New books - Active carbon: Manufacture, properties, and applications

Smíšek, Milan; Černý, S.

doi:10.1021/ac50160a026

Cited by 61 publications

(66 citation statements)

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“…Although the adsorption properties of activated carbons have been extensively studied, 2 ' 3 the optical and the electrical properties of activated carbons have not been investigated with equal vigor. So far as optical spectroscopy is concerned, infrared experiments have been carried out for activated carbon, 4 ' 5 but only to the extent of determining the surface species and their physisorption and chemisorption characteristics. Our Raman study of this material, however, yields information about the intrinsic crystalline structure of the carbon system and helps to elucidate the electrical transport results.…”

Section: Introductionmentioning

confidence: 99%

Raman scattering and electrical conductivity in highly disordered activated carbon fibers

et al. 1993

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Because of their unusually large specific surface area (SSA), Activated Carbon Fibers (ACF's) have a huge density of micropores and defects. The Raman scattering technique and low-temperature dc electrical conductivity measurements were used as characterization tools to study the disorder in ACF's with SSA ranging from 1000 m 2 /g to 3000 m 2 /g. Two peaks were observed in every Raman spectrum for ACF's and they could be identified with the disorder-induced peak near ~1360 cm" 1 and the Breit-Wigner-Fano peak near -1610 cm" 1 associated with the Raman-active E 2g2 mode of graphite. The graphitic nature of the ACF's is shown by the presence of a well-defined graphitic structure with L a values of 20-30 A. We observed that the Raman scattering showed more sensitivity to the precursor materials than to the SSA of the ACF's. From 4 K to room temperature, the dc electrical resistivity in ACF's is observed to follow the exp[(r o /T) 1/2 ] functional form and it can be accounted for by a charge-energy-limited tunneling conduction mechanism. Coulomb-gap conduction and n-dimensional (n =£ 3) variable-range hopping conduction models were also considered but they were found to give unphysical values for their parameters.

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Section: Introductionmentioning

confidence: 99%

Raman scattering and electrical conductivity in highly disordered activated carbon fibers

et al. 1993

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“…It is believed that the carbonization/activation step proceeds simultaneously with the chemical activation. It is also believed that the chemical incorporated to the interior of the precursor particles reacts with the products resulting from the thermal decomposition of the precursor, reducing the evolution of volatile matter and inhibiting the shrinking of the particle; in this way the conversion of the precursor to carbon is high, and once the chemical is eliminated after heat treatment, a large amount of porosity is formed [164]. Chemical activation is preferred over physical activation owing to the lower temperature and shorter time needed for activating the material.…”

Section: Methods Of Preparation and Activation Of Activated Carbonmentioning

confidence: 99%

Low-cost Adsorbents Derived from Agricultural By-products/Wastes for Enhancing Contaminant Uptakes from Wastewater: A Review

Sulyman

Namieśnik

Gierak

2017

Pol. J. Environ. Stud.

201

112

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A major threat to the comfort of human life has been imposed by increased industrialization and urbanization. The generation and disposal of huge amounts of toxic materials and pollutants have heavily contaminated our environment. Some Organics such as synthetic dyes (SD) and heavy metals (HM) are becoming increasingly prevalent as the most dangerous pollutants in soil and surface water environments. They are causing great concern worldwide due to their toxicity to many life forms.Environmentally friendly utilization of agricultural by-products/waste materials either as raw materials or in production of so-called activated carbons (AC) is an important issue. Because it is apparent from our literature review that the main factors characterizing these materials are their affordability, local availability, and efficiencies in removing many unwanted toxics and pollutants, they therefore could be utilized instead of more conventional but expensive adsorbent materials, particularly in developing countries where many industries lack appropriate individual sewage treatment systems; even where they exist, they lack satisfactory functioning and maintenance because of the lack of good budgets.A number of case studies are supplied in this review. These case studies have pointed to the efficient removal of SD/HM ions from aqueous solutions by the agricultural by-products/wastes in the form of a raw material, signifying spent tea leaves (STL) as a good example. Besides, the efficient removal of such ions by AC produced from these agricultural by-products/wastes has also been given in detail, suggesting a variety of AC agricultural by-products/wastes sources. Both kinds are widely used adsorbents in the treatment of wastewaters. Our review has shown that these adsorbents are characterized by many exceptional physical and chemical features that make them widely used adsorbents in the treatment of wastewaters. The adsorption efficiencies by these substances were also affected by the characteristics of AC, which depend on the physical and chemical properties of the precursor (i.e., agricultural by-products/wastes) as well as on the activation method applied, which is either chemical or physical. The structural properties of the resulting

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“…The production of ACF is via a thermochemical process involving steps of carbonization and activation at high temperatures, which promotes thermal decomposition of the carbon structure in the presence of oxidizing agents (Smísek and Cerny 1970, Gonzales et al 1995, Pastor et al 1999.…”

Section: Activated Carbon Fibersmentioning

confidence: 99%

“…In cases where the presence of oxygen is less than 8%, the stabilization results in a low amount of carbon (approximately 12%), leading to fiber deterioration. The stabilization of viscose in an air atmosphere increases the yield during the carbonization step to the range of 18 to 24% (Smísek and Cerny 1970, Gonzales et al 1995, Pastor et al 1999.…”

Section: Activated Carbon Fibersmentioning

confidence: 99%

Adsorption of SOX and NOX in activated viscose fibers

Plens

Monaro

Coutinho

2015

An. Acad. Bras. Ciênc.

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SO x and NO x are emissions resulting from combustion processes and are the main agents that contribute to the formation of acid rain, which causes harm to humans and the environment. Several techniques for removing these pollutants are applied in i.e. oil refineries, thermoelectric that use petroleum oils and vehicular pollution. Among these, highlight the adsorption of contaminants by the usage of activated carbon fibers and activated carbon, which are characterized by high surface area and uniform distribution of pores, providing appropriate conditions for application in processes of removing environmental contaminants. In the present work, activated viscose fibers (AVF) were prepared and applied in adsorption experiments of NO and SO 2 . The materials produced showed high values of surface area, with a predominance of micro pores with diameters in the range of 1.0 nm. The AVF had satisfactory performance in the removal of contaminants and are compatible with other synthetic fibers. Thus, the formation of active sites of carbon provides contaminants adsorption, demonstrating that carbon fibers cloth can be applied for the removal of pollutants.

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New books - Active carbon: Manufacture, properties, and applications

Cited by 61 publications

References 0 publications

Raman scattering and electrical conductivity in highly disordered activated carbon fibers

Raman scattering and electrical conductivity in highly disordered activated carbon fibers

Low-cost Adsorbents Derived from Agricultural By-products/Wastes for Enhancing Contaminant Uptakes from Wastewater: A Review

Adsorption of SOX and NOX in activated viscose fibers

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