THE EFFECT OF HEAVY METALS IN SURFACE WATER AND THEIR RELATIONSHIP WITH EUTROPHICATION

Heavy metals reach the aquatic ecosystems with natural sources as well as increasing anthropogenic pressures (urban and industrial pressures, diffuse sources, geothermal-driven pressures). In the study, the relationship between heavy metals which are carcinogenic, accumulating and toxic in aquatic life and eutrophication which is a natural process in lakes is investigated. The transport, dissolution, precipitation, complex formation, adsorption and bioaccumulation mechanisms of heavy metals in aquatic environments are highly complex processes and are influenced by the physicochemical properties of the water. According to this, it can be seen that due to the heavy metal pollution, the number of species decreases in aquatic organisms, some species disappear from the environment or the species with high tolerance to heavy metals are predominant in the environment. In particular, heavy metals can accumulate in the liver gill-like tissues of aquatic organisms and can interfere with the food chain. In addition, the metals stored in the sediments are directly or indirectly affected by the oxidation and reduction reactions occurring in the sediments. As a result, the eutrophication process, a natural process, affects many physicochemical properties of aquatic environments.