Heavy Metals in Waters and Sediments of Rivers Affected by Brown Coal Mine Waters

Abstract

As many as four rivers affected by brown coal mine waters were surveyed: Notec (Lubstow open-pit mine), Pichna (Tomislawice), Widawka (Belchatow), and Grojecki Channel (Drzewce). Identical procedures of sampling and laboratory analyses were applied in all of them. Heavy metal concentrations, pH reaction, and conductivity in river sediments were analyzed in warm periods of 2012 and 2013 to assess the impact of mine waters on riverbed material. Data on heavy metal concentrations, pH, and conductivity of water were recorded in warm periods in 2011-13. For the Lubstow open-pit mine, closed in the year 2009, data from water samples collected in 2004-05 were used. Results showed that the impact of lignite mine waters on total heavy metals in river sediments was low in the case of the Notec and Pichna rivers. In Grojecki Channel at the site situated 1 km below the mine waters discharge the total heavy metal concentration in the bottom substrate was significantly higher than above the mine waters discharge outlet. An opposite trend was observed in the Widawka River sediments (715 mg of heavy metals·kg -1 of dry matter), where the total heavy metal concentration in the substrate 1 km below the mine waters discharge outlet decreased by approx. 44%. This was related to low concentrations of heavy metals in the Belchatow mine waters, amounting to 0.033 mg·L -1