Facile synthesis of EDTA-functionalized halloysite nanotubes for the removal of methylene blue from aqueous phase

2019 ◽  
Vol 97 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Mengmeng Zhang ◽  
Hongchao Yu ◽  
Bibo Chen

EDTA-functionalized halloysite nanotubes (EDTA-HNTs) were synthesized by a two-step method. The structures of the EDTA-HNTs were analyzed by Fourier-transform infrared spectra, X-ray diffraction, thermogravimetric analysis, and transmission electron spectroscopy. Then, the EDTA-HNTs were applied as adsorbents for the removal of methylene blue from aqueous phase. Adsorption of methylene blue onto EDTA-HNTs was investigated with respect to adsorbent dose, contact time, initial methylene blue concentration, and temperature. A maximum adsorption capacity of 115.8 mg/g for methylene blue onto EDTA-HNTs at room temperature was achieved. The adsorption kinetics could be described by the pseudo-second-order model. Both the Langmuir and Freundlich models were employed to describe the adsorption isotherms, and the results presented that the equilibrium data obeyed the Langmuir model. Thermodynamic parameters of ΔG0 and ΔH0 verified the spontaneous and exothermic nature of the methylene blue adsorption onto EDTA-HNTs. Moreover, the EDTA-HNTs could be facilely regenerated and efficiently reused, exhibiting a good prospect for the treatment of dye effluents.

2021 ◽  
Vol 406 ◽  
pp. 348-363
Author(s):  
Larbi Haddad ◽  
Abdelkader Hima ◽  
Belkhir Dadamoussa ◽  
Asma Messai Aoun

In this study, a local mineral clay was used as an adsorbent for the elimination of a cationic dye: methylene blue (MB), in an aqueous solution by adsorption technique. Early on, we performed mineralogical and textural analyses of a clay sample using various techniques, namely X-ray diffraction, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. The experimental results showed that this adsorbent is a mesoporous and non-swelling clay with illite and kaolinite as the major components with a specific area of about 110m2/g. The study of MB adsorption on the clay was carried out by optimizing the conditions of adsorption, notably the initial concentration of pollutant C0, the mass of clay m, the contact time t, the potential of hydrogen of the solution pH and the temperature T. Experimental results have shown that the equilibrium data are well adjusted by a Langmuir isotherm equation. Thermodynamic parameters such as the changes in Gibbs free energy, enthalpy, and entropy were determined from batch experiments. Results revealed that the adsorption of MB onto illitic clay was endothermic and spontaneous process. Kinetic modeling was also carried out. Experimental data adjusted the kinetic model of pseudo-second order with two stages of intraparticle diffusion.


2015 ◽  
Vol 71 (11) ◽  
pp. 1611-1619 ◽  
Author(s):  
Jun Liu ◽  
Hongyan Du ◽  
Shaowei Yuan ◽  
Wanxia He ◽  
Pengju Yan ◽  
...  

Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T = 293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (–CO−) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions.


2021 ◽  
Vol 22 (2) ◽  
pp. 1-6
Author(s):  
Suondos K. A. Barno ◽  
Haider J. Mohamed ◽  
Siham M. Saeed ◽  
Mohammed J. Al-Ani ◽  
Ammar S. Abbas

The research discussed the possibility of adsorption of Brilliant Blue Dye (BBD) from wastewater using 13X zeolite adsorbent, which is considered a byproduct of the production process of potassium carbonate from Iraqi potash raw materials. The 13X zeolite adsorbent was prepared and characterized by X-ray diffraction that showed a clear match with the standard 13X zeolite. The crystallinity rate was 82.15% and the crystal zeolite size was 5.29 nm. The surface area and pore volume of the obtained 13X zeolite were estimated. The prepared 13X zeolite showed the ability to remove BBD contaminant from wastewater at concentrations 5 to 50 ppm and the removal reached 96.60% at the lower pollutant concentration. Adsorption measurements versus time showed 48.18% removal of the dye during just the first half-hour and the maximum removal closest to the removal at the equilibrium after one and half hour. Langmuir isotherm was described the adsorption equilibrium data with a maximum adsorption capacity of 93.46 mg/g and the kinetics data of the adsorption process was followed the pseudo-second-order.


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.


2013 ◽  
Vol 68 (2) ◽  
pp. 441-447 ◽  
Author(s):  
Diego S. Paz ◽  
Alexandre Baiotto ◽  
Marcio Schwaab ◽  
Marcio A. Mazutti ◽  
Mariana M. Bassaco ◽  
...  

In this study papaya seeds were used to remove methylene blue dye from aqueous solution. Papaya seeds were characterized as possessing a macro/mesoporous texture and large pore size. Studies were carried out in batches to evaluate the effect of contact time and pH (2–12) on the removal of dye. It was observed that the adsorption of dye was better in the basic region (pH 12). The equilibrium data were analyzed using Langmuir, Freundlich, Dubinin–Raduschkevich, Tempkin, Jovanovich, Redlich–Peterson, Sips, Toth and Radke–Prausnitz isotherms. The equilibrium data were best described by the Langmuir isotherm with a maximum adsorption capacity of 637.29 mg g–1. Adsorption kinetic data were fitted using the pseudo-first-order and pseudo-second-order model. The adsorption kinetic is very fast and was best described by the pseudo-second-order model.


2017 ◽  
Vol 76 (9) ◽  
pp. 2526-2534 ◽  
Author(s):  
Meimei Zhou ◽  
Weizhen Tang ◽  
Pingping Luo ◽  
Jiqiang Lyu ◽  
Aixia Chen ◽  
...  

Abstract Ureido-functionalized mesoporous polyvinyl alcohol/silica composite nanofibre membranes were prepared by electrospinning technology and their application for removal of Pb2+ and Cu2+ from wastewater was discussed. The characteristics of the membranes were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption analysis. Results show that the membranes have long fibrous shapes and worm-like mesoporous micromorphologies. Fourier transform infrared spectroscopy confirmed the membranes were successfully functionalized with ureido groups. Pb2+ and Cu2+ adsorption behavior on the membranes followed a pseudo-second-order nonlinear kinetic model with approximately 30 minutes to equilibrium. Pb2+ adsorption was modelled using a Langmuir isotherm model with maximum adsorption capacity of 26.96 mg g−1. However, Cu2+ adsorption was well described by a Freundlich isotherm model with poor adsorption potential due to the tendency to form chelating complexes with several ureido groups. Notably, the membranes were easily regenerated through acid treatment, and maintained adsorption capacity of 91.87% after five regeneration cycles, showing potential for applications in controlling heavy metals-related pollution and metals reuse.


2018 ◽  
Vol 34 (3) ◽  
pp. 1233-1239 ◽  
Author(s):  
Olushola S. Ayanda ◽  
Kehinde O. Sodeinde ◽  
P. O. Okolo ◽  
Ayomitide A. Ajayi ◽  
Simphiwe M. Nelana ◽  
...  

In this study, the adsorption of amido black (AB) dye onto kaolin was investigated. The characterization of kaolin was carried out by powder x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR). Adsorption studies showed that the adsorption of AB onto kaolin increased with increasing adsorbent dosage, contact time, pH and temperature but decreased with increasing dye concentration. Equilibrium data fitted perfectly into the Langmuir and Freundlich equilibrium models, moreover, the kinetic data followed the pseudo-second order model. The adsorption process is endothermic and approximately 60.75% AB reduction was achieved when 0.75 g of kaolin was mixed with 20 mL of 40 mg/L AB for 60 min at 200 rpm. Therefore, this study shows that kaolin can be harnessed for the treatment of textile wastewater.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5394
Author(s):  
En-Rui Wang ◽  
Kun-Yauh Shih

The industry development in the last 200 years has led to to environmental pollution. Dyes emitted by pharmaceutical and other industries are major organic pollutants. Organic dyes are a pollutant that must be removed from the environment. In this work, we adopt a facile microwave hydrothermal method to synthesize ZnFe2O4/rGO (ZFG) adsorbents and investigate the effect of synthesis temperature. The crystal structure, morphology, chemical state, and magnetic property of the nanocomposite are investigated by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and a vibrating sample magnetometer. Furthermore, the synthesized ZFGs are used to remove methylene blue (MB) dye, and the adsorption kinetics, isotherm, mechanism, and reusability of this nanomaterial are studied. The optimal ZFG nanocomposite had a dye removal percentage of almost 100%. The fitting model of adsorption kinetics followed the pseudo-second-order model. The isotherm model followed the Langmuir isotherm and the theoretical maximum adsorption capacity of optimal ZFG calculated by this model was 212.77 mg/g. The π–π stacking and electrostatic interaction resulted in a high adsorption efficiency of ZFG for MB adsorption. In addition, this nanocomposite could be separated by a magnet and maintain its dye removal percentage at almost 100% removal after eight cycles, which indicates its high suitability for utilization in water treatment.


2019 ◽  
Vol 37 (3-4) ◽  
pp. 185-204 ◽  
Author(s):  
Shaomin Gao ◽  
Wenwen Zhang ◽  
Zhaohui An ◽  
Shulin Kong ◽  
Donghui Chen

In this study, a magnetically separable Fe3O4/CeO2 (Fe/Ce) nanocomposite is synthesized by sol-precipitation method and characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy dispersive spectrometer , vibrating sample magnetometer, atomic absorption spectrometer, and zeta potential measurements. The Fe/Ce is used as sorbent to adsorb anionic dye of Acid Black 210 (AB210) from aqueous solutions, and the maximum adsorption capacity is about 90.50 mg/g, which is six times higher than that of the commercial CeO2. Dependence of absorption performance on essential factors, such as initial dye concentration, temperature and initial pH, are experimentally examined. The result shows that the adsorption kinetic of Fe/Ce follows pseudo-second-order model and the adsorption isotherm is well described by the Langmuir adsorption model. Furthermore, the thermodynamic analysis indicates that the adsorption of Fe/Ce for AB210 is spontaneous and endothermic.


2020 ◽  
Vol 81 (4) ◽  
pp. 694-708
Author(s):  
Qiujie Liu ◽  
Peili Ma ◽  
Penglei Liu ◽  
Hongping Li ◽  
Xiuli Han ◽  
...  

Abstract Mass production of nanomaterials to remove pollutants from water still faces many challenges, mainly due to the complexity of the synthesis methods involved and the use of dangerous reagents. The green method of preparation of nanomaterials from plants can effectively solve these problems. Fe,Cu oxide nanocomposites (Fe-Cu-NCs) were synthesized by a green and single-step method using loquat leaf extracts, and were used as an adsorbent for removal of Norfloxacin (NOR) and Ciprofloxacin (CIP) from aqueous solution. The synthesized adsorbent showed excellent adsorption properties for NOR and CIP. The experimental equilibrium data fitted the Redlich-Peterson and Koble-Corrigan models well and the maximum adsorption capacities of Fe-Cu-NCs calculated by the Langmuir model for NOR and CIP were 1.182 mmol/g and 1.103 mmol/g, respectively, at 293 K. Additionally, the morphologies and properties of Fe-Cu-NCs were characterized by transmission electron microscopy (TEM), scanning electron microscopy X-ray energy-dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis and the adsorption mechanism of NOR and CIP onto Fe-Cu-NCs was discussed. Thermodynamic parameters revealed that the adsorption process was spontaneous and endothermic. This study indicated that Fe-Cu-NCs are a potential adsorbent and provide a simple and convenient strategy for the purification of antibiotics-laden wastewater.


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