An experimental and theoretical study of the adsorption of aromatics possessing electron-withdrawing and electron-donating functional groups by chemically modified activated carbons

Radović, Ljubiša R.; Silva, I.F.; Ume, Joshua Ifeanyichukwu; Menéndez, J.Á.; Leon, Carlos A. Leon y; Scaroni, Alan W.

doi:10.1016/s0008-6223(97)00072-9

Cited by 398 publications

(215 citation statements)

References 19 publications

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“…Like surface oxygen groups, the presence of some nitrogen-containing functional groups on the carbon surface does not favour p-p interactions between AC and atrazine. Radovic et al (1997) came to the same conclusion for nitrobenzene and aniline adsorption on oxidized and aminated carbons. When the adsorption process is governed by p-p interactions, reduced adsorption is the consequence of withdrawal and/or localization of pelectrons caused by carbon oxidation and amination.…”

Section: Mechanism Of Atrazine Adsorptionsupporting

confidence: 58%

Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

et al. 2015

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Surface-modified hemp stem-based activated carbons (HACs) were prepared and used for the adsorption of atrazine from aqueous solution, and their adsorption performance was examined. A series of HACs were prepared by potassium hydroxide activation of hemp stems, followed by subsequent modification by thermal annealing, oxidation with nitric acid and amination. The resultant HACs differed in surface chemistry, while possessing similar porous structure. The surface group characteristics were examined by X-ray photoelectron spectroscopy and measurement of the point of zero charge (pH PZC ). The adsorption of atrazine from aqueous solution was performed in static conditions. The Langmuir-Freundlich and Langmuir models gave a better fit for equilibrium isotherms compared with the Freundlich model. The atrazine adsorption process was controlled by an intraparticle diffusion mechanism with a significant contribution from film diffusion. The presence of oxygen and nitrogen functionalities on the carbon surface was found to be undesirable for atrazine adsorption. The superior adsorbent was obtained by heat treatment of HAC in an inert atmosphere at 700°C, resulting in a very high adsorption capacity due to its enhanced hydrophobicity. The adsorption of atrazine on the studied HACs mainly involves p-p dispersive interactions between the atrazine ring and the graphene layers of carbon.

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Section: Mechanism Of Atrazine Adsorptionsupporting

confidence: 58%

Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

et al. 2015

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“…For instance, Radovic et al (1997) reported that the presence of electron-withdrawing functional groups will influence the π-electron distribution by removing electrons and creating positive holes in the conduction band of the π-electron system, thus decreasing the adsorption potential on the carbon surface.…”

Section: [Figure 3]mentioning

confidence: 99%

Coupling granular activated carbon adsorption with membrane bioreactor treatment for trace organic contaminant removal: Breakthrough behaviour of persistent and hydrophilic compounds

Nguyen

Hai

Kang

et al. 2013

Journal of Environmental Management

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Nghiem, L. D. (2013). Coupling granular activated carbon adsorption with membrane bioreactor treatment for trace organic contaminant removal: Breakthrough behaviour of persistent and hydrophilic compounds. Journal of Environmental Management, 119 173-181.Coupling granular activated carbon adsorption with membrane bioreactor treatment for trace organic contaminant removal: Breakthrough behaviour of persistent and hydrophilic compounds AbstractThis study investigated the removal of trace organic contaminants by a combined membrane bioreactorgranular activated carbon (MBR-GAC) system over a period of 196 days. Of the 22 compounds investigated here, all six hydrophilic compounds with electron-withdrawing functional groups (i.e., metronidazole, carbamazepine, ketoprofen, naproxen, fenoprop and diclofenac) exhibited very low removal efficiency by MBR-only treatment. GAC post-treatment initially complemented MBR treatment very well; however, a compound-specific gradual deterioration of the removal of the above-mentioned problematic compounds was noted. While a 20% breakthrough of all four negatively charged compounds namely ketoprofen, naproxen, fenoprop and diclofenac occurred within 1000-3000 bed volumes (BV), the same level of breakthrough of the two neutral compounds metronidazole and carbamazepine did not occur until 11,000 BV. Single-solute isotherm parameters did not demonstrate any discernible correlation individually with any of the parameters that may govern adsorption onto GAC, such as log D, number of hydrogen-bond donor/acceptor groups, dipole moment or aromaticity ratio of the compounds. The isotherm data, however, could differentiate the breakthrough behaviour between negatively charged and neutral trace organic contaminants. © 2013 Elsevier Ltd. AbstractThis study investigated the removal of trace organic contaminants by a combined membrane bioreactor -granular activated carbon (MBR-GAC) system over a period of 196 days. Of the 22 compounds investigated here, all six hydrophilic compounds with electronwithdrawing functional groups (i.e., metronidazole, carbamazepine, ketoprofen, naproxen, fenoprop and diclofenac) exhibited very low removal efficiency by MBR-only treatment. GAC post-treatment initially complemented MBR treatment very well; however, a compoundspecific gradual deterioration of the removal of the above-mentioned problematic compounds was noted. While a 20% breakthrough of all four negatively charged compounds namely ketoprofen, naproxen, fenoprop and diclofenac occurred within 1,000 -3,000 bed volumes (BV), the same level of breakthrough of the two neutral compounds metronidazole and carbamazepine did not occur until 11,000 BV. Single-solute isotherm parameters did not demonstrate any discernible correlation individually with any of the parameters that may govern adsorption onto GAC, such as log D, number of hydrogen-bond donor/acceptor groups, dipole moment or aromaticity ratio of the compounds. The isotherm data, however, could differentiate the breakthrough behavior between negatively ...

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“…This was attributed to the formation of an electron donor-acceptor (EDA) complex between NACs (electron acceptor) and the graphene sheets of the carbon nanotubes (electron donor). Sorption properties of NACs on activated carbon have been studied for many years and involve electrostatic and dispersive interactions between the adsorbate and the activated carbon [10,11]. Electrostatic interactions dominate when the adsorbate is dissociated under the experimental conditions, while three mecha- nisms are proposed for nonelectrostatic interactions, (1) π-π dispersion interaction, (2) hydrogen bonding [12], and (3) electron donor-acceptor complex formation [13].…”

Section: Introductionmentioning

confidence: 99%

Kinetics and thermodynamics of sorption of nitroaromatic compounds to as-grown and oxidized multiwalled carbon nanotubes

Shen

Shan

Dong

et al. 2009

Journal of Colloid and Interface Science

154

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The sorption kinetics and thermodynamics of 1,3-dinitrobenzene (DNB), m-nitrotoluene (mNT), p-nitrophenol (pNP), and nitrobenzene (NB) on as-grown and nitric acid-oxidized multiwalled carbon nanotubes (MWCNTs) were investigated. The sorption kinetics was well described by a pseudo-second-order rate model, while both Langmuir and Freundlich models described the sorption isotherms well and the sorption thermodynamic parameters of equilibrium constant (K 0 ), standard free energy ( G), standard enthalpy ( H), and standard entropy changes ( S) were measured. The values of H and G suggested that the sorption of nitroaromatics (NACs) onto MWCNTs was exothermic and spontaneous. The structure, number, and position of nitro groups of NACs were the main factors affecting the sorption rate and capacity. Treatment of the MWCNTs with nitric acid increased both the surface area and the pore volume and introduced oxygen-containing functional groups to the MWCNTs, which depressed the sorption of NACs onto MWCNTs.

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An experimental and theoretical study of the adsorption of aromatics possessing electron-withdrawing and electron-donating functional groups by chemically modified activated carbons

Cited by 398 publications

References 19 publications

Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

Coupling granular activated carbon adsorption with membrane bioreactor treatment for trace organic contaminant removal: Breakthrough behaviour of persistent and hydrophilic compounds

Kinetics and thermodynamics of sorption of nitroaromatic compounds to as-grown and oxidized multiwalled carbon nanotubes

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