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1.
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: ...counter ions. The obtained data revealed that degradation mechanism of DCF by applied treatment process using...
Keywords: Solar photocatalysis, TiO2-FeZ catalyst, Diclofenac, Degradation pathway, Biodegradability, Toxicity
Published: 21.07.2016; Views: 3476; Downloads: 0
.pdf Fulltext (2,10 MB)

2.
PREPARATION AND CHARACTERIZATION OF HIGHLY PHOTOACTIVE COATINGS ON GLASS SUPPORTS FOR DEGRADATION OF PHARMACEUTICAL SUBSTANCE PARACETAMOL IN WATER
Lidija Sinovčić, 2016, master's thesis

Abstract: Pharmaceuticals in aquatic environment are considered as emerging environmental contaminants due to their constant presence, evironmental resistance and toxic effect they could have on aquatic organisms. Studies for Slovenia have shown the presence of pharmaceutical substances in waters to be comparable with published results of pharmaceutical water pollution in Europe. As conventional methods do not reach efficient pharmaceutical removal from water sources, more powerful and effective methods like heterogeneous photocatalysis using TiO2/UV have been implemented. Titanium dioxide coatings in silicate binder were prepared by the sol-gel process and deposited on a glass support with dip-coating technique. The films showed good quality and possibility of multiple use. The characterization of the films was performed with scanning electron microscope (SEM), x-ray diffraction (XRD) and hardness test (Elcometer 501 Pencil Hardness Tester). Effectiveness and quality of prepared TiO2 coatings for photodegradation of pharmaceutical compound paracetamol (PCT) were assessed during photocatalytic treatment and compared to photolysis, a process without presence of a catalyst. Photolysis caused substantial changes in paracetamol concentration between 120 and 180 minutes of irradiation where 92% of degradation was achieved, but with no changes in mineralization. Photocatalytic treatment was much faster and effective where 95% of paracetamol degraded within 90 minutes of UV irradiation and after prolonged irradiation time from 120 to 240 minutes also mineralization of paracetamol solution increased from 59% to 83%. Accordingly, toxicity decreased, but it was still not lower than in the starting PCT solution as it was shown by acute toxicity test on Daphnia magna aquatic organisms. The master thesis represents a step forward in studying photocatalytic removal of paracetamol from water, because to my knowledge all the published investigations on this pharmaceutical up to now include photocatalyst mostly in powder and not in immobilized form, which is more advantageous from application point of view.
Found in: ključnih besedah
Keywords: Pharmaceuticals, paracetamol, titanium dioxide, photocatalytic degradation, Daphnia magna.
Published: 14.09.2016; Views: 4530; Downloads: 232
.pdf Fulltext (2,50 MB)

3.
Anaerobic digestion of brewery spent grain as a mono-substrate in a two-stage anaerobic digestion using solid-state digestion reactor and granulated biomass reactor
Marina Tišma, Bruno Zelić, Romana Marinšek Logar, Mario Panjicko, Gregor Drago Zupančič, 2016, published scientific conference contribution (invited lecture)

Abstract: Anaerobic digestion of brewery spent grain as a mono-substrate was studied. Anaerobic digestion was phase separated in solid state anaerobic digestion reactor, where mostly microbiological hydrolysis and acidogenesis and granular biomass reactor where mostly methanogenesis was performed. The overall process exhibited total solids degradation efficiency between 73.6 and 80.4%. Average specific biogas production was 424±36 L/kg, whereas biomethane production was 230±34 L/kg of brewery spent grain total solids. Granular biomass after adaptation exhibited stabile operation at C-N ratios as low as 0.2 – 0.3, which is rare in anaerobic digestion. P-cresol as a degradation product was present in concentrations up to 45 mg/L and during the process successfully degraded. The excellent adaptability of the granular biomass is confirmed by 67% shift in bacterial and a 32% shift in archaeal community structure in granular biomass reactor after 198 days of successful operation.
Found in: ključnih besedah
Summary of found: ...0.3, which is rare in anaerobic digestion. P-cresol as a degradation product was present in...
Keywords: Anaerobic digestion, biogas production, brewery spent grain, microbial biomass, p-cresol degradation, solid state anaerobic digestion
Published: 21.10.2016; Views: 3500; Downloads: 0
.pdf Fulltext (968,03 KB)

4.
Photocatalytic properties of metal modified TiO2 by photothermal techniques
Mladen Franko, Dorota Korte, Urška Lavrenčič Štangar, Olena Pliekhova, Humberto Cabrera, Zeinab Ebrahimpour, 2018, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ...eflection spectroscopy, Dye remediation, Photothermal technique, Photocatalytic degradation, Reactive Blue 19, TiO2 modification...
Keywords: Thermal lens spectrometry, Photothermal beam deflection spectroscopy, Dye remediation, Photothermal technique, Photocatalytic degradation, Reactive Blue 19, TiO2 modification
Published: 09.11.2018; Views: 1804; Downloads: 0
.pdf Fulltext (208,76 KB)

5.
6.
Managing karst in Coastal British Columbia, Canada
Paul Andre Griffiths, 2020, doctoral dissertation

Abstract: This thesis provides a detailed description and analysis of the system used for managing karst in the forests of coastal British Columbia (BC), where the major land- use activity is industrial forestry. In 2004, BC shifted from a more prescriptive forest management model (the Forest Practices Code) to a less regulated, results-based approach based primarily on the Forest and Range Practices Act (FRPA). The dissertation examines how this results-based management approach for forest resources has worked – or not worked – with respect to karst. The research focused on the five key realms of an environmental management system as defined by the International Standards Organization (ISO 14001 standard): 1) Legislation and Policy, 2) Planning, 3) Implementation, 4) Checking/Corrective Action, and 5) Management Review. The research also examined the roles of professional reliance (another major foundational element of the FRPA model), karst research, and organizational capacity as external factors which influence on the functioning of the karst management system. A combination of interviews, surveys, document reviews and field observations were used to collect qualitative information relevant to all aspects of the karst management system. This research reveals inadequacies in all five realms of BC’s current karst management framework, including gaps in legislation, a lack of implementation of existing standards and guidelines, and non-existent effectiveness and compliance monitoring. The results suggest that BC’s shift to ‘self-regulation’ has yielded unsatisfactory results so far for karst resources and has hindered progress toward implementing a fully integrated science-based ecosystem approach to karst management in the study area. Professional reliance failures are identified as one of the key factors contributing to a breakdown of the management system for karst. This is the first comprehensive study that examines the systems and processes used for managing karst in coastal BC, and consolidates knowledge for government, industry, and others that wish to study or better understand BC’s approach and methods for managing karst. The findings will be useful for private and public forest sector organizations endeavoring to implement fully-functional and effective systems for managing karst in a forestry context. This information may also have more specific applications for managing karst.
Found in: ključnih besedah
Summary of found: ...management, legislation, policies, standards and guidelines, environmental degradation, forestry impacts, professional reliance, British Columbia, Canada...
Keywords: karst ecosystems, protection and management, legislation, policies, standards and guidelines, environmental degradation, forestry impacts, professional reliance, British Columbia, Canada
Published: 02.03.2020; Views: 1596; Downloads: 28
.pdf Fulltext (136,27 MB)

7.
Preparation of porous [alpha]-Fe[sub]2O[sub]3 thin films for efficient photoelectrocatalytic degradation of basic blue 41 dye
Saim Emin, Lorena Butinar, Branka Mozetič Vodopivec, Mitja Martelanc, Manel Machreki, Takwa Chouki, 2021, original scientific article

Abstract: A novel method was developed for the preparation of porous hematite (α-Fe2O3) thin films. First, a solution containing iron precursor was spin-coated on fluorine-doped tin oxide substrate and later short heat-treated at 750 °C. The prepared α-Fe2O3 thin films were applied as dual-function catalyst in photoelectrochemical (PEC) water oxidation and textile dye degradation studies. For the first time, α-Fe2O3 thin films were used in efficient PEC degradation of a textile dye (Basic Blue 41 – B41) using in-situ generated reactive chlorine species. In comparison with photocatalytic and electrocatalytic approaches, the PEC technique allows faster degradation of B41 dye at an applied bias potential of 1.5 V versus reversible hydrogen electrode and under visible light illumination. In the presence of Cl− using the PEC approach the degradation of B41 reaches 99.8%. High-performance liquid chromatography coupled with UV–VIS system confirmed the degradation of B41 dye using PEC. Gas-chromatography coupled to mass spectrometry was used to study the by-products obtained during PEC degradation. Chemical oxygen demand analyses confirmed that the mineralization level of B41 is in the order of 68%. The α-Fe2O3 films developed in this study give a higher level of PEC degradation efficiency compared to other iron oxide-based systems.
Found in: ključnih besedah
Keywords: thin films, photoelectrocatalysis, kinetics, visible light, degradation, textile dye
Published: 10.05.2021; Views: 425; Downloads: 2
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8.
Photoelectrocatalytic water splitting and dye degradation with fluorine doped tin oxides films
Saim Emin, Takwa Chouki, Manel Machreki, 2019, published scientific conference contribution abstract

Abstract: We report the photoelectrochemical (PEC) water splitting with flourine doped tin oxide (FTO) films. This is the first study where efficient water splitting is achieved with FTO films under light illumination. Potentiostatic test at 1.7 V vs reversible hydrogen electrode (RHE) show that FTO material is very stable for water oxidation without occurence of a noticable current drop over a span of 6 hours. Mass spectrometry analysis of evolved gasses confermed the formation of oxygen and hydrogen in the two half cells (separated by a membrane). Moreover, it was demonstrated that the water splitting reaction involve formation of hydroxyl radicals (•OH) which are known oxidants for organics. We applied these FTO films for degradation of a model pollutant rhodamine B dye (1×10−5 mol/l). PEC assisted degradation of rhodamine B took about 30 min to achieve complete degradation of 60 ml model dye solution.
Found in: ključnih besedah
Keywords: FTO, thin films, dye degradation
Published: 13.05.2021; Views: 380; Downloads: 0
.pdf Fulltext (3,87 MB)

9.
Chemical (in)stability of interfaces between different metals and Bi[sub]2Se[sub]3 topological insulator
Sandra Gardonio, Matjaž Valant, Katja Ferfolja, Mattia Fanetti, 2018, published scientific conference contribution abstract

Abstract: In recent years a classification of materials based on their topological order gained popularity due to the discovery of materials with special topological character – topological insulators (TI). TI have different band structure than regular insulators or conductors. They are characterized by a band gap in the bulk of the material, but at the surface they possess conductive topological surface states (TSS) that cross the Fermi level. TSS are a consequence of the non-trivial bulk band structure and have properties that differ from ordinary surface states. They are robust toward contamination and deformation of the surface. Additionally, they are also spin polarized, which means that an electron spin is locked to a crystal momentum and, therefore, backscattering during transport is suppressed [1]. Due to their specific properties the TI could be used in fields of spintronics, quantum computing and catalysis [2]. The investigation of the interfaces between metals and the TI has not been given much attention even though its characterization is interesting from fundamental physics and applicative point of view. (In)stability of the contacts with metal electrodes, in a form of a chemical reaction or diffusion, has to be taken into account since it can affect the transport properties of the material or increase the contact resistance. Our research is dedicated to the study of the metal/TI interfaces, in particular to Bi2Se3 with deposited metals that are relevant for electrical contacts (Au, Ag, Pt, Cr, Ti). The thermal and chemical stability of the interfaces are of fundamental importance for understanding the contact behavior, therefore, we focused our work to the characterization of these properties. The metal/TI interfaces are investigated mainly with an electron microscopy (SEM, TEM, STM), EDX microanalysis and XRD. Our previous studies showed that the interface between Bi2Se3, and Ag deposited either chemically or from a vapor phase, results in the formation of new phases already at room temperature [3]. On the contrary, Au deposited on the Bi2Se3 surface shows very limited reactivity and is stable at RT, but diffusion and coalescence of the metal are observed starting from 100 °C [4]. In this contribution, we will present further characterization on the evolution of the Ag/Bi2Se3 and Au/Bi2Se3 interfaces, show preliminary results about recently investigated systems (Pt/Bi2Se3, Ti/Bi2Se3) and compare the thermal and chemical stability of the systems under investigation.
Found in: ključnih besedah
Summary of found: ...eflection spectroscopy, dye remediation, photothermal technique, photocatalytic degradation, reactive blue 19, TiO2 modification...
Keywords: thermal lens spectrometry, photothermal beam deflection spectroscopy, dye remediation, photothermal technique, photocatalytic degradation, reactive blue 19, TiO2 modification
Published: 20.08.2021; Views: 306; Downloads: 0
.pdf Fulltext (100,42 KB)

10.
Advances and Challenges in Industrial-Scale Water Oxidation on Layered Double Hydroxides
Andraž Mavrič, Chunhua Cui, 2021, review article

Found in: ključnih besedah
Summary of found: ...reaction layered double hydroxide high current density degradation stability...
Keywords: oxygen evolution reaction layered double hydroxide high current density degradation stability
Published: 09.11.2021; Views: 125; Downloads: 2
.pdf Fulltext (12,80 MB)

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