This study focussed on a comprehensive investigation on the state of pollution and identification of potential sources of contamination of some river sediments in Serbia by polycyclic aromatic hydrocarbons (PAHs), and is the basis for setting up further monitoring programs. The sediment quality of the Danube River (km 1433-845) and its tributaries in Serbia, including the Sava River (km 202-1), were analysed with respect to PAHs and total organic carbon (TOC). We found that total PAH concentration in the sediments from the Danube and its tributaries (10.0-4140 μg kg-1) was lower than total PAH concentration in Sava River sediments (265.1-11272 μg kg-1). Principal component analysis showed that concentrations of benzo[a]anthracene, chrysene, pyrene, fluoranthene, indeno[1,2,3-cd]pyrene, benzo[a] pyrene, benzo[b]fluoranthene and benzo[k]fluoranthene in the sediments were correlated with TOC. The diagnostic ratios anthracene/(anthracene+phenanthrene) and fluoranthene/(fluoranthene+pyrene) were calculated to evaluate the emission sources of the PAHs. Therefore, these ratios indicated the predominantly pyrogenic source of the PAHs in the sediments. Results have also shown that river sediments in the Danube and Sava rivers and their tributaries were not recently polluted with PAHs, excluding only one location – S4, downstream of Šabac and characterized by heavily polluted sediment.

As a result of its wide industrial applications, zinc has become an important contaminant in aquatic environment since it is a toxic heavy metal and some of its compounds such as zinc arsenate and zinc cyanide, may be extremely hazardous. Therefore, there is a growing need for developing simple methods capable of separating and recovering trace zinc from environmental waters. Nowadays, the ultra and microfiltration method for trace metals removal from waters by the addition of water-soluble polymers into the aqueous solutions has become a significant research area. The choice of watersoluble macroligands remains important for developing this technology. Sodium carboxymethyl cellulose (Na-CMC) was selected as complexing agent. The microfiltration experiments were carried out in stirred dead-end cell. To separate formed polymer-metal complex Versapor membranes were used. The concentration of heavy metal ions after microfiltration in aqueous solution was determined using atomic absorption spectroscopy (AAS). Effects of amount of complexing agent, pH value, type of anion, ionic strength and operating pressure on the flux (J) and rejection coefficient (R) were investigated. Experimental results indicate a considerable influence of the pH, ionic strength and type of anion on the rejection coefficient, while effect of amount of complexing agent is relatively insignificant. The Na-CMC used in the research proved to be very effective, which may be supported by the high rejection coefficients obtained (99%).

Buckwheat is important not only for its role in enhancing soil quality and preventing erosion but also for its excellent nutritional profile, making it suitable for use in functional foods. This study aimed to investigate how long-term storage (3, 6, and 9 months) affects chemical, nutritional, and antioxidative properties, phenolic acids, and the bioflavonoid profiles of Novosadska variety buckwheat. Standard methods were used for quality determinations, and instrumental methods (spectrophotometry, reverse-phase high-performance liquid chromatography) were employed to determine antioxidant activity and bioactive compounds in Novosadska variety buckwheat. One-way ANOVA and Tukey’s HSD post hoc tests were performed for statistical data processing. Throughout the storage period, proximate composition and starch content significantly decreased (p < 0.05), while total carbohydrates, β-glucan, and energy value significantly increased (p < 0.05). Significant decreases in pH and alcoholic acidity (pH = 0.55) and 0.33% DM were observed. Total phenol content and antioxidant activity decreased to 5.57 mg GAE/g DM TPC, 22.20 μmol Fe²⁺/g DM FRAP, and 8.12 μmol TE/g DM DPPH during storage (p < 0.05). Of the 15 phytochemical compounds, gallic, p-coumaric, trans-cinnamic acids, and epicatechin were highly abundant in this buckwheat variety, with a notable 38% decrease in epicatechin. Dihydrocaffeic and phloretic acids, daidzein, naringin, and naringenin were also quantified in buckwheat. Its easy adaptability to the environment, ability to attract various insects, being a speedy short-season growing plant for food, and numerous nutritional and health benefits give buckwheat the potential to be a sustainable and biodiversity-friendly crop.

Buckwheat is important not only as a crop that improves soil quality and reduces erosion, but its excellent nutritional profile for usage in functional foods. This study aimed to investigate how long-term storage (3, 6, and 9 months) affects Novosadska variety buckwheat's chemical, nutritional, and antioxidative properties, phenolic acids and bioflavonoids profiles. Standard traditional methods were used for quality determinations, and instrumental (spectrophotometry, reverse-phase high performance liquid chromatography) for antioxidant activity and bioactive compounds determination. One-way ANOVA, and Tukey’s HSD post-hoc were performed for statistical data processing. Throughout the storage period, proximate composition and starch content significantly decreased (p<0.05), while total carbohydrates, β-glucan, and energy value significantly increased (p<0.05). Significant decrease in pH and alcoholic acidity of 0.55 pH units, and 0.33% DM, were observed. Total phenol content and antioxidant activity decrease to 5.57 mg GAE/g DM TPC, 22.20 μmol Fe2+/g DM FRAP and 8.12 μmol TE/g DM DPPH, during the storage (p<0.05). Of fifteen phytochemical compounds, gallic, p-coumaric, trans-cinnamic acids, and epicatechin were in high abundance, with a notable decrease in epicatechin (38%). To the authors' knowledge, dihydrocaffeic and phloretic acids, daidzein, naringin, and naringenin were quantified in buckwheat flour for the first time. Easy adaptability to the environment, ability to attract various insects, speedy short-season growing plant for food, many nutritional and health benefits, gives buckwheat potential to be sustainable and biodiversity-friendly crops.