The research aimed to learn if and to what extent extraneous waters, occasionally flowing into sanitary sewer system during atmospheric precipitation, change proportions of selected pollution indices which are significant regarding biological sewage treatment. The following proportions between pollution indices should be maintained in the sewage subjected to biological treatment process: COD:BOD5 ≤ 1.8; BOD5:N ≥ 4.0, BOD5:P ≥ 25; COD:P ≥ 3.6. Investigations conducted in two sewer systems located in the Małopolskie voivodeship revealed that extraneous waters infiltrating the intercepting sewers during wet weather negatively affect all proportions between pollution indices. Increasing amount of extraneous waters in sewer systems caused the greatest changes of BOD5:N and BOD5:P proportions. On the basis of conducted research it was found that considerable quantities of nitrogen and phosphorus compounds are supplied to the sewer system with extraneous waters, which in biological denitrification and dephosphatation processes may lead to a deficit of organic compounds causing a necessity to provide an external source of carbon for the reactor chambers, such as methanol, ethanol, acetic acid, glucose or others. During the conducted investigations it was demonstrated that extraneous waters in interceptors cause not only sewage dilution, but also significantly change its chemical composition. ...
The aim of the research was to get the expertise, how location of wastewater treatment plant to basin of sewage system influences the temperature of inflowing wastewater. The analysis included four sewage systems, which are different for the sake of length of transit canal between treatment plant and residential buildings, in which domestic sewage was produced. In analysed systems sewage flew into the treatment plants with hydraulic capacity range from 100 to 300 m3•d-1, and with population equivalent less than 2000. Measurements of temperature of air and wastewater outflowing from sewage system, in analysed year 2012, were conducted continuously, with 1 hour interval, with use resistance sensors connected with data recorder. The research showed, that the distance of treatment plant to basin of sewage system has a significant impact on wastewater temperature outflowing from sewage system. In winter period mean daily wastewater temperature outflowing from transit manifolds with length from 300 to 600 m was lower even about 3oC, but in summer period up to 8oC, in comparison to transit manifolds with length less than 10 m. Moreover, it was proved that, apart from length of transit manifold, also intensity of wastewater flow has a significant impact on wastewater ...
The objective of this research was to compare the amount of extraneous water flowing into selected gravitational separate sewer systems which discharge domestic sewage from the settlement of single-family houses in Poland and France during a year with a standard annual amount of precipitation. The study included a total of four sewer systems, including two operating in Poland and discharging the sewage from settlements near Krakow in the Malopolska Province and two systems operating in France and discharging the sewage from settlements of single-family houses near Lorient, Brittany, Morbihan Department. As part of the analysis, an average daily tributaries of extraneous water into sewers under the research, values of addition and share of this water were compared. Analysis of the research results demonstrated that the hydraulic load of sewer systems with extraneous water does not depend on the age of the sewer system, but mainly on the number of house drains, and to a lesser extent its length. It was also determined that the average daily amount of extraneous water flowing into sanitary sewer systems in wet weather is 0,107 m3·d-1 per 1 sewer connection. The study showed that tributaries of extraneous water into the separate sewer system ...
The aim of the paper was an analysis of the structure of tap water consumption by rural households considering the use of its results for designing the elements of water supply and sewer systems. The analysis of this structure was based on direct measurements of water consumption conducted in 2011-2014 in 30 households located in Przeginia Duchowna village (Czernichów commune, Malopolskie province). Double measurement of water consumption (water supply connection or water draw off point outside a residential building) enabled the separation water consumption for household and additional purposes from the total water consumption per household. Analysis of the collected data revealed considerable disproportions between the real water consumption and stated in the design guidelines. Calculated on the basis of the study, averaging 85.6 dm3·I-1·d-1, accounted for only 57% of the value of 150 dm3·I-1·d-1 most commonly used in design. Because of the possible determining the water consumption structure it was demonstrated, that the divergences concerned also the volume of domestic sewage discharged from rural households. Obtained results revealed also that application of the principle, where the volume of sewage equals the volume of water consumption by rural households, for designing sewer systems is usually incorrect. In the analyzed household ...
The paper presents an analysis of sewage susceptibility to biodegradation on an example of sewage treatment plant in Wodzisław Śląski in the Śląskie province. For this purpose, dependencies between selected indices of domestic sewage pollution were applied. Descriptive statistics of the respective indices rations COD/BOD5, BOD5/TN, BOD5/TP were presented. Moreover, an analysis was conducted on the composition of raw sewage flowing into the treatment plant, pre-treated sewage and sewage leaving the studied treatment plant. The analysis was carried out on the basis of three basic indices of sewage pollution (BOD5, COD and total suspended solids) and two biogenic indices (total nitrogen and total phosphorus). Tests on the sewage composition were conducted in the years 2010-2015. Basic descriptive statistics were compiled for the values of the studied indices of sewage pollution and the obtained results were interpreted. On the basis of collected material it may be said that sewage reaching the treatment plant in Wodzisław Śląski revealed a good susceptibility to biodegradation, whereas the BOD5/TN and BOD5/TP ratios were below the optimum value. ...
