Rapid degradation of clozapine by heterogeneous photocatalysis. Comparison with direct photolysis, kinetics, identification of transformation products and scavenger study

2019 ◽  
Vol 665 ◽  
pp. 557-567 ◽  
Author(s):  
Jakub Trawiński ◽  
Robert Skibiński
Keyword(s):  
Transformation Products ◽  
Heterogeneous Photocatalysis ◽  
Direct Photolysis ◽  
Rapid Degradation

scholarly journals Heterogeneous Photocatalysis of Metronidazole in Aquatic Samples

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7612
Author(s):  
Klaudia Stando ◽  
Patrycja Kasprzyk ◽  
Ewa Felis ◽  
Sylwia Bajkacz
Keyword(s):  
Degradation Products ◽  
Transformation Products ◽  
Heterogeneous Photocatalysis ◽  
Bond Breaking ◽  
Mass Ratio ◽  
Purification Method ◽  
Photocatalytic Removal ◽  
Catalyst Type ◽  
Mineralization Degree ◽  
High Degree

Metronidazole (MET) is a commonly detected contaminant in the environment. The compound is classified as poorly biodegradable and highly soluble in water. Heterogeneous photocatalysis is the most promoted water purification method due to the possibility of using sunlight and small amounts of a catalyst needed for the process. The aim of this study was to select conditions for photocatalytic removal of metronidazole from aquatic samples. The effect of catalyst type, mass, and irradiance intensity on the efficiency of metronidazole removal was determined. For this purpose, TiO2, ZnO, ZrO2, WO3, PbS, and their mixtures in a mass ratio of 1:1 were used. In this study, the transformation products formed were identified, and the mineralization degree of compound was determined. The efficiency of metronidazole removal depending on the type of catalyst was in the range of 50–95%. The highest MET conversion (95%) combined with a high degree of mineralization (70.3%) was obtained by using a mixture of 12.5 g TiO2–P25 + PbS (1:1; v/v) and running the process for 60 min at an irradiance of 1000 W m−2. Four MET degradation products were identified by untargeted analysis, formed by the rearrangement of the metronidazole and the C-C bond breaking.

Optimization of fipronil degradation by heterogeneous photocatalysis: Identification of transformation products and toxicity assessment

2017 ◽  
Vol 110 ◽  
pp. 133-140 ◽  
Author(s):  
Oswaldo Gomes Júnior ◽  
Waldomiro Borges Neto ◽  
Antonio E.H. Machado ◽  
Daniela Daniel ◽  
Alam G. Trovó
Keyword(s):  
Transformation Products ◽  
Toxicity Assessment ◽  
Heterogeneous Photocatalysis

Granular bainite or granular ferrite? A preliminary TEM investigation of an HSLA-100 steel

1991 ◽  
Vol 49 ◽  
pp. 584-585
Author(s):  
R. Varughese ◽  
S. W. Thompson ◽  
P. R. Howell
Keyword(s):  
Room Temperature ◽  
Transformation Products ◽  
Accurate Description ◽  
Granular Bainite ◽  
Preliminary Results ◽  
The Past ◽  
Light Micrograph ◽  
Multiphase Reaction ◽  
Detailed Nature

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.

Polycaprolactone based membranes for the degradation of diclofenac present in water samples using ZnO nanoparticles as the active agent

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3153-3161
Author(s):  
Marco Antonio Juárez Sánchez ◽  
Miguel Ángel Meléndez Lira ◽  
Celestino Odín Rodríguez Nava
Keyword(s):  
Zno Nanoparticles ◽  
Wastewater Treatment Plants ◽  
Active Agent ◽  
Heterogeneous Photocatalysis ◽  
Nano Particles ◽  
Electrical Characteristics ◽  
Unit Operation ◽  
Fields Of Study ◽  
Drug Contamination ◽  
Positive Results

AbstractDrug contamination in water is one of the current fields of study. Since 1990, the presence of drugs in drinking water has been a concern to scientists and public. In Mexico, these organic compounds are not efficiently removed in wastewater treatment plants; therefore, alternative methodologies have been studied that allow these compounds to have a high percentage of degradation or be completely degraded. One example of these techniques is heterogeneous photocatalysis which has obtained positive results in the degradation of drugs using ZnO nanoparticles. These are commonly selected for their electrical characteristics, even though they disperse in water and an additional unit operation is required to separate them from the liquid medium. To eliminate drugs with nano particles in a single stage, polycaprolactone-based membranes with adhered ZnO nanoparticles, by means of electrospinning, were prepared to degrade drugs such as diclofenac. The technique used has shown to efficiently break down diclofenac in 4 hours according to the capillary electrophoresis readings.

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