2,070 research outputs found

    Interaction Mechanism of Benzene and Phenanthrene in Condensed Organic Matter: Importance of Adsorption (Nanopore-Filling)

    Get PDF
    Although microporosity and surface area of natural organic matter (NOM) are crucial to mechanistic evaluation of the sorption process for nonpolar organic contaminants (NOCs), they have wrongly been estimated by the N2 adsorption technique. Nuclear magnetic resonance spectroscopy (13C NMR), and benzene, carbon dioxide, and nitrogen adsorption techniques were used to characterize structural and surface properties for different condensed NOM samples, which were related to the sorption behavior of phenanthrene (Phen). It was found that the revised Freundlich model by taking the chemical activity into account can well describe the isotherms for benzene and Phen. The benzene and Phen adsorption volumes for the coal samples are similar to or lower than the CO2-nanopore volumes. Adsorption volumes of both benzene and Phen are significantly related to the aliphatic carbon structure, and their correlation lines are nearly overlapped, suggesting that the nanopore filling for Phen and benzene on the investigated samples is the dominating mechanism, and also is not affected by water molecules. The entrapment of benzene and/or the pore deformation in the NOM nanopore are likely responsible for the observed hysteresis of benzene. The above results demonstrate that Phen and benzene adsorption on the condensed NOM is closely associated with the aliphatic carbon structure of the investigated samples

    Interaction Mechanism of Benzene and Phenanthrene in Condensed Organic Matter: Importance of Adsorption (Nanopore-Filling)

    Get PDF
    Although microporosity and surface area of natural organic matter (NOM) are crucial to mechanistic evaluation of the sorption process for nonpolar organic contaminants (NOCs), they have wrongly been estimated by the N2 adsorption technique. Nuclear magnetic resonance spectroscopy (13C NMR), and benzene, carbon dioxide, and nitrogen adsorption techniques were used to characterize structural and surface properties for different condensed NOM samples, which were related to the sorption behavior of phenanthrene (Phen). It was found that the revised Freundlich model by taking the chemical activity into account can well describe the isotherms for benzene and Phen. The benzene and Phen adsorption volumes for the coal samples are similar to or lower than the CO2-nanopore volumes. Adsorption volumes of both benzene and Phen are significantly related to the aliphatic carbon structure, and their correlation lines are nearly overlapped, suggesting that the nanopore filling for Phen and benzene on the investigated samples is the dominating mechanism, and also is not affected by water molecules. The entrapment of benzene and/or the pore deformation in the NOM nanopore are likely responsible for the observed hysteresis of benzene. The above results demonstrate that Phen and benzene adsorption on the condensed NOM is closely associated with the aliphatic carbon structure of the investigated samples

    New contributions to the knowledge of Chinese flea beetle fauna (III): revision of Meishania Chen & Wang with description of five new species (Coleoptera: Chrysomelidae: Galerucinae)

    Get PDF
    The flea beetle genus Meishania Chen & Wang is revised and five new species—M. cangshanensis sp. nov., M. flavipen- nis sp. nov., M. fulvotigera sp. nov., and M. sichuanica sp. nov. from China and M. bhutanensis sp. nov. from Bhutan— are described. All species of Meishania are illustrated and a key to species is provided

    Penghou, a new genus of flea beetles from China (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

    Get PDF
    A new genus (Penghou) with a single new species (P. yulongshan) from Yunnan Province in China is described and illus- trated. It is compared to Hespera Weise, Hesperomorpha Ogloblin, Laotzeus Chen, Luperomorpha Weise, Mandarella Duvivier, Omeiana Chen, Stenoluperus Ogloblin and Taiwanohespera Kimoto

    Penghou, a new genus of flea beetles from China (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

    Get PDF
    A new genus (Penghou) with a single new species (P. yulongshan) from Yunnan Province in China is described and illus- trated. It is compared to Hespera Weise, Hesperomorpha Ogloblin, Laotzeus Chen, Luperomorpha Weise, Mandarella Duvivier, Omeiana Chen, Stenoluperus Ogloblin and Taiwanohespera Kimoto
    corecore