AI Summary & Key Takeaways
AI InsightThe results shown significant temporal and spatial variability in pollutant concentrations.
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Abstract
The present study shown the levels, distribution, and seasonal variation of hydrocarbons, including BTEX compounds (benzene, toluene, ethylbenzene, and xylenes), n-alkanes (C10-C26), and polycyclic aromatic hydrocarbons (PAHs), in water samples of Tirana River, Albania. It flows from the Dajti Mountain, in the north of the city of Tirana. This river was a clean before the 90s but after that, with the construction of housing and businesses near the river, it suffered great environmental stress from solid and liquid discharges. Recent years the river is undergoing in a rehabilitation process, but its waters continue to be under the pressure of urban/ anthropogenic pollution. Sampling of water in Tirana River was done at seven monitoring stations, from Tufina to Rinas (in the most urbanized part of the river), at four sampling period (October 2025, December 2025, February 2026, and April 2026). The analysis was performed using gas chromatography with flame ionization detection (GC-FID), enabling the quantification of a wide range of hydrocarbon compounds. The results shown significant temporal and spatial variability in pollutant concentrations. Total BTEX concentrations ranged from 0.03 to 0.82 µg/L, with maximum levels during the winter (February 2026), likely due to increased urban runoff and reduced volatilization. Toluene and xylenes were the dominant compounds, indicating strong influence from vehicular emissions and fuel-related activities. Total n-alkane concentrations varied between 0.03 and 1.34 µg/L, with the highest values recorded in December 2025. The predominance of mid-chain hydrocarbons (C16–C20) suggests a mainly petrogenic origin, associated with petroleum/transport inputs. In contrast, PAHs exhibited a progressive increase from autumn to spring, with concentrations ranging from 0.00 to 1.49 µg/L and reaching maximum levels in April 2026. The dominance of high molecular weight PAHs, such as benzo[a]anthracene and indeno[1,2,3-cd]pyrene, indicates a pyrogenic origin linked to combustion processes. Spatially, higher concentrations of all contaminant groups were consistently observed at downstream and urbanized stations, particularly Laknas and Rinas. The findings show that the Tirana River is significantly impacted by anthropogenic hydrocarbon pollution, highlighting the need for continuous monitoring and improved management strategies to protect water quality in urban river systems.