Yazar "Akbal, Feryal" seçeneğine göre listele

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    A comparative study of ozonation, iron coated zeolite catalyzed ozonation and granular activated carbon catalyzed ozonation of humic acid
    (Pergamon-Elsevier Science Ltd, 2017) Gumus, Dilek; Akbal, Feryal
    This study compares ozonation (O-3), iron coated zeolite catalyzed ozonation (ICZ-O-3) and granular activated carbon catalyzed ozonation (GAC-O-3) for removal of humic acid from an aqueous solution. The results were evaluated by the removal of DOC that specifies organic matter, UV254 absorbance, SUVA (Specific Ultraviolet Absorbance at 254 nm) and absorbance at 436 nm. When ozonation was used alone, DOC removal was 21.4% at an ozone concentration of 10 mg/L, pH 6.50 and oxidation time of 60 min. The results showed that the use of ICZ or GAC as a catalyst increased the decomposition of humic acid compared to ozonation alone. DOC removal efficiencies were 62% and 48.1% at pH 6.5, at a catalyst loading of 0.75 g/L, and oxidation time of 60 min for ICZ and GAC, respectively. The oxidation experiments were also carried out using <100 kDa and <50 kDa molecular size fractions of humic acid in the presence of ICZ or GAC. Catalytic ozonation also yielded better DOC and UV254 reduction in both <50 kDa and <100 kDa fractions of HA compared to ozonation. (C) 2017 Elsevier Ltd. All rights reserved.
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    Comparison of Fenton and electro-Fenton processes for oxidation of phenol
    (Elsevier, 2016) Gumus, Dilek; Akbal, Feryal
    This study compares the performance of Fenton and electro-Fenton processes for phenol degradation. The effects of operational parameters such as initial pH, current density, concentration of phenol and hydrogen peroxide on phenol removal was investigated in electro-Fenton process. The degradation and mineralization efficiency increased with an increase in hydrogen peroxide concentration and current density and decreased with an increase in initial phenol concentration and initial pH. It was found that optimum pH, current density and H2O2 concentration were 3.0, 1 mA/cm(2) and 500 mg/L, respectively. Under the optimized conditions, the phenol and chemical oxygen demand (COD) removal efficiency reached 93.32% and 87.5%, respectively. In conventional-Fenton process, the effect of hydrogen peroxide and Fe2+ concentrations on the degradation and mineralization of phenol removal were investigated. The results indicated that the conventional-Fenton process only yields 59% mineralization. An estimation of the operating costs of the processes investigated showed that electro-Fenton was the more economical system to treat the phenol containing wastewater. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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    REMOVAL OF NATURAL ORGANIC MATTER IN DRINKING WATERS AND PREVENTION OF TRIHALOMETHANES FORMATION
    (Yildiz Technical Univ, 2013) Gumus, Dilek; Akbal, Feryal
    Natural waters contain natural organic matter (NOM) ubiquitously as a result of the interactions between the hydrological cycle and the biosphere and geosphere. During the chlorination of raw water, chlorine reacts with natural organic matter to produce disinfection by-products (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs), which are believed to be harmful to human health. Among the most commonly formed DBPs are the THMs. Many countries have focused on DBPs and promulgated regulations and they have regulated THMs. Because of concerns over the health effects of these organic by-products, treatment of drinking waters contain NOM have become inevitable. Natural organic matter in drinking water treatment are removed by conventional coagulation/flocculation, actived carbon adsorption, ozonation, MIEX resin and membrane filtration.
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    Öğe
    Sulardan Humik Asit Gideriminde Demir Kapli Zeolitle (DKZ) Katalitik Ozonlama
    (Nevsehir Haci Bektas Veli Üniversitesi, 2017) Gümüs, Dilek; Akbal, Feryal
    Buçalismada hidrojen peroksit ve demir kapli zeolitle katalitik ozonlama ilehumik asit giderimi incelenmistir. Sonuçlar çözünmüs organik karbon (ÇOK),UV254, SUVA254 (254 nm'de (spesifik Ultraviyole absorbansi) ve renk absorbansi(A436) parametreleri ölçülerek degerlendirilmistir. 60 dakikada pH 6.5'da 10mg/L ozon konsantrasyonunda yalniz basina ozonlama ile %21,4 ÇOK giderimi eldeedilirken demir kapli zeolitle (0,75 mg/L) katalitik ozonlama deneylerinde %62ÇOK giderimi elde edilmis, katalitik ozonlama sistemine 1 mg/L hidrojenperoksit ilavesiyle de (%64,6 ile ) çok hafif bir artis gözlenmistir. katalitikozonlama yalniz basina ozonlamaya kiyasla UV absorplayan aromatik yapinin parçalanmasinakatkida bulunmus ve ÇOK giderimini de iyilestirmistir ancak katalitik ozonlamasistemlerinde ozon konsantrasyonunun artisi giderim veriminde kayda deger birartis saglamamistir.