Comparative degradation of 5-fluorouracil in aqueous solution by using H2O2-modified subcritical water, photocatalytic oxidation and electro-Fenton processes

2022 ◽  
Vol 204 ◽  
pp. 111898
Esra Kulaksız ◽  
Berkant Kayan ◽  
Belgin Gözmen ◽  
Dimitrios Kalderis ◽  
Nihal Oturan ◽  
1999 ◽  
Vol 39 (10-11) ◽  
pp. 225-230 ◽  
Jong-Nan Chen ◽  
Yi-Chin Chan ◽  
Ming-Chun Lu

The decomposition of chlorophenols in aqueous solution with UV-illuminated TiO2 suspensions in the presence of manganese ions was studied. It was found that the removal rate of chlorophenols would be the highest at pH 3 in the presence of 1.18×10−4 M manganese ion. The effect of ionic strength on the 2-CP decomposition can be ignored in the range from 0.1 to 0.005 M for NaClO4. This study is also to explore the relationship between the adsorption rate and reaction rate. Results showed that the more the adsorption rate the more the decomposition rate for the three chlorophenols. Manganese ions can increase the photocatalytic oxidation of 2-chlorophenol in terms of DOC. The relationship between temperature and reaction rate for 2-CP is k = 0.0043T - 1.2146.

2005 ◽  
Vol 7 (2) ◽  
pp. 79-85 ◽  
Ignazio Renato Bellobono ◽  
Franca Morazzoni ◽  
Riccardo Bianchi ◽  
Emilia Simona Mangone ◽  
Rodica Stanescu ◽  

Kinetics of photocatalytic oxidation of methane, ethane,n-heptane,n-decane, andn-dodecane, to yield intermediates, and photomineralisation of intermediates, to yield carbon dioxide and water, was studied in aqueous solution, by a laboratory-scale photoreactor and photocatalytic membranes immobilizing30±3wt.% ofTiO2, in the presence of stoichiometric hydrogen peroxide as oxygen donor. The whole volume of irradiated solution was4.000±0.005L, the ratio between this volume and the geometrical apparent surface of the irradiated side of the photocatalytic membrane was3.8±0.1cm, and the absorbed power 0.30W/cm (cylindrical geometry). A kinetic model was used, by which mineralisation of substrate toCO2was supposed to occur, by kinetic constantsk1, through one single intermediate, mediating the behaviour of all the numerous real intermediates formed in the path from the substrate toCO2(kinetic constants of formation of the latter beingk2). A competitive Langmuirian adsorption of both substrate and “intermediate” was also supposed to be operative, as expressed by apparent adsorption constantsk1andk2, possessing a, partly at least, kinetic significance. By Langmuir-Hinshelwood treatment of initial rate data, starting values of thekandKcouples were obtained, from which, by a set of differential equations, the final optimised parameters,k1andk1,k2andK2, were calculated, able fit the whole photomineralisation curve, and not only its initial segment, as the Langmuirian parameters do. The parameters of present work are critically compared with those obtained in two preceding set of studies relative ton-alkanoic acids and ton-alkanols. They are interpreted on the basis of a closer behaviour of hydrocarbons to alkanols, from the photocatalytic point of view, than to carboxylic acids are. Discussion of limiting effective quantum yields, and their comparison with maximum, theoretical values, are also carried out.

2020 ◽  
Vol 5 (6) ◽  
pp. 1912-1918
Maria V. Sherstoboeva ◽  
Anastasiya V. Bavykina ◽  
Konstantin A. Bolgaru ◽  
Yury M. Maksimov ◽  
Francesc Sastre ◽  

2012 ◽  
pp. 33-40
Norzita Ngadi ◽  
Aisyah Nosri

In this study, the ability of titania dioxide nanoparticles (TiO ) to remove methyl orange dye in aqueous solution was investigated. The effects of TiO dosage (i.e. 0.4, 0.8, 1.2, 1.6 and 2 g), pH (i.e. 4, 6, 7, 8, 10 and 12) temperature (30, 40 and 50°C) and light source (i.e. UV, sunlight and dark room) on the removal of methyl orange dye were studied. The experiments were conducted under the UV light irradiation with the presence of air bubbling. The samples were analyzed using UV-vis spectrophotometer at wavelength of 467 nm. From this study, it was found that the TiO dose, pH, temperature and the presence of light had a strong effect on the removal of dye. The removal of dye was optimum at TiO loading of 2.0 g, pH of 4, temperatureof 30°C and under UV light condition. Dalam kajian ini, kebolehupayaan titanium dioksida (TiO ) untuk menyingkirkan pewarna metil oren daripada larutan telah dikaji. Kesan-kesan dos TiO (iaitu 0.4, 0.8, 1.2, 1.6 and 2 g ), pH (iaitu 4,6,8,10 dan 12) suhu (iaitu 30, 40 and 50°C) dan sumber cahaya (UV, cahaya matahari dan bilik yang gelap) terhadap penyingkiran pewarna metil oren telah dikaji. Eksperimen telah dijalankan di bawah radiasi UV dengan kehadiran oksigen terlarut. Sampel telah dianalisa menggunakan UV-vis spektrofotometer dengan panjang gelombang 467 nm. Daripada kajian ini, telah didapati bahawa dos TiO , pH, suhu dan kehadiran cahaya memberikan kesan yang ketara terhadap penyingkiran pewarna. Penyingkiran pewarna adalah paling optimum pada dos TiO, 2 g, pH, 4, suhu, 30°C dan dibawah cahaya UV.

Wilson Augusto Lima Venancio ◽  
Caio Rodrigues-Silva ◽  
Mylena Spina ◽  
José Roberto Guimarães

Abstract This study presents a comparison of three methods for TiO2-N synthesis that were applied in the photocatalytic oxidation of the fluoroquinolones (FQs) ciprofloxacin, ofloxacin, and lomefloxacin in aqueous solution. The TiO2-N bandgap is small enough to allow the use of solar energy in the photocatalytic oxidation (PCO) reactions. The TiO2 doped by a sol-gel method with titanium butoxide (TiO2–N–BUT) and titanium isopropoxide (TiO2–N–PROP) as the precursor were effective as the TiO2 (P25) impregnation with urea (TiO2-N-P25) to degrade the FQs. The FQ degradation was higher by 74, 65, and 91%, respectively for TiO2–N–BUT, TiO2–N–PROP, and TiO2-N (load 50 mg L−1, 20 min of reaction under 28 W UV-ASolar). The TiO2-P25 with urea showed the best performance in FQ degradation. The reaction intermediates might present modifications in their acceptor groups by PCO and, because of that the antimicrobial activity dropped as the reaction time increased. Reactions with TiO2-N-P25 (100 mg L−1) and TiO2-N-BUT (100 mg L−1) achieved ≥ 80% of antimicrobial activity removal from the mixed FQ solution (Cciprofloxacin = 100 μg L−1; Cofloxacin = 100 μg L−1; Clomefloxacin = 100 μg L−1) after 40 min of reaction, for both for Escherichia coli and Bacillus subtilis.

Mehdi Shirzad Siboni ◽  
Mohamadreza Samarghandi ◽  
Jae-Kyu Yang ◽  
Seung-Mok Lee

AbstractIn this work, photocatalytic oxidation of reactive Black-5(RB-5) dye was investigated with illuminated TiO

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