Photocatalytic Oxidation of Rhodamine 6G Dye Using Magnetic TiO2@Fe3O4/FeZSM-5

Efficient decolorization of Rhodamine 6G dye (Rh 6G) using magnetic TiO2@Fe3O4/FeZSM-5 photocatalyst was carried out in a batch reactor equipped with two visible lights (high-pressure Na lamps). The photocatalyst was synthesized and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, diffuse reflectance spectroscopy and vibrating sample magnetometry. The effects of initial Rh 6G concentration, catalyst loading, and pH were investigated on photocatalytic oxidation of Rh 6G. Maximum decolorization of 98.2 % was found at optimum conditions of 20 ppm Rh 6G, 1 g L–1 of catalyst, and pH of 13.04. Central composite design was used for the optimization of photocatalytic degradation of Rh 6G. Predicted decolorization efficiencies were found to be in good agreement with experimental values with high regression coefficient of 98.8 %. In addition to color removal, the toxicity of the Rh 6G aqueous solution was significantly reduced after photocatalytic oxidation. Small reduction of activity (from 34.6 % to 30.5 %) showed the stability of the catalyst after three consecutive runs. Due to the magnetic property of the catalyst, it could be removed from the solution with the help of external magnetic field. This prevents the loss of catalyst and reduces the extra separation cost, which is desired in industrial or large-scale applications. This work is licensed under a Creative Commons Attribution 4.0 International License

Treatment of Bisphenol-A Using Sonication-assisted Photo-Fenton Hybrid Process: Influence of Reaction Parameters

Sonication-assisted photo-Fenton oxidation of an endocrine disrupting compound, bisphenol-A (BPA), was studied under visible-light irradiation in the presence of a LaFeO3 perovskite catalyst. The effects of the parameters: initial BPA concentration ([BPA]0), H2O2 concentration ([H2O2]0), catalyst loading, initial pH of the BPA solution, and reaction temperature were studied on the sonication-assisted photo-Fenton oxidation of an aqueous BPA solution. The optimum conditions for the oxidation were determined to be: [BPA]0 = 10 ppm, [H2O2]0 = 4.8 mM, catalyst loading = 0.75 g L–1, pH = 2.6, temperature = 313 K. During all runs, sonication power of 40 W, visible lights power of 150 W+150 W, BPA solution volume (0.5 L), and stirring speed of 500 rpm were kept constant. Under these conditions, degradation of 56.3 %, COD removal of 50.9 %, and TOC removal of 15.6 % were achieved after 6 h of reaction. The small amount of iron that leached into the solution indicated high stability of the catalyst. The sonication-assisted photo-Fenton oxidation of BPA was described by the second order kinetics with an activation energy of 15.34 kJ mol–1. Toxicity tests were also performed and the results revealed that the intermediates formed in the sonication-assisted photo-Fenton oxidation of BPA were less toxic compared to the parent BPA molecule at a neutral pH value. However, the same interpretation was not valid at the acidic pH of 2.6

Synthesis of Visible-Light heterostructured photocatalyst of Ag/AgCl deposited on (0 4 0) facet of monoclinic BiVO4 for efficient carbamazepine photocatalytic removal

2-s2.0-85088823142Visible light photocatalysis of Ag/AgCl/BiVO4 was synthesized by the selective doping of Ag/AgCl on (0 4 0) facet of monoclinic BiVO4. The as-prepared catalyst was characterized by XRD, SEM, EDS, UV–Vis DRS, XPS, and nitrogen adsorption studies. The photocatalytic activity of Ag/AgCl/BiVO4 was tested on the removal of a pharmaceutical drug carbamazepine (CBZ). A CBZ removal of 70.6% and COD and TOC decrements of 21% and 9.6% were achieved within a reaction time of 4 h. The results demonstrated that the addition of oxidants improved the photocatalytic activity (97.9% and 100% CBZ removal in the presence of H2O2 and PS). Photocatalytic mechanism of the Ag/AgCl/BiVO4 plasmonic composite photocatalyst under visible LED light irradiation was clarified and O[rad]2? radicals were found as the most dominant radicals. The toxicity decrement was 21.7% for the treated CBZ solution. Furthermore, the Ag/AgCl/BiVO4 heterostructured photocatalyst has high stability under visible light irradiation which could be reused after three consecutive runs with a small Ag leaching (<0.1 ppm). © 2020 Elsevier B.V.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 218M616The authors are grateful for the financial support from T?B?TAK (The Scientific and Technological Research Council of Turkey) under project number of 218M616. We appreciate Prof. Dr. G?n?l G?nd?z for guiding us during this study. We would like to express our sincere thanks to Prof. Dr. ?erife ?. Helvac? for Uv-Vis DRS analysis.The authors are grateful for the financial support from TÜBİTAK (The Scientific and Technological Research Council of Turkey ) under project number of 218M616. We appreciate Prof. Dr. Gönül Gündüz for guiding us during this study. We would like to express our sincere thanks to Prof. Dr. Şerife Ş. Helvacı for Uv-Vis DRS analysis

The sonochemical decolourisation of textile azo dye Orange II: Effects of Fenton type reagents and UV light

WOS: 000329771500051PubMed ID: 24071562The removal of Orange II (O-II) from aqueous solution under irradiation at 850 kHz has been studied. The effects of both homogeneous (with FeSO4/H2O2), and heterogeneous (Fe containing ZSM-5 zeolite/H2O2) Fenton type reagents are reported together with the effect of UV irradiation in combination with ultrasound both alone and with homogeneous Fenton-type reagent. Degrees of decolourisation of 6.5% and 28.9% were observed using UV radiation and ultrasound, respectively, whereas under the simultaneous irradiation of ultrasound and UV light, the decolourisation degree reached 47.8%, indicating a synergetic effect of ultrasound and UV light. The decolourisation was increased with the addition of Fenton's reagent with an optimal Fenton molar reagent ratio, Fe2+:H2O2 of 1:50. In the combined process of ultrasound and UV light with the homogeneous Fenton system 80.8% decolourisation could be achieved after 2 h indicating that UV improves this type of Orange II degradation. The degree of decolourisation obtained using the heterogeneous sono-Fenton system (Fe containing ZSM-5 zeolite catalysts + H2O2 + ultrasound) were consistently lower than the traditional homogeneous ultrasound Fenton system. This can be attributed to the greater difficulty of the reaction between Fe ions and hydrogen peroxide. In all cases the Orange II ultrasonic decolourisation was found to follow first order kinetics. (C) 2013 Elsevier B.V. All rights reserved.Council of Higher Education of TurkeyMinistry of National Education - TurkeyDuring this study, Dr. Meral Dukkanci was funded by a scholarship from The Council of Higher Education of Turkey as a postdoctoral researcher. The kind help of Professor Gonul Gunduz before and during this study is also acknowledgement