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Number of results: 7
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Abstract

The restoration of the anthropogenic Pławniowice water reservoir with the hypolimnion withdrawal method (the Olszewski's tube) began in December 2003. The decision to restore the reservoir had been taken due to its terrible condition resulting from the hypertrophy, which had been indicated by the research from the years 1993–1998. The following paper presents the results of eight-year-long research into the formation of oxygen conditions and restoration settings. They were compared with the data obtained from the research before the restoration. Positive changes were witnessed. It was showed that grasping the changes in oxygen conditions enables the comparison of oxygen profiles in the same months in subsequent years. The ratio of anoxic water layer thickness to the oxygenated layer thickness was suggested as a factor characterizing oxygen conditions. The area described with an izooxa in the xy coordinate system was suggested as a factor [O2 mg/m2] allowing researchers to understand and describe occurring changes. It was observed that the oxygen solved in water as a result of the restoration occurred in the whole water column in the third decade of July. The oxygen concentration in the hypolimnion gradually rose in May, June and July each year. It was showed that the improvement in oxygen conditions stemmed from progressing oligotrophy of the reservoir.
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Abstract

The article presents changes in the thickness and duration of the ice cover found in the restored anthropogenic water reservoir of Pławniowice. It also defines the role the ice cover plays in the formation of the reservoir limnological cycle. Characteristic and significant changeability of the ice cover thickness and duration was observed. The changes in the ice cover demonstrate that they are cyclical but not regular. The ice cover did not always form in the analyzed period. It happened twice, i.e. in 1988 and 2007 (a gap of 20 years). The longest lake freezing period lasted 119 days. Changes in the ice cover duration also show certain periodicity. The shortest periods occurred approx. every 7 years. Maximum values of the ice cover thickness ranged between 10 and 52 cm. There is a relation between the ice cover thickness and its duration period. The rate of increase in the ice cover thickness varied between 0.296 and 3.6 cm/d. The hypolimnion removal impact on the ice cover duration period and thickness was not observed. On the other hand, the ice cover duration period affects the spring circulation duration. Thus, it has an influence on the oxygen balance of the limnic ecosystem.
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Abstract

The inter-reservoir enrichment phenomenon was exploited to curtail the reservoir eutrophication process. The Plawnowice reservoir (South Poland - Upper Silesia Region) has an area of 225 ha, volume of 29 mln m3, and a depth of 15 meters. According to the monitoring results in the years 1993-1998 the reservoir was qualified as hypereutrophic. Beginning in December 2003 a bottom pipe for hypolimnetic withdrawal was installed. In the period 2004-2010 a negative phosphorous balance was achieved. The discharge load of total phosphorous was in the beginning twice as high as the inflowing. During the first eight years with an inflow of 75 Mg P, the removed load of total phosphorus was 103 Mg P. In effect the net balance was 28 Mg P. The load, in respect to the surface area, of 2.2 to 3.3 gP/m2 per year, was reduced to a negative load of - 0.48 to - 3.3 gP/m2. The hypolimnetic maximum concentration of orthophosphates equal to 1.254 mg P-PO4/dm3 in 2004, was reduced to 0.236 mg P-PO4/dm3 in 2011. The respective factors and rate of eutrophication curtailing, including changes of phosphorus compounds have been discussed. Also changes of pH and visibility of the Secchi disc are presented. It was concluded that the presented method of hypolimnetic withdrawal is a lasting and effective process
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Abstract

The research objective was to study temporal and spatial relations between specific phosphorus species as well as to examine total phosphorus content in the bottom sediments of an anthropogenic, hypertrophic limnic ecosystem Rybnik Reservoir, functioning under thermal pollution conditions. The chemical extraction procedure for the speciation of bioavailable phosphorus forms was used. It was found that available algae phosphorus was the most dominant phosphorus species in both sediment layers (83%), while the lower share was readily desorbed phosphorus form (0.1%). The phosphorus species concentrations depended on the organic matter concentration. The differences between phosphorus species contents in the upper (5 cm) and lower (15–20 cm) sediment core layers were low. The biologically active sediment layer extended from the sediment surface to at least 20 cm depth of the sediment core. Distributions of the concentrations within the year and at specific sampling points resulted from the variability observed for particular points and transformation intensity. Furthermore in the following study, the reaction rate constant for the increase and decrease in the concentrations of the phosphorus species in sediments was given. It was indicated that the speed of the phosphorus species transformations was affected by the environment temperature. In the heated water discharge zone (water temp. 17–35°C) the concentrations of selected speciation phosphorus forms increased more than in the dam zone (5–25°C). It was also found that the abundance of the bottom sediments with phosphorus species was related to the oblong and transverse asymmetry of reservoir depth.
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Abstract

The study presents the results of the research into different phosphorus forms in the bottom sediments of anthropogenic limnic ecosystems i.e. the reservoirs of Pławniowice, Rybnik and Goczałkowice (SP). The bottom sediments of dam reservoirs were investigated by chemical extraction procedure for phosphorus forms. The lowest value of the mean AAP form percentage in the Pławniowice bottom sediments reflected the effect of reclamation with the hypolimnetic removal that had been conducted in the reservoir since 2003. The highest percentage of the RDP form (2%) was found in the Goczałkowice bottom sediments. The order of the specific speciation forms in the bottom sediments of the examined reservoirs was: Rybnik: AAP > EP > WDP > RDP; 4,630> 3,740 > 117 > 65 > 3.5 mgP/kg Pławniowice: AAP > EP > WDP > RDP; 916 > 783 > 107 > 15 > 1.4 mgP/kg Goczałkowice: AAP > WDP > EP > RDP; 686 > 628 > 51 > 7 > 0.14 mgP/kg The mutual correlations between the phosphorus speciation forms (AAP : EP : WDP : RDP) were as follows: Rybnik: 1,323 : 1,068 : 33 : 18 : 1; Pławniowice: 654 : 559 : 76 : 11 : 1; Goczałkowice: 4,900 : 4,485 : 364 : 50 : 1. The comparison of the mean concentration values for specific phosphorus forms in the bottom sediments of the three investigated reservoirs demonstrated that the Rybnik sediments had the highest contents of phosphorus. The contents in Pławniowice and Goczałkowice were 5-7 times lower
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Abstract

The prevalence of heavy metals in wastewater is the cause of death of numerous organisms which take part in biological treatment of wastewater, that is why the aim of the study has been to asses the influence of cadmium and copper ions upon the microfauna of activated sludge. 5, 10, 50, and 100 mg/l of Cd2+ and Cu2+ were added into the samples of activated sludge and then, after 24 hours, the microscopic observations of activated sludge microfauna were carried out, and all changes concerning the amount of microfauna, functional groups, and species composition were determined. The results obtained allowed to find a high level of toxicity of Cd2+ and Cu2+ ions to activated sludge microfauna, which resulted in the changes in the value of the Sludge Biotic Index and classes of sludge, survivability of microfauna, and reduction in the number of taxonomic units. It was observed that Cu2+ ions are more toxic to activated sludge microfauna than Cd2+ ions in identical doses. Organisms sensitive to Cd2+ and Cu2+ ions have been found to be testate amoebae, Aspidisca sp. and Epistylis sp., as well as organisms relatively sensitive to tested metals, which turned out to be ciliates of Opercularia and Vorticella convalaria genera.
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Abstract

The content of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of the Blachownia reservoir (South Poland) was investigated. Spatial variability of PAH concentrations in the longitudinal profi le of the tank was determined. PAHs in samples were determined by gas chromatography coupled with mass spectrometric detection (GC-MS QP-2010 Plus Shimadzu) using an internal standard. Concentrations ranged from 0.103 μg/L to 2.667 μg/L (Σ16 PAHs) in water samples and from 2.329 mg/kg d.w. to 9.078 mg/kg d.w. (Σ16 PAHs) in sediment samples. A pollution balance was calculated and it was estimated that the infl ow load was 17.70 kg PAHs during the year and the outfl ow load was 9.30 kg PAHs per year. Accumulation of about 50% of the annual PAH loads (8.90 kg) is a threat to the ecological condition of the ecosystem. It was calculated that the PAH loads in bottom sediment were about 80 kg, which limits their economic use. Improvement of the ecological status of this type of reservoir can be achieved by removing the sediment. Analysis of the diagnostic ratios obtained for selected PAHs showed that the potential sources of PAH emissions in small agricultural – forest catchments can be combustion of a coal, wood, plant material (low emission, forest fi res, burning grass, etc.). Transportation is also signifi cant.
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