| Abstract [eng] |
The investigations of active sludge taken from Vilnius, Utena and Nemenčinė wastewater treatment plants was carries out. The main goal was investigate the effects of wastewater pollutants on communities of microorganisms taken from activated sludge and to identify indicator species of this impact assessment. Investigations were carried out with these pollutants: 3,5 - dichlorophenol (3,5 - DCP), ethanol, and salt (NaCl). Active sludge was analyzed microbiologically, number of species and number of individuals (ind. / ml) were counted. In this study 16 experiments was carried out and microbiological composition of wastewater treatment plants was estimated. Results showed that activated sludge microorganisms adapted to low (2.5 ppm, 5 ppm and 7.5 ppm) concentrations of 3,5 – DCP, but high (15 ppm and 20 ppm) concentrations reduced abundance of microorganisms. Ethanol stimulated community of activated sludge, because concentration of activated sludge and number of bacterial colonies increased. Low concentrations (3 g/l, 5 g/l ir 7 g/l) of NaCl also stimulated abundance of active sludge community, microorganisms adapted to the concentration of 10 g/l, and number of microorganisms decreased when concentration of NaCl was high (15 g/ l). Acineria uncinata, Aspidisca costata, A. lynceus, Vorticella spp., Ptelomonas sp., gymnamoebae and bacteria (which makes clusters) – this was the most sensitive species of microorganism in activated sludge. A. costata resisted quite high (even 10 ppm) 3,5 – DCP concentration better than other microorganisms. Number of bacterial colonies increased when the activated sludge suspension was treated with ethanol. Acineria uncinata showed capability for acclimatization to NaCl in terms of abundance. And Ptelomonas sp. were the microorganisms least affected by the high (20 g/l) NaCl concentration. |
