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Trace Elements in Lakes Located in an Agricultural-Forest Catchment: A Case Study of Lake Raczyńskie, Poland
The enrichment of bottom sediments with trace elements due to anthropogenic factors is of growing concern worldwide. With the development of industry, agriculture, and urbanization, the risk of freshwater contamination with trace elements is increasing. As trace elements are poorly soluble in water, they have a tendency to accumulate in bottom sediments. The study focused on the evaluation of the trace element contents in the surface layer of bottom sediments of Lake Raczyńskie, located in Poland, and assessing the risks posed by these sediments. The pollution of bottom sediments was estimated based on the index of the geo-accumulation (Igeo), enrichment factor (EF), Nemerow multi-factor index (Pn), and pollution load index (PLI). The assessment of environmental risk was evaluated by the potential ecological risk index (RI) and mean PEL quotient method. The results obtained showed that the average contents of Cd, Cu, Ni, Pb, and Zn exceeded the national geochemical background values (Bn), indicating possible enrichment of bottom sediments due to human activity. Only for Mn were the observed contents below the Bn. This evaluation was confirmed by the PLI and Pn values, which indicated sediment pollution from anthropogenic sources. However, the risk assessment by RI and mean PEL showed a low risk of contamination. The results of principal component analysis (PCA) and values of Igeo and EF suggested that Cd, Cu, Mn, and Zn mainly originate from geogenic sources, while Ni and Pb probably come from an unrecognized anthropogenic source. The distribution of Cd, Mn, and Ni depended on the contents of silt and clay fractions. Additionally, organic carbon influenced Cu, Mn, Ni, and Zn contents in bottom sediments.
Opportunities for the Transformation and Development of Power Plants Under Water Stress Conditions: Example of Adamów Power Plant
In the vicinity of the Adamów power plant, which operates in the catchment area of the Kiełbaska river, there is a significant shortage of water resources caused by the intensive use of water by the energy industry and agriculture. The development of the plant by replacing the outdated coal-fired (lignite-fired) units with modern gas and steam units may contribute significantly to reducing the negative impact on the environment and reduce the demand for water resources relative to coal technology. Gas and steam units are a much more energy-efficient technology. This implies a lower demand for water, a reduction in pollutant emissions, and greater operational flexibility, which enables the units to adapt to changing hydrological and environmental conditions. The high efficiency of these units limits the need for frequent water-refilling, while allowing for a more sustainable and stable production of energy. Based on an analysis of hydrological data for the years 2019–2023, it was estimated that water stress is observed in this catchment area on 198 days per year, which accounts for c.a. 54% of the hydrological year. Therefore, it is assumed that inter-catchment pumping stations with a flow of 0.347 m3∙s−1 will be required. This sets the demand for water at 5.95 million m3 per year. The planned water transfer will be carried out from Jeziorsko reservoir on the Warta river through the catchment area of Teleszyna river. Moreover, there are plans for the reconstruction of the layout of Kiełbaska Duża and Teleszyna rivers, which would involve the restoration of natural run-offs, following the discontinuation of open-pit lignite mining. This will additionally be supported by the reduced demand for water in the water use system when using the modernised power plant. The analysed data made it possible to develop hydrological scenarios that take the future reduction in water stress into account by implementing plans to restore the former hydrographic system in the region. These investments would also foresee the creation of new retention reservoirs (in former mining pits) with a capacity of nearly 900 million m3, which will significantly increase the region’s water resources and retention potential, supporting hydrological and energy security for the years to come.
Variability of concentrations of phosphorus forms under the conditions of weir renovation – The Głuszynka river-lake system case study
To fill the knowledge gap on the functioning of the river-lake system during the modernisation of the weir, an analysis of the variability of selected physico-chemical indicators was carried out. In the parameter analysis, particular emphasis was placed on phosphorus (P) and orthophosphate(V) (OP) content in the hydrological year 2022 and water quality was compared before, during and after the maintenance work on the discharge weir. Physico- chemical parameters were analysed monthly at four stations. Concentrations of P and OP increased significantly as a result of the refurbishment works at the measurement point located downstream of the weir (P4), which contributed to the determination of a statistically significant change point. At the same time, when high P and OP contents were observed, high electrolytic conductivity and ammonium nitrogen in water were also recorded. The content of P and OP indicators was further reduced, but their content was still several times higher than before the renovation. The renovation of the weir below Lake Jeziory Wielkie contributed to a significant deterioration of water quality in the river-lake system. Due to the nature of this system, this was of great importance for the downstream reservoirs. The statistical analysis showed that the renovation of the weir below Lake Jeziory Wielkie contributed to a significant deterioration of water quality in the river-lake system.