Five novel pyrazolylnucleosides have been evaluated theoretically for their corrosion inhibition efficiency on the Cu(111) surface in acidic media. DFT calculations were carried out to exhibit the intrinsic properties such as lowest unoccupied (ELUMO) and highest occupied (EHOMO) molecular orbital energies, as well as energy gap (∆E), chemical hardness (η), chemical softness (σ), electronegativity (χ), electrophilicity (ω) and nucleophilicity (ε). The theoretical FT-IR spectra were recorded to indicate the presence of the specific bonds in the studied molecules. The surface interactions between the inhibitor molecules and the metal surface were investigated using molecular dynamics simulations and Monte Carlo (MC) simulations. As a result, we have found that the inhibitor pyrazolylnucleosides 5a–e have strong interactions with Cu(111) surface, and therefore have excellent predictive inhibition power against copper corrosion.

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Abstract. The presence of contaminants in water is a very serious environmental issue. In order to overcome this problem, the present paper is dedicated to the development and evaluation of the efficiency of materials derived from orange peels toward the removal of dissolved organic molecules from aqueous solutions. UV-VIS spectroscopy was used for the evaluation of the methylene blue (MB) before and after the sorption process. The analysis of the performance of these materials is done by comparing their sorption efficiency with the derived materials from orange peels, directly or with acid-treated ones. Furthermore, the results were compared with activated carbon, which is a well-known material with high sorption performance. The study also involved the evaluation of different conditions (concentration, stirring, adsorption time, etc.) in the sorption efficiency of this molecule. The results show that the material derived from orange peel has very good adsorption properties, making it a serious candidate toward practical applications in wastewater treatment.

The environment and its components have been severely contaminated over the years due to massive pollution. The multiple use of heavy metals in industrial, domestic, agricultural, medical and technological applications have led to their wide distribution in the environment. Different studies implied that the primary contribution to the ecological risk index, originated from various anthropogenic influences such as industrialization and urbanization. This has compromised the ability of the environment to foster life and render its intrinsic values due to the heavy usage of these elements. This research illustrates the assessment of heavy metals in waste, water, sludge and soil. Monitoring was performed in vicinity of a cement factory on the southern Kosovo, where the sampling and measurements were performed in the autumn season of 2018. With the use of atomic absorption spectroscopy technique (AAS), the elements determined in this study were Pb, Zn, Cu, Ni, Fe, Mn, and Al. The findings of this study revealed a little change in the concentrations of these elements in the environment samples, especially in water, apart from that there is slight pollution of the environment with heavy metals in this zone.

Abstract. Heavy metal ions in liquid samples, apart from classical methods of extraction, can also be efficiently and environmentally friendly extracted by the use of supercritical CO2, containing a suitable complexing agent -ligand. This study represents the experimental data for the extraction of three heavy metals (Cu, Zn and Cd) from aqueous samples in the presence of dithizone as a ligand. The extractions by supercritical CO2 were accomplished at p=120 bars with t=50°C through the use of the dynamic technique. After the CO2 addition to the aqueous solution containing corresponding heavy metal ions, the pressure and temperature were set and extraction was performed in three different time periods: 30, 60 and 120 min (t=const., p=const. with a CO2 flow rate of 2 mL min −1 ). Once the extraction was stopped, the CO2 was released slowly through a restrictor. Methanol was used as a modifier (v/v) 10% and the pH value was set to 10. After the accomplishment of the extraction process, the leftover aqueous solution in the extractor was analyzed for its metal content by the use of the Atomic Absorption Spectrophotometer (AAS). The overall performance of the use of the dithizone as a ligand in all three cases of heavy metal ions enhanced greatly the extraction efficiency of these ligand/metal species.