Abstract
Study of heavy metals in sediments is vital in order to understand their impact on water ecosystems. They are usually present at low concentrations in aquatic environments, but deposits of anthropogenic origin have raised their concentrations, causing environmental problems in creeks.
This research was undertaken in order determine and analyse selected heavy metals present in sediment sampled from Smolnik creek, Slovakia, which is a historical Cu, Fe, Ag, Au-mining area that was exploited from the 14-th century to 1990. The Smolnik mine was definitely closed and flooded from 1990 till 1994. Waters from the earth surface penetrated the mine and they were enriched with metals and their pH values decreased. Acidity is caused mainly by the oxidation of sulphide minerals. The whole mine complex produce large amounts of AMD, discharging from the flooded mine (pH = 3-4, Fe 500-400 mg/L; Cu 3-1 mg/L; Zn 13-8 mg/L and Al 110-70 mg/L), that acidified and contaminated the Smolnik creek water and sediments which transported pollution into the Hnilec River catchment.
The mine-system represents partly opened geochemical system into which rain and surface water drain. Potential ecological risk indexes were used to study the pollution status of heavy metals in sediment and assess their potential ecological risk to environment, for the metals Cu, Zn, As, Cd and Pb. The calculated potential ecological risk indices the level of water environment pollution by heavy metals.
