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

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.

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

Applied Water Science ◽

10.1007/s13201-021-01458-6 ◽

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.

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

Nanomaterials ◽

10.3390/nano11123315 ◽

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.

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

Pigment & Resin Technology ◽

10.1108/prt-06-2019-0057 ◽

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.

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

Water Science & Technology ◽

10.2166/wst.2016.329 ◽

2016 ◽

Vol 74 (7) ◽

pp. 1644-1657 ◽

Cited By ~ 8

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.

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Itaconic acid-modified layered double hydroxide as a ‎novel adsorbent for effective removal of Congo red from aqueous solutions

10.21203/rs.3.rs-345643/v1 ◽

2021 ◽

Author(s):

Mohammad Dinari ◽

Shirin Shabani

Keyword(s):

Layered Double Hydroxide ◽

Itaconic Acid ◽

Congo Red ◽

Aqueous Media ◽

Freundlich Isotherm ◽

Second Order ◽

Order Kinetic ◽

Solution Ph ◽

Pseudo Second Order ◽

Double Hydroxide

Abstract Herein, we report the synthesis of Cu-Ca-Al/NO3-based layered double hydroxide through co-precipitation methodology. The prepared layered double hydroxide was then modified with itaconic acid. The physicochemical properties of the prepared materials were studied using Fourier transform-infrared spectroscopy, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric analysis, and nitrogen adsorption/desorption technique. The prepared materials were then applied as novel adsorbents for the removal of Congo red as a model of an anionic dye from aqueous media. To reach maximum adsorption, the effect of parameters including sample solution pH, adsorbent amount, contact time, and initial concentration of Congo red on the adsorption process was investigated. Kinetic studies were also conducted to study the mechanism of adsorption. In this regard, the kinetic models of pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion were studied. The results showed that the adsorption of Congo red onto Cu-Ca-Al-LDH and LDH-ITA adsorbents followed the pseudo-second-order kinetic model. To evaluate the equilibrium adsorption data, different isotherms including Langmuir, Freundlich, and Dubinin-Radushkevich were also applied. The data revealed that the Freundlich isotherm provided the best fit with the equilibrium data of both adsorbents. Maximum adsorption capacities of 81 and 84 mg g− 1 were obtained using Cu-Ca-Al-LDH and LDH-ITA adsorbents, respectively.

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A Study of The Equilibrium, Kinetics, and Thermodynamics of Malachite Green Dye Adsorption Onto Lignin

10.21203/rs.3.rs-1009760/v1 ◽

2021 ◽

Author(s):

Vani Gandham ◽

UMA Addepally ◽

Bala Narsaiah T

Keyword(s):

Malachite Green ◽

Group Analysis ◽

Dye Adsorption ◽

Second Order ◽

Isotherm Models ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Adequate Treatment ◽

Pseudo Second Order ◽

Kinetics And Isotherms

Abstract Malachite Green (MG), a cationic synthetic dye is considered hazardous when discharged into the water bodies without any adequate treatment. It can affect the multiple segments of the environment leading to irreversible persistent changes. So, there is a need for remediation with cost-effective method to remove dyes from effluents. Adsorption is one such technique to remove dyes from wastewater and is effective and economical. The present study describes the removal of MG cationic dye from wastewater using eco-friendly and biodegradable lignin extracted from hydrothermally treated rice straw by adsorption process. Functional group analysis and morphological characterisation was done to the extracted lignin after quantification. The maximum percent removal of MG 92 ± 0.2 % was observed from a series of batch experiments at optimum process parameters of: contact time 80 min, initial dye concentration 50 ppm, lignin dosage 0.25g, pH 7, temperature 300c and with 100 rpm agitation speed. The adsorption kinetics and isotherms were determined for the experimental data using four kinetic models (pseudo-first-order, second order, pseudo-second-order and intra-particle diffusion model) and two isotherm models (Langmuir and Freundlich). The results suggested that the kinetics data fit to the pseudo-second-order kinetic model with the maximum adsorption capacity 36.7 mg/g and the two isotherm models were applicable for the adsorption of MG onto the lignin. Additionally, the thermodynamic parameters ΔSo, ΔHo and ΔGo were evaluated. Therefore, lignin which is an environmental friendly and low cost carbon material that can be used as an adsorbent for dye removal.

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Treatment of effluent from fertilizer industry by adsorption on willow sawdust-removal of Ni(II) and Cd(II) from the effluent

Ion Exchange Letters ◽

10.35933/iel.2021.13.001 ◽

2021 ◽

pp. 1-12

Author(s):

Raafia Najam ◽

Syed Muzaffar Ali Andrabi

Keyword(s):

Aqueous Solution ◽

Adsorption Process ◽

Low Cost ◽

Second Order ◽

Maximum Adsorption Capacity ◽

Solution Ph ◽

The World ◽

Pseudo Second Order ◽

Almost All ◽

Willow Tree

Sawdust of willow has been investigated as an adsorbent for the removal of Ni(II), and Cd(II) ions from aqueous solution. Since willow tree is widely grown in almost all parts of Kashmir, it can be a common most easily available, sustainable, low cost adsorbent for the treatment of wastewaters in this part of the world where growing industrialization is affecting water quality like elsewhere in the world. Therefore, it is worthwhile to investigate the potential of sawdust of willow tree as an adsorbent for the removal of Ni(II) and Cd(II) ions from aqueous solution as a first step. Batch experiments were conducted to study the effect of some parameters such as contact time, initial concentration of metal ions, solution pH and temperature. Langmuir and Freundlich models were employed for the mechanistic analysis of experimental data obtained. Results reveal that in our system adsorption follows the Langmuir isotherm. The maximum adsorption capacity of Ni(II) and Cd(II) were found to be 7.98 and 7.11 mg/g respectively at optimum conditions. The pseudo-ﬁrst-order and pseudo-second-order models were employed for kinetic analysis of adsorption process. The adsorption process follows pseudo-second-order kinetics. The efficacy of the adsorbent in the treatment of effluent from fertilizer factory has been investigated and the results have been found encouraging.

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Adsorption of congo red dye from aqueous solution onto amino-functionalized silica gel

Engenharia Sanitaria e Ambiental ◽

10.1590/s1413-41522018172982 ◽

2018 ◽

Vol 23 (6) ◽

pp. 1053-1060 ◽

Cited By ~ 9

Author(s):

Raquel Studart de Farias ◽

Hugo Leonardo de Brito Buarque ◽

Mabel Ribeiro da Cruz ◽

Luana Meg Freitas Cardoso ◽

Tamyris de Aquino Gondim ◽

...

Keyword(s):

Aqueous Solution ◽

Silica Gel ◽

Congo Red ◽

Second Order ◽

Functionalized Silica ◽

Congo Red Dye ◽

Major Mode ◽

Effects Of Ph ◽

Pseudo Second Order ◽

Red Dye

ABSTRACT This study investigates the potential use of amino-functionalized silica gel as an adsorbent for the recovering of congo red dye from aqueous solution. The effects of pH, contact time, and temperature were determined and evaluated. Equilibrium isotherms were also studied. The adsorption kinetics was modeled by pseudo-first order and pseudo-second order. Furthermore, desorption of congo red was preliminarily studied. The pH range from 4.5 to 7.0 was favorable for the adsorption of congo red onto amine modified silica at 25ºC. Higher adsorption capacity was obtained at 50ºC. Langmuir and Freundlich models were fitted to the adsorption equilibrium data. The best fittings were obtained with the pseudo-second order and Langmuir model for kinetics and equilibrium, respectively. Desorption studies suggest that ion exchange might be the major mode of adsorption. KOH solution was the best desorbing agent for recovering the adsorbed dye.

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Comparative studies on adsorptive removal of heavy metal ions by biosorbent, bio-char and activated carbon obtained from low cost agro-residue

Water Science & Technology ◽

10.2166/wst.2015.504 ◽

2015 ◽

Vol 73 (2) ◽

pp. 423-436 ◽

Cited By ~ 17

Author(s):

Çisem Kırbıyık ◽

Ayşe Eren Pütün ◽

Ersan Pütün

Keyword(s):

Activated Carbon ◽

Metal Ion ◽

Low Cost ◽

Chemical Activation ◽

Second Order ◽

Isotherm Models ◽

Standard Entropy ◽

Order Kinetic ◽

Solution Ph ◽

Pseudo Second Order

In this study, Fe(III) and Cr(III) metal ion adsorption processes were carried out with three adsorbents in batch experiments and their adsorption performance was compared. These adsorbents were sesame stalk without pretreatment, bio-char derived from thermal decomposition of biomass, and activated carbon which was obtained from chemical activation of biomass. Scanning electron microscopy and Fourier transform–infrared techniques were used for characterization of adsorbents. The optimum conditions for the adsorption process were obtained by observing the influences of solution pH, adsorbent dosage, initial solution concentration, contact time and temperature. The optimum adsorption efficiencies were determined at pH 2.8 and pH 4.0 for Fe(III) and Cr(III) metal ion solutions, respectively. The experimental data were modelled by different isotherm models and the equilibriums were well described by the Langmuir adsorption isotherm model. The pseudo-first-order, pseudo-second-order kinetic, intra-particle diffusion and Elovich models were applied to analyze the kinetic data and to evaluate rate constants. The pseudo-second-order kinetic model gave a better fit than the others. The thermodynamic parameters, such as Gibbs free energy change ΔG°, standard enthalpy change ΔH° and standard entropy change ΔS° were evaluated. The thermodynamic study showed the adsorption was a spontaneous endothermic process.

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Congo Red Dye Removal Using Ca-Al Layered Double Hydroxide: Kinetics and Equilibrium

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.814.463 ◽

2019 ◽

Vol 814 ◽

pp. 463-468 ◽

Cited By ~ 1

Author(s):

Hong Tham Nguyen Thi ◽

Duy Chinh Nguyen ◽

Thi Thuong Nguyen ◽

Van Thuan Tran ◽

Huu Vinh Nguyen ◽

...

Keyword(s):

Layered Double Hydroxide ◽

Congo Red ◽

Removal Rate ◽

Isotherm Models ◽

Order Kinetic ◽

Initial Concentration ◽

Equilibrium Data ◽

Pseudo Second Order ◽

Red Dye ◽

Double Hydroxide

This In this study, the Ca-Al layered double hydroxide was used as a potential adsorbent for the removal of Congo red from aqueous solutions. The effects of Initial concentration and contact time on the adsorption properties of Congo red by Ca-Al LDHs were studied. The removal rate of Conge red reached to 59.416 mg/g under room temperature with 0.2g of adsorbent, initial concentration of 50 ppm, adsorption time of 210 min, shaking speed of 90r/min. The experimental equilibrium data for the removal of Congo red were evaluated by various isotherm models. The pseudo-second-order kinetic models were found to fit the adsorption kinetics, and the equilibrium data were appropriately fitted to Langmuir and Freundlich model adsorption isotherm.

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