Transformation products and mechanistic pathway of levofloxacin degradation in aqueous solution using advanced oxidation processes in the presence of BiVO4 and visible light

2020 ◽  
Vol 183 ◽  
pp. 325-334
Author(s):  
Mohammed A. Meetani ◽  
Ahmed Alzamly ◽  
Naji Al-Dubaili ◽  
Mohamed F. Malik ◽  
Nada Elmerhi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Visible Light ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Transformation Products ◽  
Oxidation Processes ◽  
Mechanistic Pathway

scholarly journals Degradation of Carbamazepine by Photo(electro)catalysis on Nanostructured TiO2 Meshes: Transformation Products and Reaction Pathways

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 169 ◽  
Author(s):  
Silvia Franz ◽  
Ermelinda Falletta ◽  
Hamed Arab ◽  
Sapia Murgolo ◽  
Massimiliano Bestetti ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Advanced Oxidation Processes ◽  
Scale Up ◽  
Advanced Oxidation ◽  
Transformation Products ◽  
Reaction Pathways ◽  
Oxidation Processes ◽  
Electro Catalysis ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Carbamazepine (CBZ) is a pharmaceutical compound recalcitrant to conventional wastewater treatment plants and widely detected in wastewater bodies. In the present study, advanced oxidation processes for carbamazepine removal are investigated, with particular regard to the degradation pathways of carbamazepine by photoelectrocatalysis and conventional photocatalysis. Photoelectrocatalysis was carried out onto TiO2 meshes obtained by Plasma Electrolytic Oxidation, a well-known technique in the field of industrial surface treatments, in view of an easy scale-up of the process. By photoelectrocatalysis, 99% of carbamazepine was removed in 55 min while only 65% removal was achieved by photolysis. The investigation of the transformation products (TPs) was carried out by means of UPLC-QTOF/MS/MS. Several new TPs were identified and accordingly reaction pathways were proposed. Above 80 min the transformation products disappear, probably forming organic acids of low-molecular weight as final degradation products. The results demonstrated that photoelectrocatalysis onto TiO2 meshes obtained by plasma electrolytic oxidation is a useful alternative to common advanced oxidation processes as wastewater tertiary treatment aimed at removing compounds of emerging concern.

Novel MoSe2 hierarchical microspheres for applications in visible-light-driven advanced oxidation processes

Nanoscale ◽  
2015 ◽  
Vol 7 (47) ◽  
pp. 19970-19976 ◽  
Author(s):  
Chu Dai ◽  
Enping Qing ◽  
Yong Li ◽  
Zhaoxin Zhou ◽  
Chao Yang ◽  
...  
Keyword(s):  
Visible Light ◽  
Self Assembly ◽  
Advanced Oxidation Processes ◽  
Three Dimensional ◽  
Advanced Oxidation ◽  
Oxidation Processes ◽  
Hierarchical Microspheres ◽  
Molybdenum Diselenide ◽  
Visible Light Driven

Self-assembly of three-dimensional molybdenum diselenide hierarchical microspheres and their visible-light-driven advanced oxidation processes.

scholarly journals Synthesis, structure, and visible-light-driven activity of o-YbFeO3/h-YbFeO3/CeO2 photocatalysts

2021 ◽  
Vol 8 (4) ◽  
pp. 20218407
Author(s):  
Sofia M. Tikhanova ◽  
Lev A. Lebedev ◽  
Svetlana A. Kirillova ◽  
Maria V. Tomkovich ◽  
Vadim I. Popkov
Keyword(s):  
Visible Light ◽  
Cerium Dioxide ◽  
Advanced Oxidation Processes ◽  
Aqueous Media ◽  
Visible Region ◽  
Methyl Violet ◽  
Advanced Oxidation ◽  
Solution Combustion ◽  
Oxidation Processes ◽  
Method Of Solution

Photo-Fenton-like oxidation of organic substances is one of the key advanced oxidation processes based on the reversible Fe2+↔Fe3+ transition and the generation of a strong oxidant ·OH in the presence of H2O2 and is currently considered as a promising method for the purification of polluted aqueous media. However, the absence of effective and stable photocatalysts of this process, operating under the action of visible light, necessitates the exploratory studies, mainly among iron oxides and ferrites of various compositions and structures. In this work, using the method of solution combustion followed by heat treatment in air the heterojunction nanocomposites based on ytterbium orthoferrite and cerium dioxide of the composition o-YbFeO3/h-YbFeO3/CeO2 (0–20 mol.%) with high absorption in the visible region and advanced photo-Fenton-like activity were obtained. The nanocomposites were studied by EDS, SEM, XRD, BET, and DRS methods. The photo-Fenton-like activity of the nanocomposites was investigated during the degradation of methyl violet under the action of visible (λmax = 410 nm) radiation. As a result, the formation of I-type heterojunction based on stable rhombic (55.4–79.0 nm) and metastable hexagonal (19.5–24.0 nm) modifications of ytterbium orthoferrite (o-YbFeO3 and h-YbFeO3, respectively) and cubic cerium dioxide CeO2 (13.2–19.2 nm) nanocrystals was established. It was shown that the obtained nanocomposites had foamy morphology and were characterized by a specific surface in the range of 9.1–25.0 m2/g, depending on the CeO2 content. It was found that nanocrystalline components were chemically and phase-pure, uniformly spatially distributed over the nanocomposite, and had multiple contacts with each other. Based on this fact and the established electronic structure of the nanocomposite components, the formation of I-type heterojunction with the participation of o-YbFeO3 (Eg = 2.15 eV), h-YbFeO3 (Eg = 2.08 eV), and CeO2 (Eg = 2.38 eV) was shown, the presence of which increased photocatalytic activity of the resulting nanocomposite. The optimal content of CeO2 in the nanocomposite was 5%, and the o-YbFeO3/h-YbFeO3/CeO2–5% sample was characterized by the highest rate constant of photo-Fenton-like degradation of methyl violet under the action of visible light equal to k = 0.138 min–1, which was 2.5 to 5 times higher than for nanocomposites based on ytterbium orthoferrite. The obtained results obtained indicate that the developed nanocomposites can be considered as a promising basis for the advanced oxidation processes for the purification of aqueous media from organic pollutants.

Chemical and toxicological evaluation of transformation products during advanced oxidation processes

2013 ◽  
Vol 68 (9) ◽  
pp. 1976-1983 ◽  
Author(s):  
C. vom Eyser ◽  
A. Börgers ◽  
J. Richard ◽  
E. Dopp ◽  
N. Janzen ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Advanced Oxidation ◽  
Transformation Products ◽  
Product Formation ◽  
Toxicological Evaluation ◽  
H2o2 Treatment ◽  
Oxidation Processes ◽  
Estrogenic Potential

The entry of pharmaceuticals into the water cycle from sewage treatment plants is of growing concern because environmental effects are evident at trace levels. Ozonation, UV- and UV/H2O2-treatment were tested as an additional step in waste water treatment because they have been proven to be effective in eliminating aqueous organic contaminants. The pharmaceuticals carbamazepine, ciprofloxacin, diclofenac, metoprolol and sulfamethoxazole as well as the personal care products galaxolide and tonalide were investigated in terms of degradation efficiency and by-product formation in consideration of toxic effects. The substances were largely removed from treatment plant effluent by ozonation, UV- and UV/H2O2-treatment. Transformation products were detected in all tested treatment processes. Accompanying analysis showed no genotoxic, cytotoxic or estrogenic potential for the investigated compounds after oxidative treatment of real waste waters. The results indicate that by-product formation from ozonation and advanced oxidation processes does not have any negative environmental impact.

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