Highly efficient adsorption of uranyl ions using hydroxamic acid-functionalized graphene oxide

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed A. Gado ◽  
Bahig M. Atia ◽  
Mohamed F. Cheira ◽  
Mohamed E. Elawady ◽  
Mohamed Demerdash

Abstract A chelating matrix prepared by immobilizing N-hydroxyl amine onto graphene oxide functionalized with aspartic acid (GO-HDX) was applied to recover UO2 2+ from their SO4 2− leach liquor. SEM-EDAX, FT-IR, TGA, and XRD instruments, in addition, Raman spectroscopy (IR-Raman), were used to analyze the synthesized GO-HDX. The static extraction technique optimized various physicochemical parameters that impacted the UO2 2+ extraction. The optimal pH, time of contact, initial concentration, GO-HDX dose, temp., foreign ions, and eluting agents were gained. The experimental equilibrium documents were assessed using Langmuir and Freundlich equations. The Langmuir equation model quite fits the investigational adsorption data with a maximum uptake of 277.78 mg/g, and it implied the attending of monolayer coverage of adsorbed molecules. Pseudo-first- and pseudo-second-order analyses were done to inspect the kinetic results. The data indicated that pseudo-second-order kinetics fit all concentrations. The intended thermodynamic factors were ∆G° negative values and ∆H° positive value. The data signified that the UO2 2+ extraction onto GO-HDX was spontaneous adsorption and endothermic at higher temperatures. The regeneration efficiency of GO-HDX was 98% using 1 M HCl.

2012 ◽  
Vol 446-449 ◽  
pp. 2960-2963
Author(s):  
Jing Yan Song ◽  
Jing Yang

The adsorption properties of the attapulgite and the rectorite were investigated by removal of a cationic dye, methylene blue (MB) from aqueous solution. The attapulgite and the rectorite were characterized by Fourier transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). The analysis of the isotherm equilibrium data using the Langmuir and Freundlich equations showed that the data fitted better with Langmuir model. Pseudo-first-order and pseudo-second-order models were considered to evaluate the rate parameters. The experimental data were well described by the pseudo-second-order kinetic model. The results indicate that the attapulgite exhibited higher adsorption capacity for MB than rectorite and could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.


2020 ◽  
Vol 18 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Huayu Huang ◽  
Yang Wang ◽  
Yubin Zhang ◽  
Zhiying Niu ◽  
Xinli Li

AbstractAmino-functionalized graphene oxide (GO-NH2) was synthesized by grafting (3-aminopropyl) triethoxysilane on the graphene oxide (GO) surface. The GO-NH2 with high surface area and numerous active sites can efficiently adsorb Cr(VI), Cu(II), Pb(II) and Cd(II) ions. The maximum adsorption capacities of GO-NH2 for Cr(VI), Cu(II), Pb(II) and Cd(II) were 280.11, 26.25, 71.89 and 10.04 mg g−1, respectively. The pseudo-first-order and pseudo-second-order kinetic models were employed to describe the kinetic processes. The experimental data agreed well with the pseudo-second-order kinetic equation, and the adsorption of heavy metals onto GO-NH2 occurs via chemical adsorption. The characteristics of Cr(VI), Cu(II), Pb(II) and Cd(II) in the GO-NH2 adsorption processes were analyzed using the Langmuir and Freundlich isotherm models. The adsorption processes of Pb(II) and Cd(II) on GO-NH2 were fit by the Langmuir model. The Freundlich isotherm model was well correlated to Cr(VI) and Cu(II). The GO-NH2 is a promising material for the removal of heavy metal ions from industrial wastewater. This study provides an effective pathway to process industrial wastewater, and the GO-NH2 has a good adsorption effect for the treatment of heavy metals in industrial wastewater.


2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.


2012 ◽  
Vol 11 (02) ◽  
pp. 1250019 ◽  
Author(s):  
RAJESH KUMAR ◽  
S. K. JAIN

This study was carried out to evaluate the environmental application of functionalized carbon nanotubes through the experimental removal of strontium (II) from water. The aim was to find the optimal condition for the removal of strontium from water under different conditions such as initial concentration of strontium, contact time and neutral pH. The functionalized multi wall carbon nanotubes (f-MWCNT) were characterized by FT-IR and scanning electron microscopy (SEM). The adsorption isotherms were correlated to Freundlich and Langmuir models and it was found that the adsorption data could be fitted better by Langmuir model than Freundlich one. The kinetic data shows that the adsorption describes well with the pseudo-second order kinetic model. Functionalized MWCNT can be used as good adsorbent for the removal of the strontium ions from polluted water according to results.


Author(s):  
Tasrina R. Choudhury ◽  
Snahasish Bhowmik ◽  
M. S. Rahman ◽  
Mithun R. Nath ◽  
F. N. Jahan ◽  
...  

Sawdust supported nano-zerovalent (NZVI/SD) iron was synthesized by treating sawdust with ferrous sulphate followed by reduction with NaBH4. The NZVI/SD was characterized by SEM, XRD, FTIR and Chemical method. Adsorption of As (III) by NZVI/SD was investigated and the maximum uptake of As (III) was found at pH value of 7.74 and equilibrium time of 3 hrs. The adsorption isotherm modelling revealed that the equilibrium adsorption data were better fitted with the Langmuir isotherm model compared with the Freundlich Isotherm model. This study revealed that the maximum As (III) ions adsorption capacity was found to be 12.66 mg/g for using NZVI/SD adsorbent. However, the kinetics data were tested by pseudo-first-order and pseudo-second-order kinetic models; and it was observed that the adsorption data could be well fitted with pseudo-second-order kinetics for As (III) adsorption onto NZVI/SD depending on both adsorbate concentration and adsorption sites. The result of this study suggested that NZVI/SD could be developed as a prominent environment-friendly adsorbent for the removal of As (III) ions from aqueous systems.


2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.


2020 ◽  
Vol 38 (9-10) ◽  
pp. 325-343 ◽  
Author(s):  
Hossam Mohammed Abdel-Aziz ◽  
Rabie Saad Farag ◽  
Soha Ali Abdel-Gawad

Green synthesis approach was successful used extract was successful in preparing bimetallic zero-valent Iron/Copper nanoparticles [FB-nZVFe/Cu]. Scanning Electron Microscope [SEM], Fourier Transform Infrared Spectroscopy [FTIR], and Dispersive X-ray Spectroscopy [EDX] showing the synthesizing of FB-nZVFe/Cu. The removal efficiency of Caffeine [5 mg L−1] reached 86% under the conditions [0.2 g L−1, 45 min, and pH 5]. The adsorption data are more appropriate by the Langmuir model [R2 = 0.9987] with qmax = 34.34 mg g −1. Kinetic results showed that Caffeine uptake is following pseudo-second-order. Langmuir and pseudo-second-order are more appropriate in linear and non-linear models. Overall, FB-Fe/Cu is a committed green substance for removal Caffeine from aqueous solutions. Functional parameters affect investigated using the Linear regression analysis, we found them to account for over 98% of the variables affecting the removal procedure.


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.


2012 ◽  
Vol 30 (1) ◽  
pp. 1-21 ◽  
Author(s):  
R.B. Rabelo ◽  
R.S. Vieira ◽  
F.M.T. Luna ◽  
E. Guibal ◽  
M.M. Beppu

Cross-linked chitosan was synthesized with glutaraldehyde (chitosan–GLA) and epichlorohydrin (chitosan–ECH). The structures of these matrices were characterized by elemental analysis, Fourier-transform infrared spectrometry (FT-IR), the degree of de-acetylation and the surface topography as determined via scanning electron microscopy (SEM). After promoting interaction with the metal ion, the adsorbent was also studied using FT-IR and energy dispersive X-ray spectroscopy (EDXS). Adsorption studies for Cu(II) and Hg(II) ions were carried out in a batch process. The adsorption kinetics were tested using three models, viz. pseudo-first-order, pseudo-second-order and intra-particle diffusion. The experimental kinetic data were best fitted by the pseudo-second-order model for Cu(II) ions (R2 ≥ 0.98) and for Hg(II) ions (R2 = 0.99). Higher rate constants (k2) were obtained for the adsorption of Cu(II) ions onto chitosan–GLA [1.40 g/(mmol h)] and for Hg(II) ions onto raw chitosan [5.65 g/(mmol h)]. The adsorption rate depended on the concentration of Cu(II) and Hg(II) ions on the adsorbent surface and on the quantity of ions adsorbed at equilibrium. At 293 K, the Langmuir–Freundlich model provided a better fit to the adsorption isotherms on both raw and cross-linked chitosan membranes. The maximum adsorption capacity for Cu(II) ions was obtained with the chitosan–GLA matrix (2.7 mmol/g). A maximum adsorption capacity of 3.1 mmol/g was attained for Hg(II) ions onto the chitosan–ECH matrix.


2011 ◽  
Vol 8 (4) ◽  
pp. 1512-1521 ◽  
Author(s):  
A. Esmaeili ◽  
P. Beirami ◽  
S. Ghasemi

The batch removal of Ni2+from aqueous solution and wastewater using marine dried (MD) red algaeGracilariaand its activated carbon (AC) was studied. For these experiments, adsorption of Ni2+was used to form two biomasses of AC and MD. Both methods used different pH values, biomass and initial concentration of Ni2+. Subsequently adsorption models and kinetic studies were carried out. The maximum efficiencies of Ni2+removal were 83.55% and 99.04% for MD and AC respectively developed from it. The experimental adsorption data were fitted to the Langmuir adsorption model. The nickel(II) uptake by the biosorbents was best described by pseudo-second order rate model. The kinetic studies showed that the heavy metal uptake was observed more rapidly by the AC with compared to MD. AC method developed from MD biomass exhibited higher biosorption capacity. Adsorption capacity is related to the pH of solution, pH 5.0 is optimal for nickel. The maximum efficiencies of Ni2+removal were for AC method. The capacity is related to the pH of solution, pH 5.0 is optimal for nickel. The equilibrium adsorption data are correlated by Langmuir isotherm equation. The adsorption kinetic data can be described by the second order kinetic models


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