Ozge Turkay

Optimization and modelling using the response surface methodology (RSM) for ciprofloxacin removal by electrocoagulation.

In this study, response surface methodology (RSM) was used to investigate the effects of different operating conditions on the removal of ciprofloxacin (CIP) by the electrocoagulation (EC) with pure iron electrodes. Box-Behnken design was used for the optimization of the EC process and to evaluate the effects and interactions of process variables such as applied current density, process time, initial CIP concentration and pH on the removal of CIP by the EC process. The optimum conditions for maximum CIP removal (86.6%) were found as pH = 4; Co = 5 mg.L(1-); Id = 4.325 mA.cm(2-); tprocess = 10 min. The model adequacy and the validity of the optimization step were confirmed with additional experiments which were performed under the proposed optimum conditions. The predicted CIP removal as 86.6% was achieved at each experiment by using the optimum conditions. These results specify that the RSM is a useful tool for optimizing the operational conditions for CIP removal by the EC process.

Experimental and theoretical study on catalytic ozonation of humic acid by ZnO catalyst

ABSTRACT Ozonation and catalytic ozonation of humic acid (HA) in the presence of ZnO were examined in a batch scale reactor. The degradation of HA by catalytic ozonation was found to be much more effective than ozonation alone. The quantum chemistry calculations showed that the reaction of the O3 disproportionation on the surface of ZnO corresponds to the barrierless mechanism. The activation energy of the transition state formation was −5.25 eV. The active oxygen atom formed on the surface of ZnO was found as interacting with both water molecules and dissolved organic molecules, which might lead to further oxidizing reactions.

Kanser İlaçları Atıksularının Elektrooksidasyon Prosesi ile Giderimi

Bu calismada, kanser ilaclari ureten fabrikadan temin edilen Metotraksat (MTX), Iyoheksol (IOX) ve Kapasitabin (CPC) iceren atiksularin, elektrooksidasyon prosesi ile giderimi calisilmistir. Anodik oksidasyon karisik metal oksit (KMO) (Ti/IrO2-Ru, Ti/Ru, Ti/IrO2-Ru (EC 300)) ve bor katkili elmas (BKE) elektrotlar kullanilarak saglanmistir. Karisik metal oksit elektrotlar ile MTX, CPC ve IOX icin sirasiyla %56,8, %35,4 ve %52 giderim verimi elde edilmistir. Bor katkili elmas elektrot ile yurutulen elektrooksidasyon prosesi ile elde edilen giderim verimleri MTX, CPC ve IOX icin sirasiyla %86,1, %99,0 ve %53,4 olarak tespit edilmistir. Daha yuksek gerilim potansiyeline sahip BKE elektrotlar, elektrooksidasyon prosesinde kullanilan KMO elektrot materyallerine gore daha yuksek giderim verimi saglamistir.

Elektro-oksidasyon Prosesi ile Methotrexate Gideriminin Yüzey Yanıt Metodu ile Optimizasyonu

Atik sularda bulunan ilac kalintilari sucul ortam uzerinde oldukca toksik etkilere sebep olmalari nedeniyle birincil kirleticiler kapsaminda degerlendirilmeye baslanmistir. Atik sularda ve yuzeysel sularda ilac kalintilarinin konsantrasyonlari µg/L ve ng/L gibi cok dusuk seviyelerde olmasina ragmen kronik etkileri nedeniyle arastirma yapilmasina gerek duyulmaktadir. Bu toksik kimyasallar, biyo-bozunur olmadiklarindan dolayi su ve atik sulardan gidermek icin klasik biyolojik aritma yontemleri yetersiz kalmaktadir. Bu yuzden ileri aritma yontemlerinin gelistirilmesi oldukca onemlidir. Ozellikle elektrokimyasal aritma yontemleri bu tur kimyasallari aritmak icin oldukca basarili yontemler olarak dikkat cekmektedir. Bu calismada, Methotrexate (MTX) adli etken maddenin elektro-oksidasyon yontemi ile aritimi calisilmistir. MTX uzun yillardir kanser tedavisinde yaygin olarak kullanilan bir kimyasaldir. Calismada, Ti/IrO 2 /RuO 2 karisik metal oksit elektrotu kullanilmistir. Optimum calisma sartlarinin belirlenmesi amaciyla yuzey yanit metodu (YYM) kullanilarak elektro-oksidasyon metodunun MTX giderimi icin optimizasyonu yapilmistir.

Electrochemical treatment of anti-cancer drug carboplatin on mixed-metal oxides and boron doped diamond electrodes: Density functional theory modelling and toxicity evaluation

This study represents the electrooxidation of anti-cancer drug carboplatin (CrbPt) with different mixed metal oxide (MMO) and boron doped diamond (BDD) electrodes. The most effective anode was found as Ti/RuO2 with the complete degradation of CrbPt in just 5min. The effect of applied current density, pH and electrolyte concentration on CrbPt degradation has been studied. The degradation of CrbPt significantly increased at the initial stages of the process with increasing current density. However, further increase in current density did not affect the degradation rate. While complete degradation of CrbPt was provided at pH 7, the degradation rates were 49% and 75% at pH 9 and 4, respectively. Besides, increasing supporting electrolyte (Na2SO4) concentration provided higher degradation rate but further increase in Na2SO4 concentration did not provide higher degradation rate due to excess amount of SO4-2. According to the DFT calculations, the formation of [Pt(NH3)2 (H2O)2]2+ and [Pt(NH3)2 (OH)2] takes place with molecular weights of 265 and 263gmol-1, respectively. Toxicity of treated samples at BDD and Ti/RuO2 electrodes has been also evaluated in this study. The results showed that Ti/RuO2 anode provided zero toxicity at the end of the process.

Degradation of Toxic Indigo Carmine Dye by Electrosynthesized Ferrate (VI)

Response surface methodology was applied for optimizing indigo carmine (IC) dye removal by electrochemically produced ferrate (VI). Box-Behnken design was employed in this study, and design parameters were pH, Fe (VI) dose and initial dye concentration (C o ). R 2 and adjusted R 2 values were very high that indicated very good accuracy for the employed model. Optimum operational conditions were: 4.08-7.69 for pH, 24-118.83 mg/L for Fe (VI) dose and 60.68-99.13 mg/L for complete removal of IC. Produced by electrochemical method Ferrate (VI) provides high effectiveness for IC dye-containing synthetic wastewater.