Comparison of long-term environmental monitoring data show that in August and September 2002 heavy metal (Cu, Pb and Zn) concentrations increased in Lithuanian rivers. Resent investigation has indicated that increase of heavy metals (Cu, Pb and Zn) by 60-81 % in all the rivers that are subject to the State River Monitoring and could be correlative with land fires. Fires of forests and peat bogs have outspread all over Lithuania in the summer and the first half of autumn of 2002. This paper attempts to prove an assumption that these fires could have caused a significant increase of heavy metal concentrations in the water of Lithuanian rivers in August 2002. It also means that land fires should be evaluated as an environmental risk factor with a serious impact on the state of aquatic environment and must be taken into account in calculations of environmental damage.
It is widely accepted that heavy metal contamination in sediment, soil, and groundwater is one of the largest threats to environmental and human health. Sediments are the principle sinks for heavy metals in aquatic environments and can result in a secondary contamination source affecting the ecosystem. Analysis of heavy metal amounts in sediments and comparison with reference levels is a reliable indicator of ecosystem health, however understanding the distribution of pollutants is among most essential information for environmental research and critical for environmental management and decision-making. 64 samples were collected from surface (0-0.6 m) and subsurface (0.6-1.2 m) layers of sediments in the northern part (bay) of Lake Babrukas, which had undergone pollution by municipal wastewater in 1964-2002. The level of pollution attributed to heavy metals was evaluated using X-Ray fluorescence analysis and comparison with several reference levels (maximum allowable concentrations in soil, background concentrations in Lithuanian soils and background concentrations in Lithuanian lake sediments) in order to determine anthropogenically derived sediment contamination of bottom sediments. Spatial distribution patterns of metals in sediments were demonstrated by employing ordinary kriging interpolation. Results of heavy metal pollution analysis reveal a significant anthropogenic impact on the northern part of Lake Babrukas with concentrations of several heavy metals in both surface and subsurface layers of sediments exceeding not only background concentrations in Lithuanian soils and lake sediments, but even maximum concentrations allowable by Lithuanian legislation. Detected levels of arsenic (As), cadmium (Cd), antimony (Sb), mercury (Hg) and tin (Sn) demonstrate a significant pollution anomaly and high potential threat to the water ecosystem and even human health by exceeding maximum allowable concentration up to 10.6 times, while detected levels of chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) show the effects of anthropogenic activity on the lake by exceeding background concentrations in Lithuanian soils and lake sediments up to 7.25 times. A comparison of heavy metal amounts and spatial distribution patterns in the two layers of sediments reveals much higher pollution levels in the subsurface (0.6-1.2 m) than surface (0-0.6 m) level by most metals, namely As, Cd, Hg, Ni, Sb and Sn, while Zn was the only metal with higher concentrations in the surface level. Spatial distribution analysis demonstrates irregular distribution of most metals due to complexity of influencing physical and chemical processes, but the general trend of high concentration anomalies stretching through the south-eastern and north-eastern parts of the bay towards its northern point is explained by former discharges of wastewater into the littoral zone of the eastern shoreline and water currents towards excess water overflow into Lake Lovka (Olauka), interconnected with Lake Babrukas in the north.
An experimental investigation on the removal of petroleum products (PP) from wastewater by natural sorbent zeolite was carried out in a laboratory on a pilot-scaled test bench. The pilot test bench consisted of: a tank in which gasoline (1 portion) and diesel (1 portion) were mixed mechanically with water; a pump for supplying the mixture to a filter model; a filter model filled with a zeolite layer of 0,2 m height. Zeolite used in this study was from a deposit near the village of Sokyrnytsa in the Ukrainian Transcarpathian region. The test zeolite particle size was 2,53,0 mm; 1,5 2,0 mm; 0,631,0 mm. The concentration of PP in water was measured before and after the filter every hour. The TOG/ TPH analyser was used for concentration measurements. The experimental study showed that the best adsorption results were reached in the filter with 0,631,0 mm particle size of zeolite media. There were 2,25 mg/l of light hydrocarbons left in the filtrate. Such a concentration satisfies the requirements of standards regulating the percentage of PP in treated wastewater.
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Road maintenance chlorides have a negative environmental impact. Chemical solutions of melting snow inevitably get into the soil and change its chemical composition. They also get into ponds. Five water basins in Vilnius city, at 5–80 m from roads, were chosen for investigation. The highest chloride concentrations were established by roads where winter road maintenance is performance at the highest level. The hydrophysical and chemical parameters of the investigated lakes depend on anthropogenic processes. Diatoms were used as indicators for reconstruction of the paleo‐ecological history of the lakes. They respond sensitively to changes in lake water salinity. The total number of 35 indifferentic‐halophilic species from all the 78 diatom taxa were identified in the lake bottom sediments. Fluctuations of their abundance could be caused by the impact of salts in different periods stimulating the productivity of indifferentic‐halophilic specie
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