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 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. ...
