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EN
The storage and disposal of sewage sludge from municipal wastewater treatment plants is becoming an increasing problem on a global scale. The attention of scientists is directed to the search for unique technologies to manage them. Firing sewage sludge in furnaces and producing lightweight aggregates and granules constitutes an innovative method of its disposal. The resulting granules could be a substitute for commonly used materials such as perlite, vermiculite, expanded clay, or LSA, and could be used as a secondary material in the construction industry, including road construction, as various types of ballast, and as an equivalent to aggregate in concretes. However, given that sewage sludge is increasingly used in biogas production, it does not completely decompose in the process and is still a problematic waste for many municipal treatment plants. Therefore, the use of sewage sludge pellets in construction, or any other industry, could revolutionize the market. The purpose of the conducted research was to evaluate the heat-insulating properties of granules produced from sewage sludge from the Municipal Wastewater Treatment Plant "Łyna" in Olsztyn used as a heat-insulating material.
PL
Zaostrzające się wymogi, dotyczące jakości ścieków odprowadzanych do odbiornika, doprowadziły do opracowania wielu urządzeń wykorzystywanych podczas biologicznego oczyszczania. Obecne badania prowadzone w sektorze wodno-ściekowym skupiają się często na poszukiwaniu efektywnych energetycznie rozwiązań technicznych i technologicznych, wywierających jak najmniej negatywny wpływ na środowisko „przy jednoczesnym obniżeniu kosztów eksploatacyjnych. W systemach oczyszczania powszechnie wykorzystuje się właściwości struktur mikroorganizmów w postaci kłaczków osadu czynnego, które usuwają organiczne i biogenne związki zawarte w ściekach. Ważnym elementem powyższego rozwiązania jest zastosowanie układu mieszania i napowietrzania bioreaktorów w odpowiedniej konfiguracji. W oczyszczalni ścieków, z częścią biologiczną, działającej w technologii SBR, stosuje się wiele rodzajów urządzeń do mieszania. W niniejszym artykule przedstawiono zastosowanie innowacyjnego wolnoobrotowego systemu mieszania w sekwencyjnych bioreaktorach porcjowych, w których czynnikiem procesowym jest osad czynny.
EN
Increasing demands on the quality of wastewater discharged to the receiving water have led to the development of many biological treatment devices. Current research in the water and wastewater sector often focuses on finding energy-efficient solutions that have the least negative impact on the environment while reducing operating costs. In wastewater treatment systems, it is common to utilize the properties of microbial structures in the form of activated sludge flocs that remove organic compounds and biogenic contained in wastewater. An important part of the solution is the mixing and aeration system configuration used. In the treatment plant operating in the SBR technology, there are many types of mixing devices that are used in the process of wastewater treatment. This paper presents the application of an innovative slow-speed mixing system in sequential batch bioreactors in which activated sludge is a process factor.
EN
In this study, the effect of bioaugmentation on the sequencing batch reactor (SBR) performance while treating municipal wastewater and reject water under various temperature conditions was examined. Two lab-scale SBRs, each with the active volume of 8 L were used to perform this research. For bioaugmentation, a mixture of wildliving Bacteria and Archaea in a dose 0.25 mL was added to SBR A, while SBR B was a control one. Both reactors were fed with a mixture of wastewater and 13% v/v reject water. During the experiment, 5 phases with different temperature range were distinguished, each one lasted 14 d. The temperatures were investigated in 5°C increments, i.e. 20, 25, 30, 25 and 20°C. The obtained results indicated that in the bioaugmented reactor (SBR A), lower concentrations of NH4+–N, TSS, NO2-–N in effluent were observed as compared to control (SBR B). While for NH4+–N, regardless the temperature, the observed differences were statistically significant. Importantly, in both SBRs, the process was carried out in a stable way.
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
In the present study, the influence of bioaugmentation strategy on the co-treatment of 13% v/v reject water and municipal wastewater at a decreasing temperature was evaluated. The experiment was performed in two identical laboratory sequencing batch reactors with the active volume of 8 L. Each one was operated using a 12-hour cycle at sludge retention time of 3 d. The SBR A was bioaugmented with a mixture of wild-living bacteria and Archaea in a dose 0.25 ml. In turn, the comparative reactor (SBR B) was non-bioaugmented, the Archaea product was replaced with an equal volume of dechlorinated tap water. The experiment was divided into 3 phases, each with a different temperature range (20, 15 and 10°C). The temperature reduction did not adversely affect the process performance in the bioaugmented and non-bioaugmented system. Significant removal efficiencies were achieved in both SBRs. The major differences were observed for the COD content in the bioaugmented SBR at a temperature of 10°C. In this case, statistically lower concentrations in the effluent were observed in the bioaugmented system than in the non-bioaugmented one. Additionally, at a temperature of 10°C, an improved process performance was observed in the Archaea presence, but the differences were of no statistical significance.
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.
EN
Materials scientists are seeking to produce metals with reduced weight and dimensions while maintaining the appropriate mechanical properties. There are several ways to improve the internal structure of metals, such as the ultrasound used to solidify liquid metal. The homogeneity of the grains and the uniformity of the metal structure affects its mechanical strength. This paper presents the results of investigations into the effects of hot deformation parameters in compression on the austenite grain size in the HSLA (High Strength Low Alloy) steel (0.16% C, 0.037% Nb, 0.004% Ti, 0.0098% N). The axisymmetric compression investigations were performed on cylindrical investigation specimens using a Gleeble 3800 thermomechanical simulator with the strain rate of 1÷15.9 s-1 and strain degree ε = 1.2. Before deformation, the research specimens were austenitized at TA = 1100÷1250 °C. The metallographic observations of the primary austenite grains were conducted with an optical microscope, while the structure of dynamically recrystallized austenite, inherited by martensite, was examined by using a scanning electron microscope.
8
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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