Adsorption of C.I. Reactive Red 228 and Congo Red dye from aqueous solution by amino-functionalized Fe3O4 particles: kinetics, equilibrium, and thermodynamics

2013 ◽  
Vol 69 (3) ◽  
pp. 612-621 ◽  
Author(s):  
Ting-guo Yan ◽  
Li-juan Wang
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Congo Red ◽  
Magnetic Adsorbent ◽  
Film Diffusion ◽  
X Ray ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Vibration Sample Magnetometry ◽  
Red Dye

A magnetic adsorbent was synthesized by γ-aminopropyltriethoxysilane (APTES) modification of Fe3O4 particles using a two-step process. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and vibration sample magnetometry were used to characterize the obtained magnetic adsorbent. EDS and XPS showed that APTES polymer was successfully introduced onto the as-prepared Fe3O4/APTES particle surfaces. The saturation magnetization of the magnetic adsorbent was around 65 emu g−1, which indicated that the dye can be removed fast and efficiently from aqueous solution with an external magnetic field. The maximum adsorption capacities of Fe3O4/APTES for C.I. Reactive Red 228 (RR 228) and Congo Red (CR) were 51.4 and 118.8 mg g−1, respectively. The adsorption of C.I. Reactive Red 228 (RR 228) and Congo Red (CR) on Fe3O4/APTES particles corresponded well to the Langmuir model and the Freundlich model, respectively. The adsorption processes for RR 228 and CR followed the pseudo-second-order model. The Boyd's film-diffusion model showed that film diffusion also played a major role in the studied adsorption processes for both dyes. Thermodynamic study indicated that both of the adsorption processes of the two dyes are spontaneous exothermic.

scholarly journals Sulphate-Crosslinked Chitosan as an Adsorbent for the Removal of Congo Red Dye From Aqueous Solution

2018 ◽  
Vol 11 ◽  
pp. 117862211881168 ◽  
Author(s):  
Christine Jeyaseelan ◽  
Nisha Chaudhary ◽  
Ravin Jugade
Keyword(s):  
Adsorption Capacity ◽  
Congo Red ◽  
Water Bodies ◽  
X Ray ◽  
Modified Chitosan ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Crosslinked Chitosan ◽  
Wastewater Samples ◽  
Red Dye

Dyes are a major cause of concern nowadays as large quantities are being released into water bodies causing pollution. In this article, modified chitosan (sulphate crosslinked) has been studied for the removal of Congo red (a benzidine-based anionic diazo dye) which is a toxic dye introduced into water bodies from textile industries. Sulphate-crosslinked chitosan (SCC) was prepared in the laboratory and the characterization of SCC was done by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Various parameters such as pH, contact time, adsorbent dosage, and concentration of adsorbent were optimized. The adsorption capacity was determined at pH 3.0, at which the percentage recovery was about 90% and followed Freundlich adsorption isotherm with an adsorption capacity of 91.8 mg/g. The adsorption followed pseudo-second-order kinetics. Various thermodynamic parameters were also determined for the change in adsorption with temperature. The SCC was regenerated with NaOH and showed good recycling capacity. The modified chitosan was applied for the removal of Congo red from industrial wastewater samples (spiked).

scholarly journals Synthesis of Nanoscale Zerovalent Iron (nZVI) Supported on Biochar for Chromium Remediation from Aqueous Solution and Soil

2019 ◽  
Vol 16 (22) ◽  
pp. 4430 ◽  
Author(s):  
Haixia Wang ◽  
Mingliang Zhang ◽  
Hongyi Li
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Zero Valent Iron ◽  
Zerovalent Iron ◽  
X Ray ◽  
Nanoscale Zerovalent Iron ◽  
Before And After ◽  
Pseudo Second Order ◽  
Xrd Patterns ◽  
Co Precipitation

Maize straw biochar-supported nanoscale zero-valent iron composite (MSB-nZVI) was prepared for efficient chromium (Cr) removal through alleviating the aggregation of zero-valent iron particles. The removal mechanism of MSB-nZVI was investigated by scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). Cr(VI) removal from aqueous solution by MSB-nZVI was greatly affected by pH and initial concentration. The removal efficiency of Cr(VI) decreased with increasing pH, and the removal kinetics followed the pseudo-second-order model. XRD patterns of MSB-nZVI before and after reaction showed that reduction and precipitation/co-precipitation (FeCr2O4, Fe3O4, Fe2O3) occurred with the conversion of Cr(VI) to Cr(III) and Fe(0) to Fe(II)/Fe(III). The produced precipitation/co-precipitation could be deposited on the MSB surface rather than being only coated on the surface of nZVI particles, which can alleviate passivation of nZVI. For remediation of Cr(VI)-contaminated saline–alkali soil (pH 8.6–9.0, Cr 341 mg/kg), the released amount of Cr(VI) was 70.7 mg/kg, while it sharply decreased to 0.6–1.7 mg/kg at pH 4.0–8.0, indicating that the saline–alkali environment inhibited the remediation efficiency. These results show that MSB-nZVI can be used as an effective material for Cr(VI) removal from aqueous solution and contaminated soil.

Mg(OH)2/Graphene Nanocomposites Prepared by Cathodic Electrodeposition for the Adsorption of Congo Red

NANO ◽  
2017 ◽  
Vol 12 (02) ◽  
pp. 1750017 ◽  
Author(s):  
Xinzhong Deng ◽  
Yaowu Wang ◽  
Jianping Peng ◽  
Kejia Liu ◽  
Naixiang Feng ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Congo Red ◽  
Anionic Dyes ◽  
Graphene Nanocomposites ◽  
X Ray ◽  
Cathodic Electrodeposition ◽  
Transmission Electron ◽  
Pseudo Second Order ◽  
Energy Formula

A facile cathodic electrodeposition process was developed to prepare Mg(OH)2/Graphene nanocomposites (MGN), which was used to remove Congo Red (CR), an anionic dye from aqueous solution. The morphology and phase structure were analyzed by transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman and X-ray photoelectron spectroscopy (XPS). The effects of experimental parameters, such as graphene content, adsorption time, initial concentrations of CR and pH values, on the adsorption capacity of CR were studied. The obtained MGN shows the good performance in CR, with an adsorption capacity of 1986.43[Formula: see text]mg[Formula: see text]g[Formula: see text]. The equilibrium adsorption and kinetics data fit with Langmuir isotherm and the pseudo-second-order model, respectively. Thermodynamic data suggest that CR adsorption onto MGN is spontaneous ([Formula: see text]: –9.62[Formula: see text]kJ[Formula: see text]mol[Formula: see text] at 313[Formula: see text]K, endothermic ([Formula: see text]: 36.261[Formula: see text]kJ[Formula: see text]mol[Formula: see text] and the degree of disorder increased ([Formula: see text]: 146.848[Formula: see text]J[Formula: see text]moL[Formula: see text][Formula: see text]K[Formula: see text] at the solid-solution interface. Moreover, the adsorption activation energy ([Formula: see text]: 38.929[Formula: see text]kJ[Formula: see text]mol[Formula: see text] of CR evaluated from the Arrhenius equation illustrates that it is a physical process. This adsorbent exhibits efficient adsorption properties and high recycling efficiency, making it a promising adsorbent for removing anionic dyes.

scholarly journals Adsorption of Hexavalent Chromium Using Banana Pseudostem Biochar and Its Mechanism

2018 ◽  
Vol 10 (11) ◽  
pp. 4250 ◽  
Author(s):  
Shuang Xu ◽  
Weiguang Yu ◽  
Sen Liu ◽  
Congying Xu ◽  
Jihui Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pyrolysis Temperature ◽  
Low Cost ◽  
Surface Adsorption ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Adsorption Processes ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Porosity Analysis

A low-cost biochar was prepared through slow pyrolysis of banana pseudostem biowaste at different temperatures, and characterized by surface area and porosity analysis, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was shown that the biochar prepared at low pyrolysis temperature was rich in oxygen-containing groups on the surface. Adsorption experiments revealed that the biochar prepared at 300 °C (BB300) was the best adsorbent for Cr(VI) with 125.44 mg/g maximum adsorption capacity at pH 2 and 25 °C. All the adsorption processes were well described by pseudo-second-order and Langmuir models, indicating a monolayer chemiadsorption. Furthermore, it was demonstrated that adsorption of Cr(VI) was mainly attributed to reduction of Cr(VI) to Cr(III) followed by ion exchange and complexation with the biochar.

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

2018 ◽  
Vol 23 (6) ◽  
pp. 1053-1060 ◽  
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.

scholarly journals Fabrication of Amino Functionalized Magnetic Expanded Graphite Nanohybrids for Application in Removal of Ag(I) from Aqueous Solution

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Ying-Xia Ma ◽  
Yong-Xin Ruan ◽  
Dan Xing ◽  
Xue-Yan Du ◽  
Pei-Qing La
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Expanded Graphite ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
One Pot ◽  
X Ray ◽  
Pseudo Second Order

Ethylenediamine functionalized magnetic expanded graphite decorated with Fe3O4 nanoparticles (MEG-NH2) was fabricated by one-pot solvothermal method. The as-prepared MEG-NH2 nanohybrids were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Zeta potential analyzer. The effects of Fe3O4 content in MEG-NH2 nanohybrids, pH, initial concentration, contact time, and dosage on adsorption properties of the MEG-NH2 nanohybrids for Ag(I) from aqueous solution were investigated by batch experiments. The pseudo-first-order and the pseudo-second-order kinetic models were utilized to study adsorption kinetics. The experimental data was also analyzed with Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models. The results show that Ag(I) was reduced to silver in the process of the adsorption by MEG-NH2 nanohybrids; the experimental data was better fitted to pseudo-second-order model and Langmuir isotherm model which revealed that the adsorption process was a chemical adsorption by the formation of silver on the surface of MEG-NH2 nanohybrids.

Photoluminescence and Photocatalytic Properties of Bi2O3 Nanostructures

2017 ◽  
Vol 17 ◽  
pp. 166-170 ◽  
Author(s):  
M. Ahila ◽  
D. Pathinettam Padiyan
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Congo Red ◽  
Uv Light ◽  
X Ray Diffraction ◽  
Initial Concentration ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Red Dye

Bi2O3 nanostructures were synthesized through a simple electrolysis based oxidation using NaOH electrolyte and annealed at 300 °C, 400 °C, 500 °C and 600 °C. The obtained Bi2O3 nanostructures were characterized using X-ray diffraction and photoluminescence spectroscopy (PL). Bi2O3 crystal structure was confirmed by XRD. When free electron and holes are combined together then emission signals are emitted from PL spectra. With this process, it is studied about the recombination and separation of photo generated holes and electrons. The photocatalytic activities of Bi2O3 films were evaluated for the degradation of Congo red in aqueous solution under UV light irradiation. Among the four samples, Bi2O3 films annealed at 300 °C have better efficiency in removing the congo red dye. For Bi-3, the initial concentration of 10 ppm decreases to 1.11 ppm after 420 min.

Diatomite modified by TiO2 for adsorption of U(VI)

2018 ◽  
Vol 106 (9) ◽  
pp. 733-742 ◽  
Author(s):  
Ni Yuan ◽  
Peng Liu ◽  
Wangsuo Wu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Water Environment ◽  
X Ray ◽  
Ph Values ◽  
Batch Technique ◽  
Adsorption Processes ◽  
Novel Material ◽  
Pseudo Second Order ◽  
Synthesized Materials

Abstract Diatomite was modified with TiO2. The synthesized materials were characterized and used for removal of U(VI) from aqueous solutions. The influences of pH, contact time and temperature on U(VI) adsorption onto TiO2@diatomite were studied by batch technique, and X-ray photoelectron spectroscopy (XPS) was employed to analyze the experimental data. We compared the adsorption of U(VI) onto natural diatomite, TiO2 and TiO2@diatomite made by sol-gel method. The dynamic process showed that the adsorption of U(VI) onto TiO2@diatomite matched the pseudo-second-order kinetics model, and the adsorption of U(VI) was significantly dependent on pH values. Through simulating the adsorption isotherms by Langmuir, Freundlich and Dubini–Radushkevich (D–R) models, respectively, it could be seen that the adsorption patterns of U(VI) onto TiO2@diatomite were mainly controlled by surface complexation, and the adsorption processes were endothermic and spontaneous. The modification of diatomite by TiO2 shows a novel material for removing U(VI) from water environment for industrialized application.

scholarly journals Removal and Comparative Adsorption of Anionic Dye on Various MgAl synthetic Clay

2021 ◽  
Vol 11 (6) ◽  
pp. 14986-14997
Keyword(s):  
Congo Red ◽  
Adsorption Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Batch System ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Red Dye ◽  
Synthetic Clay

In this study, the adsorption of Congo red dye in an aqueous solution on two synthetic clay adsorbents, MgAl-LDH (2:1) and MgAl-LDH (3:1), was investigated using batch system experiments. The adsorbents' characterization was carried out by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy FT-IR. The conditions applied in the adsorption experiments including the mass of adsorbent, initial concentration, contact time, pH, and temperature. The kinetic data were modeled by pseudo-first-order and pseudo-second-order. Langmuir and Freundlich's models analyzed the adsorption isotherms of Congo red on the two adsorbents. It was found that the adsorption process could be described by Langmuir isotherm. The maximum amount of adsorption is 285.71 and 166.66 mg/g for MgAl-LDH (2:1) and MgAl-LDH (3:1), respectively. Thermodynamic parameters such as enthalpy ∆H°, enthalpy ∆S°, and free enthalpy ∆G° were also evaluated to predict the nature of adsorption.

scholarly journals ADSORPTION KINETICS, ISOTHERMS, THERMODYNAMICS STUDIES ON THE REMOVAL OF CONGO RED DYE USING ANNONA SQUAMOSA (CUSTARD APPLE) PEEL

2019 ◽  
pp. 228-234
Author(s):  
Sarang Agarwal ◽  
Sowmya Vilvanathan ◽  
Shanthakumar S
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Adsorption Process ◽  
Annona Squamosa ◽  
Congo Red Dye ◽  
Apple Peel ◽  
Custard Apple ◽  
Pseudo Second Order ◽  
Red Dye ◽  
Adsorbent Dose

The present study evaluates the feasibility of an adsorbent prepared from Annona squamosa (custard apple) peel, in removing Congo red dye from its aqueous solution. Batch experiments were carried out to study the effect of various parameters like pH (2-8), adsorbent dose (0.005-0.5 g/100mL), contact time (5-120 min), initial dye concentration (25-200 mg/L) and temperature (298-308 K) to determine its effectiveness as an adsorbent. Maximum dye removal attained at pH 2, adsorbent dose 0.1 g/100mL in equilibrium time of 45 min at 308K. Adsorption kinetics using pseudo-first order and pseudo-second order models, and adsorption isotherm using Langmuir and Freundlich models were studied. The adsorption process was found to follow pseudo-second order kinetic model and more favourably described the Langmuir isotherm model. The Gibbs free energy was found to be negative, signifying the spontaneous nature of the adsorption process. Removal of Congo red dye from its aqueous solution by custard apple peel was found to be an endothermic process. The results of the present study suggest that custard apple can be effectively used as an adsorbent to remove Congo red dye from aqueous solution.

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