Yazar "Akcay, Guelten" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    The equilibrium and kinetics studies of flurbiprofen adsorption onto tetrabutylammonium montmorillonite (TBAM)
    (Elsevier, 2009) Akcay, Guelten; Kilinc, Ersin; Akcay, Mehmet
    In this study, the adsorption of flurbiprofen (FBP, is a non-steroidal anti-inflammatory drug) on tetrabutylammonium (TBA)-montmorillonite (TBAM) was studied. The adsorption kinetics was interpreted using pseudo-first-order kinetic model and pseudo-second-order kinetic model. The pseudo-second-order model provides the best correlation with the experimental data ofTBAM adsorption. The adsorption data could be fitted with Freundlich and Dubinin-Radushkevich equation to find the characteristic parameters of each model. The adsorption energy, E and adsorption capacity (q(m)) for organic compound adsorbing on organo montmorillonite were estimated using the Dubinin-Radushkevich (D-R) equation. From DR isotherm, it was also determined that the type of adsorption can be considered as physical adsorption mechanism. Thermodynamic parameters (Delta g(a)=-1.897 and -3.456 kJ/mol, Delta h(a)=-28.722 and -30.948 kJ/mol, Delta s(a)=-0.0964 and -0.0989 kJ/mol K for 298 and 313 K, respectively) were calculated by a new approximate from the adsorption isotherms of FBP on organo montmorillonite. The first order and second order coefficients (K-1ads = 2.50 and 14.30 mmol/g min, K-2ads = 0.0130 and 0.03120 g min/mu mol, respectively) were obtained at 298 and 313 K, respectively. (C) 2008 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    Removal of nicotine and its pharmaceutical derivatives from aqueous solution by raw bentonite and dodecylammonium-bentonite
    (Natl Inst Science Communication, 2008) Akcay, Guelten; Yurdakoc, Kadir
    Dodecylammonium bentonite (DAB) and bentonite (B) were used as sorbents for nicotine (N), nicotinic acid (NA), isonicotinic acid (INA), nicotinic acid hydrazide (NH), and iso-nicotinic acid hydrazide (INH). The obtained data were modeled according to Freundlich and Dubinin-Raduslikevich adsorption isotherms. Sorption energy (E) and adsorption capacity (q(m)) for N and its derivatives adsorbing on DAB and raw B were estimated using Dubinin-Raduslikevich (D-R) equation. Sorption energy of N and its pharmaceutical derivatives on DAB and raw B increased in order of NA < INA < N=INH < NH and INI-I < NH < N < NA < INA, respectively.
  • [ X ]
    Öğe
    Synthesis of clay-based superabsorbent composite and its sorption capability
    (Elsevier Science Bv, 2009) Bulut, Yasemin; Akcay, Guelten; Elma, Duygu; Serhatli, I. Ersin
    A novel superabsorbent composite was synthesized by copolymerization reaction of partially neutralized acrylic acid (AA) on bentonite micropowder using N,N'-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator in aqueous solution. The superabsorbent composite (SAC) was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The water retention test of SAC was also performed. The water absorbency of SAC synthesized was found to be 352 and 110 g H(2)Og(-1) in distilled water and 0.2% NaCl, respectively. Sorption capacity of SAC was investigated for heavy metal ions (HMI) using Langmuir and Freundlich model of adsorption. The maximum adsorption capacity (Q(m)) of HMI onto the bentonite-based SAC from their solution was 1666.67, 270.27, 416.67 and 222.22 mg g(-1) for Pb(II). Ni(II), Cd(II) and Cu(II), respectively. All results suggested that SAC offers excellent potential for HMI removal from contaminated water. (C) 2009 Elsevier B.V. All rights reserved.