Hydrochemical and Ecotoxicological Characterisation of Water Samples from Moldova Noua Area, Romania

The abandoned copper mine in the Moldova Noua area is still producing mining pollution today due to the drying of tailings ponds and the carrying of contaminated dust by the winds, leading to potential contamination of surface waters and groundwaters. The purpose of this study is the assessment of some surface waters and groundwaters potentially contaminated by mining pollutants from Moldova Noua area regarding their hydrochemical and ecotoxicological properties. The physicochemical parameters (pH, conductivity, dissolved oxygen, and turbidity) were determined in situ, with the concentrations of heavy metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) being determined in the laboratory. Inhibition of acid phosphatase enzymatic activity and yeast toxicity tests were the two ecotoxicological tests used for the evaluation of mining pollution effects on the quality of surface waters and groundwater. The results highlighted that most of the physicochemical parameters and heavy metal concentrations were within normal limits. With the exception of the surface water sample collected from the Bosneag River, upstream of Moldova Noua, all samples induced inhibition compared to the positive control in the ecotoxicological tests applied. Statistically significant correlations were observed, with the total concentration of iron ions presenting the most statistically significant correlations with other parameters. A grading scale was used to assess the state of the waters, highlighting the weak impact of mining pollutants on the analysed samples.