Search Results (3)

In the mining industry, one of the principal issues is the management of the waste generated during ore concentration, which represents a potential source of environmental pollution. The most acute issue originates from the mining heritage in the form of dumps formed of mining tailings that were created before the introduction of waste storage standards and may be located in urban areas. This research investigated this problem using the example of the tailings dump “Krasnaya Glinka”, located in a residential area of Pitkäranta (Karelia, Russia) in close proximity to the shoreline of Lake Ladoga. A complex approach, including the investigation of the natural water of the study area and tailings material and an experiment simulating the interaction of this material with atmospheric precipitation, allowed us to obtain the first data on the current status of the tailings dump and its surroundings and to identify environmental pollutants. This research used XRF, XRD, and EPMA analytical methods for assaying the tailings materials obtained from the dump and ion chromatography, potentiometric titration, ICP-MS, and AES for the water samples. The results show the influence of the tailings dump’s materials on the formation of the environmental impact—in the water from the area of the tailings dump, increased concentrations of chalcophilic elements are observed, for example, Zn up to 5028 µg/L. Based on this study of the tailings dump’s materials and the conducted experiment, an attempt is made to connect the chemical compositions shown in the natural water data with the specific mineral phases and processes occurring during supergene transformations in the tailings storage. As a result of the conducted research, it was found that despite more than 100 years of exposure of the tailings materials under natural factors, mostly atmospheric precipitation, equilibrium with the environment has not come. The processes of extracting toxic elements and carcinogenic mineral phases into the environment are continuing. In the process of studying the tailings materials, it was found that they are probably of economic interest as a technogenic source of W and Sn due to the contents of these components exceeding industrially significant values in the exploited fields. Full article

Abandoned mines are sources of potentially toxic chemical elements, although the development of these objects was completed. The Lupikko I mine area (Karelia Republic, Russia) is an excellent example of such technogenic objects. It is one of the largest mines in the Pitkäranta area, which was abandoned more than one hundred years ago. The dump rocks here are characterized by significant mineral diversity. Disseminated ore mineralization of the study area contains heavy metals, which enter the natural waters due to the oxidative dissolution of sulfides. Dump rocks and water from the Lupikko I mine area were collected to research the behavior of toxic elements. The samples were analyzed using ICP-MS, ICP-AES, potentiometric titration, ionic chromatography, X-ray microanalysis, X-ray fluorescence, and SEM to obtain information about the geochemical environment. According to new data, the content of Fe, Zn, Cu, Pb, Cd, and Ni in the natural waters of the mine significantly exceeds the geochemical background. For a more detailed study of the behavior of heavy metals, equilibrium-kinetic modeling, which considers the dissolution rate of ore minerals and the accumulation of toxic elements over time, was applied. A comparison of modeling data and field observations agreed. It was also found that for accurate modeling of Fe behavior, it is necessary to consider the organic matter content. Despite some model limitations, such retrospective assessments allow us to approve the applicability of this method for forecasting estimates. Full article

The trophic state of Lake Ladoga was studied during the period 1997–2019, using the Copernicus Marine Environmental Monitoring Service (CMEMS) GlobColour-merged chlorophyll-a OC5 algorithm (GlobColour CHL-OC5) satellite observations. Lake Ladoga, in general, is mesotrophic but certain parts of the lake have been eutrophic since the 1960s due to the discharge of wastewater from industrial, urban, and agricultural sources. Since then, many ecological assessments of the Lake’s state have been made. These studies have indicated that various changes are taking place in the lake and continuous monitoring of the lake is essential to update the current knowledge of its state. The aim of this study was to assess the long-term trend in chl-a in Lake Ladoga. The results showed a gradual reduction in chl-a concentration, indicating a moderate improvement. Chl-a concentrations (minimum-maximum values) varied spatially. The shallow southern shores did not show any improvement while the situation in the north is much better. The shore areas around the functioning paper mill at Pitkäranta and city of Sortavala still show high chl-a values. These findings provide a general reference on the current trophic state of Lake Ladoga that could contribute to improve policy and management strategies. It is assumed that the present warming trend of surface water may result in phytoplankton growth increase, thus partly offsetting a decrease in nutrient load. Precipitation is thought to be increasing, but the influence on water quality is less clear. Future studies could assess the current chemical composition to determine the state of water quality of Lake Ladoga. Full article