wcm.03.2025.433.440

Water is a valuable natural source and essential for the life in every single cell, organism, or ecosystem. Freshwaters are used as drinking water sources, for domestic and industrial purposes, in energy production, etc. However, a considerable amount of polluted water is discharged into environment, because of inappropriate and intensive use for different purposes. Therefore, an important number of water ecosystems are considered polluted from anthropogenic activities. Agricultural activities, untreated or partly treated wastewater, industrial activities add nutrients and other chemicals to water bodies, influencing the water quality and biological parameters of the ecosystem. Nutrient (nitrogen and phosphorous forms) overloading results in increase of water plants that leads to eutrophication of the water body. Eutrophication is one of the most dangerous types of water pollution with direct effects in fauna due to dissolved oxygen loss that leads to fish death. Enrichment of water systems with nutrients is associated with algal “bloom” and with the degradation of natural water quality. Considering the effects of different pollutants in natural water bodies, the study of water quality in these systems receives a particular importance. The main purpose of this paper is to determine the pollution and the eutrophication level in the lake water, because of the increase of pollutant and nutrient concentration with anthropogenic origin. Belshi Lake, a karstic lake situated in Albania and considered as a case study, takes pollutants mainly from untreated wastewaters and from agricultural practices. The chemical water parameters are measured over a three-year period. Experimental data for the chosen water system are compared with international water quality standards. The chemical measured parameters are used to determine the lake trophic state according to several literature suggestions. Statistical data analysis shows the correlation between chemical parameters measured experimentally.