In large urbanized areas is used rainwater drainage and that has a negative impact on the functionality of the sewerage system during heavy rainfall. Pipes and objects on the sewer network are being overloaded. This causes quick floods. In our research, we are focused on the assessment of part of the sewerage of Trnava city. The collectors C and D belonging to the eastern part of the city. In our assessing we use boundary rain from ombrografic station of Trnava City.

In connection with the optimization of operation at the selected Wastewater Treatment Plant (WWTP), it is important to perform an energy audit with an assessment of the use of electricity and the subsequent economic optimization of the equipment of the WWTP. We can perform the energy balance through Life Cycle Assessment (LCA) analysis in relation to EN ISO 140 40 [1].The aim of this study case is the analysis of the energy balance of WWTP. The appraisal was performed on three different interpretation variants of specific electricity consumption. The conclusion is a comparison of variants of quantification of specific electricity consumption.

Serbia is among the countries with the lowest percentage of industrial and municipal wastewater treatment plants. Approximately 72.0% of the cities have a sewerage system, while only 60.0% of the population are connected to the sewerage network. This article is about recent state of sewerage and wastewater treatment in Serbia. It consists of an analysis of the development and the percentage of population connections to the sewerage network. It provides data on the state of wastewater treatment plants in Serbia, as well as on the amount and method of wastewater treatment. The paper aims to analyse the current situation in the field of wastewater treatment.

In the process of design and operation of sewerage system are used empirical formulas, which are in many cases, become obsolete and unusable when somebody can use nowadays modern technologies and materials. Therefore there is the possibility of using the mathematical models enormous importance for the enhanced environmental protection with the lowest operating and investment costs. In this modern method of analyzing of sewers has been designated as the first object, the object sedimentation tank. The purpose of the primary and secondary settling tank is to ensure the reduction of concentration the floating solids. For the solution of research work has been chosen, after consultations with representatives of the Western Slovakia Water Company as interesting object of sedimentation tank located on the waste water treatment plant Nitra-Dolné Krškany. Measurements on the object settlement tank situated at waste water treatment plant Nitra confirmed the expected speed parameters of the sewage in the tank. The velocity of wastewater is in the most cases very low, and even insignificant. However, finding that the sludge cloud has a non-standard form of a double wave gives the opportunity to optimize the operation of facilities sedimentation tank. The measured parameters are used as calibration parameters to input to the mathematical simulations, which are created by software ANSYS fluent.

This research deals with creating a hydrodynamic combined sewerage overflow chamber model an ANSYS Workbench 19.2, Fluid Flow (Fluent). The 3D graphics model was created in the SpaceClaim modeling software, which serves as the basis for hydrodynamic modeling. The model was created according to a real combined sewerage overflow chamber in Banská Bystrica. The cores of the work are simulations that should correspond to the estimated flow in the combined sewerage overflow chamber. The aim of this paper is to compare the impact of inflow speed and flow rakes.