International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The presence of antibiotic residues in aquatic ecosystems has become an increasing environmental and public health concern due to their persistence, potential to disrupt microbial communities, and contribution to the development of antimicrobial resistance. These contaminants are often insufficiently removed by conventional wastewater treatment systems, allowing them to accumulate in surface waters and sediments, where they pose ecological risks. Understanding their occurrence, environmental behavior, and interactions with sediment is therefore essential for effective risk assessment and mitigation strategies. This study investigates the environmental occurrence and sediment-water partitioning behavior of the antibiotics ciprofloxacin (CFC) and clindamycin (CMC) in the Ishmi River basin, Albania. Both compounds were frequently detected in surface waters and sediments, with the highest concentrations found near urban sewage discharge points, where CFC and CMC reached up to 1.8 and 0.2 μg L-1 in water and 1068 and 37.8 μg kg-1 in sediments, respectively. Declining concentrations with decreasing urban impact were observed. The sediment-water partition coefficient (Kd) indicates high sorption tendencies for CFC and low to moderate for CMC. Partitioning behavior for CFC was influenced significantly by sediment pH, organic carbon and cations content. In case of CMC, however, organic carbon and iron (Fe) content were the main determining factors. The pH dependent n-octanol-water distribution coefficient (Dow), highlights the prominent sediment pH effect on CFC partitioning, and suggests that electrostatic interactions with negatively charged functional groups influence its environmental fate. These findings underscore the role of physicochemical interactions in controlling antibiotic distribution in sediments and highlight CFC and CMC as priority contaminants in regions with insufficient wastewater treatment.

The quality of surface waters in Albania is an issue particularly as the country aims to join the EU. Organic compounds in water matrix are difficult to remove, and recent Ishmi river monitoring shows that the anti-inflammatory such as naproxen is predominant among other pharmaceuticals. The commonly used antiepileptic such as carbamazepine is also detected. Thus, their removal from effluents is of high environmental relevance. Therefore, ternary magneto-biochar-clay (MBC 1:2:1) adsorbent was prepared from low-cost feldspar (FLC), grape cluster stalk waste (GC) biochar, and iron oxide magnetic nanoparticles (MNP), and was used as an adsorbent. Adsorption
experiments tested the effect of solution pH (2.5-10) of naproxen and carbamazepine with simulated contaminated and Ishmi river water, after pH optimization. The results showed that the maximum adsorption was achieved at a pH value of 2.5 for naproxen and carbamazepine in a single compound solution. Interestingly, for naproxen in both cases (single and combined), the maximum adsorption was achieved at pH value of 2.5, while for carbamazepine the maximum adsorption was achieved at pH value of 2.5 for single and no significant adsorption was achieved in combined compound solution. The adsorption of naproxen and carbamazepine at optimized pH of 4.5 in Ishmi water remained stable, with the only difference for carbamazepine in single compound, where the adsorption was lower compared to simulated contaminated water. This study demonstrated that in addition to easy handling, the MBC 1:2:1 adsorbent was efficient for naproxen and carbamazepine removal.