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  • Küçük Resim
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    Degradation of poplar and spruce wood chips using alkaline glycerol
    (TAYLOR & FRANCIS INC, 2005) Demirbas, A; Celik, A
    Poplar and spruce wood chips were degraded by using glycerol as a solvent and alkaline glycerol with and without alkali media at different temperatures: 440, 450, 460, 470, 480, 490, and 500 K, then the results were compared with the other organic solvent systems. The degradation reactions were mainly occurred as delignification and partly decomposition of cellulose. The effects of solvent, temperature, catalyst, delignification time and wood species on the yield of delignification were discussed. Major byproducts from delignification rections of wood chips include lignin degradation products. Lignin and its degradation products can be utilized as fuels.
  • Küçük Resim Yok
    Öğe
    Is serum matrix metalloproteinase tissue inhibitor type 1 levels higher in dipper hypertensive patients?
    (LIPPINCOTT WILLIAMS & WILKINS, 2005) Onrat, E; Serteser, M; Celik, A; Kaya, D; Kahraman, A; Koken, T; Alpaslan, M.
    [Abstract not Available]
  • Küçük Resim
    Öğe
    Removal of heavy metal ions from aqueous solutions via adsorption onto modified lignin from pulping wastes
    (TAYLOR & FRANCIS INC, 2005) Celik, A; Demirbas, A
    The aim for this research is to study inexpensive and effective metal ion adsorbents from biomass sources of modified lignin to offer these adsorbents as replacements for existing commercial materials. The initial concentrations were increased up to 12.7 ppm for Pb2+, Cd2+, and Zn2+ in order to reach the plateau values which represent saturation of the active points which are available for interaction with metal ions on the lignin samples. The maximum adsorption capacities are 11.3, 17.5, and 7.7 mg per g of the lignin for Zn2+, Pb2+, and Cd2+, respectively. The maximum adsorption capacity is higher than 20 mg per g of the lignin for Cu2+ ion. The maximum adsorption percentage is 96.7 for Pb2+ for 4 h at 330 K and is 95.0 for Zn2+ for 10 h at 290 K. The adsorption of all heavy metal ions first increases with pH and almost reaches a plateau value around 4.0 for Cu2+, 4.5 for Zn2+, 5.0 for Pb2+. High adsorption at higher pH values implies that metal ions interact with lignin by ion exchange.