Yazar "Gholami, Peyman" seçeneğine göre listele

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  • Küçük Resim
    Öğe
    Sonocatalytic degradation of an anthraquinone dye using TiO2-biochar nanocomposite
    (ELSEVIER SCIENCE BV, 2017) Khataee, Alireza; Kayan, Berkant; Gholami, Peyman; Kalderis, Dimitrios; Akay, Sema
    TiO2-biochar (TiO2-BC) nanocomposite was synthesized by sol-gel method. The characteristics of the prepared nanocomposite were examined using X-ray fluorescence, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and N-2 adsorption-desorption analysis. The performance of synthesized TiO2-BC nanocomposite as efficient sonocatalyst was studied for the degradation of Reactive Blue 69 (RB69). Sonocatalytic degradation of RB69 in the presence of TiO2-BC nanocomposite could be explained by the mechanisms of hot spots and sonoluminescence. The optimized values for main operational parameters were determined as pH of 7, TiO2-BC dosage of 1.5 g/L, RB69 initial concentration of 20 mg/L and ultrasonic power of 300 W. Furthermore, the effect of (OH)-O-center dot, h(+) and O-2(center dot-) scavengers on the RB69 degradation efficiency was studied. Gas chromatography-mass spectroscopy analysis was used to identify intermediate compounds formed during the RB69 degradation. The results of repeated applications of TiO2-BC in the sonocatalytic process verified its stability in long-term usage.
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    Sonocatalytic degradation of Reactive Yellow 39 using synthesized ZrO2 nanoparticles on biochar
    (ELSEVIER SCIENCE BV, 2017) Khataee, Alireza; Kayan, Berkant; Gholami, Peyman; Kalderis, Dimitrios; Akay, Sema; Dinpazhoh, Laleh
    ZrO2-biochar (ZrO2-BC) nanocomposite was prepared by a modified sonochemical/sol-gel method. The physicochemical properties of the prepared nanocomposite were evaluated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray fluorescence, Fourier transform infrared spectroscopy and Brtmauer-Emmett-Teller model. The sonocatalytic performance of ZrO2-BC was investigated in sonochemical degradation of Reactive Yellow 39 (RY39). The high observed sonocatalytic activity of the ZrO2-BC sample could be interpreted by the mechanisms of sonoluminescence and hot spots. Parameters including ZrO2-BC dosage, solution pH, initial RY39 concentration and ultrasonic power were selected as the main operational parameters and their influence on RY39 degradation efficiency was examined. A 96.8% degradation efficiency was achieved with a ZrO2-BC dosage of 1.5 g/L, pH of 6, initial RY39 concentration of 20 mg/L and ultrasonic power of 300 W. In the presence of (OH)-O-center dot radical scavengers, RY39 degradation was significantly inhibited, providing evidence for the key role of hydroxyl radicals in the process. The sonodegradation intermediates were identified using gas chromatography-mass spectroscopy and the possible decomposition route was proposed.
  • Küçük Resim
    Öğe
    Synthesis of ZrO2 nanoparticles on pumice and tuff for sonocatalytic degradation of rifampin
    (Elsevier Science Bv, 2018) Khataee, Alireza; Gholami, Peyman; Kayan, Berkant; Kalderis, Dimitrios; Dinpazhoh, Laleh; Akay, Sema
    ZrO2-pumice and ZrO2-tuff nanocomposites were synthesized via a modified sol-gel method and used as efficient catalysts for sonocatalytic degradation of rifampin (RIF). The physico-chemical properties of the prepared catalysts were examined using XRF, SEM, EDX, FT-IR and BET analyses and compared to pure pumice and tuff samples. Subsequently, the efficacy of catalysts in degradation of RIF was assessed under various experimental conditions. Both ZrO2-pumice and ZrO2-tuff (1.5 g L-1) exhibited promising catalytic activity for sonocatalytic degradation of RIF at its initial concentration of 20 mg L-1, natural pH and under ultrasonic irradiation power of 300 W. In this condition, about 95% and 83% of RIF was removed through US/ZrO2-pumice and US/ZrO2-tuff processes, respectively. Furthermore, the influence of the addition of a number of scavengers, enhancers and gases on the degradation of RIF was studied. The pronounced degradation effectiveness of the catalysts under ultrasound irradiation could be assigned to their synergetic ability to produce reactive species and subsequent radical reactions. The intermediate products formed in the solution from degradation of RIF were also identified and a decomposition pathway was proposed using GC-MS, COD, TOC and IC analyses.