The Studies of Equilibrium and Thermodynamic Adsorption of Pb(II), Cd(II) and Cu(II) Ions from Aqueous Solution onto SWCNTs and SWCNT–COOH Surfaces

Moradi, Omid; Zare, Kazem; Monajjemi, Majid; Yari, Mohammad; Aghaie, H.

doi:10.1080/15363831003783005

Cited by 127 publications

(38 citation statements)

References 52 publications

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“…Based on our simulations, the adsorption capacity of divalent metal ions in the presence of the COOfunctional group on the CNT is higher due to the presence of additional oxygen binding site.Hence, the adsorption capacity of all the metal ions (Cd 2+ , Cu 2+ , Pb 2+ and Hg 2+ ) on functionalized CNT-COO -(seeFigure 8) is higher than that seen in the presence of other functional groups (-OH and -CONH 2 ) and bare CNT. The total amount adsorption (q m ) of metal ion on CNT surface at equilibrium will saturate with increase in the initial concentration (C 0 ) of metal ion, as observed in various experimental works 1,20,32. However, the relative amount of adsorption ∆C/C 0 will decrease with the increase in concentration (C 0 ) of metal ion in the…”

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confidence: 82%

Removal of Heavy Metal Ions Using a Functionalized Single-Walled Carbon Nanotube: A Molecular Dynamics Study

2015

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The adsorption behaviors of heavy metal ions Cd(2+), Cu(2+), Pb(2+), and Hg(2+), in aqueous media using functionalized single-walled carbon nanotube (SWCNT) with functional groups -COO(-), -OH, and -CONH2 are studied using molecular dynamics (MD) simulations. The results show that adsorption capacity is improved significantly using surface modification of SWCNT with carboxyl, hydroxyl, and amide functional groups. In addition, the adsorption capacity is found to increase with increasing metal-ion concentration. It is observed that the CNT-COO(-) surface effectively adsorbs over 150-230% more metal ions than the bare CNT surface. On the contrary, -OH and -CONH2 are relatively weak functional groups where excess metal-ion adsorption compared to the bare CNT is in the range 10-47%. The structural properties, self-diffusion coefficients, and adsorption isotherms of the metal ions are computed and analyzed in detail. Moreover, the potential of mean force (PMF) is computed to understand the free energy of metal ions, in the presence of functional groups, which is remarkly higher in absolute terms, leading to significant affinity for adsorption compared to the case for the bare CNT. In general, the following order of adsorption of the metal ions on functionalized CNT is observed: Pb(2+) > Cu(2+) > Cd(2+) > Hg(2+).

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confidence: 82%

Removal of Heavy Metal Ions Using a Functionalized Single-Walled Carbon Nanotube: A Molecular Dynamics Study

2015

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“…Those of ox-MWCNT were best in the pH range of 6-10 whereas Cd(II) sorption was only slightly dependant on pH for as-grown MWCNT. Adsorption on to all HNO 3 or NaOCl or KMnO 4 Scheme 1 Mechanism of adsorption of divalent metal ions on to SWCNT-COOH [39] (With permission from Moradi et al [39]) three types of CNT increased rapidly with contact time (30 min for equilibrium to be achieved). They also found that affinity for Cd(II) from aqueous solutions was greater for e-MWCNT than for ox-MWCNT and as-grown MWCNT.…”

Section: Functionalised Cntmentioning

confidence: 97%

“…Moradi et al [39] compared the adsorption of Pb(II), Cd(II), and Cu(II) from aqueous solutions on to SWCNT and SWCNT-COOH (Scheme 1). Adsorption capacities of SWCNT-COOH for Pb(II), Cu(II), and Cd(II) were 96.02, 77.00, and 55.89 mg/g, respectively.…”

Section: Oxidised Cntmentioning

confidence: 99%

Carbon nanotube-based extraction and electrochemical detection of heavy metals

2011

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In this mini review, recent trends and challenges in developing carbon nanotube-based extraction and electrochemical detection of heavy metals in water are reviewed. Carbon nanotubes (CNT) have electrical, mechanical, chemical, and structural properties superior to those of conventional materials, for example graphite and activated carbon. CNT-based procedures are also more efficient than traditional techniques and methods, for example liquid-liquid extraction, atomicabsorption spectroscopy, flame photometry, and inductively coupled plasma, because they can enable rapid, sensitive, simple, and low-cost on-site detection. Different forms of CNT, including as-grown, oxidised, and functionalised CNT, can be well suited to metal adsorption. The measurement procedure relies on adsorbing the metal on the CNT surface after reasonable contact time, either by applying an electrical potential or under open-circuit conditions, and subsequent quantification. Different types of CNT-based electrode, including composite, paste, and binderfree, can be fabricated and used for metal detection. Application of CNT and their novel properties to the adsorption and detection of heavy metals is discussed in detail.

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“…Various thermodynamic parameters (standard Gibbs free energy, standard enthalpy, and entropy) were calculated by equations (10-12): (10) (11) (12) ...where K C is the equilibrium constant, T is the absolute temperature (K), and R is the universal gas constant (8.314 J/mol·K) [41]. ΔHº and ΔSº were calculated from the slope and intercept of the plot of LnK C vs. 1/T using equation 12 (Fig.…”

Section: Adsorption Thermodynamic Studiesmentioning

confidence: 99%

Decontamination of 4-Chloro-2-Nitrophenol from Aqueous Solution by Graphene Adsorption: Equilibrium, Kinetic, and Thermodynamic Studies

Mehrizad¹,

Gharbani²

2014

Pol. J. Environ. Stud.

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Phenol and its compounds are one of the major materials commonly used in the petrochemical, coking, coal refining, chemical, and pharmaceutical industries [1,2]. The harmful effects due to the presence of phenols in industrial wastewaters have been confirmed [3,4]. Thus, development of suitable methods for the decontamination of phenols is necessary. Research has studied the removal of phenol from aqueous solutions, including advanced oxidation processes [5,6], biological degradation [7,8], ozonation [9,10], adsorption [11][12][13][14] [19] have been tested for adsorption of phenol and its compounds from aqueous solutions. Among them, carbon materials show significant adsorption yields. This may be because of their large surface area and good distribution of pore size. Therefore, using new carbonaceous materials as adsorbents is interesting for scientists. An example of a new carbonaceous material is graphene, whose atoms are arranged in a 2D honeycomb structure [20]. As literature results show, graphene has a high adsorption capacity for removal of aqueous pollutants [21][22][23][24][25].In the present study, the potential application of graphene for 4-chloro-2-nitrophenol (4C2NP) adsorption Pol. J. Environ. Stud. Vol. 23, No. 6 (2014), 2111-2116 Original (4C2NP) is an important chemical widely used in the pharmaceuticals, herbicide, and pesticide industries. The ability of graphene to remove 4C2NP from aqueous solutions was performed as a function of contact time, amounts of adsorbent, pH, initial 4C2NP concentrations, and temperatures using a batch technique. Based on the results, the amount of 4C2NP adsorption increased with increasing initial concentration, whereas the alkaline pH range, higher graphene dosage, and higher temperature were unfavorable. Non-linear regression methods suggest that the isotherm data can be well described by the Freundlich isotherm equation. The adsorption kinetic data were analyzed using the non-linear rate equations of pseudo-first and pseudo-second order. It was found that the pseudo-second-order kinetic model was the most appropriate model, describing the adsorption kinetics. The observed changes in the standard Gibbs free energy (ΔGº), standard enthalpy (ΔHº), and standard entropy (ΔSº) show that the adsorption of 4C2NP by graphene is feasible, spontaneous, and exothermic in the temperature range 298-328 K.

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The Studies of Equilibrium and Thermodynamic Adsorption of Pb(II), Cd(II) and Cu(II) Ions from Aqueous Solution onto SWCNTs and SWCNT–COOH Surfaces

Cited by 127 publications

References 52 publications

Removal of Heavy Metal Ions Using a Functionalized Single-Walled Carbon Nanotube: A Molecular Dynamics Study

Removal of Heavy Metal Ions Using a Functionalized Single-Walled Carbon Nanotube: A Molecular Dynamics Study

Carbon nanotube-based extraction and electrochemical detection of heavy metals

Decontamination of 4-Chloro-2-Nitrophenol from Aqueous Solution by Graphene Adsorption: Equilibrium, Kinetic, and Thermodynamic Studies

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