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EN
The representation of Peritricha ciliates was studied in the activated sludge of two wastewater treatment plants (WWTP), one of which operates using a technology that includes alternating aerobic, anoxic and anaerobic conditions in bioreactors (Lublin, Poland), and the other – only aerobic conditions (Sumy, Ukraine). During the study, 14 Peritricha species were identified in the WWTP Lublin, and 13 species were identified in the WWTP Sumy. The similarity of species lists was 81.5% (Sørensen index). On the basis of on the similarity and taking into account the occurrence rate (≥ 60%), a common group of Peritricha species characteristic of the activated sludge from these two types of treatment facilities was identified, which includes 4 species of colonial Peritricha: Carchesium polypinum, Epistylis coronata, Epistylis longicaudatum and Opercularia articulata, and also 4 species of solitary Peritricha: Vorticella aquadulcis, Vorticella convallaria, Vorticella infusionum and Vorticella microstoma. Despite the very high similarity in species composition, statistical analysis of the population structure of Peritricha showed a clear separation of two WWTPs with different wastewater treatment technologies. If there is a significant similarity in the species composition of Peritricha, the species, based on their abundance and occurrence, are divided into two groups, focused on different technological schemes. The population structure of Peritricha responds to the changes in purification technology, showing the changes not so much in species composition as in their quantitative structure. The differences in bioreactor conditions and increased effluent treatment efficiency demonstrated by the WWTP Lublin result in differences in Peritricha species structure, which are reflected in higher Peritricha abundance in WWTP Lublin compared to WWTP Sumy.
EN
The use of modern methods as well as modeling and simulation tools in the design of bioreactors allows for the analysis of the flow phenomena in a short period of time without the need of physical model preparation, and thus for the optimization of existing solutions. The article presents the simulations of the aeration process in an SBR-type bioreactor, realized by means of computational fluid dynamics (CFD) and ANSYS 12.1 software. The subject of the analysis was a diffuser of own design. The Design Modeler 12.1 module was used for the preparation of geometry representing the analyzed design, and the discretization of the continuous domain was carried out with the ANSYS Meshing 12.1 tool. The ANSYS Fluent 6.3 solver was used For model calculations. On the basis of the results obtained from the conducted simulations, it is possible to predict the parameters which will increase efficiency and effectiveness without the need to build a real set of prototype models of aeration systems. The results obtained indicate that an increase in the aeration velocity results in a decrease in the minimum Y-axis velocity for both the mixture and air. The observed differences are caused by the shape of the geometric model and the velocity of the air outlet through the openings, which affects the hydraulic process in the chamber. These processes affect both the amount of oxygen dissolved in the bioreactor and the behavior of the suspension in volume. The turbulence intensity during the aeration process is concerned mainly in the range from 3.9 to 8.7% and is comparable with the average values of turbulence degree obtained by other researchers. The air bubble diameter ranged from 0.3 to 4.5 mm, in the case of aeration velocity 5.68 cm/s, a significant part of the chamber were air bubbles with a diameter of 2.6 to 3.9 mm, i.e. they were not the limit values.
EN
One of the widespread sources of river pollution is the wastewater coming from both wastewater treatment plants and the stormwater system. Wastewater can vary significantly in composition and concentration of substances introduced into water bodies. Municipal effluents may contain significant amounts of organic matter and ammonia. Storm drains are diverse in composition and depend on the nature of the surface from which the water collects, but carry more suspended solids and less nutrients. The research was aimed at assessing the effect of surface runoff collected by the stormwater system from the territory of the city of Lublin on the Bystrica River using popular environmental indices, calculated on the basis of periphytonic algae species abundances: species number, Shannon’s H, rarefied species number, Pielou’s evenness, trophic diatom index (TDI). It was observed that the correspondence between a species diversity and the quality of the environment is not always straightforward. Therefore, the periphytonic algae diversity increases under the influence of runoff, as evidenced by the Shannon index. Nevertheless, pronounced changes are noted in the structure of the algal community, as shown by the Pielou index and NMDS. However, these changes in the structure are invisible if the trophic diatom index (TDI) is relied upon.
4
Content available Effect of Stormwater System on the Receiver
EN
The surface water quality assessment could be based on a combined physical and chemical analysis, but it could also be determined with bioindication methods. Classical physicochemical analysis is in most cases more expensive and time-consuming than the bioindication methods. This type of analysis also requires expensive equipment and shows the situation in the water only at the moment of sampling. Although the bioindication methods are often complicated, they allow a relatively inexpensive estimation of the water quality. Moreover, during their implementation, the substances harmful to the environment are not generated, and the obtained results usually reflect the total interaction of all factors and substances to the analyzed living organisms. Indicator organisms or their communities applied to the research, with identified ranges of tolerance to selected factors, could help to determine the physical and chemical parameters of water. This paper presents a bioindication study with an effect of stormwater system on the receiver – the Bystrzyca river, in Lublin, Poland. The level of saprophyty of the river sector was calculated based on the selected species of algae (diatoms and green algae) and the influence of the stormwater discharge on the communities of these organisms was determined.
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