Ecological assessment of mobile cadmium in sediments from cartej mining site, Hunedoara country, Romania

Abstract

The aim of this paper is to assess the impact on the aquatic environment due to cadmium pollution from Certej mining site from Romania. The total and mobile concentrations of Cd were analyzed in thirty sediment and surface water samples collected from Certej catchment area (Hunedoara County, Romania) in three sampling campaignes performed in 2012. Atomic absorption spectrometry in air/acetylene flame was used for determination of Cd content. Four different extraction methods were applied in order to evaluate the mobile Cd fraction and the most appropiate method was selected using a lake sediment certified reference material (BCR 701). The mining activities of non ferrous ore developed in the region for several hundred years has been generated acid wastewaters with high concentration of heavy metals. Total and mobile cadmium values were situated in the range 1 to 7.3 mg/kg dry matter, exceeding the maximum admissible value, which is 0.8 mg/kg in Romania Legislation. In order to estimate the impact of the highest concentration of Cd2+ occured in Certej sediments on the living organisms, ecotoxicological studies were performed. The Cd2+ toxicity was measured using a bioassay batery with fish (Cyprinus carpio), planktonic crustaceean (Daphnia magna) and luminiscent bacteria (Vibrio fischery). The results showed a major toxicity on all tested organisms, with L(E)C50<1 mg/l which indicated an adverse impact on aquatic biota.