and KL = 0.070 L/g at 308 K. Kinetic experiments were modeled using Pseudo second order model and higher values of R2 (>0.97) were obtained. The Pseudo second order kinetic constants, namely, equilibrium uptake (qe) and rate constant (k2), were evaluated as 59.17 mg/g and 40.2 × 10−4 g mg−1 min−1 at an initial mercury concentration of 100 mg/L and temperature of 308 K.

scholarly journals Orthophosphoric Acid Activated Babul Seed Carbon as an Adsorbent for the Removal of Methylene Blue

2008 ◽  
Vol 5 (4) ◽  
pp. 742-753 ◽  
Author(s):  
M. Sujatha ◽  
A. Geetha ◽  
P. Sivakumar ◽  
P. N. Palanisamy
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Adsorption Kinetics ◽  
Orthophosphoric Acid ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
Blue Dye ◽  
Equilibrium Data ◽  
Pseudo Second Order

An Experimental and theoretical study has been conducted on the adsorption of methylene blue dye using activated carbon prepared from babul seed by chemical activation with orthophosphoric acid. BET surface area of the activated carbon was determined as 1060 m2/g. Adsorption kinetics, equilibrium and thermodynamics were investigated as a function of initial dye concentration, temperature and pH. First order Lagergren, pseudo-second order and Elovich kinetic models were used to test the adsorption kinetics. Results were analyzed by the Langmuir, Freundlich and Temkin isotherm models. Based on regression coefficient, the equilibrium data found fitted well to the Langmuir equilibrium model than other models. The characteristics of the prepared activated carbon were found comparable to the commercial activated carbon. It is found that the babul seed activated carbon is very effective for the removal of colouring matter.

scholarly journals Removal of Carcinogenic Dyes Congo red (CR) and Bismarck brown Y (BBY) by Adsorption onto Reusable Hydrogels Derived from Acrylamide

2021 ◽  
Vol 2063 (1) ◽  
pp. 012011
Author(s):  
Huda S Al-Niaeem ◽  
Ali A Abdulwahid ◽  
Whidad S Hanoosh
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Congo Red ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Sulphonic Acid ◽  
Isotherm Models ◽  
Anionic Dyes ◽  
Best Fitting ◽  
Pseudo Second Order

Abstract Hydrogels of acrylamide (AM), acrylamide\ 2-acrylamido-2-methyl-1-propane sulphonic acid (AMS), and acrylamide\ 2-acrylamido-2-methyl-1-propane sulphonic acid\graphene oxide (AMSGO) were prepared as adsorbents to remove carcinogenic dyes Congo red (CR) and Bismarck brown Y (BBY) from aqueous solutions. Hydrogels were characterized using FSEM and XRD analyses. For both dyes, the synthesized hydrogels demonstrated high adsorption capability at near-neutral pH. Experimental adsorption data were analyzed using the Langmuir and Freundlich isotherm models. It was found that the Langmuir model was more suitable for the experimental data. Kinetic studies found that the pseudo-second-order model demonstrated the best fitting to the experimental data. In addition, thermodynamic studies suggest that the adsorption process was spontaneous and endothermic. The prepared hydrogels were regenerated and reused in four consecutive cycles and it could be applied to remove anionic dyes from aqueous solutions as an effective adsorbent.

Adsorption of Methylene Blue by Hydroxyl-Aluminum Pillared Montmorillonite

2020 ◽  
Vol 42 (4) ◽  
pp. 550-550
Author(s):  
Houria Rezala Houria Rezala ◽  
Houda Douba Houda Douba ◽  
Horiya Boukhatem and Amaya Romero Horiya Boukhatem and Amaya Romero
Keyword(s):  
Methylene Blue ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Basal Spacing ◽  
Solution Ph ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Kinetics And Isotherms

A purified raw montmorillonite and hydroxy-aluminum pillared montmorillonite have been prepared from a natural bentonite from Maghnia, Algeria. These materials have been analyzed by X-ray fluorescence spectroscopy, X-ray diffraction, Infrared spectroscopy and nitrogen adsorption-desorption measurement. The pillared montmorillonite provided a certain increase of interlayer basal spacing and BET surface area and consequently the improvement of its capacities adsorption and decolorization of Methylene Blue. The adsorption properties of these materials were studied as a function of contact time, solution pH, initial Methylene Blue concentration and temperature. The adsorption kinetics and isotherms were well fitted by pseudo-second order and Freundlich models, respectively. In addition to that, thermodynamic studies showed an exothermic and a spontaneous process.

scholarly journals Removal of zinc ions as zinc chloride complexes from strongly acidic aqueous solutions by ionic exchange

2014 ◽  
Vol 12 (8) ◽  
pp. 821-828 ◽  
Author(s):  
Emilia Gîlcă ◽  
Andrada Măicăneanu ◽  
Petru Ilea
Keyword(s):  
Kinetic Studies ◽  
Sorption Kinetics ◽  
Exchange Capacity ◽  
Second Order ◽  
Isotherm Models ◽  
Ionic Exchange ◽  
Order Kinetic ◽  
Zinc Ions ◽  
Chloride Complexes ◽  
Pseudo Second Order

AbstractThe aim of this study was to compare several anion exchangers and to investigate the capacity of Amberlite IRA410 to remove zinc as chloride [ZnCl3]− from hydrochloric solutions (1 M). Influence of the process parameters such as stirring rate, resin quantity and zinc initial concentration over the removal process, was considered. The highest experimental ionic exchange capacity between the considered anionic exchangers, in the same working conditions (500 rpm, 5 g resin and 500 mg L−1), was obtained for Amberlite IRA410, 8.34 mg g−1. With an increase of zinc ions concentration, ionic exchange capacity increased up to 19.31 mg g−1 (1100 mg L−1). The experimental data were analysed using Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The results were also analyzed using sorption kinetics models, pseudo-first-, pseudo-second-order, intra-particle and film diffusion models. From the Dubinin-Radushkevich and Temkin isotherm models the mean free energy and heat of sorption were calculated to be 7.45 kJ mol−1, respectively 1×10−4 kJ mol−1, which indicates that zinc sorption is characterized by a physisorption process. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model.

Zinc Adsorption Property of Gamma-MnO2 Nanostructure: Equilibrium and Kinetic Studies

2016 ◽  
Vol 708 ◽  
pp. 3-8
Author(s):  
Van Phuc Dinh ◽  
Ngoc Chung Le ◽  
Thi Phuong Tu Nguyen ◽  
Thi Dong Thuong Hoang ◽  
Van Dong Nguyen ◽  
...  
Keyword(s):  
Adsorption Property ◽  
Kinetic Studies ◽  
Sorption Process ◽  
Second Order ◽  
Isotherm Models ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
The Mean ◽  
Influence Of Ph ◽  
Sorption Time

In this work, gamma–MnO2 nanostructure was used as a sorbent to remove Zn (II) ion from aqueous solution. The influence of pH, sorption time and Zn (II) ion initial concentration were examined. The results showed that equilibrium adsorption was obtained after 60 minutes with 240 rpm of shaking speed at pH = 4.0. The experimental data were analyzed using five non-linear isotherm models: Langmuir, Freundlich, Sips, Tempkin and Dubinin – Radushkevich. The adsorption capacity (qm) from the Langmuir isotherm model for Zn (II) is founded as 55.23 mg/g. The heat of sorption process and the mean free energy were estimated from Temkin and Dubinin – Redushkevich isotherm models to be less than 8 kj/mol which vividly proved that the adsorption experiment followed a physical process. Kinetic studies have shown that although the adsorption data partially followed pseudo-first-order and pseudo-second-order equation for different time, it was well expressed by pseudo-second-order model.

scholarly journals The effect of alkaline pretreatment on surfactant-modified clinoptilolite for diclofenac adsorption: isotherm, kinetic, and thermodynamic studies

2020 ◽  
Author(s):  
Fateme Poorsharbaf Ghavi ◽  
Fereshteh Raouf ◽  
Ahmad Dadvand Koohi
Keyword(s):  
Ph Effect ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Thermodynamic Studies ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Modified Clinoptilolite ◽  
Kinetic And Thermodynamic Studies

Abstract The elimination of diclofenac traces from aqueous environments is important. In this research, the effect of alkaline (NaOH) pretreatment on clinoptilolite before its modification with a surfactant (HDTMA) for diclofenac adsorption under the speculation of the sole presence of diclofenac in the aqueous solution is investigated. The results are compared through isotherm, kinetic, and thermodynamic studies and supplemented by FTIR, SEM, BET, and the zeta potential analyses. The contact time was investigated in a 0–180-min range. The pH effect was studied in a range of 5–10 because of diclofenac dissociation below pH = 5. The effect of the temperature on diclofenac adsorption was also considered by establishing the experiments at 25, 35, and 45 °C. For HDTMA-modified clinoptilolite, Temkin, and for NaOH-HDTMA-modified clinoptilolite, Dubinin–Radushkevich, and Freundlich isotherm models and in both cases, the pseudo-second-order kinetic model fitted the experimental data best. All the enthalpy and the entropy changes were negative, suggesting exothermic adsorption with a decrease in the degree of freedom of diclofenac anions after the adsorption. Furthermore, diclofenac physisorption was confirmed through isotherm and kinetic studies.

scholarly journals Adsorbing low concentrations of Cr(VI) onto CeO2@ZSM-5 and the adsorption kinetics, isotherms and thermodynamics

2018 ◽  
Vol 77 (9) ◽  
pp. 2327-2340 ◽  
Author(s):  
Jianrui Niu ◽  
Xiuxiu Jia ◽  
Yaqing Zhao ◽  
Yanfang Liu ◽  
Weizhang Zhong ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Photoelectron Spectroscopy ◽  
Bet Surface Area ◽  
Isotherm Models ◽  
X Ray ◽  
Low Concentrations ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Isotherms And Thermodynamics ◽  
Kinetics Of

Abstract The CeO2@ZSM-5 was prepared by the dipping method. We used ZSM-5 and CeO2 as the carrier and load components, respectively. The aim was to reduce the low concentration of Cr(VI) in simulated wastewater (the concentration of Cr(VI) ranged from 0.2 to 1 mg/L). The characteristics of ZSM-5 and CeO2@ZSM-5 samples were determined by X-ray powder diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET). Characterization results showed that the particle size, BET surface area and pore volume for CeO2@ZSM-5 was around 0.783 nm, 421.307 m2/g and 0.313 m3/g, respectively. In addition, the optimum conditions were obtained by the orthogonal test, and the details were as follows: optimal pH, adsorbent dose, initial concentration of Cr(VI) and equilibrium time were 3, 5 g/L, 0.6 mg/L and 70 min respectively. The removal of Cr(VI) was 99.56% in these conditions. The pseudo-second-order model best described the adsorption kinetics of Cr(VI) onto CeO2@ZSM-5. Isotherm data were treated according to Langmuir, Freundlich and Temkin isotherm models. The results showed that the Freundlich adsorption isotherm model fitted best in the temperature range studied. Adsorption capacity increased with temperature, showing the endothermic nature of Cr(VI) adsorption. The desorption results showed the best recovery of Cr(VI) using 0.1 M HCl.

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