Adsorption of 2-nitrophenol by multi-wall carbon nanotubes from aqueous solutions

Arasteh, Rouhollah; Masoumi, Mahsa; Rashidi, Alimorad; Moradi, Leila; Samimi, V.; Mostafavi, S.T.

doi:10.1016/j.apsusc.2010.01.057

Cited by 158 publications

(68 citation statements)

References 39 publications

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“…这意味着硝基咪唑类药物的吸附动力学服从准二级动力学模型. 此类现象比较常见 [26,27] , 原因是在计算准一级模型的各参数之前需要通过实验确定平衡吸附量 q e , 而这在实际过程中很难做到. 然而准二级方程包含了吸附的所有过程(外部液膜扩散、表面吸附和颗粒内扩散等), 可真实、全面地反映甲硝唑、奥硝唑、替硝唑在固体表面的吸附机理.…”

Section: 准一级模型与准二级模型为了深入了解吸附过程的特性将间歇实验的数据用准一级和准二级动力学模型进行拟合unclassified

Adsorption Behavior of Three Nitroimidazoles in Aqueous Solutions to Magnetic-modified Multi-walled Carbon Nanotubes

Ren¹,

Xiong²

2013

Acta Chim. Sinica

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The magnetic multi-walled carbon nanotubes (MWCNTs) were synthesized by wet chemical treatments. Firstly, an amount of 1.0 g of purified MWCNTs was suspended in 200 mL of mixed solution containing 1.7 g of ammonium ferrous sulfate and 2.5 g of ammonium ferric sulfate, which was followed by a slow addition of 10.0 mL of 8 mol•L -1 NH 4 OH solution at constant temperature of 50 ℃, under nitrogen atmosphere, with the aid of ultrasonic stirring for 10 min. The pH of the final mixture was controlled in the range of 11～12. The reaction was allowed to continue for 30 min, which results in the color of the suspension changing from black to brown. After the completion of the reaction, the suspension was allowed to cool at room temperature. The magnetic MWCNTs was isolated from the mixture by a permanent magnet, afterwards dried under vacuum. The size and morphology of the synthesized magnetic MWCNTs were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and vibrating sample magnetometer. The magnetic MWCNTs was used to adsorbing the three nitroimidazoles,-metronidazole, ornidazole and tinidazole-in aqueous solutions. The adsorption kinetic (or isotherms) experiments were carried out by adding 250 mg of magnetic MWCNTs to a 50 mL flask which containing a solution made up of one or three nitroimidazoles with known initial concentration (10 mg•L -1 ) at natural pH, then agitating in a temperature-controlled shaker at (25±1) for different time interval ℃ s (1～480 min). The effect of pH was performed by dispersion of 250 mg of magnetic MWCNTs in 50 mL aqueous solution which containing 10 mg•L -1 of three nitroimidazoles of each. The results showed that the removal of metronidazole, ornidazole and tinidazole reached 92.86%, 94.44%, 94.91% respectively when the dosage of magnetic MWCNTs was 5 g•L -1 , the pH values was 7 and the time of adsorption was 300 min. Adsorption kinetic analysis demonstrated that pseudo-second order model could interpret the kinetics of the adsorption process, and Freundlich model could better explains the isotherm for adsorption process under different temperatures. The overall adsorption rate appeared to be influenced by both the external mass transfer and the intraparticle diffusion, and mainly governed by the intraparticle diffusion. The adsorption mechanism could be explained by electrostatic attraction between MWCNTs and nitroimidazoles, and by π-π stacking interaction. The obtained thermodynamic parameters (ΔH 0 , ΔS 0 , ΔG 0 ), calculated from adsorption process revealed that 1) ΔG 0 ＜0 indicated that the adsorption of nitroimidazoles on magnetic MWCNTs was spontaneous; 2) ΔG 0 indicated that the adsorption is physical process; 3) ΔH 0 ＜0 indicated that the absorption reaction was exothermic and that low temperatures were favorable for adsorption, and 4) ΔS 0 ＞0 indicated that the adsorption process was an entropy enhancing process in the experimental temperature range. Finally, the leaching of Fe from adsorbent into the treat...

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Section: 准一级模型与准二级模型为了深入了解吸附过程的特性将间歇实验的数据用准一级和准二级动力学模型进行拟合unclassified

Adsorption Behavior of Three Nitroimidazoles in Aqueous Solutions to Magnetic-modified Multi-walled Carbon Nanotubes

Ren¹,

Xiong²

2013

Acta Chim. Sinica

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“…The adsorption isotherm is an equation relating to the amount of solute adsorbed onto the solid and the equilibrium concentration of the solute in solution at a given temperature (31). Equilibrium data can be analyzed using several well-known adsorption isotherms.…”

Section: Adsorption Isothermmentioning

confidence: 99%

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

Rafiee

Samadi

2017

Avicenna J Environ Health Eng

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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.

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“…Multiwalled carbon nanotubes (MWCNTs) can be used for effective removal of aromatic organic compounds like phenol, nitrophenols, chlorophenols, etc., from contaminated water (Arasteh et al, 2010;Li et al, 2013;Liao et al, 2008;Pan and Zhang, 2014;Podkos´cielny et al, 2014;Shen et al, 2009;To´th et al, 2012;Wis´niewski et al, 2012;Wu et al, 2012;Yang and Xing, 2010;Yang et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Adsorption of phenol from aqueous solutions on original and oxidized multiwalled carbon nanotubes

Dąbrowski

2017

Adsorption Science & Technology

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The surface heterogeneity of the multiwalled carbon nanotubes is investigated on the basis of adsorption isotherms from dilute aqueous phenol solutions at various temperatures. The Dubinin-Astakhov isotherm connected with the non-symmetrical distribution function of adsorption energies has been applied to describe adsorption equilibrium. Theoretical isosteric heats of adsorption connected with the Dubinin-Astakhov isotherm have been estimated as well. It is known that the decrease of the isosteric heat of adsorption with adsorbate loading is characteristic for the energetically heterogeneous surfaces. Theoretical description of kinetics is based on the Statistical Rate Theory of Interfacial Transport. The Statistical Rate Theory approach links the rate of transport between two phases with the difference in the chemical potentials of the molecules in these phases. Theoretical studies were verified successfully using the literature experimental adsorption data.

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Adsorption of 2-nitrophenol by multi-wall carbon nanotubes from aqueous solutions

Cited by 158 publications

References 39 publications

Adsorption Behavior of Three Nitroimidazoles in Aqueous Solutions to Magnetic-modified Multi-walled Carbon Nanotubes

Adsorption Behavior of Three Nitroimidazoles in Aqueous Solutions to Magnetic-modified Multi-walled Carbon Nanotubes

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

Adsorption of phenol from aqueous solutions on original and oxidized multiwalled carbon nanotubes

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