scholarly journals LDH Nanocubes Synthesized with Zeolite Templates and Their High Performance as Adsorbents

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3315
Author(s):  
Moftah Essa Elkartehi ◽  
Rehab Mahmoud ◽  
Nabila Shehata ◽  
Ahmed Farghali ◽  
Shimaa Gamil ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Average Pore Size ◽  
Second Order ◽  
Polluted Water ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Average Pore ◽  
X Ray ◽  
Pseudo Second Order

In this work, the efficiency of the adsorptive removal of the organic cationic dye methylene blue (MB) from polluted water was examined using three materials: natural clay (zeolite), Zn-Fe layered double hydroxide (LDH), and zeolite/LDH composite. These materials were characterized via X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) diffraction (XRF), low-temperature N2 adsorption, pore volume and average pore size distribution and field emission scanning electron microscopy (FE-SEM). The properties of the applied nanomaterials regarding the adsorption of MB were investigated by determining various experimental parameters, such as the contact time, initial dye concentration, and solution pH. In addition, the adsorption isotherm model was estimated using the Langmuir, Freundlich, and Langmuir–Freundlich isotherm models. The Langmuir model was the best-fitting for all applied nanomaterials. In addition, the kinetics were analyzed by using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, and the pseudo-second-order model was an apparent fit for all three applied nanomaterials. The maximum Adsorption capacity toward MB obtained from the materials was in the order zeolite/LDH composite > zeolites > Zn-Fe LDH. Thus, the zeolite/LDH composite is an excellent adsorbent for the removal of MB from polluted water.

Chiral poly(amide-imide)/ZnS nanocomposite as a new adsorbent for simultaneous removal of cationic dyes from aqueous solution

2020 ◽  
pp. 095400832093914
Author(s):  
Maryam Sadeghi ◽  
Zahra Rafiee
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
High Efficiency ◽  
Second Order ◽  
Isotherm Models ◽  
Simultaneous Removal ◽  
Base Interaction ◽  
X Ray ◽  
Operational Variables ◽  
Pseudo Second Order

A new adsorbent, poly(amide-imide)/zinc sulfide nanocomposite (PAI/ZnS NC), was fabricated and identified by Fourier-transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, field emission-scanning electron microscopy, and transmission electron microscopy. Then, the obtained NC was applied for the simultaneous removal of auramine O (AO) and rhodamine B (RB) dyes from aqueous solution via the interactions of hydrogen bonding, π– π stacking, and Lewis acid–base interaction. The effects of operational variables including pH, PAI/ZnS NC mass, AO and RB concentration, and sonication time on removal efficiency were examined and optimized values were found to be 8.0, 16 mg, 11 mg L−1, and 6 min, respectively. The adsorption capacities of PAI/ZnS NC for the removal of AO and RB dyes were found to be 70.92 and 91.74 mg g−1, respectively. Ultraviolet–visible spectrophotometer was used to determine the amount of residual dye in solution. Fitting the experimental equilibrium data to isotherm models such as Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich reveals the suitability of the Langmuir model with high correlation coefficients ( R 2 = 0.998 for AO and R 2 = 0.999 for RB). Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models applicability was tested and the pseudo-second-order equation controls the kinetics of the adsorption process. Furthermore, this study establishes that PAI/ZnS NC can be successfully applied as a low-cost adsorbent and conserve its high efficiency after nine cycles for the removal of AO and RB dyes.

scholarly journals Effect of structural differences of pumice on synthesis of pumice-supported nFe0: removal of Cr (VI) from water

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Bilsen Tural ◽  
Erdal Ertaş ◽  
Mehmet Güzel ◽  
Servet Tural
Keyword(s):  
Iron Content ◽  
Second Order ◽  
Zero Valent Iron ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Support Material ◽  
Solution Ph ◽  
Nanoscale Zero Valent Iron ◽  
Pseudo Second Order

AbstractIn this study, pumice from different regions of Turkey (Diyarbakir, Southeast Turkey and Bitlis, East Turkey) has been supplied and used as supporting material for nanoscale zero-valent iron (nFe0). Native Bitlis pumice (NBP)-supported nanoscale zero-valent iron (BP-nFe0) and native Diyarbakir pumice (NDP)-supported nanoscale zero-value iron (DP-nFe0) were synthesized under the same conditions. Native pumice (NDP, NBP) and pumice-supported nFe0 (DP-nFe0 and BP-nFe0) adsorbents were morphologically and structurally characterized by SEM, EDX, XRF and BET. When using NBP as support material, the iron content of the BP-nFe0 increased 1.9-fold from 1.99 to 3.83%. However, iron content of NDP (2.08%) increased approximately 29 times after it is used as a support material in synthesis of DP-nFe0 (60%). The removal potential of native pumice (NBP and NDP) and iron-modified pumice (BP-nFe0 and DP-nFe0) samples was investigated to remove Cr(VI) ions. The parameters of solution pH, initial metal concentration, contact time and the amount of adsorbent in the removal of chromium (VI) ions were investigated. Langmuir, Freundlich, Temkin, Dubinin–Radushkevich and Jovanovic isotherm models were used to evaluate the adsorption equilibrium data. The equilibrium adsorption was found so as to be well described by the Langmuir isotherm model for all the adsorbents studied. The maximum adsorption capacity of Cr(VI) ions for NDP, NBP, DP-nFe0 and BP-nFe0 was 10.82, 14.30, 161.29 and 17.39 mg/g, respectively. The rate of Cr(VI) removal was subjected to kinetic analysis using pseudo-first-order, pseudo-second-order, intraparticle diffusion and Elovich models. Kinetic studies suggest that adsorption of NDP, NBP, DP-nFe0 and BP-nFe0 described more favorably by the pseudo-second-order kinetic model. The results showed that NDP is a much better support material for nFe0 when compared to NBP.

scholarly journals Cr6+ adsorption by modified vermiculite

2020 ◽  
Author(s):  
Valeria Medoro ◽  
Celia Marcos Pascual ◽  
Giacomo Ferretti ◽  
Giulio Galamini ◽  
Massimo Coltorti
Keyword(s):  
Earth Sciences ◽  
Inductively Coupled Plasma ◽  
Contact Time ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
X Ray ◽  
Pseudo Second Order

<p><strong>Abstract</strong>: <strong>Cr<sup>6+</sup> adsorption by modified vermiculite</strong></p><p><strong> </strong></p><p>Valeria Medoro- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p>Celia Marcos Pascual-University of Oviedo, Department of Geology, Spain</p><p>Giacomo Ferretti- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p>Giulio Galamini- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p>Massimo Coltorti- University of Ferrara , Department of Physics and Earth Sciences, Italy</p><p> </p><p>This work aimed at investigating the adsorption of Cr<sup>6+</sup> in water by exfoliated vermiculite. The adsorbant tested in this experiment was a vermiculite (from China) which has been subjected to heating at 1000 °C for 1 minute, resulting in an exfoliated vermiculite.</p><p>Three effects were studied: 1) contact time; 2) initial concentracion of Cr<sup>6+</sup>; 3) adsorbent mass. Samples were analysed by X Ray Fluorescence (XRF), X Ray Diffraction (XRD) and the solutions with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to quantify the adsorbed Cr<sup>6+</sup> by the vermiculite.</p><p>Results from XRD diffraction showed a conversion of vermiculite into flogopite  after heating at 1000°C for 1 minute because of: 1) high content of potassium, 2) dehydration and 3) structural re-ordering; after the contact of vermiculite with Cr<sup>6+</sup>, the mineral structure did not change. The adsorption of Cr<sup>6+</sup> was studied by Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR) isotherm models. DKR model, indicative of a cooperative process, described adsorption equilibrium better than the other two models and the maximum adsorption capacity obtained was of 2.81 mol/g. Kinetic was studied using pseudo-first and pseudo-second order kinetic models, with a better description of the process by pseudo-second order model with correlation coefficient almost unitary (R<sup>2</sup>=0.9984; other kinetic parameters were k<sub>2</sub>=0.0015 and the absorption initial rate of 0.2x10<sup>-8</sup> mg g<sup>-1</sup> h<sup>-1</sup>). </p><p>The present study demonstrates the effectiveness of modified vermiculite adsorbents for the treatment of hexavalent chromium-contaminated waters and that its adsorption depends on the experimental conditions (such as contact time, initial concentracion of Cr<sup>6+</sup> and adsorbent mass).</p>

scholarly journals Kinetics, Isotherm, Thermodynamics, and Recyclability of Exfoliated Graphene-Decorated MnFe2O4 Nanocomposite Towards Congo Red Dye

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Van Thinh Pham ◽  
Hong-Tham T. Nguyen ◽  
Thuan Van Tran ◽  
Duyen Thi Cam Nguyen ◽  
Hanh T. N. Le ◽  
...  
Keyword(s):  
Congo Red ◽  
Analytical Techniques ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Exfoliated Graphene ◽  
Pseudo Second Order ◽  
Red Dye ◽  
Adsorption Desorption

Herein, we described the use of exfoliated graphene- (EG-) decorated magnetic MnFe2O4 nanocomposite (EG@MnFe2O4) for the removal and adsorption of Congo red (CR) dye from wastewater. Firstly, the precursors (EG, MnFe2O4) and EG@MnFe2O4 were fabricated, characterized using several physical analytical techniques such as X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and N2adsorption/desorption isotherm measurement. For the adsorption experiments, the effect of contact time (0–240 min), concentration (10–60 mg/L), solution pH (2–10), adsorbent dosage (0.03–0.07 g), and temperature (283–313 K) was rigorously studied. To elucidate the adsorption mechanism and behaviour of CR over EG@MnFe2O4 and MnFe2O4 adsorbents, the kinetic models (pseudo-first-order, pseudo-second-order, Elovich, and Bangham) and isotherm models (Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich) have been adopted. The kinetic results indicated that models adhered to the pseudo-second-order equation, exhibiting the chemisorption mechanism in heterogeneous phrase. Meanwhile, the isotherm results revealed the adsorption of CR over EG@MnFe2O4 obeyed the monolayer behaviour (Langmuir model) rather than multilayer behaviour (Freundlich equation) over MnFe2O4. The thermodynamic study also suggested that such adsorption was an endothermic and spontaneous process. With high maximum adsorption capacity (71.79 mg/g) and good recyclability (at least 4 times), EG@MnFe2O4 can be a potential alternative for the adsorptive removal of CR dye from water.

scholarly journals Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 661
Author(s):  
Zhiwei Ying ◽  
Xinwei Chen ◽  
He Li ◽  
Xinqi Liu ◽  
Chi Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Urban Pollution ◽  
Maximum Adsorption Capacity ◽  
One Pot ◽  
Average Pore ◽  
X Ray ◽  
Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

Kinetic and equilibrium studies of fluoride sorption onto surfactant-modified smectites

Clay Minerals ◽  
2012 ◽  
Vol 47 (4) ◽  
pp. 429-440 ◽  
Author(s):  
S. Gamoudi ◽  
N. Frini-Srasra ◽  
E. Srasra
Keyword(s):  
Aqueous Solution ◽  
Thermodynamic Parameters ◽  
Adsorption Kinetics ◽  
Equilibrium Constants ◽  
Second Order ◽  
Operating Conditions ◽  
Polluted Water ◽  
Isotherm Models ◽  
Fluoride Ions ◽  
Pseudo Second Order

AbstractThe use of organoclays as adsorbents in the remediation of polluted water has been the subject of many recent studies. In the present work, a Tunisian smectite modified with two cationic surfactants was used as an adsorbent to examine the adsorption kinetics, isotherms and thermodynamic parameters of fluoride ions from aqueous solution. Various pH values, initial concentrations and temperatures have been tested. Two simplified kinetic models, first-order and pseudo-second-order, were used to predict the adsorption rate constants. It was found that the adsorption kinetics of fluoride onto modified smectites at different operating conditions can best be described by the pseudo-second-order model. Adsorption isotherms and equilibrium adsorption capacities were determined by the fitting of the experimental data to well known isotherm models including those of Langmuir and Freundlich. The results showed that the Langmuir model appears to fit the adsorption better than the Freundlich adsorption model for the adsorption of fluoride ions onto modified smectites. The equilibrium constants were used to calculate thermodynamic parameters, such as the change of free energy, enthalpy and entropy. Results of this study demonstrated the effectiveness and feasibility of organoclays for the removal of fluoride ions from aqueous solution.

Removal of acetaminophen (ACT) from aqueous solution by using nanosilica adsorbent: experimental study, kinetic and isotherm modeling

2020 ◽  
Vol 49 (1) ◽  
pp. 55-62
Author(s):  
Akbar Eslami ◽  
Zahra Goodarzvand Chegini ◽  
Maryam Khashij ◽  
Mohammad Mehralian ◽  
Marjan Hashemi
Keyword(s):  
Removal Rate ◽  
Synthesis Method ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Content Type ◽  
Bet Analysis ◽  
Pseudo Second Order

Purpose A nanosilica adsorbent was prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET. Design/methodology/approach The optimum conditions for the highest adsorption performance were determined by kinetic modeling. The adsorbent was used for the adsorption of acetaminophen (ACT), and the parameters affecting the adsorption were discussed like pH, initial concentration, contact time and adsorbent dosage. The adsorbent have been characterized by SEM, XRD and BET analysis. The kinetic models including pseudo-first-order and pseudo-second-order with Langmuir and Freundlich isotherm models were applied to investigate the kinetic and isotherms parameters. Findings The adsorption of ACT increased to around 95% with the increase of nanosilica concentration to 30 g/L. Moreover, the adsorption process of ACT follows the pseudo-second-order kinetics and the Langmuir isotherm with the maximum adsorption capacity of 609 mg/g. Practical implications This study provided a simple and effective way to prepare of nanoadsorbents. This way was conductive to protect environmental and subsequent application for removal of emerging pollutants from aqueous solutions. Originality/value The novelty of the study is synthesizing the morphological and structural properties of nanosilica-based adsorbent (specific surface area, pore volume and size, shape and capability) and improving its removal rate through optimizing the synthesis method; and studying the capability of synthesis of nanosilica-based adsorbent for removal of ACT as a main emerging pharmaceutical water contaminant.

scholarly journals Water polishing of phenol by walnut green hull as adsorbent: an insight of adsorption isotherm and kinetic

2016 ◽  
Vol 6 (4) ◽  
pp. 544-552 ◽  
Author(s):  
H. Godini ◽  
F. Hashemi ◽  
L. Mansuri ◽  
M. Sardar ◽  
Ghasem Hassani ◽  
...  
Keyword(s):  
Langmuir Isotherm ◽  
Surface Characteristics ◽  
Xrd Analysis ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Xrd Techniques

The present paper aims to investigate water purification of phenol by walnut green hull adsorbent. The surface characteristics of the adsorbent were studied using Fourier transform infra-red (FTIR), scanning electron microscope, and X-ray diffraction (XRD) techniques. The presence of functional groups such as hydroxyl and carbonyl onto walnut green hull surface was proved by FTIR analysis. Also quartz, cellulose and hematite were detected in the XRD analysis of samples by an X-ray diffractometer. The maximum sorption was achieved at pH 4.0. Data were evaluated for compliance with the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. The results indicate that the data for adsorption of phenol onto walnut green hull fitted well with the Langmuir isotherm. The maximum adsorption capacity of the adsorbent was achieved by Langmuir isotherm 17.8 mg g–1. Also, the adsorption kinetics of phenol on the adsorbent were studied. The rates of sorption were found to conform to pseudo-second-order kinetics with good correlation.

Adsorption of heavy metals from aqueous solutions by Mg–Al–Zn mingled oxides adsorbent

2016 ◽  
Vol 74 (7) ◽  
pp. 1644-1657 ◽  
Author(s):  
Mona El-Sayed ◽  
Gh. Eshaq ◽  
A. E. ElMetwally
Keyword(s):  
Heavy Metals ◽  
Metal Ion ◽  
Second Order ◽  
Ion Concentration ◽  
Precipitation Method ◽  
Isotherm Models ◽  
Infrared Spectrometry ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Pseudo Second Order

In our study, Mg–Al–Zn mingled oxides were prepared by the co-precipitation method. The structure, composition, morphology and thermal stability of the synthesized Mg–Al–Zn mingled oxides were analyzed by powder X-ray diffraction, Fourier transform infrared spectrometry, N2 physisorption, scanning electron microscopy, differential scanning calorimetry and thermogravimetry. Batch experiments were performed to study the adsorption behavior of cobalt(II) and nickel(II) as a function of pH, contact time, initial metal ion concentration, and adsorbent dose. The maximum adsorption capacity of Mg–Al–Zn mingled oxides for cobalt and nickel metal ions was 116.7 mg g−1, and 70.4 mg g−1, respectively. The experimental data were analyzed using pseudo-first- and pseudo-second-order kinetic models in linear and nonlinear regression analysis. The kinetic studies showed that the adsorption process could be described by the pseudo-second-order kinetic model. Experimental equilibrium data were well represented by Langmuir and Freundlich isotherm models. Also, the maximum monolayer capacity, qmax, obtained was 113.8 mg g−1, and 79.4 mg g−1 for Co(II), and Ni(II), respectively. Our results showed that Mg–Al–Zn mingled oxides can be used as an efficient adsorbent material for removal of heavy metals from industrial wastewater samples.

Chlorate Removal by Calcined Mg/Fe/Ce Layered Double Hydroxides

2015 ◽  
Vol 737 ◽  
pp. 537-540
Author(s):  
Yan Wei Guo ◽  
Hua Zhang ◽  
Zhi Liang Zhu
Keyword(s):  
Polluted Water ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph ◽  
Langmuir Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Double Hydroxide ◽  
Double Hydroxides ◽  
Kinetics Of

A novel Mg/Fe/Ce layered double hydroxide (LDHs) and its calcined product (CLDH) were synthesized and CLDH was used as adsorbents for the removal of chlorate ions. Results showed that the initial solution pH was an important factor influencing the chlorate adsorption. The adsorption behavior of chlorate followed the Langmuir adsorption isotherm with a maximum adsorption capacity of 18.2 mg/g. The adsorption kinetics of chlorate on CLDH can be described by the pseudo-second-order kinetic model. It was concluded that the CLDH material is a potential adsorbent for the purification of polluted water with chlorate.

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