Yazar "Demirel, Muhammet" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Application of response surface methodology and central composite design for the optimization of textile dye degradation by wet air oxidation
    (Springer Berlin Heidelberg, 2012) Demirel, Muhammet; Kayan, Berkant
    Background: The present study is aimed at investigating the degradation of azo dye solution of AR 274 by wet air oxidation conditions. The central composite design matrix and response surface methodology were applied in designing the experiments to evaluate the interactive effects of the three most important operating variables. Thus, the interactive effects of oxygen pressure (3.0 to 5.0 MPa), temperature (100°C to 250°C), and time (30 to 90 min) on the degradation of dye were investigated. Results: The predicted values were found to be in good agreement with the experimental values (R2 = 0.9981 and Adj-R2 = 0.9965), which define the propriety of the model and the achievement of CCD in the optimization of WAO process. Conclusions: Intermediates of dye degradation were detected by GC-MS, the possible degradation mechanism for the WAO of dye was discussed, and the probable degradation pathway was deduced. © 2012, Demirel and Kayan; licensee Springer.
  • Küçük Resim
    Öğe
    Degradation of nitroaromatic compounds in subcritical water: application of response surface methodology
    (Desalination Publications, 2017) Kayan, Berkant; Akay, Sema; Gözmen, Belgin; Gizir, A. Murat; Demirel, Muhammet; Kalderis, Dimitrios
    In this study, subcritical water has been used as a medium for degradation of 2,4-dinitrotoluene (2,4-DNT), 4-nitrotoluene (4-NT) and 2-amino-4-nitrotoluene (2-A-4-NT). The effect of temperature, oxidant concentration and time were studied and the optimal combination of reaction parameters was established using response surface methodology in a Box-Behnken design. Of all the parameters examined, temperature showed the most positive effect on the degradation of the nitroaromatic compounds. Optimal reaction conditions were found to be a temperature of 240 degrees C, 210 degrees C and 236 degrees C, time of 180, 178 and 172 min, oxidant concentration of 100, 99.64 and 99.61 mM for 2,4-DNT, 4-NT and 2-A-4-NT, respectively. Since high-temperature was applied, the possibility of formation of subcriticaldegradation products existed; therefore, total amounts of degraded nitroaromatic compounds and formed intermediate products were determined by gas chromatographic-mass spectrometric analysis.