Evaluation of the Environmental State and WQI Variations in Waters of Tirana Artificial Lake

A study of the water quality due to nutrients concentration in waters of the artificial Lake of Tirana was conducted in six different stations of the lake, during the period 2011-2014. A total of 14 water quality parameters were measured, while Water Quality Index, WQI was calculated in order to classify the water quality. The physical and chemical variables were temperature, dissolved oxygen (DO), conductivity, pH, total dissolved solid (TDS), chlorophyll- a, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), ammonia, nitrite and nitrate-N and phosphate Results show that based on WQI, the waters of Tirana Lake are mainly classified as “class II”, which is suitable for recreational activities and allows body contact. With respect to the Water Quality Standard (WQS), parameters like DO, pH, turbidity, BOD, COD and ammonia-N are categorized under class II. Comparison with eutrophic status related to chlorophyll-a concentration, indicated that the lake appears to be on mesotrophic condition. In general, water quality indicators varied temporally and spatially in waters of Tirana Lake.