Borislav N. Malinovic

Wastewaters from the textile industry have a high content of organic matter, high coloration, various minerals and metals, and often toxic and carcinogenic substances. Azo dyes are the most common used dyes in the textile industry. Due to their complex structure, the removal of azo dyes from wastewater is challenging. In this study, electrooxidation and the electro-Fenton process, as one of the most effective Electrochemical Advanced Oxidation Processes (EAOPs) for the removal of organic pollutants in wastewater, were used for the treatment of synthetic wastewater containing “Bemacid Red” dye as a pollutant. Several process parameters affecting the efficiency of OH. formation and dye degradation were examined. Stainless steel (SS) was used as the cathode material, and the anodes used were mixed metal oxides (MMO) - Ru mixed oxide (titanium substrate coated with 6g Ru/m2) and Ru-Ir mixed oxide (titanium substrate coated with 6g Ru- Ir/m2). The results showed that the Ru:SS electrode pair is more efficient comapred to the Ru-Ir:SS pair, and that the electro-Fenton process is more efficient compared to electrooxidation.

The electrooxidation (EO) of three important environmental contaminants, anticorrosive 1H-benzotriazole (BTA), plasticizer dibutyl phthalate (DBP), and non-ionic surfactant Triton X-100 (tert-octylphenoxy[poly(ethoxy)] ethanol, t-OPPE), was studied as a possible means to improve their elimination from wastewaters, which are an important emission source. EO was performed in a batch reactor with a boron-doped diamond (BDD) anode and a stainless steel cathode. Different supporting electrolytes were tested: NaCl, H₂SO₄, and Na₂SO₄. Results were analysed from the point of their efficacy in terms of degradation rate, kinetics, energy consumption, and transformation products. The highest degradation rate, shortest half-life, and lowest energy consumption was observed in the electrolyte H₂SO₄, followed by Na₂SO₄ with only slightly less favourable characteristics. In both cases, degradation was probably due to the formation of persulphate or sulphate radicals. Transformation products (TPs) were studied mainly in the sulphate media and several oxidation products were identified with all three contaminants, while some evidence of progressive degradation, e.g., ring-opening products, was observed only with t-OPPE. The possible reasons for the lack of further degradation in BTA and DBP are too short of an EO treatment time and perhaps a lack of detection due to unsuitable analytical methods for more polar TPs. Results demonstrate that BDD-based EO is a robust method for the efficient removal of structurally diverse organic contaminants, making it a promising candidate for advanced water treatment technologies.

This study explores the effectiveness of electrocoagulation (EC) for removing toxic hexavalent chromium (Cr(VI)) from industrial wastewater using iron and aluminum electrodes in both batch and continuous modes. Iron electrodes demonstrated superior performance, achieving up to 99.8% Cr(VI) removal in batch mode at an optimal current density of 5 mA/cm2, while continuous operation at 50 L/h achieved comparable removal after 30 minutes, with slightly lower efficiency due to reduced retention time. The lowest specific energy consumption (2.82 kWh/kg Cr(VI)) was also recorded under these optimal conditions, highlighting economic feasibility. Fourier-transform infrared (FTIR) analysis of the sludge confirmed the reduction of Cr(VI) to the less toxic Cr(III), primarily in the form of Cr(OH)3. Characteristic peaks indicate Cr-O vibrations in chromium hydroxide, while the presence of hydroxyl (-OH) groups confirms the formation of iron hydroxide complexes that facilitate Cr(VI) adsorption and precipitation. Additional spectral features suggest the presence of iron oxides, further supporting the electrocoagulation mechanism involving the generation of coagulant species in situ. Overall, the results affirm EC as a highly efficient and cost-effective treatment method, particularly suitable for large-scale applications.

Dissolution of water-insoluble drugs is an important challenge in drug delivery. Adsorbing water-insoluble drugs onto nanoporous carriers such as zeolites can improve drug dissolution. The drug molecules adsorbed in a thin layer onto nanoporous carriers are fully exposed to the solvent, enhancing the dissolution process. This presentation will give new insights into the adsorption of water-insoluble letrozole drug onto the nanoporous clinoptilolite zeolite from a nanoscale-science point of view based on experimental and theoretical considerations. Adsorption of the letrozole drug on clinoptilolite zeolite will be conducted from the colloidal dispersion state. The amount of letrozole adsorbed in a monolayer will be evidenced by thermogravimetric measurements, while optical spectroscopy techniques will reveal the interactions of the letrozole drug on the nanoporous zeolite framework. Positive adsorption energy at the letrozole-clinoptilolite interface calculated using density functional theory models suggests a small affinity for letrozole adsorption, suggesting the letrozole release is more favorable than the adsorption process. Thus, this presentation will show new possibilities in adsorption and dissolution of water-insoluble drugs.

This present work describes an optimized electrochemical sensor made of a carbon electrode modified with TiO2 nanoparticles, which was used for the electrochemical characterization of polyphenols in natural wine. The aim of this study is to investigate the influence of specific binders and nanoparticles on the physicochemical and electro-chemical properties of modified carbon electrodes. The imaging techniques (scanning electron microscopy with energy dispersive X-ray spectroscopy, atomic force microscopy) showed that the electrode material becomes denser with a higher binder content and that TiO2 nanoparticles are almost evenly distributed despite the manual preparation of the carbon paste. The results show that the modified carbon paste with 40 vol.% paraffin oil and 8 wt.% TiO2 nanoparticles has the lowest surface roughness, anodic current and electroactive surface area, which is consistent with the reported lowest resistance, as well as the highest degree of reversibility compared to the standard reversible redox system ([Fe(CN)6]3-/4-) within the electrode material.

This paper aims to examine the lightfastness of yellow water-based ink using a light-accelerated aging chamber. Mondy Maestro Print uncoated offset paper (120 g/m²) was used as printing substrate. The printing was carried out on an inkjet printing machine using water-based inks, and the light exposure was tested within the Solarbox climate chamber. The study was conducted through the analysis of colour differences, as well as changes in chroma and lightness, across light, mid and dark tonal patches, as well as the paper substrate. It is hypothesised that the paper substrate will influence the tonal patches through its changes, and that the colour differences will be greater with higher tonal coverage. Experimental results obtained throught spectrophotometric measurements indicate significant color differences. It was found that the paper substrate, through its alterations, influenced the yellow tonal patches. Furthermore, higher tonal coverage resulted in more pronounced colour changes. An exception was observed in the 70% tonal value (TV), which exhibited greater changes compared to the solid patch. These studies are crucial for better understanding of the application and efficiency of this type of ink in the graphic arts industry.

In addition to the already well-known application in metal production, electroplating, electrochemical energy sources, electrochemistry is also applied in other branches of industry. Today, electrochemical technologies for the treatment of wastewater and drinking water are increasingly present. In recent years, new advanced oxidation processes based on electrochemical technology - Electrochemical advanced oxidation processes (EAOPs), have been developed for the treatment of persistent pollutants, which cannot be removed by conventional water treatments. EAOPs are based on “in situ” electrolytic formation of strong oxidants in an electrochemical reactor, able to degrade almost all organic pollutants. Despite their effectiveness in degrading different types of pollutants, the biggest challenge for EAOPs is high electricity demand to power these systems, which can have serious consequences from both an ecological and an economic point of view. The use of electricity from the distribution network to power electrochemical reactors is the biggest barrier to achieving commercial success of this technology. A possible solution to this challenge is the application of direct solar UV radiation to produce electric energy by use of a solar photovoltaic (PV) arrays for power supply of EAOPs. The aim of the research was to demonstrate the feasibility of using EAOPs directly powered by PV systems, as a sustainable system for efficient water treatment.

The positive effects of polyphenolic compounds on the sensory characteristics of wine and human health indicate a great need for a simple, fast and easily accessible method to determine the content of polyphenols in wine. The aim of this study is the electrochemical characterization of polyphenolic compounds in natural wine samples using a modified carbon paste electrode with TiO2 nanoparticles (MCPE/npTiO2) and improved voltammo­gram processing to obtain indicative data for polyphenols. The most marked influence of the modification of CPE with TiO2 nanoparticles was an increased sensitivity to electrooxi­dation, which is reflected in an increase of the anodic peak current. Of the five tested poly­phenols, i.e., gallic acid (GA), caffeic acid (CA), catechin (CT), quercetin (QV) and resveratrol (RE), the current maximum of the first two oxidation peaks increased only for GA by a factor of about 2 and for CT by a factor of about 1.5. Of the three red wines, Vranac (VR), Merlot (ME), Cabernet Sauvignon (CS); three white wines, Graševina (GR), Temjanika (TE), Char­donnay (CS) and one rose wine, Belrose Mediterranée Rosé (RO) tested, an increase by a factor of about 2.5 was observed for two red wines (VR, CS) and by a factor of 1.5 for one red wine (ME), one white wine (GR), and the rose wine (RO), while no increase in the current signal was observed for one of the white wines (CS). The most significant increase in the voltam­metric signal of GA at the MCPE/npTiO2 compared to other studied polyphenols can be explained by its higher affinity for adsorption on TiO2 nanoparticles. The investigated modified electrode provides an improved, linear and reproducible voltammetric response in wine samples. Consequently, MCPE/npTiO2 represents a good basis for the further deve­lopment of an integrated sensor/data system with the possibility of a broader application for the detection of polyphenols, especially GA, as an aroma and visually relevant parameter in winemaking.

Polyphenols are the most common organic compounds in wine. They improve both the sensory aspects of wine and human health by activating antioxidant systems. Therefore, there is a great need for a simple, fast and accessible method to determine the polyphenol content of wine. The aim of this study is to characterize polyphenolic compounds in natural wine samples using an electrochemical method and a modified carbon paste electrode with TiO2 nanoparticles. This work is motivated by the promising improvement of the sensing properties of a TiO2 nanoparticle-modified carbon paste electrode observed in the electrooxidation of different polyphenols. Since the voltammetric response of wine is largely irreversible, another motivation was the possibility of improving the processing of voltammograms to obtain data indicative of wine polyphenols, based on the approach described in the seminal work by Espinoza et al. The modified electrode studied provides an improved and reproducible voltammetric response of gallic acid in wine samples and provides a good basis for further development of an integrated sensor/data system with the possibility of wider application for the quantification of gallic acid as a flavor and visually relevant parameter in winemaking.

The book titled Explosives and Explosive Materials Engineering covers the subject matter studied within the course of the same name. The material is presented across seven main chapters: Historical Development, Energetic Materials (Explosives), Characteristics of Energetic Materials, Explosive Processes, Important Aspects of Energetic Materials, Methods for Detection and Identification of Explosive Materials, and Terrorism and Explosive Materials. It outlines the historical development and use of energetic materials, their various fields of application, and the classification of explosive materials based on different criteria. The fundamental physicochemical characteristics, as well as specific aspects of these materials, are thoroughly addressed. The chapter on detection and identification methods and techniques presents instrumental methods used for the qualitative and quantitative determination of explosive materials. The chapter Terrorism and Explosive Materials examines the use of explosive materials in executing terrorist attacks.The literature used spans various time periods and authors, with an emphasis on the latest advancements in the field. Certain professional terms and terminology are also provided in English to facilitate terminological understanding in relation to literature that is not available in the Serbian language.The book is primarily intended for students of the Faculty of Security Sciences at the University of Banja Luka, but it can also be highly useful to other readers across various professional and scientific fields of interest.