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Université de Neuchâtel

Adsorption of Phenolic Compounds from Aqueous Solutions, by Activated Carbons, Described by the Dubinin−Astakhov Equation

Stoeckli, Fritz ; López-Ramón, María Victoria ; Moreno-Castilla, Carlos

In: Langmuir, 2001, vol. 17, no. 11, p. 3301–3306

It is shown that the adsorption of phenol and 3-chlorophenol from aqueous solutions, by basic active carbons and at an equilibrium solution pH below that of dissociation of the phenols, can be described by an equation of the DRK type with exponent n = 4. The principle of temperature invariance is fulfilled between 283 and 313 K, which means that predictions can be made on the basis of a...

Université de Neuchâtel

Specific and Nonspecific Interactions between Methanol and Ethanol and Active Carbons

López-Ramón, María Victoria ; Stoeckli, Fritz ; Moreno-Castilla, Carlos ; Carrasco-Marín, Francisco

In: Langmuir, 2000, vol. 16, no. 14, p. 5967–5972

The interaction of methanol and ethanol with active carbons of different origins and containing between 0.81 and 7 mmol g-1 surface oxygen has been examined by immersion calorimetry and by vapor adsorption at 293 K, benzene being the reference. The results obtained by these independent techniques are in excellent agreement. With respect to pure carbons, the surface oxygen leads to...

Université de Neuchâtel

Adsorption of Phenol from Dilute and Concentrated Aqueous Solutions by Activated Carbons

Fernandez, Elena ; Hugi-Cleary, Deirdre ; López-Ramón, M. Victoria ; Stoeckli, Fritz

In: Langmuir, 2003, vol. 19, no. 3, p. 9719–9723

Combined calorimetric and adsorption techniques show that in the case of phenol adsorption from either dilute or concentrated aqueous solutions, water is always adsorbed preferentially by the oxygen-containing surface groups of the carbon. This reduces the surface and/or the micropore volume accessible to the phenol molecule and quantitatively explains the decrease in the limiting adsorption of...

Université de Neuchâtel

The Myers–Prausnitz–Dubinin Theory and Non-ideal Adsorption in Microporous Solids

Stoeckli, Fritz ; Couderc, Gaëtan ; Sobota, R. ; Lavanchy, André

In: Adsorption Science and Technology, 2002, vol. 20, no. 2, p. 189-197

The adsorption of vapour and liquid mixtures of benzene + 1,2-dichloroethane, chlorobenzene + carbon tetrachloride, chlorobenzene + cyclohexane and 1-bromo,2-chloroethane + 1,2-dichloroethane on two activated carbons and on two zeolites (UC13X and ZSM-5) was examined near room temperature. It was shown that the combination of the recent Myers–Prausnitz–Dubinin (MPD) theory with the activity...

Université de Neuchâtel

Chars and Activated Carbons Prepared from Asturian Apple Pulp

Fernandez, Elena ; Centeno, Teresa A. ; Stoeckli, Fritz

In: Adsorption Science and Technology, 2001, vol. 19, no. 8, p. 645-653

Asturian apple pulp was carbonised under nitrogen at 400ºC and 750ºC and subsequently activated with CO2 at 750ºC. The resulting active carbon exhibited properties in line with those expected from precursors of vegetable origin, with the carbonisation stage appearing to have only a limited influence on the final porosity. In the case of carbonisation at 400ºC, the initial micropore...

Université de Neuchâtel

The Microporosity of Activated Carbon Fibre KF1500 Assessed by Combined CO2 Adsorption and Calorimetry Techniques and by Immersion Calorimetry

Guillot, André ; Stoeckli, Fritz ; Bauguil Y.

In: Adsorption Science and Technology, 2000, vol. 18, no. 1, p. 1-14

The microporous structure of the activated carbon fibre KF1500 was investigated by applying a new technique as presented here. This was based on a combination of high-pressure CO2 adsorption measurements between 253 K and 353 K with direct measurement of the differential heats of adsorption at 298 K at low and medium coverages. The validity of this approach was tested by using two...