The purpose of the study was to present the principles of creating and implementing an integrated water and wastewater management system based on hydrodynamic modeling of water distribution and sewerage disposal systems in small and medium-sized municipal enterprises. The computer modeling of...

Mathematical models of activated sludge process are well recognised and widely implemented by researchers since 1980’s. There is also numerous software available for modelling and simulation of activated sludge plants, but practical application of those tools is rather limited. One of the main...

Water and energy are the main natural resources, and their rational use is the basis for sustainable development. Therefore, the energy efficiency of water supply networks is one of the priorities for the management system of water utilities. Many methods and indicators can be used to assess the energy efficiency of water distribution networks (WDNs), and their choice should be adapted to the characteristics of a WDN. This paper presents an energy audit of WDNs that are supplied from five reservoirs located above the supply area, to which water is supplied from four underground and surface water intakes. In the analysis of the system operation, a hydrodynamic computer model of the water distribution network was used to estimate the operating parameters that are necessary to determine the energy efficiency indicators. A new method for calibrating the emitter coefficient used for water loss modeling is also proposed. The conducted audit showed that more than 70% of the energy supplied to the WDS was “lost”, mainly due to friction (37%) and water losses (27%). Thanks to hydraulic modeling, it was possible to indicate that 34% of the energy lost in the system was related to the use of pressure-reducing valves (PRV), and that only 3% was directly related to friction. In turn, the majority of leaks are attributed to service connections (17.4% vs. 8.8% in the water distribution network).

The age of water in the municipal water supply system is one of the main factors influencing water quality. To create a good quality hydraulic model, one must achieve a high level of calibration accuracy with real life measurement data. Before we start building our model, we must decide on the model’s level of detail, that is, its complexity. We must know if skeletonization of the network graph and different hydraulic timesteps have an influence on simulation results. This study strives to prove that this decision can lead to unforeseen problems during the calibration process, thus making it impossible to achieve the required calibration precision. In order to prove this, two different model variants were created with different levels of graph detail, and simulation data results were used to determine which model variant is best suited to achieve the highest fidelity simulation results. Following this, the chosen model was run with different hydraulic timestep settings, which made it possible to showcase the large influence this setting has on achieved results.

Most of the small water companies supplying a small number of consumers with water are struggling with the extremely tight budget, often making any large-scale modernisation impossible. In effect network managed by these companies is often very leaky and unreliable. One possible and cheap way of leakage reduction is the reduction of average pressure in the network. Thanks to new computing technologies, the device selection process for pressure reduction is accurate and easy to do. This study uses the hydraulic model to select required pressure-reducing valves and correct locations accurately and adequately approximate the resulting absolute water loss reduction thanks to this approach.

Monitoring and computer modeling of water networks is an effective tool supporting water management in the city. The aim of this paper is to present the results of measurement campaigns carried out in Polanica-Zdrój, preceding the construction, calibration and validation of the hydrodynamic model of the water supply network. The obtained results showed that the changed conditions of the functioning of the local community during a pandemic also significantly affect the way water is used. Daily distribution of water consumption by residents of multi-family housing has been significantly “flattened” due to remote work and extended time at home. This confirms the necessity to conduct on-line measurements in order to calibrate the model reliably and effectively use the results of computer simulations.