WPŁYW ANTROPOPRESJI NA CHEMIZM WÓD POZIOMU PLEJSTOCEŃSKIEGO W REJONIE KOPALNI PIASKU MACZKI-BÓR W ŚWIETLE BADAŃ MODELOWYCH

Abstract

INFLUENCE OF ANTHROPOPRESSURE ON CHEMICAL COMPOSITION OF GROUNDWATER IN THE PLEISTOCENE AQUIFER IN THE AREA OF MACZKI-BÓR OPEN SAND PIT – GEOCHEMICAL MODELLING RESEARCH

Abstract. The paper presents time and spatial evolution of groundwater chemistry in the Pleistocene sandy aquifer situated in the lower section of the Biała Przemsza buried valley (Sosnowiec, south Poland). Factors and processes controlling chemical composition of groundwater were also identified. Gathered data come from archival hydrogeochemical analyses carried out in the period of 1994–2008 within the framework of the groundwater monitoring in the area of Maczki-Bór open sand pit and the landfill in Sosnowiec as well as from fieldwork and laboratory research carried out in April 2009. Water of considered Pleistocene aquifer belongs according to Szczukariew-Prikłoński classification to the Cl–Na, HCO₃–SO₄–Ca–Mg, Cl–SO₄–Ca–Na–Mg, Cl–SO₄–HCO₃–Na–Mg–Ca types and is characterized by increased concentrations of ions such as iron, manganese and zinc. Concentrations of individual components in 90’s were mainly increasing and nowadays
show the decreasing tendency. Composition of groundwater is strongly linked to anthropogenic factors (longlasting lowering of the groundwater table connected with the mining drainage, pollution sources such as landfills of post-mining and communal wastes). Increased thickness of the unsaturated zone contributed to the intensification of the oxidation processes. One of the most important geochemical processes influencing the groundwater chemistry is oxidation of iron sulfides to sulphates, what results in releasing of large amounts of SO₄^2- and Fe²⁺ into groundwater. The numerical simulations of the hydrogeochemical processes were performed by using PHREEQC codes.