Investigation of the effect of heavy metals and emissions on the lake Sapanca using air and water quality models

Sapanca Lake, which is the most important fresh water resource for the province of Sakarya and its surroundings, mostly meets water intended for human consumption in region. Due to its location, Sapanca Lake is exposed to many pollutant sources, especially the D-100 and E-80 TEM highway. In this study, a mass balance model and ecological risk assessment was done in order to evaluate the pollution of Al, As, Ba, Cd, Co, Cr, Cu, Fe, Ni, Pb and Zn heavy metals in Sapanca Lake. Within the scope of the study, samples of lake water, lake sediment, water from the streams feeding the lake, groundwater, basin soil and atmospheric accumulation were taken from the Sapanca lake basin between 2015-2017, considering the seasonal changes and the heavy metal concentrations were determined using ICP-MS and ICP-OES. At the same time, physico-chemical parameters (organic matter, pH, ORP, conductivity, DO etc.) affecting the mobility and accumulation of heavy metals in receiving environments were measured simultaneously with the samples taken and the effects of these parameters on heavy metals were taken into account as setting the model. In the receiving environment samples taken from Sapanca lake and basin, Al and Fe were detected in higher concentrations compared to other heavy metals and it was determined that this was due to the structure of the basin. According to ecological risk assessment models; although there is no ecological risk in aquatic environments, heavy metal contamination has been observed in soil and sediment and has been found to be anthropogenic (traffic and industry) origin. Especially, As and Zn contamination in the air has been found to be anthropogenic and ecological risk has been observed in atmospheric accumulation. In the light of this information, a seasonal heavy metal mass balance model was created and it was determined that there was heavy metal contaminant input from unknown sources to Sapanca Lake, considering the pollutant inputs. It was concluded that the unknown pollutant sources were related to the accumulation of heavy metals detected in soil, sediment and groundwater samples.