Yazar "Saygili, Guelbahar Akkaya" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    Chemical modification of a cellulose-based material to improve its adsorption capacity for anionic dyes
    (Taylor & Francis Inc, 2017) Saygili, Guelbahar Akkaya; Guzel, Fuat
    A cellulosic material was modified to enhance its anionic dye adsorption capacity. The chemically modified cucumber peel was characterized by FTIR, SEM, TGA, XRD, proximate and ultimate analyses, and pH(zpc) measurements, and was used for the removal of toxic textile dyes. The kinetic data followed the pseudo-first-order model. The isotherm data fitted to the Langmuir model giving maximum capacities of 95.24 and 129.87mg g(-1) for Reactive Black 5 and Direct Blue 71, respectively. Thermodynamic parameters suggest that the process is spontaneous and endothermic. The recovery of the adsorbed dyes was achieved by NH3 and NaOH solutions.
  • [ X ]
    Öğe
    Hydrothermal conversion of lignocellulosic waste to value-added biomaterial for high-performance contaminant removal: Focusing on synthesis route and uptake mechanism
    (Elsevier Science Sa, 2022) Saygili, Guelbahar Akkaya; Saygili, Hasan
    In this paper, a novel carbonaceous material was successfully synthesized from lignocellulosic waste by a green conversion technology. Pomegranate (Punica granatum L.) pulp waste (PPW) was transformed to hydrochar (PPWHC) through hydrothermal carbonization (HTC) and the key affecting factors including the holding temperature (HT; 180-220 C) and holding time (Ht; 6-24 h) were explored. The physico-chemical, structural, functional, morphological properties were discussed by C-13 NMR, BET, XRD, XPS, SEM/EDX, FT-IR, Raman, and CHNS elemental analysis. Based on the carbon content, higher heating value and energy densification values, a HT of 220 C and Ht of 12 h were determined as optimal operational conditions. Further, PPWHC was utilized for the removal of Rhodamine B (RhB) in batch mode. The maximum uptake was 121.95 mg/g at 323 K. Adsorption thermodynamics parameters were calculated. Additionally, reusability studies demonstrated that PPWHC exhibited a superior removal performance for RhB after five consecutive sorption/desorption cycles.
  • [ X ]
    Öğe
    Surface modification of black tea waste using bleaching technique for enhanced biosorption of Methylene blue in aqueous environment
    (Taylor & Francis Inc, 2018) Saygili, Hasan; Saygili, Guelbahar Akkaya; Guzel, Fuat
    In the current study, the bleaching technique with sodium hypochlorite (NaOCl) was used to modify black tea waste (BTW) for enhancing its biosorption performance of Methylene blue (MB) dye. Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), (thermogravimetric-differential thermal analysis) TG/DTA, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis and surface acidity and pH(pzc) measurements were employed to determine the textural structure and surface chemistry of the raw and NaOCl-modified BTW. The results indicate that after using bleaching modification, the MB biosorption capacity of BTW was enhanced approximately threefold. Maximum biosorption capacities were found as 125 mg g(-1) for BTW and 416.67 mg g(-1) for bleached black tea waste (BBTW).