Daniela V Sojic | University of Novi Sad, Faculty of Sciences (original) (raw)

Papers by Daniela V Sojic

Journal of Environmental Chemical Engineering, 2024

This research aimed to investigate the removal efficiency of the pesticide clomazone, as well as ... more This research aimed to investigate the removal efficiency of the pesticide clomazone, as well as two pharmaceutically active compounds, ciprofloxacin and 17α-ethynilestradiol, using sustainable heterogeneous photocatalysis with newly synthesized binary coupled ZnO/MeOx nanopowders (ZnO/MgO, ZnO/CeO2, and ZnO/ZrO2) as photocatalysts, under various experimental conditions (catalyst loading and initial pH). The newly synthesized nanomaterials were characterized using XRD, SEM-EDS, TEM, DLS, Raman and UV/Vis spectroscopy, and zeta potential. The XRD proved the nanocrystalline size of the synthesized photocatalysts in the range 40−17 nm. The difference in morphology (shape and size) was determined and all elements were quantified using SEM-EDS. TEM images confirmed the successful formation of ZnO/MeOx heterojunctions. DLS measurements showed distributions with mean hydrodynamic particle diameters of 1226, 1042, and 944 nm for ZnO/MgO, ZnO/CeO2, and ZnO/ZrO2 powders, respectively. Raman also proved the successful preparation of binary nanomaterials. Considering the UV/Vis spectroscopy results, bandgap energy was found to be in the range 3.241–3.249 eV. BET analysis was used to determine specific surface area, 13.6852, 11.0554, and 8.5519 m2/g for ZnO/MgO, ZnO/CeO2, and ZnO/ZrO2. Optimal photocatalytic experimental conditions were defined using chemometrics. Chemical oxygen demand and ion chromatography analyses additionally confirmed the successful pollutant removal. The mechanism of CIP photocatalytic degradation and photocatalyst reutilization study were conducted under optimal conditions. After two consecutive runs, the reutilization study revealed that there was no loss of photocatalytic efficiency, while the contribution of various reactive species was: h+ ˃ •
> •. And finally, the toxicity of mixtures was observed on wheat samples.

Chemical Engineering Journal, 2017

Efficiency of photodegradation of anxiolytic drug alprazolam by advanced oxidation processes was ... more Efficiency of photodegradation of anxiolytic drug alprazolam by advanced oxidation processes was investigated. The structural and morphological properties of ZnO were investigated in detail. It was found that ZnO has wurtzite structure with crystallite size about 41 nm, specific surface area about 6.5 m 2 /g, and intraparticle system of pores (maximum pore width about 160 nm). The efficiency of photocatalytic degradation of alprazolam was examined as a function of the type of irradiation (UVA, visible, and simulated solar irradiation) and photocatalyst (ZnO, TiO 2 Degussa P25), loading of photocatalyst, pH, as well as the presence of hydroxyl radical scavenger (ethanol and methanol). By examining the effect of types of irradiation and catalysts, it was found that the UVA/ZnO system is the most efficient for alprazolam removal. The optimum catalyst loading was 1.0, and 2.0 mg/mL for ZnO and TiO 2 Degussa P25, respectively. In the case of ZnO, the pH 7 was selected as an optimal condition, while in aqueous suspension of TiO 2 Degussa P25, degradation rate increases in whole investigated pH range (3.4-8.8), but increasing is not as pronounced as in case of ZnO. By studying the effect of hydroxyl radical scavengers, it was found that the heterogeneous catalysis takes place mainly via hydroxyl radicals. The results of total organic carbon and ionic chromatography analysis showed that after 60 min of irradiation using both catalysts alprazolam was completely mineralized. Also, reaction intermediates formed using both catalysts were studied in detail using LC-ESI-MS/MS, whereby the main intermediates were hydroxyl derivates.

Chemical Engineering Journal, 2016

h i g h l i g h t s Annular slurry reactor (ASR) for photodegradation of commercial pesticides wa... more h i g h l i g h t s Annular slurry reactor (ASR) for photodegradation of commercial pesticides was tested. Different AOPs were investigated in the presence of UVA and visible light irradiation. 7.2Fe/TiO 2 /H 2 O 2 system using both type of irradiation was the most efficient. ASR design showed the highest photodegradation efficiency for pesticide removal. For ZnO/H 2 O 2 system general reaction mechanism was assumed.

Applied Catalysis B: Environmental, 2011

(AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier a... more (AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier and the University of Turin. Changes resulting from the publishing process-such as editing, corrections, structural formatting, and other quality control mechanisms-may not be reflected in this version of the text. The definitive version of the text was subsequently published in

Journal of the Serbian Chemical Society

In this paper the efficiency of photocatalytic degradation of different pesticides was investigat... more In this paper the efficiency of photocatalytic degradation of different pesticides was investigated using bare TiO2 and TiO2 nanoparticles modified with polyaniline under simulated solar irradiation. Sulcotrione showed the highest percentage degradation and further experiments were related to this herbicide. Mineralization and cytotoxicity of the starting compound and intermediate species formed during the decomposition in double distilled water (DDW), as well as the efficiency of removal from various environmental waters were studied. The contents of the most abundant ions present in the River Danube were simulated in DDW and their influence was evaluated. It was found that cytotoxicity was in all cases below 11 % and the efficiency of photocatalytic degradation in environmental waters was decreased compared with DDW. Furthermore, addition of different scavengers revealed that the main path of degradation is through holes, while the presence of H2O2 decreased and KBrO3 increased th...

Journal of Hazardous Materials, 2009

A Surveyor LC system (Thermo Fisher Scientific) was used for the separation of the analytes on an... more A Surveyor LC system (Thermo Fisher Scientific) was used for the separation of the analytes on an Agilent Technologies reverse-phase Zorbax Eclipse ® XDB-C18 column (75 mm × 4.6 mm i.d., particle size 3.5 µm, 20 °C). An Agilent Technologies guard column (12.5 mm × 4.6 mm i.d., particle size 5 µm) was used. The mobile phase consisted of methanol (A) and 10% acetic acid (B), with the following gradient: 0 min -A 30%, B 70%; 15 min -A 60%, B 40%; 15.10 min -A 100%, B 0%; 19 min -A 30%, B 70%. The initial conditions were reestablished and held for 15 min. The flow rate of the mobile phase was 0.6 mL min -1 , the injection volume was 10 µL. An LCQ Advantage quadrupole ion trap mass spectrometer (Thermo Fisher Scientific) equipped with an electrospray ionization unit was used to perform the mass spectrometric analysis. Spray voltage was set to 4.5 kV and sheath gas flow rate optimized at 23 au (arbitrary units, from a scale of arbitrary units in the 0−100 range defined by the LCQ Advantage system). High-purity helium was used as the collision gas. Full scan mode (m/z range 70-500) was used to select the precursor ion for metoprolol tartrate and for each intermediate . Then, product ion scan in MS/MS mode was used for structure elucidation of each degradation intermediate.

Chemosphere, Jan 3, 2015

The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound ... more The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0mgmL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiatio...

Journal of the Serbian Chemical Society, 2007

Lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenolammonium tetraphe... more Lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenolammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 4.0-6.0 from a large volume of aqueous solutions of various samples. After filtration, the solid mass consisting of the lead complex and naphthalene was dissolved with 5 mL of dimethylformamide and the metal was determined by third derivative spectrophotometry. Lead complex can alternatively be quantitatively adsorbed on ammonium tetraphenylboratenaphthalene adsorbent packed in a column and determined similarly. About 0.2 µg of lead can be concentrated in a column from 300 mL of aqueous sample, where its concentration is as low as 0.7 ng/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed have been utilized for the trace determination of lead in various samples.

Applied Catalysis B: Environmental, 2004

The kinetics and possible mechanism of the photocatalytic degradation of herbicide mecoprop, in U... more The kinetics and possible mechanism of the photocatalytic degradation of herbicide mecoprop, in UV illuminated aqueous colloids of synthesized nanosized TiO2 were investigated. The rate of degradation was studied by 1H NMR, UV spectrometry, as well ...

Chemosphere, Jan 3, 2015

The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound ... more The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0mgmL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiatio...

Chemosphere, 2018

The surface modification of commercial TiO2 Hombikat (TiO2) using nanoparticles of fullerene C60 ... more The surface modification of commercial TiO2 Hombikat (TiO2) using nanoparticles of fullerene C60 with tetrahydrofuran (THF-nC60), as well as fullerenol C60(OH)24 nanoparticles (FNP) was investigated in this study. Characterization of THF-nC60, FNP, TiO2, TiO2/THF-nC60, and TiO2/FNP was studied by using DES, ELS, TEM, SEM, DRS and BET measurements and their photoactivity has been examined on the mesotrione degradation under simulated sunlight. It was found that FNP in self-assembled nanocomposite TiO2/FNP increased negatively charge, as well as catalytic surface of TiO2. In addition, TiO2/FNP exhibits a shift of band gap energy to lower values compared to TiO2 and TiO2/THF-nC60. BET surface area has not showed significant differences among catalysts. Furthermore, it was found that the highest photoactivity was obtained for TiO2/FNP system. Besides, influence of different concentrations of electron acceptors (H2O2 and KBrO3), as well as scavengers on the kinetics of mesotrione removal...

Chemosphere, 2013

h i g h l i g h t s UV/TiO 2 treatment eliminates efficiently clomazone from water. Photocatalyti... more h i g h l i g h t s UV/TiO 2 treatment eliminates efficiently clomazone from water. Photocatalytic degradation follows the pseudo-first order kinetics. Five intermediates were identified by LC-ESI-MS/MS and 1 H NMR. Toxicity toward the H-4-II-E and MRC-5 cell lines decreased by irradiation. River, ground, and thermal water lower the rate of photodegradation.

Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2005

Visible light (λ > 420 nm) induced photocatalytic degradation of rhodamine B (RhB) in the presenc... more Visible light (λ > 420 nm) induced photocatalytic degradation of rhodamine B (RhB) in the presence of H 2 O 2 by one-dimensional (1D) nanorods of goethite (R-FeOOH) and hematite (R-Fe 2 O 3 ) has been investigated, and results were compared to those of micrometer-sized rods. R-FeOOH nanorods were self-assembled by oriented attachment of R-FeOOH primary nanoparticles, while porous R-Fe 2 O 3 rods were prepared by thermal dehydration of respective R-FeOOH precursors via a topotactic transformation. The as-prepared samples were characterized by powder X-ray diffraction, micro-Raman spectroscopy, diffuse reflectance UV-visible spectroscopy, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption, high-angle annular darkfield scanning transmission electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. Nanosized R-FeOOH and R-Fe 2 O 3 particles appeared to be more active than microsized ones in terms of surface area normalized reaction rate, suggesting intrinsic photocatalytic properties of nanorods as compared to microrods in both R-FeOOH and R-Fe 2 O 3 . In addition, R-Fe 2 O 3 nanorods exhibited the greatest activity among the as-prepared samples. The observed photocatalytic performance by iron oxide particles was attributed to the synergetic effects of the particle composition, size, porosity, and the variations of local structure. The results from current study will be potentially applicable to a range of naturally abundant semiconducting minerals and compounds (e.g., metal oxyhydroxides and metal oxides).

Reaction Kinetics, Mechanisms and Catalysis, 2014

ABSTRACT The role of •OH radicals (adsorbed and free) and valence band holes as primary oxidants ... more ABSTRACT The role of •OH radicals (adsorbed and free) and valence band holes as primary oxidants in the photodegradation of clomazone in UV-illuminated TiO2 suspension was investigated. Significant inhibition of the photodegradation of clomazone in the presence of NaI (hole and surface •OH scavenger) suggesting that the surface degradation mechanism played a crucial role rather than the bulk degradation pathway. Also, less impact of tert-butanol on the photodegradation indicated that free •OH radicals were not majorly involved in the photodegradation process of clomazone. On the other hand, when the surface is covered by fluoride, it was concluded that the kinetic pathways for reaction with subsurface holes and with free •OH in solution are predominant. The LC–ESI–MS/MS analyses of the irradiated solution of clomazone in the presence of NaF indicated formation of the same intermediates when free •OH played a crucial role in mechanism instead of surface •OH radicals. Besides, molecular oxygen, H2O2, KBrO3, and (NH4)2S2O8 are generally used as electron scavengers in heterogeneous photocatalytic reactions. It was found that the addition of electron scavengers such as H2O2, KBrO3, and (NH4)2S2O8 has resulted in higher pollutant degradation rate compared to molecular oxygen alone.

Science of The Total Environment, 2013

Toxicity study of metoprolol and its photocatalytic degradation mixtures • Toxicity evaluation in... more Toxicity study of metoprolol and its photocatalytic degradation mixtures • Toxicity evaluation in vitro in H-4-II-E, HT-29 and MRC-5 cell lines • TiO 2 Wackherr and Degussa P25 promoted a time-dependent increase in toxicity.

Applied Catalysis B: Environmental, 2014

Titanium dioxide nanotubes (TNT) were synthesized via hydrothermal method and calcined at various... more Titanium dioxide nanotubes (TNT) were synthesized via hydrothermal method and calcined at various temperatures. The obtained calcined TiO 2 nanomaterials with specific elongation orientation were characterized by transmission and scanning electron microscopy (TEM, SEM), X-ray diffraction (XRD), UV/Vis diffuse reflection spectroscopy (DRS), Laser Doppler electrophoresis (LDE) and their textural properties were evaluated. The photocatalytic activity of obtained nanopowders was evaluated considering photodegradation rate of herbicide clomazone, rarely studied herbicide. The influence of calcination temperature of catalysts with elongated morphology on their photocatalytic activity was evaluated. The best results were obtained with TNT annealed at 700 • C, which can be assigned to the best balance between crystal structure, morphology and surface properties of nanoparticles induced by annealing. Also, the photocatalytic degradation rates of another two herbicides (picloram, and mecoprop) were compared, due to possibility that the efficiency of photocatalytic degradation is greatly influenced by the molecular structure. The mineralization degree of selected herbicides in the presence of TiO 2 based photocatalysts was evaluated applying total organic carbon (TOC) measurements.

Journal of Molecular Catalysis A: Chemical, 2014

ABSTRACT The photocatalytic degradation of the herbicide mesotrione (0.05 mM) in aqueous suspensi... more ABSTRACT The photocatalytic degradation of the herbicide mesotrione (0.05 mM) in aqueous suspensions of TiO2 Degussa P25 and ZnO was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.00 mg/mL under UV light at the pH 4.0 (TiO2 Degussa P25) and pH 9.2 (ZnO). In the first stage of the reaction, the photocatalytic degradation of mesotrione followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds mainly via •OH radicals, and partly also via holes. The results showed that the disappearance of mesotrione led to the formation of a number of organic intermediates and ionic byproducts, whereas its complete mineralization occurred after about 4 h. Tentative photodegradation pathways were proposed and discussed as a function of the type of photocatalyst. A comparison of the evolution of toxicity that was evaluated in vitro in the rathepatoma (H-4-II-E) and human fetal lung (MRC-5) cell lines with the degradation kinetics indicates that the cell growth of both cell lines was only mildly affected by the mixture of mesotrione and its photocatalytic degradation intermediates obtained using TiO2 Degussa P25, and moderately affected by the mixtures obtained using ZnO, whereby at 120 min toxicity decreased.

Applied Catalysis B: Environmental, 2013

ABSTRACT A study of photocatalytic activity of bare as prepared, bare aged and dopamine surface m... more ABSTRACT A study of photocatalytic activity of bare as prepared, bare aged and dopamine surface modified colloidal TiO2 nanoparticles was obtained following degradation reaction of herbicide RS-2-(4-chloro-o-tolyloxy)propionic acid under UV light irradiation. Results showed that the most active photocatalyst is bare aged TiO2 and the least active are dopamine modified nanoparticles. Results are discussed in the light of surface structure of TiO2 nanoparticles. The study of surface modification of TiO2 nanoparticles (4.5 nm, TiO2 NPs) with dopamine was also performed. The formation of inner-sphere charge-transfer complexes results in red shift of semiconductor absorption threshold (600 nm), compared to bare TiO2 NPs (380 nm). Effective band gap energy of 3.2 eV for bare TiO2 NPs is reduced to 2.1 eV for TiO2/dopamine charge transfer complexes. The binding structure was investigated by UV-vis and FTIR spectroscopy. The obtained optimal geometry for binding of dopamine to surface Ti atoms was binuclear bidentate-bridging. From the Benesi–Hildebrand plot, stability constant of the order 103 M−1 has been determined.

Chemosphere, 2015

The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound ... more The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0mgmL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiation of sulcotrione solution and Tangenta® formulation using TiO2 catalyst on three mammalian cell lines.

Journal of Environmental Chemical Engineering, 2024

This research aimed to investigate the removal efficiency of the pesticide clomazone, as well as ... more This research aimed to investigate the removal efficiency of the pesticide clomazone, as well as two pharmaceutically active compounds, ciprofloxacin and 17α-ethynilestradiol, using sustainable heterogeneous photocatalysis with newly synthesized binary coupled ZnO/MeOx nanopowders (ZnO/MgO, ZnO/CeO2, and ZnO/ZrO2) as photocatalysts, under various experimental conditions (catalyst loading and initial pH). The newly synthesized nanomaterials were characterized using XRD, SEM-EDS, TEM, DLS, Raman and UV/Vis spectroscopy, and zeta potential. The XRD proved the nanocrystalline size of the synthesized photocatalysts in the range 40−17 nm. The difference in morphology (shape and size) was determined and all elements were quantified using SEM-EDS. TEM images confirmed the successful formation of ZnO/MeOx heterojunctions. DLS measurements showed distributions with mean hydrodynamic particle diameters of 1226, 1042, and 944 nm for ZnO/MgO, ZnO/CeO2, and ZnO/ZrO2 powders, respectively. Raman also proved the successful preparation of binary nanomaterials. Considering the UV/Vis spectroscopy results, bandgap energy was found to be in the range 3.241–3.249 eV. BET analysis was used to determine specific surface area, 13.6852, 11.0554, and 8.5519 m2/g for ZnO/MgO, ZnO/CeO2, and ZnO/ZrO2. Optimal photocatalytic experimental conditions were defined using chemometrics. Chemical oxygen demand and ion chromatography analyses additionally confirmed the successful pollutant removal. The mechanism of CIP photocatalytic degradation and photocatalyst reutilization study were conducted under optimal conditions. After two consecutive runs, the reutilization study revealed that there was no loss of photocatalytic efficiency, while the contribution of various reactive species was: h+ ˃ •
> •. And finally, the toxicity of mixtures was observed on wheat samples.

Chemical Engineering Journal, 2017

Efficiency of photodegradation of anxiolytic drug alprazolam by advanced oxidation processes was ... more Efficiency of photodegradation of anxiolytic drug alprazolam by advanced oxidation processes was investigated. The structural and morphological properties of ZnO were investigated in detail. It was found that ZnO has wurtzite structure with crystallite size about 41 nm, specific surface area about 6.5 m 2 /g, and intraparticle system of pores (maximum pore width about 160 nm). The efficiency of photocatalytic degradation of alprazolam was examined as a function of the type of irradiation (UVA, visible, and simulated solar irradiation) and photocatalyst (ZnO, TiO 2 Degussa P25), loading of photocatalyst, pH, as well as the presence of hydroxyl radical scavenger (ethanol and methanol). By examining the effect of types of irradiation and catalysts, it was found that the UVA/ZnO system is the most efficient for alprazolam removal. The optimum catalyst loading was 1.0, and 2.0 mg/mL for ZnO and TiO 2 Degussa P25, respectively. In the case of ZnO, the pH 7 was selected as an optimal condition, while in aqueous suspension of TiO 2 Degussa P25, degradation rate increases in whole investigated pH range (3.4-8.8), but increasing is not as pronounced as in case of ZnO. By studying the effect of hydroxyl radical scavengers, it was found that the heterogeneous catalysis takes place mainly via hydroxyl radicals. The results of total organic carbon and ionic chromatography analysis showed that after 60 min of irradiation using both catalysts alprazolam was completely mineralized. Also, reaction intermediates formed using both catalysts were studied in detail using LC-ESI-MS/MS, whereby the main intermediates were hydroxyl derivates.

Chemical Engineering Journal, 2016

h i g h l i g h t s Annular slurry reactor (ASR) for photodegradation of commercial pesticides wa... more h i g h l i g h t s Annular slurry reactor (ASR) for photodegradation of commercial pesticides was tested. Different AOPs were investigated in the presence of UVA and visible light irradiation. 7.2Fe/TiO 2 /H 2 O 2 system using both type of irradiation was the most efficient. ASR design showed the highest photodegradation efficiency for pesticide removal. For ZnO/H 2 O 2 system general reaction mechanism was assumed.

Applied Catalysis B: Environmental, 2011

(AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier a... more (AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier and the University of Turin. Changes resulting from the publishing process-such as editing, corrections, structural formatting, and other quality control mechanisms-may not be reflected in this version of the text. The definitive version of the text was subsequently published in

Journal of the Serbian Chemical Society

In this paper the efficiency of photocatalytic degradation of different pesticides was investigat... more In this paper the efficiency of photocatalytic degradation of different pesticides was investigated using bare TiO2 and TiO2 nanoparticles modified with polyaniline under simulated solar irradiation. Sulcotrione showed the highest percentage degradation and further experiments were related to this herbicide. Mineralization and cytotoxicity of the starting compound and intermediate species formed during the decomposition in double distilled water (DDW), as well as the efficiency of removal from various environmental waters were studied. The contents of the most abundant ions present in the River Danube were simulated in DDW and their influence was evaluated. It was found that cytotoxicity was in all cases below 11 % and the efficiency of photocatalytic degradation in environmental waters was decreased compared with DDW. Furthermore, addition of different scavengers revealed that the main path of degradation is through holes, while the presence of H2O2 decreased and KBrO3 increased th...

Journal of Hazardous Materials, 2009

A Surveyor LC system (Thermo Fisher Scientific) was used for the separation of the analytes on an... more A Surveyor LC system (Thermo Fisher Scientific) was used for the separation of the analytes on an Agilent Technologies reverse-phase Zorbax Eclipse ® XDB-C18 column (75 mm × 4.6 mm i.d., particle size 3.5 µm, 20 °C). An Agilent Technologies guard column (12.5 mm × 4.6 mm i.d., particle size 5 µm) was used. The mobile phase consisted of methanol (A) and 10% acetic acid (B), with the following gradient: 0 min -A 30%, B 70%; 15 min -A 60%, B 40%; 15.10 min -A 100%, B 0%; 19 min -A 30%, B 70%. The initial conditions were reestablished and held for 15 min. The flow rate of the mobile phase was 0.6 mL min -1 , the injection volume was 10 µL. An LCQ Advantage quadrupole ion trap mass spectrometer (Thermo Fisher Scientific) equipped with an electrospray ionization unit was used to perform the mass spectrometric analysis. Spray voltage was set to 4.5 kV and sheath gas flow rate optimized at 23 au (arbitrary units, from a scale of arbitrary units in the 0−100 range defined by the LCQ Advantage system). High-purity helium was used as the collision gas. Full scan mode (m/z range 70-500) was used to select the precursor ion for metoprolol tartrate and for each intermediate . Then, product ion scan in MS/MS mode was used for structure elucidation of each degradation intermediate.

Chemosphere, Jan 3, 2015

The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound ... more The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0mgmL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiatio...

Journal of the Serbian Chemical Society, 2007

Lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenolammonium tetraphe... more Lead is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenolammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 4.0-6.0 from a large volume of aqueous solutions of various samples. After filtration, the solid mass consisting of the lead complex and naphthalene was dissolved with 5 mL of dimethylformamide and the metal was determined by third derivative spectrophotometry. Lead complex can alternatively be quantitatively adsorbed on ammonium tetraphenylboratenaphthalene adsorbent packed in a column and determined similarly. About 0.2 µg of lead can be concentrated in a column from 300 mL of aqueous sample, where its concentration is as low as 0.7 ng/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed have been utilized for the trace determination of lead in various samples.

Applied Catalysis B: Environmental, 2004

The kinetics and possible mechanism of the photocatalytic degradation of herbicide mecoprop, in U... more The kinetics and possible mechanism of the photocatalytic degradation of herbicide mecoprop, in UV illuminated aqueous colloids of synthesized nanosized TiO2 were investigated. The rate of degradation was studied by 1H NMR, UV spectrometry, as well ...

Chemosphere, Jan 3, 2015

The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound ... more The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0mgmL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiatio...

Chemosphere, 2018

The surface modification of commercial TiO2 Hombikat (TiO2) using nanoparticles of fullerene C60 ... more The surface modification of commercial TiO2 Hombikat (TiO2) using nanoparticles of fullerene C60 with tetrahydrofuran (THF-nC60), as well as fullerenol C60(OH)24 nanoparticles (FNP) was investigated in this study. Characterization of THF-nC60, FNP, TiO2, TiO2/THF-nC60, and TiO2/FNP was studied by using DES, ELS, TEM, SEM, DRS and BET measurements and their photoactivity has been examined on the mesotrione degradation under simulated sunlight. It was found that FNP in self-assembled nanocomposite TiO2/FNP increased negatively charge, as well as catalytic surface of TiO2. In addition, TiO2/FNP exhibits a shift of band gap energy to lower values compared to TiO2 and TiO2/THF-nC60. BET surface area has not showed significant differences among catalysts. Furthermore, it was found that the highest photoactivity was obtained for TiO2/FNP system. Besides, influence of different concentrations of electron acceptors (H2O2 and KBrO3), as well as scavengers on the kinetics of mesotrione removal...

Chemosphere, 2013

h i g h l i g h t s UV/TiO 2 treatment eliminates efficiently clomazone from water. Photocatalyti... more h i g h l i g h t s UV/TiO 2 treatment eliminates efficiently clomazone from water. Photocatalytic degradation follows the pseudo-first order kinetics. Five intermediates were identified by LC-ESI-MS/MS and 1 H NMR. Toxicity toward the H-4-II-E and MRC-5 cell lines decreased by irradiation. River, ground, and thermal water lower the rate of photodegradation.

Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2005

Visible light (λ > 420 nm) induced photocatalytic degradation of rhodamine B (RhB) in the presenc... more Visible light (λ > 420 nm) induced photocatalytic degradation of rhodamine B (RhB) in the presence of H 2 O 2 by one-dimensional (1D) nanorods of goethite (R-FeOOH) and hematite (R-Fe 2 O 3 ) has been investigated, and results were compared to those of micrometer-sized rods. R-FeOOH nanorods were self-assembled by oriented attachment of R-FeOOH primary nanoparticles, while porous R-Fe 2 O 3 rods were prepared by thermal dehydration of respective R-FeOOH precursors via a topotactic transformation. The as-prepared samples were characterized by powder X-ray diffraction, micro-Raman spectroscopy, diffuse reflectance UV-visible spectroscopy, X-ray photoelectron spectroscopy, nitrogen adsorption-desorption, high-angle annular darkfield scanning transmission electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. Nanosized R-FeOOH and R-Fe 2 O 3 particles appeared to be more active than microsized ones in terms of surface area normalized reaction rate, suggesting intrinsic photocatalytic properties of nanorods as compared to microrods in both R-FeOOH and R-Fe 2 O 3 . In addition, R-Fe 2 O 3 nanorods exhibited the greatest activity among the as-prepared samples. The observed photocatalytic performance by iron oxide particles was attributed to the synergetic effects of the particle composition, size, porosity, and the variations of local structure. The results from current study will be potentially applicable to a range of naturally abundant semiconducting minerals and compounds (e.g., metal oxyhydroxides and metal oxides).

Reaction Kinetics, Mechanisms and Catalysis, 2014

ABSTRACT The role of •OH radicals (adsorbed and free) and valence band holes as primary oxidants ... more ABSTRACT The role of •OH radicals (adsorbed and free) and valence band holes as primary oxidants in the photodegradation of clomazone in UV-illuminated TiO2 suspension was investigated. Significant inhibition of the photodegradation of clomazone in the presence of NaI (hole and surface •OH scavenger) suggesting that the surface degradation mechanism played a crucial role rather than the bulk degradation pathway. Also, less impact of tert-butanol on the photodegradation indicated that free •OH radicals were not majorly involved in the photodegradation process of clomazone. On the other hand, when the surface is covered by fluoride, it was concluded that the kinetic pathways for reaction with subsurface holes and with free •OH in solution are predominant. The LC–ESI–MS/MS analyses of the irradiated solution of clomazone in the presence of NaF indicated formation of the same intermediates when free •OH played a crucial role in mechanism instead of surface •OH radicals. Besides, molecular oxygen, H2O2, KBrO3, and (NH4)2S2O8 are generally used as electron scavengers in heterogeneous photocatalytic reactions. It was found that the addition of electron scavengers such as H2O2, KBrO3, and (NH4)2S2O8 has resulted in higher pollutant degradation rate compared to molecular oxygen alone.

Science of The Total Environment, 2013

Toxicity study of metoprolol and its photocatalytic degradation mixtures • Toxicity evaluation in... more Toxicity study of metoprolol and its photocatalytic degradation mixtures • Toxicity evaluation in vitro in H-4-II-E, HT-29 and MRC-5 cell lines • TiO 2 Wackherr and Degussa P25 promoted a time-dependent increase in toxicity.

Applied Catalysis B: Environmental, 2014

Titanium dioxide nanotubes (TNT) were synthesized via hydrothermal method and calcined at various... more Titanium dioxide nanotubes (TNT) were synthesized via hydrothermal method and calcined at various temperatures. The obtained calcined TiO 2 nanomaterials with specific elongation orientation were characterized by transmission and scanning electron microscopy (TEM, SEM), X-ray diffraction (XRD), UV/Vis diffuse reflection spectroscopy (DRS), Laser Doppler electrophoresis (LDE) and their textural properties were evaluated. The photocatalytic activity of obtained nanopowders was evaluated considering photodegradation rate of herbicide clomazone, rarely studied herbicide. The influence of calcination temperature of catalysts with elongated morphology on their photocatalytic activity was evaluated. The best results were obtained with TNT annealed at 700 • C, which can be assigned to the best balance between crystal structure, morphology and surface properties of nanoparticles induced by annealing. Also, the photocatalytic degradation rates of another two herbicides (picloram, and mecoprop) were compared, due to possibility that the efficiency of photocatalytic degradation is greatly influenced by the molecular structure. The mineralization degree of selected herbicides in the presence of TiO 2 based photocatalysts was evaluated applying total organic carbon (TOC) measurements.

Journal of Molecular Catalysis A: Chemical, 2014

ABSTRACT The photocatalytic degradation of the herbicide mesotrione (0.05 mM) in aqueous suspensi... more ABSTRACT The photocatalytic degradation of the herbicide mesotrione (0.05 mM) in aqueous suspensions of TiO2 Degussa P25 and ZnO was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.00 mg/mL under UV light at the pH 4.0 (TiO2 Degussa P25) and pH 9.2 (ZnO). In the first stage of the reaction, the photocatalytic degradation of mesotrione followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds mainly via •OH radicals, and partly also via holes. The results showed that the disappearance of mesotrione led to the formation of a number of organic intermediates and ionic byproducts, whereas its complete mineralization occurred after about 4 h. Tentative photodegradation pathways were proposed and discussed as a function of the type of photocatalyst. A comparison of the evolution of toxicity that was evaluated in vitro in the rathepatoma (H-4-II-E) and human fetal lung (MRC-5) cell lines with the degradation kinetics indicates that the cell growth of both cell lines was only mildly affected by the mixture of mesotrione and its photocatalytic degradation intermediates obtained using TiO2 Degussa P25, and moderately affected by the mixtures obtained using ZnO, whereby at 120 min toxicity decreased.

Applied Catalysis B: Environmental, 2013

ABSTRACT A study of photocatalytic activity of bare as prepared, bare aged and dopamine surface m... more ABSTRACT A study of photocatalytic activity of bare as prepared, bare aged and dopamine surface modified colloidal TiO2 nanoparticles was obtained following degradation reaction of herbicide RS-2-(4-chloro-o-tolyloxy)propionic acid under UV light irradiation. Results showed that the most active photocatalyst is bare aged TiO2 and the least active are dopamine modified nanoparticles. Results are discussed in the light of surface structure of TiO2 nanoparticles. The study of surface modification of TiO2 nanoparticles (4.5 nm, TiO2 NPs) with dopamine was also performed. The formation of inner-sphere charge-transfer complexes results in red shift of semiconductor absorption threshold (600 nm), compared to bare TiO2 NPs (380 nm). Effective band gap energy of 3.2 eV for bare TiO2 NPs is reduced to 2.1 eV for TiO2/dopamine charge transfer complexes. The binding structure was investigated by UV-vis and FTIR spectroscopy. The obtained optimal geometry for binding of dopamine to surface Ti atoms was binuclear bidentate-bridging. From the Benesi–Hildebrand plot, stability constant of the order 103 M−1 has been determined.

Chemosphere, 2015

The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound ... more The photocatalytic degradation of the herbicide sulcotrione (0.05mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0mgmL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiation of sulcotrione solution and Tangenta® formulation using TiO2 catalyst on three mammalian cell lines.