Elektrohemijska i hemijska sinteza i karakterizacija katalizatora i sorbenata na bazi jedinjenja bizmuta i njihova primena u tretmanu vode

This dissertation is a part of the research performed within the Projects of the Ministry of Education, Science and Technological Development of the Republic of Serbia: Grant No. TR 34008 and Agreement No. 451-03-68/2020-14/200124. The experimental part of this thesis was done in the Laboratory for Applied and Environmental chemistry, Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš. Some of the analyzes of material characterization were done at the Faculty of Engineering and Science, University of Greenwich, UK, the Faculty of Technology in Leskovac, University of Niš, the Materials Science Laboratory, Institute of Nuclear Sciences, University of Belgrade, the Faculty of Chemistry, University of Belgrade. The aim of this doctoral dissertation was to develop chemical and electrochemical procedures for obtaining highly efficient photocatalysts and sorbents based on bismuth compounds. The bismuth oxo citrate photocatalyst was synthesized by precipitation method with subsequent thermal treatment. The preparation of sorbents based on basic bismuth nitrates was performed by the method of cathodic electrodeposition from an acidic solution of Bi(III) ions with subsequent thermal treatment. Material characterization was performed by the following methods: SEM-EDX, adsorption/desorption of N2, XRD, FTIR, CHNS/O and acid-base analysis. The basic parameters of the photocatalytic and sorption process were examined and the optimal conditions for the removal of textile dye Reactive Blue 19 (RB19) were determined. The obtained results showed that the synthesized materials can be successfully applied for the removal of dye from real polluted waters and that their efficiency is higher compared to other materials based on bismuth compounds which can be found in the available literature

Electrochemical synthesis and characterization of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O: a potential highly efficient sorbent for textile reactive dye removal

A new method of synthesis was developed for the preparation of basic bismuth nitrate [Bi6O5(OH)3](NO3)5·2H2O (ECBBN). Electrochemical synthesis of the material was carried out by galvanostatic electrodeposition from an acidic Bi(III) solution on a Ti substrate and further thermal treatment in air at 200 °C. Characterization of ECBBN was conducted by employing SEM–EDX, N2 adsorption, XRD and FTIR, and its pI was also determined. The analyses showed that the material obtained was pure [Bi6O5(OH)3](NO3)5·2H2O. Morphologically, ECBBN aggregates were composed of crystals, some smaller than 50 nm. Electrochemically synthesized sorbent (ECBBN) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solutions of polluted river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. A kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibration of the sorption process was attained in several minutes, i.e. the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Redlich–Peterson and Brouers–Sotolongo isotherm. Using Langmuir isotherm, the maximum sorption capacity of ECBBN was reached at pH 2 and was 1049.19 mg g−1

Actual contamination of the Danube and Sava Rivers at Belgrade (2013)

This study was focussed on a comprehensive investigation on the state of pollution of the Danube and Sava Rivers in the region of Belgrade. Different complementary analytical approaches were employed covering both i) organic contaminants in the river water by target analyses of hormones and neonicotinoids as well as non-target screening analyses and ii) heavy metals in the sediments. Finally, some common water quality parameters were analysed. The overall state of pollution is on a moderate level. Bulk parameters did not reveal any unusual observations. Moreover, quantification of preselected organic contaminants did not indicate to elevated pollution. More significant contaminations were registered for chromium, nickel, zinc and partially copper in sediments with values above the target values according to Serbian regulations. Lastly, non-target screening analysis revealed a wider spectrum of organic contaminants comprising pharmaceuticals, technical additives, personal care products and pesticides. The study presented a comprehensive view on the state of pollution of the Sava and Danube Rivers and is the base for setting up further monitoring programs. As a superior outcome, it was illustrated how different chemical analyses can result in different assessments of the river quality. A comparison of target and non-target analyses pointed to potential misinterpretation of the real state of pollution

Elektrohemijska i hemijska sinteza i karakterizacija katalizatora i sorbenata na bazi jedinjenja bizmuta i njihova primena u tretmanu vode

This dissertation is a part of the research performed within the Projects of the Ministry of Education, Science and Technological Development of the Republic of Serbia: Grant No. TR 34008 and Agreement No. 451-03-68/2020-14/200124. The experimental part of this thesis was done in the Laboratory for Applied and Environmental chemistry, Department of Chemistry, Faculty of Sciences and Mathematics, University of Niš. Some of the analyzes of material characterization were done at the Faculty of Engineering and Science, University of Greenwich, UK, the Faculty of Technology in Leskovac, University of Niš, the Materials Science Laboratory, Institute of Nuclear Sciences, University of Belgrade, the Faculty of Chemistry, University of Belgrade. The aim of this doctoral dissertation was to develop chemical and electrochemical procedures for obtaining highly efficient photocatalysts and sorbents based on bismuth compounds. The bismuth oxo citrate photocatalyst was synthesized by precipitation method with subsequent thermal treatment. The preparation of sorbents based on basic bismuth nitrates was performed by the method of cathodic electrodeposition from an acidic solution of Bi(III) ions with subsequent thermal treatment. Material characterization was performed by the following methods: SEM-EDX, adsorption/desorption of N2, XRD, FTIR, CHNS/O and acid-base analysis. The basic parameters of the photocatalytic and sorption process were examined and the optimal conditions for the removal of textile dye Reactive Blue 19 (RB19) were determined. The obtained results showed that the synthesized materials can be successfully applied for the removal of dye from real polluted waters and that their efficiency is higher compared to other materials based on bismuth compounds which can be found in the available literature

Synthesis of mesoporous triple-metal nanosorbent from layered double hydroxide as an efficient new sorbent for removal of dye from water and wastewater

In this study, co-precipitation synthesis of the mesoporous triple-metal nanosorbent from Fe, Cu, Ni layered double hydroxide (FeCuNi-LDH), on the basis of the data obtained from the TG analysis was carried out. The FTIR spectroscopy and XRD results confirm the formation of CuO, NiO and Fe O nanoparticles, while the EDX analysis does not show significant variations on the surface in elemental composition. BET analysis shows that FeCuNi-280 (FeCuNi-LDH calcinated at 280 °C) with mesoporous structure, has larger surface area compared to FeCuNi-LDH and FeCuNi-550 (FeCuNi-LDH calcinated at 550 °C). The value of pH of FeCuNi-280 is found to be 8.66. Obtained FeCuNi-280 material showed the ability for efficient removal of dye Reactive Blue 19 (RB19) from water, with a very high sorption capacity of 480.79 mg/g at optimal conditions: the sorbent dose of 0.6 g/dm , stirring speed of 280 rpm and pH 2. The kinetics results of the sorption process were well fitted by pseudo-second order and Chrastil model, and the sorption isotherm was well described by Sips, Langmuir and Brouers-Sotolongo model. FeCuNi-280 was easily regenerated with aqueous solution of NaOH, and reutilization was successfully done in five sorption cycles. The present study show that easy-to-prepare, relatively inexpensive nanosorbent FeCuNi-280 is among the best sorbents for the removal of RB19 dye from water solution and wastewater from textile industry in wide range of pH

Electrochemically synthesized Molybdenum oxides for enhancement of atmospheric pressure non-thermal pulsating corona plasma induced degradation of an organic compound

MoO2 and MoO3 were applied as catalysts for plasma degradation of organic compound. They were prepared by electrodeposition (MoO2) and electrodeposition followed by thermal treatment (MoO3), and then characterized by the cyclic voltammetry, SEM, EDX, XRD, and FTIR. The RB 19 was degraded by self-made non-thermal atmospheric pressure pulsating plasma corona reactor. Decolourization mechanism, parameters, kinetics, and influence of the catalysts were examined. Mo-oxides enhanced degradation reactions rate constants by 45% – 50%, increased decolourization rate at all the tested pHs, discharged current densities, and decreased energy consumption. Degradation followed the pseudo-first kinetics order and proceeded via plasma-generated ⋅OH radical, which attacked dye molecule; MoO2 and MoO3, excited by plasma-generated UV radiation and high-energy chemical species bombardment, enhanced decomposition of plasma-generated H2O2 into ⋅OH radicals, thus enhancing production of degradation agent. Higher percentage of mineralization was attained in the presence of catalysts, which maintained their degradation activity after 5 uses

New Way of Synthesis of Basic Bismuth Nitrate by Electrodeposition from Ethanol Solution: Characterization and Application for Removal of RB19 from Water

A new method of synthesis was developed for the preparation of sorbent basic bismuth nitrate [Bi6O5(OH)(3)](NO3)(5)center dot 2H(2)O (BBN-EtOH). This electrochemical method includes electrodeposition from an acidic Bi(III) solution in 96% ethanol at a constant current density of 150.0 mA cm(-2). Final product was obtained by thermal treatment at 200 degrees C. Characterization of BBN-EtOH was conducted by employing XRD, FTIR, SEM-EDX as well as BET, and its pI was also determined. The analysis showed that the material obtained is pure [Bi6O5(OH)(3)](NO3)(5)center dot 2H(2)O. Morphologically, it is composed of aggregates which were formed of several smaller particles of various shapes and sizes, some smaller than 100 nm. Electrochemically synthesized sorbent (BBN-EtOH) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solution of river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. Kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibrium of the sorption process was attained in several minutes, i.e., the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Sips and Brouers-Sotolongo isotherm. The maximum sorption performance was achieved at pH 2.0, and according to the Langmuir isotherm, it is 1344.99 mg g(-1)

A New Photocatalyst Bismuth Oxo Citrate: Synthesis, Characterization, and Photocatalytic Performance

A new photocatalyst bismuth oxo citrate was synthesized by facile precipitation process with calcination at 200 8C. The photocatalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fouriertransform infrared (FTIR) spectroscopy, N2 sorptometry, and elemental analysis. Morphologically, it is composed of polyhedral particles with different, irregular shapes and sizes. The specific surface area (SSA) of the photocatalyst was 8.92 m2 g-1. It showed very good photocatalytic performance and reusability. Total decolorization of Reactive Blue 19 (RB19) was achieved in less than 10 minutes, which is much faster in comparison with TiO2 P25. Also, bismuth oxo citrate showed higher photocatalytic activity than other photocatalysts based on bismuth compounds reported by other authors. Optimal photocatalysis parameters were pH 2 and photocatalyst dose of 250 mg dm-3. The decolorization rate was found to decrease as initial dye concentration increased. The photocatalytic data best fitted to L-H kinetic model with pseudo-first order reaction rate. Chrastil diffusion model showed that diffusion has not influence on the process. Water Environ. Res., 90, 719 (2018). © 2018 Water Environment Federation

Heterogeneous photocatalytic degradation of anthraquinone dye Reactive Blue 19: optimization, comparison between processes and identification of intermediate products

Treatment of textile wastewater using heterogeneous photocatalysis began in the the last decade and attracted the attention of researchers due to its versatile application. The variety of applications of TiO2 as a photocatalyst was due toits numerous positive properties, such as low operating temperature, biologically inert nature, low energy consumption, water insolubility, availability and photoactivity, low toxicity, high chemical stability, suitable flat band potential, narrow bandgap and the fact that it is environmentally benign. Heterogeneous UV-TiO2 photocatalysis is capable of removing organic pollutants from textile wastewater; this has been widely studied, with the technology also having been commercialized in many developing countries. Decolorization of anthraquinone dye Reactive Blue 19 (RB 19) by heterogeneous advanced oxidation processes TiO2/UV/H2O2, TiO2/UV/KBrO3 and TiO2/UV/(NH4)2S2O8 was studied under different conditions and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate ((NH4)2S2O8). Decolorization was very fast for all three processes, and complete dye decolorization was achieved in 10 min. The effect of various ions (Cl–, SO42– and HCO3–) on RB 19 decolorization was also studied. The optimal condition for the decolorization of the dye were determined to be: TiO2 concentration 1 g∙dm–3, electron acceptor concentration 30.0 mmol∙dm–3, dye concentration 50.0 mg∙dm–3, UV intensity 1 950 μW∙cm–2, at temperature 25 ± 0.5°C. In addition, experiments were performed and compared in three different matrices. In the surface water and dyebath effluent water, the removal efficiency for RB 19 was lower than that achieved in the deionized water because of the interference of complex constituents in the surface water and effluent. LC-MS analysis was carried out and the detected intermediates were compared with the previously published data for anthraquinone dyes