scholarly journals Preparation of Magnetic Multi-Walled Carbon Nanotubes to Adsorb Sodium Dodecyl Sulfate (SDS)

2017 ◽  
Vol 4 (1) ◽  
pp. 61902-61902 ◽  
Author(s):  
Zahra Rahmani ◽  
Mohammad Taghi Samadi
Keyword(s):  
Experimental Data ◽  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Sodium Dodecyl ◽  
Kinetic Studies ◽  
Xrd Analysis ◽  
Sorption Kinetics ◽  
Order Kinetic ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Surfactants are one of the main groups of pollutants released into aqueous solutions due to human activities and their harmful effects have been proven on human. In this study, first, magnetic multi-walled carbon nanotubes (MMWCNTs) were synthesized and then, the effects of operating parameters such as surfactant concentration, adsorbent dosage, and pH values were analyzed on the adsorption process. MMWCNTs were characterized by means of X-ray diffraction (XRD) analysis and fourier transform infrared spectroscopy (FTIR). The optimal adsorption conditions were achieved at initial pH = 4.6, adsorbent concentration = 0.5 g/L, and initial SDS concentration = 15 mg/L. In addition, the equilibrium of sorption reached after 120 min and the maximum capacity of SDS for monolayer coverage was found to be 61 mg/g at 25°C. Kinetic studies were performed under optimal conditions and the sorption kinetics was described using the pseudo-second-order kinetic model. The experimental data were studied using Freundlich, Langmuir, and Sips models. Finally, the experimental data were fitted reasonably by Langmuir isotherm. The results demonstrated that MMWCNTs with respect to their high adsorption capacity, relatively low equilibrium time, and capability to be separated from aqueous solutions (after adsorption) could be applied to wastewater treatment.

scholarly journals Removing lead ions from aqueous solutions by the thiosemicarbazide grafted multi-walled carbon nanotubes

2017 ◽  
Vol 76 (2) ◽  
pp. 302-310 ◽  
Author(s):  
Ying Zhou ◽  
Jingang Yu ◽  
Xinyu Jiang
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Adsorption Process ◽  
Lead Ions ◽  
Maximum Adsorption Capacity ◽  
Gravimetric Analysis ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A novel multi-walled carbon nanotubes (MWCNTs) material functionalized with thiosemicarbazide was synthesized successfully and used to remove lead ions from aqueous solutions. The technologies of Fourier Transform Infrared Spectroscopy, scanning electron microscopy and thermal gravimetric analysis were used to characterize the structure and properties of thiosemicarbazide grafted MWCNTs. The adsorption conditions, such as pH, contact time and temperature, were investigated. The results showed pH affected the adsorption process greatly, and the adsorption process reached equilibrium within 60 min. The maximum adsorption capacity was 42.01 mg/g. The adsorption process fitted well with the pseudo-second-order kinetic model and the Langmuir model. The thermodynamic parameters indicated the adsorption process was endothermic and spontaneous in nature.

Removal of tetracycline antibiotic from contaminated water media by multi-walled carbon nanotubes: operational variables, kinetics, and equilibrium studies

2016 ◽  
Vol 74 (5) ◽  
pp. 1202-1216 ◽  
Author(s):  
Ali Akbar Babaei ◽  
Eder C. Lima ◽  
Afshin Takdastan ◽  
Nadali Alavi ◽  
Gholamreza Goudarzi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Background Electrolyte ◽  
P Value ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray ◽  
Operational Variables ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs) were purified and oxidized by a 4 mol L−1 mixture of H2SO4:H2O2 and then were used as adsorbent for tetracycline (TC) adsorption from aqueous solutions. The purified MWCNTs were characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and N2 adsorption/desorption isotherms. The adsorption of TC onto the MWCNT was investigated as a function of the initial pH of the solution, adsorbent dosage, and background electrolyte cations and anions. The results of the one-way analysis of variance (ANOVA) showed that Fe3+ ion significantly affected and decreased TC adsorption onto the MWCNT (P-value < 0.05), while other studied cations and anions did not affect TC adsorption (P-value>0.05). Nonlinear pseudo-first-order, pseudo-second-order, general order, and Avrami fractionary-order kinetic models were used to investigate the kinetics of TC adsorption. The fractionary-order kinetic model provided the best fit to experimental data. In addition, the adsorption isotherms data were well described by nonlinear equation of the Liu isotherm model with the maximum adsorption capacity of 253.38 mg g−1. The results of this study indicate that the oxidized MWCNTs can be used as an effective adsorbent for TC removal from aqueous solutions.

scholarly journals Adsorption of Reactive Blue 116 Dye and Reactive Yellow 81 Dye from Aqueous Solutions by Multi-Walled Carbon Nanotubes

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2757 ◽  
Author(s):  
Christian De Benedetto ◽  
Anastasia Macario ◽  
Carlo Siciliano ◽  
Janos B. Nagy ◽  
Pierantonio De Luca
Keyword(s):  
Carbon Nanotubes ◽  
Kinetic Model ◽  
Aqueous Solutions ◽  
Chemical Vapour ◽  
Solid Matrix ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The multi-walled carbon nanotubes obtained by catalytic chemical vapour deposition synthesis are used as a solid matrix for the adsorption of the Reactive Blue 116 dye and the Reactive Yellow 81 dye from aqueous solutions at different pH values. The batch tests carried out allowed us to investigate the different effects of pH (2, 4, 7, 9 and 12) and of the contact time (2.5 ÷ 240 min) used. The liquid phase was analysed using ultraviolet-visible spectrophotometry in order to characterise the adsorption kinetics, the transport mechanisms and the adsorption isotherms. The adsorption of the optimal dye was observed at pH 2 and 12. The pseudo-first order kinetic model provided the best approximation of experimental data compared to the pseudo-second order kinetic model. The predominant transport mechanism investigated with the Weber and Morris method was molecular diffusion for both Reactive Yellow 81 and Reactive Blue 116, and the equilibrium data were better adapted to the Langmuir isothermal model. The maximum adsorption capacity for Reactive Yellow 81 and Reactive Blue 116 occurred with values of 33.859 mg g−1 and 32.968 mg g−1, respectively.

Removal of Paraquat from Aqueous Solutions Using Multi-Walled Carbon Nanotubes: Kinetic, Isotherm and Thermodynamic Studies

2015 ◽  
Vol 1088 ◽  
pp. 13-17 ◽  
Author(s):  
Han Hao ◽  
Jian Guo Feng ◽  
Wen Jun Liu ◽  
Xue Min Wu
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Diffusion Mechanism ◽  
Considerable Effect ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNT) were used as an efficient adsorbent to remove Paraquat (PQ) molecules from its aqueous solutions. The initial PQ concentration, adsorption time and temperature had considerable effect on the removal of PQ onto MWCNT. The adsorption of PQ onto MWCNT followed the pseudo second-order kinetic model involving the particle-diffusion mechanism. The adsorption isotherms were fitted by the Langmuir isotherm, with the maximum adsorption capacity based on the former of 79.365 mg·g-1. Thermodynamic parameters, including Gibbs free energy changes (ΔG0), as well as changes in enthalpy (ΔH0) and entropy (ΔS0), were also calculated. The results demonstrated that PQ was adsorbed onto MWCNT spontaneously and endothermically in nature.

Kinetics and thermodynamics of the sorption of furaltadone from aqueous solutions on magnetic multi-walled carbon nanotubes

2014 ◽  
Vol 70 (6) ◽  
pp. 964-971
Author(s):  
Xu Chen ◽  
Zhen-hu Xiong
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Sorption Data ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Experimental Data Analysis ◽  
Walled Carbon Nanotubes

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g · L−1, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and π–π stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater.

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