Characterization and assessment of potential environmental risk of tailings stored in seven impoundments in the Aries river basin, Western Romania

BACKGROUND: The objective of this study was to examine the potential environmental risk of tailings resulted after precious and base metal ores processing, stored in seven impoundments located in the Aries river basin, Romania. The tailings were characterized by mineralogical and elemental composition, contamination indices, acid rock drainage generation potential and water leachability of hazardous/priority hazardous metals and ions. Multivariate statistical methods were used for data interpretation. RESULTS: Tailings were found to be highly contaminated with several hazardous/priority hazardous metals (As, Cu, Cd, Pb), and pose potential contamination risk for soil, sediments, surface and groundwater. Two out of the seven studied impoundments does not satisfy the criteria required for inert wastes, shows acid rock drainage potential and thus can contaminate the surface and groundwater. Three impoundments were found to be highly contaminated with As, Pb and Cd, two with As and other two with Cu. The tailings impoundments were grouped based on the enrichment factor, geoaccumulation index, contamination factor and contamination degree of 7 hazardous/priority hazardous metals (As, Cd, Cr, Cu, Ni, Pb, Zn) considered typical for the studied tailings. Principal component analysis showed that 47% of the elemental variability was attributable to alkaline silicate rocks, 31% to acidic S-containing minerals, 12% to carbonate minerals and 5% to biogenic elements. Leachability of metals and ions was ascribed in proportion of 61% to silicates, 11% to acidic minerals and 6% to the organic matter. A variability of 18% was attributed to leachability of biogenic elements (Na, K, Cl(-), NO(3)(-)) with no potential environmental risk. Pattern recognition by agglomerative hierarchical clustering emphasized the grouping of impoundments in agreement with their contamination degree and acid rock drainage generation potential. CONCLUSIONS: Tailings stored in the studied impoundments were found to be contaminated with some hazardous/ priority hazardous metals, fluoride and sulphate and thus presents different contamination risk for the environment. A long term monitoring program of these tailings impoundments and the expansion of the ecologization measures in the area is required

Observations on Groundwater Contamination with Nitrogen Compounds: A Case Study from Medias town, Sibiu County

Worldwide, the groundwater (water well and public spring) is used as drinking water source. The water quality is important due to the possible negative effects on the consumers’ health, especially for infants. Nitrogen compounds (NO2-, NO3-, NH4+) are present as natural components of the nitrogen cycle and their presence in the groundwater is ubiquitous. But, due to the anthropogenic activities high concentrations of nitrogen compounds are release into the groundwater, thereby the chemical compounds concentrations exceed the maximum allowable concentrations (MACs). The purpose of the present study was to assess the content of nitrogen compounds in groundwater, namely private water wells and public springs used as drinking water sources by the Medias town population. The study results show alarming NO2- and NO3- concentrations; the NO3- concentrations exceed 5 times the MAC and NO2- concentrations exceed3 times the MAC.

Soil pollution assessment in the Baia Mare area after partial closure of ore processing activities

The paper presents the assessment of the soil pollution with Cu, Pb and Zn in the Baia Mare area, historically polluted with metals resulted from mining and processing of non-ferrous ores. Despite the closure of mines and reducing the activity related to ore processing, Baia Mare is still a highly polluted site with Pb, Cu and Zn. The Tessier extraction scheme carried out on soil samples recently collected revealed the residual fraction as dominant for all three metals, followed by the reducible fraction bound to Fe and Mn oxides. The exchangeable fraction, considered as the most mobile fraction and that bound to carbonates, which can be mobilized under acidic conditions, were lower. The presence of the oxidisable metal fraction was also observed

Levels of polycyclic aromatic hydrocarbons in monitoring wells from municipal landfill determined by solid-phase microextraction and gas chromatography/flame ionization detection

This study reports the levels of 16 polycyclic aromatic hydrocarbons (PAHs) in the monitoring wells from a municipal landfill. The used analytical method for the simultaneous determination of PAHs was the solid-phase microextraction (SPME)-gas chromatography (GC)-flame ionization detection (FID). Total PAHs concentrations in the samples varied between 1.75 and 9.01 pg/1, with benzo[a]pyrene the most predominant species and reflect the spatial distribution of the monitoring wells

ASSESSMENT OF Pb, Cd, Cu AND Zn AVAILABILITY FOR PLANTS IN BAIA MARE MINING REGION

In order to evaluate the mobility of heavy metals in soil from Baia Mare mining region, the total, water and DTPA extractable metal contents were determined. The results showed that despite the high total metals contents and the high percentages of plant available metals only a low percent was water soluble, indicating a potential accumulation of metals in trophic chain and a potential risk for public health. Among the investigated metals, the plant available Pb and Cd species are the most severe contaminants. Significant correlations between total and DTPA extractable metals were found for Cu (r=0.510) and Pb (0.418), and also an affinity between total and water extractable metals were identified for Cu (0.366), Pb (0.502) and Zn (0.597)