Search

In the present study, the effect of bioaugmentation strategy on the sequencing batch reactor (SBR) performance while treating reject water and municipal wastewater under various temperature conditions was examined. The experiment was performed in two lab-scale SBRs, each with the active volume of 8 L and operating at sludge retention time of 3 d. For bioaugmentation, a mixture of wild-living 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. The study was divided into 5 phases, with different temperature range, 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 found as compared to non-bioaugmented one (SBR B). In the case of NH4+ - N, regardless the temperature, the observed differences were statistically significant. Importantly, in both SBRs, the process was carried out in a stable way.

The use of modern methods and modelling and simulation tools in the design of bioreactors allows for the analysis of 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 simulations of the aeration process in the bioreactor of SBR type realized by means of computational fluid dynamics (CFD) and ANSYS 12.1 software. The subject of the analysis was a diffuser of own design. For the preparation of geometry representing the analyzed design the Design Modeler 12.1 module was used and the discretization of the continuous domain was carried out with the ANSYS Meshing 12.1 tool. For model calculations the ANSYS Fluent 6.3 solver was used. 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 real set of prototype models of aeration systems. The results obtained indicate that an increase in 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 are in the range from 3.9 to 8.7 % and are comparable with the average values of turbulence degree obtained by other researchers. The air bubble diameter range are 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 limit values.

In the present study, the influence of bioaugmentation strategy on co-treatment of 13% v/v reject water and municipal wastewater at decreasing temperature was evaluated. The experiment was performed in two equal 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. While 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 10oC). 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 bioaugmented SBR at a temperature of 10oC. 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 10oC the improved process performance was observed in Archaea presence, but the differences were no of statistical significance.

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 (this is a patent of Toyota Motors Company). 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 HSLA steel (0.16% C, 0.037% Nb, 0.004% Ti, 0.0098% N). The axisymmetric compression investigations were performed on cylindrical investigation specimens of d=1.2 using the Gleeble 3800 simulator. The strain rate=1s-1÷15.9s-1 and strain degree ε=1.2. Before deformation, the research specimens were austenitized at TA = 1100 ÷ 1250°C. 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 EBSD technique using a scanning electron microscope

One of the widespread sources of river pollution is wastewater coming from both wastewater treatment plants and stormwatater 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 [Strom et al., 1976]. 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 the assessment of the effect of surface runoff collected by 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). We observed, that the correspondence between a species diversity and the quality of the environment is not always straightforward. So, 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 we rely on the trophic diatom index (TDI).

The spatial distribution of ciliate assemblages was studied in a shallow floodplain lake with a sharp division of space by oxygen conditions. The surface zone occupied by the “carpet” of Lemna trisulca and L. minor was characterized by a large daily amplitude of oxygen content with periodic exceeding of 100% of saturation; the underlying water layer was characterized by microaerobic conditions throughout most of the year, with seasonal deviations towards oxygen-free conditions (in winter and mid-summer) or increased oxygen content (before freezing and after ice melt); stable oxygen-free conditions were maintained in the bottom layer of water and at the bottom of the lake. There were 111 species of ciliated protozoa recorded in the lake. The ciliated protozoa were clearly structured and formed three almost non-overlapping assemblages in terms of species composition, which retained their isolation during all seasons of the year. On the basis of the analysis performed using the R indicspecies package, species of ciliated protozoa were identified as indicators of conditions with different oxygen regimes, which are determined by the level of organic pollution and the distribution of photosynthetic organisms.

One of the important factors determining the biochemical processes in bioreactors is the quality of the wastewater inflow to the wastewater treatment plant (WWTP). Information on the quality of wastewater, sufficiently in advance, makes it possible to properly select bioreactor settings to obtain optimal process conditions. This paper presents the use of classification models to predict the variability of wastewater quality at the inflow to wastewater treatment plants, the values of which depend only on the amount of inflowing wastewater. The methodology of an expert system to predict selected indicators of wastewater quality at the inflow to the treatment plant (biochemical oxygen demand, chemical oxygen demand, total suspended solids, and ammonium nitrogen) on the example of a selected WWTP—Sitkówka Nowiny, was presented. In the considered system concept, a division of the values of measured wastewater quality indices into lower (reduced values of indicators in relation to average), average (typical and most common values), and upper (increased values) were adopted. On the basis of the calculations performed, it was found that the values of the selected wastewater quality indicators can be identified with sufficient accuracy by means of the determined statistical models based on the support vector machines and boosted trees methods.

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.

The improvement of energy efficiency ensuring high nutrients removal is a great concern for many wastewater treatment plants (WWTPs). The energy balance of a WWTP can be improved through the application of highly efficient digestion or its intensification, e.g., through the introduction of the co-substrates with relatively high energy potential to the sewage sludge (SS). In the present study, the overview of the energetic aspect of the Polish WWTPs was presented. The evaluation of energy consumption at individual stages of wastewater treatment along with the possibilities of its increasing was performed. Additionally, the influence of co-digestion process implementation on the energy efficiency of a selected WWTP in Poland was investigated. The evaluation was carried out for a WWTP located in Iława. Both energetic and treatment efficiency were analyzed. The energy balance evaluation of this WWTP was also performed. The obtained results indicated that the WWTP in Iława produced on average 2.54 GWh per year (7.63 GWh of electricity in total) as a result of the co-digestion of sewage sludge with poultry processing waste. A single cubic meter of co-substrates fed to the digesters yielded an average of 25.6 ± 4.3 Nm3 of biogas (between 18.3 and 32.2 Nm3/m3). This enabled covering the energy demand of the plant to a very high degree, ranging from 93.0% to 99.8% (98.2% on average). Importantly, in the presence of the co-substrate, the removal efficiency of organic compounds was enhanced from 64% (mono-digestion) to 69–70%.

The work is devoted to the task of simplifying the assessment of the effect of effluents from treatment facilities on the river hydrobiocenosis. The studies were carried out on the mountain river Uzh (Uzhgorod, Ukraine). Our approach to assessing the impact of waste treatment facilities on the river receiver is based on the estimate of the similarity of species composition and quantitative characteristics of populations of organisms from the aerotank and from the river. It is shown that the quantitative development of populations of species of ciliates from the aeration tank is a good indicator for assessing the degradation of organic matter coming with wastewater. The use of qualitative and quantitative characteristics of the protozoa from the wastewater treatment plant as a criterion for assessing the quality of the environment in the area of wastewater discharge showed their representativeness and effectiveness. The use of a limited number of species makes it possible to conduct an express assessment of the effect of effluents on receiving reservoirs for specialists working with activated sludge in the laboratories of treatment facilities.

The paper presents the results of studies on the modeling and optimization of organic pollutant removal from an aqueous solution in the course of simultaneous adsorption onto activated carbons with varied physical characteristics and oxidation using H2O2. The methodology for determining the models used for predicting the sorption and catalytic parameters in the process was presented. The analysis of the influence of the sorption and catalytic parameters of activated carbons as well as the oxidizer dose on the removal dynamics of organic dyes-phenol red and crystal violet-was carried out based on the designated empirical models. The obtained results confirm the influence of specific surface area (S) of the activated carbon and oxidizer dose on the values of the reaction rate constants related to the removal of pollutants from the solution in a simultaneous process. It was observed that the lower the specific surface area of carbon (S), the greater the influence of the oxidizer on the removal of pollutants from the solution. The proposed model, used for optimization of parameters in a simultaneous process, enables to analyze the effect of selected sorbents as well as the type and dose of the applied oxidizer on the pollutant removal efficiency. The practical application of models will enable to optimize the selection of a sorbent and oxidizer used simultaneously for a given group of pollutants and thus reduce the process costs.

The subject of the research involves a rotating biological contractor with a bi-directional longitudinal flow as an element of a synchronized system of disposal and biological treatment of domestic wastewater in small-bore sewerage. The rotor design is based on a system of corrugated protective pipes, arranged in coils wound around its rotation axis. The pipes are wound in a way that enables a bi-directional flow of liquids. During the rotor rotation in wastewater, the contactor is simultaneously emptied and filled with wastewater. The role of corrugated protective pipes is twofold; on the one hand, they constitute a surface for the biofilm development and on the other, they enable the flow of liquids, thus ensuring its aeration. The contactor design aims to achieve intensive aeration of transported wastewater, which will allow for greater development of microorganism populations participating in hybrid wastewater treatment, i.e. the methods involving activated sludge and trickling filter. An analysis on the influence of rotor operation kinematics on the efficiency of liquid aeration was conducted. The aeration capacity for variable rotational speed (0.7 rpm, 1.5 rpm, 2.0 rpm, 3.0 rpm) and direction of the contactor rotating element were calculated. In the considered case, oxygen transfer coefficient KLa was within the range of 0.011 ÷ 0.023 1/min. The obtained results indicate a clear connection between the system kinematics and the degree of liquid aeration in the contactor

The paper discusses the issue of removing persistent organic pollutants (POPs) from wastewater, especially the polycyclic organic hydrocarbons (PAHs). The results obtained in literature studies indicate that the commonly employed traditional methods of wastewater treatment are not always efficient in eliminating the hardly bio-degradable pollutants. Therefore, extensive research is being conducted on the application of efficient POPs removal technologies. One of the considered variants involves incorporating advanced oxidation processes (AOP) into the wastewater treatment systems based on the biological processes. These include the reagentless methods, e.g. the processes involving ultrasounds and hydrodynamic cavitation. On the basis of the author’s own studies conducted in a laboratory system comprising a static cavitation reactor, the possibility of applying hydrodynamic cavitation for the decomposition of PAHs was evaluated on the basis of model solutions of anthracene and phenanthrene. It was shown that the employed advanced oxidation process with hydro-cavitation has a significant impact on reducing the concentration of the considered PAHs. It was confirmed that the degradation degree of a substance depends on the intensity and the course of the cavitation process. The energy efficiency of the conducted process was analyzed as well and expressed as the ratio pertaining to the amount of the degraded compound to the electric energy supplied to the system.

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO2) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO2are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO2is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO2emissions is still unknown. The emission of CO2caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO2emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO2produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.

The work presented the possibility of implementing an innovative system of simultaneous transportation and treatment of sanitary wastewater in scattered dwelling areas. Small-bore sewerage with a balanced flow enables simple and inexpensive simultaneous disposal and pre-treatment of fluid with from vast, undeveloped areas.

This paper is concerned with the issues of cybersecurity and it presents AHP multi-criteria analysis methodology applied for assessing the level of real threats arising from cyberspace that affect the information security. Based on the results of surveys conducted among employees of a selected state institution, we carried out an analysis of awareness of the dangers of cyberspace and ways employees respond to incidents in systems. Taking into account the research results, an appropriate mechanism for the provision of an adequate level of information security was proposed.

The statistical analysis was carried out on the material collected from the Vorskla River (a first-order tributary of the Dnieper River) and the system of connected water bodies in the territory of the Getmanski National Nature Park (Sumy region, Ukraine). The methods of cluster analysis has enabled us to, first, isolate groups analogous to those obtained with the use of the method of dominants and, secondly, to compare the degree of their coincidence. From the comparison of the associations with the groups of the aquatic vegetation’s species, a minimal overlapping could be seen in the composition of associations and clusters. In contrast, the groups identified by the hierarchical clustering method and by the k-means method showed significant similarities in the composition. For the objective assessment and classification of plant associations, it is most productive to use several methods with the coincidence of the results of which, it is possible to assert with more confidence that these combinations of species in nature are in fact not random.