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Stability and toxicity of selected chlorinated benzophenone-type UV filters in waters
Polonca Trebše, Darko Dolenc, Romina Žabar, Tatjana Tišler, Gorica Grbović, Jun Yao, Rensheng Zhuang, 2013, original scientific article

Abstract: Stability and toxicity of selected chlorinated benzophenone-type UV filters in waters
Found in: ključnih besedah
Keywords: UV filter, photostability, chlorination, toxicity, Vibrio fischeri
Published: 05.01.2016; Views: 3919; Downloads: 1

Removal of diclofenac from water by zeolite-assisted advanced oxidation processes
Urška Lavrenčič Štangar, Daria Juretic Perisic, Vanja Gilja, Mirjana Novak Stankov, Zvonimir Katancic, Hrvoje Kusic, Dionysios D. Dionysiou, Ana Loncaric Bozic, 2016, original scientific article

Found in: ključnih besedah
Summary of found: ...Diclofenac, FeZSM5, Biodegradability, Toxicity, Catalyst stability...
Keywords: Diclofenac, FeZSM5, Biodegradability, Toxicity, Catalyst stability
Published: 24.02.2016; Views: 3455; Downloads: 0
.pdf Fulltext (3,50 MB)

Diclofenac removal by simulated solar assisted photocatalysis using TiO2-based zeolite catalyst; mechanisms, pathways and environmental aspects
Dionysios D. Dionysiou, Urška Lavrenčič Štangar, Sandra Babich, Hrvoje Kušić, Martina Biosic, Daria Juretic Perisic, Subhan Salaeh, Ana Lončarić Božić, 2016, original scientific article

Abstract: The study explores the potential of immobilized TiO2-based zeolite composite photocatalyst (TiO2-FeZ) made of commercial AEROXIDE TiO2 P25 and iron-exchanged zeolite of ZSM5 type (FeZ), for solar assisted treatment of diclofenac (DCF), pharmaceutical included in the ‘‘watch list” during last prioritization in water legislation by EU. In this study the efficiency of applied photocatalytic treatment, solar/TiO2-FeZ/H2O2, of DCF water solution was evaluated on basis of DCF removal and conversion kinetics, as well as the changes of common parameters for assessing water quality. Hence, the changes in the removal and mineralization of overall organic content, biodegradability, toxicity to Vibrio fischeri, dechlorination of DCF and its formed by-products, were monitored during the treatment. The obtained data were correlated with the evolution of DCF by-products, identified and monitored during the treatment by HPLC/MSMS analysis. In order to estimate the influence of water matrix, all experiments were performed in the presence of chloride or sulphate as counter ions. The obtained data revealed that degradation mechanism of DCF by applied treatment process using immobilized TiO2-FeZ includes the adsorption onto photocatalyst surface and consequent degradation. The contribution of homogeneous Fenton reaction due to leached iron ions was found to be negligible. The adsorption and degradation pathway of DCF were influenced by the type of counter ions, which was reflected in the observed changes of water quality parameters.
Found in: ključnih besedah
Summary of found: ...removal and mineralization of overall organic content, biodegradability, toxicity to Vibrio fischeri, dechlorination of DCF and its...
Keywords: Solar photocatalysis, TiO2-FeZ catalyst, Diclofenac, Degradation pathway, Biodegradability, Toxicity
Published: 21.07.2016; Views: 3961; Downloads: 0
.pdf Fulltext (2,10 MB)

Comparative analysis of UV-C/H2O2 and UV-A/TiO2 processes for the degradation of diclofenac in water
Urška Lavrenčič Štangar, Hrvoje Kušić, Marin Kovacic, Daria Juretic Perisic, Vedrana Marin, Ana Lončarić Božić, 2016, original scientific article

Abstract: The study investigates the treatment of diclofenac (DCF), a pharmaceutical included in the first watch list of the European Water Framework Directive as a new potential priority substance in water. Since the conventional wastewater treatment technologies do not efficiently remove DCF, advanced treatment technologies capable of its complete removal or destruction of its biological activity, need to be evaluated and eventually employed. For that purpose, typical representatives of photooxidative and photocatalytic advanced oxidation processes were applied. The effectiveness of UV-C/H2O2 and UV-A/TiO2 were compared regarding DCF conversion and mineralization kinetics, water quality parameters for assessing biodegradability and toxicity. In spite of similar biodegradability profiles, the obtained results indicate different DCF degradation pathways, which are reflected in different profiles of toxicity towards Vibrio fischeri. The observed DCF conversion and mineralization kinetics revealed the benefits of UV-C/H2O2 process. However, lower toxicity favored the application of photocatalytic over photooxidative treatment for DCF removal.
Found in: ključnih besedah
Summary of found: ...kinetics, water quality parameters for assessing biodegradability and toxicity. In spite of similar biodegradability profiles, the obtained...
Keywords: Diclofenac, Photooxidation, Photocatalysis, Biodegradability, Toxicity
Published: 21.07.2016; Views: 3494; Downloads: 0
.pdf Fulltext (496,03 KB)

Arbuscular mycorrhizal fungi alter Hg root uptake and ligand environment as studied by X-ray absorption fine structure
Alojz Kodre, Iztok Arčon, Marta Debeljak, Mateja Potisek, Matevž Likar, Katarina Vogel-Mikuš, 2017, original scientific article

Abstract: Mercury (Hg) – plant – fungal interactions are only poorly studied. Hg speciation and ligand environment in maize roots inoculated with arbuscular mycorrhizal (AM) fungi were investigated in order to better understand the role of AM in Hg soil to root transfer. The maize plants were grown in Hg polluted substrate (50 mg g1 as dissolved HgCl2) and inoculated with AM fungi originating from: a) highly Hg polluted environment of a former Hg smelting site in Idrija, Slovenia, (Glomus sp. – sample AmI), and b) non-polluted environment (commercial AM inoculum Symbivit1 – sample AmC). Hg speciation and ligand environment in maize roots was studied by Hg-L3 XANES and EXAFS with emphasis on XAS methodology – modelling and fitting the XAFS spectra to extract in a reliable way as much information on Hg coordination as possible. The AmI plants developed more arbuscules and less vesicles than the AmC plants, and also accumulated more Hg in the roots. A clear difference in Hg coordination between the AM (AmC & AmI) and the control (ConC & ConI) plants is recognized in Hg L3-edge EXAFS analysis: in the ConC & ConI maize roots 73–80% of Hg is attached between two sulphur atoms at the distance of 2.34 Å. The remaining ligand is nitrogen at 2.04 Å. In AmI & AmC roots another Hg-S attachment encompassing four thiol groups at the S-distance of 2.50 Å are identified, accounting for 21–26%. AM fungi can modify Hg ligand environment in plant roots, thus playing an important role in biogeochemical cycling of Hg in terrestrial ecosystems.
Found in: ključnih besedah
Summary of found: ...EXAFS XANES Arbuscular mycorrhiza Phytoremediation Toxicity Hg coordination Ligand environment...
Keywords: EXAFS XANES Arbuscular mycorrhiza Phytoremediation Toxicity Hg coordination Ligand environment
Published: 27.09.2016; Views: 4398; Downloads: 0
.pdf Fulltext (1,82 MB)

Ketevan Neparidze, 2017, undergraduate thesis

Abstract: Over the last few decades, numerous pharmaceuticals coming from domestic sewage, livestock, hospitals and industries have been determined in ground, surface and drinking waters. A common example of these pollutants are fluoroquinolones, which are powerful antibiotics used in human and veterinary medicine. The presence of fluoroquinolones in the environment even at low concentration constitutes a threat to ecosystems and human health because they can lead to bacterial resistance issues. Up to now the environmental impacts of fluoroquinolones and their degradation products are not fully understood but it is known that they can negatively affect plants and aquatic organisms. In this study the degradation of ciprofloxacin (CIP) present in synthetic freshwater was investigated under simulated sunlight. Concentrations before and after degradation were determined using HPLC-DAD. The mineralisation rate of the treated solution was monitored on a total organic carbon analyser. The ecotoxicity of the initial samples and the degradation mixtures was assessed on organisms belonging to different trophic levels: a marine bacterium (Vibrio fischeri), a freshwater invertebrate (Daphnia magna) and seed clover (Trifolium repens). In parallel, the EC50 of CIP was determined for all organisms. The Vibrio fischeri and Trifolium repens tests showed that EC50 value was more than 250 mg/L and for Daphnia magna was 190 mg/L. Photolysis of CIP showed that after 90 min of irradiation, CIP was almost totally degraded (99%). Photolysis process of CIP led to the formation of toxic by-products towards Vibrio fischeri. The toxicity test results on Trifolium repens did not show significant difference between the control and the treated plants. Thus, CIP and its degradation products have no effect on the germination or root length of Trifolium repens. Tests on Daphnia magna after 240 min irradiation showed a 94% reduction of the toxic effect. Non-purgeable organic carbon (NPOC) analysis showed that there is no significant mineralisation of the sample even after 240 min of irradiation.
Found in: ključnih besedah
Summary of found: ...a total organic carbon analyser. The eco toxicity of the initial samples and the degradation...
Keywords: Key words: fluoroquinolones, ciprofloxacin, photolysis, toxicity tests, EC50 determination
Published: 31.01.2017; Views: 4381; Downloads: 255
.pdf Fulltext (947,78 KB)

Arsenic in natural waters: hydrogeochemistry characterization and toxicity effects
Doroteja Gošar, 2018, master's thesis

Abstract: Arsenic contamination in natural water is a worldwide problem and a major health concern. In master thesis hydrogeochemistry and toxicity effects of natural waters rich in arsenic were studied. The main objective of the master thesis was to evaluate As pollution of the Freixeda stream and groundwater in abandoned Freixeda gold mine area in NE Portugal near Mirandela city (41.413767 N 7.103562 W) and compare it with the data from previous studies. Further on, toxicological evaluation of selected water samples was performed in the in vitro system of human cell line Caco-2. Chemical analyses of sampled water samples with use of different modelling sofware show that groundwater have higher sulphate and bicarbonate values than surface water, which could be the reason for As desorption and higher As values in groundwater. Water-rock interaction promotes reduction and dissolution of sulphide minerals and in reductive environments dissolution of secondary Fe minerals releases adsorbed As into solution. Toxicological testing on human cells included cytotoxicity assay, genotoxicity assay and production of reactive oxigene species (ROS). Genotoxicity was only modestly affected by a short-term exposure to As-contaminated water samples, however, higher concentrations of As in real samples lead to higher level of oxidative stress and decreased cell viability. Exposure of cells to pure As(III) solution show clear concentration dependent decrease in cell metabolism and viability, strong genotoxicity and increased ROS generation. Considering the worldwide extent of As contamination in natural waters and ability of intestinal epithelium to reduce the potential harmful effects of As, more studies evaluating the human intestinal permeability for As should be done in the future.
Found in: ključnih besedah
Keywords: Water quality, arsenic, hydrogeochemistry, toxicity, Caco-2 cell line
Published: 26.09.2018; Views: 3346; Downloads: 138
.pdf Fulltext (3,76 MB)

Impact of microplastics on growth, photosynthesis and essential elements in Cucurbita pepo L.
Stefano Loppi, Cristina Gonnelli, Andrea Coppi, Sara Pignattelli, Elisabetta Bianchi, Maria Beatrice Castellani, Ilaria Colzi, Luciana Renna, 2022, original scientific article

Abstract: In this study, Cucurbita pepo L., one of the most cultivated, consumed and economically important crop worldwide, was used as model plant to test the toxic effects of the four most abundant microplastics identified in contaminated soils, i.e. polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), and polyethyleneterephthalate (PET). Cucurbita plants were grown in pots with increasing concentrations of the microplastics, then plant biometry, photosynthetic parameters and ionome of treated vs. untreated samples were compared to evaluate the toxicity of each plastic. All the pollutants impaired root and, especially, shoot growth. Specific and concentration-dependant effects of the different microplastics were found, including reduction in leaf size, chlorophyll content and photosynthetic efficiency, as well as changes in the micro- and macro-elemental profile. Among all the microplastics, PVC was identified as the most toxic and PE as the less toxic material. PVC decreased the dimensions of the leaf lamina, the values of the photosynthetic performance index and the plant iron concentration to a higher extent in respect to the other treatments. Microplastic toxicity exerted on the growth of C. pepo raises concerns about possible yield and economic loss, as well as for risks of a possible transfer into the food chain.
Found in: ključnih besedah
Summary of found: ...untreated samples were compared to evaluate the toxicity of each plastic. All the pollutants impaired...
Keywords: microplastic toxicity, leaf traits, chlorophyll fluorescence, ionome, zucchini
Published: 17.12.2021; Views: 430; Downloads: 1
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