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The preparation of activated carbon fibers (ACFs) by phosphoric acid activation of Nomex [poly(m-phenylene isophthalamide)] polyaramid fibers was studied. Nomex pyrolysis in the presence of phosphoric acid was followed by thermogravimetry and infrared spectroscopy in order to establish the nature of transformations involved. Then, ACFs were obtained by impregnating Nomex with different amounts of...
The bioadsorption of Pb(II), Cd(II), and Cr(VI) using bacteria and activated carbon has been studied. Preliminary studies yielded the chemical and textural characterization of the carbons. The adsorption of bacteria on the activated carbons modified their surface characteristics, reducing the volume of pores and the pH of the point of zero charge, with a resulting increase in the density of the negative...
Adsorption of p-cresol, nitrobenzene and p-nitrophenol on treated and untreated carbons is investigated systematically. The effects of carbon surface chemistry and solution pH are studied and discussed. All adsorption experiments were carried out in pH-controlled solutions to examine the adsorption properties of the adsorption systems where the solutes are in molecular as well as ionic forms. Using...
The aim of this research is to investigate how ammonia treatment of the surface can influence the activity of a viscose-based activated carbon cloth (ACC) for the oxidative retention of H 2 S and SO 2 in humid air at 25 o C. Surface basic nitrogen groups were introduced either by treatment with ammonia/air at 300 o C or with ammonia/steam at 800 o C. The pore...
Two activated carbons containing different amounts of chlorine were obtained by chlorination of an activated carbon prepared from olive stones. Variations in surface physics and chemistry of the samples were studied by N 2 and CO 2 adsorption, mercury porosimetry, TPD, XPS, pH PZC measurements, and by testing their behaviour as catalysts in the decomposition reaction...
Studies on the adsorption of manganese ions from aqueous solution on carbon obtained from a mixture of biomass products indicate the importance of acidic surface oxides for manganese ion adsorption that is predominantly site specific. The results show that oxygen remaining from the raw material participates in the formation of surface oxides and indicates the possibility of controlling the content...
Synthetic activated carbons were prepared by phosphoric acid activation of a styrene-divinylbenzene copolymer in an air atmosphere at various temperatures in the 400-900 o C interval. The carbons were characterized by elemental analysis, cation-exchange capacity measurement, infrared spectroscopy, potentiometric titration, copper adsorption from solution and physical adsorption of N 2...
The impact of chemical treatment (oxidation, reduction) of microporous carbon prepared from plum stones on the structural parameters was analysed using the nitrogen adsorption method. The effects of pre-adsorption of 2,4,6-trinitrotoluene (TNT) and 1-chloro-2,4-dinitrobenzene (CDNB) on the characteristics of the interfacial water layers in the aqueous suspensions of these materials were explored using...
The objective of this work was to increase the understanding of the adsorption competition between an odour compound, 2-methylisoborneol, and natural organic material (NOM). Part I describes the characterisation of six commercially available activated carbons, undertaken using nitrogen gas adsorption, surface titrations, and Fourier transform infrared spectroscopy. The natural organic material (NOM)...
A predominantly microporous activated carbon produced from polyethyleneterephthalate (PET) by physical activation (burn-off 50%) has a BET surface area of 1170 m 2 /g and a total pore volume of 0.625 cm 3 /g. Its surface possesses an amphoteric nature due to the oxygen functionalities present, however, the majority of the groups are basic. The adsorption of phenol and 2,3,4-trichlorophenol...
Nitrogen-containing functional groups were introduced onto the surface of activated carbon fibers (ACF) by activating an ethylene tar pitch-based carbon fiber with ammonia water. The activity of the ACF for the conversion of SO 2 to aq. H 2 SO 4 in the presence of H 2 O and O 2 is significantly higher than that of other commercial ACF studied before. Both the...
Pitch-based activated carbon fibers (ACFs) were modified with nitric acid and sodium hydroxide. Their physicochemical properties were investigated in terms of N 2 adsorption, mass titration, FTIR and metal adsorption. The specific surface area of the ACFs decreased after oxidation with 1 M nitric acid, but the total acidity increased three times compared to the untreated ACFs, resulting in...
Liquid-phase adsorption of phenol, iodine and tannic acid onto commercial grade granular activated carbons and activated carbon fabric was conducted to explore the influence of the mesopore volume and the size of adsorbates on the adsorption capacity. These carbons have different mesopore volumes, while possessing similar surface areas and micropore volumes, which are believed to determine the adsorption...
Carbon adsorbents with different properties were obtained from furfural with variations in the activation reagents and conditions of treatment. They possess insignificant ash and sulfur contents. Pore volume, pore size distribution and the chemical character of the surface of the obtained carbon adsorbent depend on the activation reagent and temperature of treatment. Various oxygen-containing groups...
The activities of activated carbon fibers (ACFs) from ethylene tar pitch and cellulose with various surface areas were examined for the oxidative conversion of SO 2 into aq.H 2 SO 4 in the presence of H 2 O and O 2 , and compared to those of coal tar pitch and polyacrylonitrile based ACFs. Cellulose ACF with surface area of ∼1000 m 2 /g after calcination...
The present study concerns anodic oxidation of activated carbon fibers (ACFs) in order to introduce the surface functional groups onto ACF surfaces. The surface oxides of ACFs were measured using titration and FT-IR spectrometry. As a result, it was observed that the amount of adsorption and the adsorption rate of Cr(VI) increase with increases in the surface oxide groups of ACFs, even though both...
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