Arsenic contamination in groundwater is a significant public health concern, with As(III) posing a greater and more challenging risk than As(V) due to its higher toxicity, mobility, and weaker adsorption affinity. Fe-Mn-based adsorbents offer a promising solution, simultaneously oxidizing As(III) to As(V), enhancing its adsorption. This study evaluates an Fe-Mn nanocomposite across typical batch (20 mg of adsorbent), fixed-bed column (28 g), and pilot-scale (2.5 kg) studies, bridging the gap between laboratory and real-world applications. Batch experiments yielded maximum adsorption capacities of 6.25 mg/g and 4.71 mg/g in a synthetic matrix and real groundwater, respectively, demonstrating the impact of the water matrix on adsorption. Operational constraints and competing anions led to a lower capacity in the pilot (0.551 mg/g). Good agreement was observed between the breakthrough curves in the pilot (breakthrough at 475 bed volumes) and the fixed-bed column studies (365–587 bed volumes) under similar empty bed contact times (EBCTs). The Thomas, Adams–Bohart, and Yoon–Nelson models demonstrated that lower flow rates and extended EBCTs significantly enhance arsenic removal efficiency, prolonging the operational lifespan. Our findings demonstrate the necessity of continuous-flow experiments using real contaminated water sources and the importance of optimizing flow conditions, EBCTs, and pre-treatment in order to successfully scale up Fe-Mn-based adsorbents for sustainable arsenic removal.

This study investigates the regeneration, reuse, stabilization, and environmental safety of Fe–Mn polymer nanocomposites for arsenic (As) removal and their environmental safety. The regeneration performance of Fe–Mn polymer nanocomposites (PS-FMBO) used in this study was assessed through batch adsorption–desorption cycles using various eluents, including NaOH, NaOH–NaCl, and NaOH–NaOCl mixtures. The results demonstrated that 0.1 M NaOH yielded the best regeneration performance, maintaining higher adsorption efficiency over multiple cycles. Stronger desorption agents caused a significant decline in removal efficiency due to possible structural degradation of the PS-FMBO nanocomposite, suggesting that aggressive desorption conditions could compromise its long-term effectiveness. The stabilization of PS-FMBO with cement and quicklime was evaluated for immobilizing As, iron (Fe), and manganese (Mn). Leaching tests indicated that the composites effectively immobilized these contaminants, with minimal leaching observed even after prolonged aging, ensuring compliance with environmental safety regulations. Furthermore, chitosan-based foams were analyzed for their chemical stability, with leaching tests confirming low concentrations of As, Fe, and Mn, even under aggressive conditions, further reinforcing the material’s safety and environmental compliance. These findings underscore the potential of PS-FMBO composites and chitosan-based foams as sustainable materials for hazardous waste management and eco-friendly construction applications. Their ability to immobilize contaminants while maintaining structural integrity highlights their practical significance in reducing environmental pollution and advancing circular economy principles.

This study investigates the environmental risks posed by heavy metals in sediment from the Great Bačka Canal using both active and passive sampling methods. The necessity of this research lies in the critical need to address sediment contamination in ecological hotspots and enhance sediment management practices. Active sampling revealed total heavy metal concentrations, while sequential extraction showed bioavailability varied across metal fractions. Passive sampling with SPeeper™ quantified freely dissolved metal concentrations in sediment pore water, identifying zinc (41 μg/L) as the most bioavailable metal. Risk indices, including I_geo (geo-accumulation index) and IWCTU (interstitial water criteria toxic units), revealed low to moderate contamination levels. Although copper content classified the sediment as extremely polluted (195.7 mg/kg), its low bioavailability (16 μg/L in pore water) mitigates immediate ecological risks. These findings emphasize the importance of integrating passive sampling in regulatory frameworks for a realistic environmental risk assessment of sediments.

Arsenic contamination in groundwater is a significant public health concern, with As(III) posing a greater and more challenging risk than As(V), due to its higher toxicity, mobility, and weaker adsorption affinity. Fe-Mn-based adsorbents offer a promising solution, simultaneously oxidizing As(III) to As(V), enhancing its adsorption. This study evaluates an Fe-Mn nanocomposite across typical batch (20 mg of adsorbent), fixed-bed column (28 g) and pilot-scale (2.5 kg) studies, bridging the gap between laboratory and real-world applications. Batch experiments yielded maximum adsorption capacities of 6.25 mg/g and 4.71 mg/g in synthetic and real groundwater respectively, demonstrating the impact of water matrix on adsorption. Operational constraints and competing anions lead to a lower capacity at the pilot (0.551 mg/g). Good agreement was obtained by the breakthrough curves at the pilot (breakthrough at 475 Bed Volumes) and the fixed-bed column studies (365–587 Bed Volumes) under similar empty bed contact times (EBCT). The Thomas, Adams-Bohart, and Yoon-Nelson models demonstrated that lower flow rates and extended EBCT significantly enhance arsenic removal efficiency, prolonging operational lifespan. Our findings demonstrate the necessity of continuous-flow experiments using real contaminated water sources, and the importance of optimising flow conditions, EBCT and pre-treatment, in order to successfully scale up Fe-Mn-based adsorbents for sustainable arsenic removal.

The paper explores sediment management issues in watercourses, highlighting the complexity and shortcomings of existing methods. It emphasizes that total concentrations of pollutants are insufficient for a realistic assessment of harmful effects, considering the bioavailability and complexity of sediment. A multi-criteria risk assessment model integrating FUCOM and SAW methods is presented, applied to the Veliki Bački Canal. The results of the analysis demonstrate the importance of a multidisciplinary approach in optimizing sediment management measures. Based on the model, it is concluded that the VBK sediment does not exhibit significant potential for negative environmental and human health impacts, providing a basis for further sediment management.

Dietary exposure to tropane alkaloids (TAs) in Serbia remains insufficiently investigated, while awareness among consumers and agricultural producers of potential exposure and related health risks, particularly for children, is low. Barley, a cereal widely used in food production, is still not included in the EU and Serbian regulations on maximum allowable atropine and scopolamine concentrations in food. However, the CONTAM panel established the group ARfD of 0.016 µg/kg bw/day for the sum of atropine and scopolamine. Therefore, a study was conducted on barley samples from organic and conventional production systems, in order to quantify the presence of atropine and scopolamine by LC-MS/MS. In all of the tested samples, both TAs were detected at concentrations above the LOD. The most contaminated sample was from the organic production, with the sum of atropine and scopolamine being 3.2 µg/kg. In order to evaluate the consumer risk from At and Sc in barley-based products, the EFSA framework for acute dietary exposure assessment was applied. The exposure was assessed for seven population groups consuming barley-based foods and beverages: toddlers, children, adolescents, adults, elderly, vegetarians, and pregnant women. The estimated daily intake, calculated according to the three consumption scenarios, did not exceed the established ARfD value. Since barley is not the only source of TA intake in Serbia, a prospective study on TA exposure should be performed in order to monitor TA concentrations, estimate exposure, and manage the risk.