Novel in situ Synthesized Fe@C Magnetic Nanocapsules Used as Adsorbent for Removal of Organic Dyes and its Recycling

NANO ◽  
2016 ◽  
Vol 11 (02) ◽  
pp. 1650013 ◽  
Author(s):  
Ranran Li ◽  
Jieyi Yu ◽  
Asif Shah ◽  
Xinglong Dong ◽  
Xiaona Li ◽  
...  

Core/shell type carbon-coated Fe nanocapsules (Fe@C NCs) were in situ synthesized by DC arc-discharge plasma method in methane atmosphere. Such Fe nanocapsules have saturation magnetization of 29.32[Formula: see text]emu/g and specific surface area of 85.86[Formula: see text]m2/g. The carbon shell of Fe@C NCs was functionalized with oxygen-containing groups (such as –OH or –COOH) by using H2O2. The adsorption of organic dye, e.g., methylene blue (MB) was systematically investigated in different conditions, such as contact time, pH values and temperature. The maximum adsorption capacity (46.5[Formula: see text]mg/g) was calculated by fitting the adsorption isotherms with Langmuir model, coincident with the experimental result of 44.5[Formula: see text]mg/g. Kinetics data supported pseudo-second order model, and the thermodynamic process of adsorption was revealed as endothermic and spontaneous physisorption. The MB-absorbed Fe@C NCs can be entirely separated from the contaminative solution by a magnetic field and then successfully cycled for regeneration. After repetitive cycles of the adsorption/desorption experiments for five times, the removal efficiency can be maintained over 90%.

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 167 ◽  
Author(s):  
Yuanli Liu ◽  
Liushuo Song ◽  
Linlin Du ◽  
Peng Gao ◽  
Nuo Liang ◽  
...  

Surface-functionalized polymeric microspheres have wide applications in various areas. Herein, monodisperse poly(styrene–methyl methacrylate–acrylic acid) (PSMA) microspheres were prepared via emulsion polymerization. Polyaniline (PANI) was then coated on the PSMA surface via in situ polymerization, and a three-dimensional (3D) structured reticulate PANI/PSMA composite was, thus, obtained. The adsorption performance of the composite for organic dyes under different circumstances and the adsorption mechanism were studied. The obtained PANI/PSMA composite exhibited a high adsorption rate and adsorption capacity, as well as good adsorption selectivity toward methyl orange (MO). The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm. The maximum adsorption capacity for MO was 147.93 mg/g. After five cycles of adsorption–desorption, the removal rate remained higher than 90%, which indicated that the adsorbent has great recyclability. The adsorbent materials presented herein would be highly valuable for the removal of organic dyes from wastewater.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2295
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Hagar Morsy

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett-Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.


1990 ◽  
Vol 39 (12) ◽  
pp. 1965
Author(s):  
ZHANG FANG-QING ◽  
ZHANG YA-FEI ◽  
YANG YING-HU ◽  
LI JING-QI ◽  
CHEN GUANG-HUA ◽  
...  

2010 ◽  
Vol 160-162 ◽  
pp. 1804-1809
Author(s):  
Qiang Bi ◽  
Juan Qin Xue ◽  
Ying Juan Guo ◽  
Yu Jie Wang ◽  
Yun Feng Xue

The adsorption of cadmium in simulated wastewater by chitosan was investigated. The influence of temperature, contact time and pH on adsorption efficiency of cadmium was examined. Some related mathematical models were used in the fitting of experimental data. The results showed that at room temperature, the optimum pH of adsorption is between 4 and 7. At lower pH values, a strong competition existed between cadmium ions and protons for sorption sites and the sorption efficiency was decreased. After 60 minutes the adsorption equilibrium can be achieved. Chitosan is very effective at removing cadmium with the maximum adsorption capacity is 112.05mg•g-1. The adsorption kinetic curves agree with the pseudo-second-order adsorption kinetic equations and the adsorption isotherms could be well described by Langmuir isotherm equations.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5436-5449
Author(s):  
Chao Cao ◽  
Lupeng Shao ◽  
Lucian A. Lucia ◽  
Yu Liu

Magnetic lignin-based adsorbent (MLA) was successfully fabricated to remove methyl orange dye from aqueous solution. The synthesized MLA was characterized by means of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). In the process of adsorption, influence factors and recycling performance were considered, and the adsorption mechanisms such as isotherm and kinetics were investigated. The result showed that the equilibrium data was consisted with the Langmuir model with a maximum adsorption capacity of 85.0 mg/g. The adsorption kinetics followed a pseudo-second-order model. Based the adsorption performance, MLA showed good recyclability. Therefore, these results demonstrate that MLA could offer a great potential as an efficient and reusable adsorbent in the wastewater treatments.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 151 ◽  
Author(s):  
Juan Tan ◽  
Shuibo Xie ◽  
Guohua Wang ◽  
Chuck Wah Yu ◽  
Taotao Zeng ◽  
...  

In this work, the thermo-sensitive materials N-isopropylacrylamide (NIPAM) and acrylic acid (AA) were crosslinked with carboxymethyl cellulose (CMC) (CMC/P (NIPAM-co-AA)) via a free radical polymerization method for the removal of U(VI) from aqueous solution. The L16 (45) orthogonal experiments were designed for the optimization of the synthesis condition. The chemical structures of the crosslinking hydrogel were confirmed by FTIR spectroscopy. The microstructural analyses were conducted though scanning electron microscopy (SEM) to show the pore structure of the hydrogel. The adsorption performance of the CMC/P (NIPAM-co-AA) hydrogel for the uptake of U(VI) from simulated wastewater was also investigated. The adsorption reached equilibrium within 1 h. Under the reaction of pH = 6 and a temperature of 298 K, an initial concentration of U(VI) of 5 mg·L−1, and 10 mg of the CMC/P(NIPAM-co-AA) hydrogel, the maximum adsorption capacity was 14.69 mg g−1. The kinetics fitted perfectly with the pseudo-second-order model, and the isotherms for the composite hydrogel adsorption of U(VI) was in accordance with the Langmuir model. The chemical modification confirmed that the acylamino group played an important role in uranium adsorption. The desorption and reusability study revealed that the resolution rate was still available at approximately 77.74% after five alternate heating cycles at 20 and 50 °C of adsorption-desorption.


2020 ◽  
Vol 860 ◽  
pp. 338-344
Author(s):  
Iis Nurhasanah ◽  
Kadarisman ◽  
Vincensius Gunawan ◽  
Heri Sutanto

This study explored adsorptive property of ceria nanocrystal as an adsorbent for amoxicillin removal from water. Ceria nanocrystal was synthesized by employing precipitation method and characterized by using XRD and N2 adsorption-desorption analysis. The adsorption experiment was performed by managing amoxicillin in natural condition. Then, parameters in the adsorption experiment, such as adsorbent dosage, contact time, temperature and initial concentration of amoxicillin are varied. The XRD pattern illustrated that the average crystallite size of ceria nanocrystal formation was 13.08 nm. N2 adsorption-desorption analysis showed that ceria nanocrystal was mesoporous with specific surface area of ​​65.26 m2/g. The amoxicillin adsorption of ceria nanocrystal adsorbent was described by Langmuir isotherm model with maximum adsorption capacity of 37.17 mg/g. The adsorption kinetic of ceria nanocrystal corresponded to the pseudo-second order model. Removal efficiency of amoxicillin by ceria nanocrystal was approximately 80% within 60 minutes over temperature range 303-323K. Those parameter results are described that ceria nanocrystal adsorbent is feasible as a rapid amoxicillin removal from water.


2014 ◽  
Vol 70 (7) ◽  
pp. 1236-1243 ◽  
Author(s):  
Jun Chen ◽  
Xiaoqin Hong ◽  
Qingdong Xie ◽  
Diankai Li ◽  
Qianfeng Zhang

Polyaniline/sepiolite (PANI/sepiolite) nanofibers were prepared by in situ chemical oxidation polymerization in the presence of sepiolite. The effect of aniline/sepiolite weight ratio on the nanostructure of PANI/sepiolite composites was investigated by field-emission scanning electron microscopy. The adsorption of Cr(VI) onto the PANI/sepiolite nanofibers was highly dependent on pH values. The pseudo-second-order and Langmuir isothermal models can well describe the adsorption kinetics and adsorption isotherm, respectively. The maximum adsorption capacity of the PANI/sepiolite nanofibers for Cr(VI) was up to 206.6 mg/g at 25 °C and increased with the increase in temperature. Desorption experiments indicated that PANI/sepiolite can be regenerated and reused for two consecutive cycles with no loss of its removal efficiency. PANI/sepiolite nanofibers can be used as a highly efficient and economically viable adsorbent for Cr(VI) removal due to their excellent adsorption characteristics.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 963
Author(s):  
Marwa El-Azazy ◽  
Iman Nabil ◽  
Siham S. Hassan ◽  
Ahmed S. El-Shafie

Olive stone biochars (OSBC), both pristine and following magnetization (MAG–OSBC), were utilized as eco-friendly and cost-effective sorbents for the antituberculosis, clofazimine (CLOF). Morphologies, textures, surface functionalities, and thermal stabilities of both adsorbents were explored using SEM, EDX, TEM, BET, FT-IR, Raman, XRD and TGA analyses. SEM analysis showed meso- and macroporous surfaces. BET data showed that the MAG–OSBC possesses a larger surface area (33.82 m2/g) and pore volume. Batch adsorption studies were conducted following the experimental scenario of Box–Behnken (BB) design. The adsorption efficiency of both adsorbents was evaluated in terms of the % removal (%R) and the sorption capacity (qe, mg/g). Dependent variables (%R and qe) were maximized as a function of four factors: pH, sorbent dose (AD), the concentration of CLOF ([CLOF]), and contact time (CT). A %R of 98.10% and 98.61% could be obtained using OSBC and MAG–OSBC, respectively. Equilibrium studies indicated that both Langmuir and Freundlich models were perfectly fit for adsorption of CLOF. Maximum adsorption capacity (qmax) of 174.03 mg/g was obtained using MAG–OSBC. Adsorption kinetics could be best illustrated using the pseudo-second-order (PSO) model. The adsorption–desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 92% after the sixth cycles.


Surfaces ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 41-53
Author(s):  
Emad Elshehy

Decontamination of water from radionuclides contaminants is a key priority in environmental cleanup and requires intensive effort to be cleared. In this paper, a microporous iron-doped zeolite-like sodium zirconosilicate (F@SZS) was designed through hydrothermal synthesis with various Si/Zr ratios of 5, 10, and 20, respectively. The synthesized materials of F@SZS materials were well characterized by various techniques such as XRD, SEM, TEM, and N2 adsorption–desorption measurements. Furthermore, the F@SZS-5 and F@SZS-10 samples had a crystalline structure related to the Zr–O–Si bond, unlike the F@SZS-20 which had an overall amorphous structure. The fabricated F@SZS-5 nanocomposite showed a superb capability to remove cesium ions from ultra-dilute concentrations, and the maximum adsorption capacity was 21.5 mg g–1 at natural pH values through an ion exchange mechanism. The results of cesium ions adsorption were found to follow the pseudo-first-order kinetics and the Langmuir isotherm model. The microporous iron-doped sodium zirconosilicate is described as an adsorbent candidate for the removal of ultra-traces concentrations of Cs(I) ions.


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