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  • [ X ]
    Öğe
    Oxygen plasma treated petroleum coke adsorbent: characterization, synthesis, mechanism, and application for enhancement of malachite green removal
    (Taylor & Francis Ltd, 2023) Saka, Cafer; Olcenoglu, Gulten Elci; Sahin, Omer
    The main purpose of this study is to modify the petroleum coke sample (PCS) for the first time by oxygen plasma treatment (OPT) as an alternative to the existing surface modification methods and to remove the malachite green (MG) colourant from the aqueous medium with the obtained adsorbent. The changes caused by OPT on the PCS surface were observed with photoelectron spectroscopy(XPS), infrared spectroscopy(FTIR), scanning electron microscopy(SEM) and surface area analysis. The atomic percentages of the oxygen for the raw and plasma treated sample were found at 4.021% and 9.363%, respectively. In the light of the obtained results, it was seen that new active groups containing oxygen on PCS increased by OPT. The functional groups such as -COOH, -C-O and -C = O with oxygen plasma on PCS were interpreted to the mechanism possible. The adsorption capacity of MG was 66.66 mg/g at 30 degrees C for the PCS treated with oxygen plasma. The Delta G, Delta H and Delta S values were 168.76 kJ/mol, 84,49 kJ/mol and -278,19 J/mol K.
  • [ X ]
    Öğe
    Surface modification of coal sample with oxygen plasma treatment
    (Taylor & Francis Ltd, 2020) Olcenoglu, Gulten Elci; Saka, Cafer
    In this study, it was aimed to modify the coal sample (CS) with oxygen plasma treatment for the first time. The plasma treatment process on the CS was evaluated by malachite green (MG) dye adsorption. The oxygen plasma treatment on the surface of CS was analysed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption. It was found from the analysis results that the number of oxygenated groups on the CS surface increased. The mechanism for oxygen plasma on the CS was evaluated. It was concluded that oxygen plasma treatment was suitable for surface modification of the CS and that the adsorbent obtained was effective for MG adsorption.