Paweł Suchorab

The primary objective of water supply systems is to ensure a reliable delivery of water in appropriate quantity, quality, and pressure. Designing water supply networks involves determining their geometric layout and capacity by selecting suitable pipe routes and sizes. Since the network layout influences pipe diameters, routing and sizing should be conducted simultaneously. This paper presents an application of the fractal-based method for designing water distribution networks (WDNs) in which the pipe routes and diameters are mathematically justified. The proposed approach takes into account the total pipe length, the total angular change in pipeline routing, construction costs, and water delivery priorities. Additionally, the method was tested under both quasi-real conditions (in the virtual city of Micropolis) and in real-world complex settlement. The results of the sizing process were also compared with those obtained using the genetic algorithm approach. Verification of the proposed method in both quasi-real and real-world scenarios showed a smaller total pipe length (by 9.53% and 12.17%), a lower maximum water age (11 and 87 h), and a comparable energy demand. The SRS method enables simultaneous determination of pipe diameters and layout routing, while ensuring proper hydraulic performance of the network due to the application of evolution theory rules which results in quasi-optimal solutions for WDN designing.

Uncontrolled water outflows from water supply pipes can pose a serious threat to human safety and infrastructure due to the washing out of soil particles and the formation of subsurface voids, leading to soil subsidence (suffosion). One way to mitigate these hazards is by determining water outflow zones (WOZ) around underground pipes, within which water may emerge on the soil surface. This paper presents the final stage of a broader study on the use of fractal geometry for determining WOZ. Suffosion hole locations form point structures that exhibit features of probabilistic fractals, and their parameters depend on the number of points in the structure. The objectives of the study were: (1) to determine the minimum number of points required for a structure to be considered representative; (2) to establish a relationship for calculating the WOZ radius; and (3) to empirically verify the theoretical WOZ radius values. Representative structures were identified and used to calculate the R_fr parameter, which, after scaling to real conditions, enabled determination of the WOZ radius, ranging from 3.5 to 5.5 m. Empirical verification confirmed the method’s validity, as theoretical zones covered up to 100% of actual outflow points (96% overall). The developed method can be applied into decision-support systems for sustainable infrastructure planning, and more efficient use of water resources.

The process of designing water distribution networks is divided into two main stages: network layout routing and pipe sizing. However, routing and sizing are not separate tasks—the shape of the network affects the diameters of the pipes, and vice versa. This paper presents an innovative fractal-based method, which enables the simultaneous layout routing and pipe sizing of water supply networks. The developed pipe routes and diameters selected according to the method are mathematically justified; the selection considers the total length of the pipes, the number of rotation angles of the base section, the cost of the water supply system construction and the priority of water supply to individual customers. The novelty of the method lies in the possibility of carrying out the processes of routing and sizing of the network in a recursive manner by the adoption of the principles of fractal geometry and Murray’s law. The method was tested under the conditions of a synthetic settlement. The obtained results enable us to conclude that the method is universal and suitable for shaping water supply networks, while determining the pipes’ diameters, both under the conditions of a single- and multi-sided water supply source.

Introduction and objective: Milking wastewater (MW) is an under-recognised reservoir of antibiotic resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). The aim of the study is to evaluate MW as a point source pollutant for the presence of ARB and ARGs, to develop a treatment...

The efficient use of energy is a sign of conscious environmental responsibility. Sustainable management also refers to water resources, where emphasis is placed on the possibility of retaining rainwater at the point of the precipitation occurrence. This article focused on the reuse of runoff from a rest area (RA) along the expressway, wherever drinking water quality is not required. The runoff from RAs can be significantly contaminated due to the traffic-related issues. The objective of this article was to evaluate the energy efficiency of preliminary treatment of raw meltwater from a selected rest area using electrodialysis for Cl⁻ and Na⁺ removal. The treatment was carried out under various conditions, including different solution temperatures (20 °C and 30 °C) and electric voltages (10 V, 20 V, 30 V). The energy efficiency assessment was preceded by a characterization of runoff quality and the analysis of pollutant removal efficiency in the electrodialysis process. The most energy-efficient variant was characterized with the 0.097 Wh/(mg/L) energy expenditure ratio and 93% efficiency removal for Cl⁻ and 0.147 Wh/(mg/L) and 90% for Na⁺. In this variant, the permissible Cl⁻ and Na⁺ concentrations limits were achieved after 27 min with an energy consumption of 57 Wh. In general, the observed highest energy efficiency occurred at the beginning of the electrodialysis process and decreased over time.

Failures of water supply pipes are undesirable events with a random nature, yet they are an inevitable part of the operation of water infrastructure. Therefore, ongoing research is being conducted to develop methods for minimising their effects or securing underground infrastructure. One of the methods of limiting the effects of the suffosion phenomenon is determination of the water outflow zone, within which water will possibly flow to the soil surface after a pipe leak. The aim of this paper was to assess hypothetical structures created by outflowing water in terms of their potential use in determining the water outflow zone on the soil surface after a water pipe failure. Based on the laboratory test results, the Monte Carlo method was applied to generate the hypothetical population of points representing the places of water outflow. Three parameters characterising hypothetical structures were analysed: fractal dimension, length of a section, and the product of above parameters. The conducted research showed that it is possible to build a reliable hypothetical structure that allows for estimating the water outflow zone radius, knowledge of which would facilitate sustainable management of the water supply network by water utilities by enabling the estimation of the water outflow zone radius in practice.

Water pipe failures result in real water losses in the form of water outflowing into the porous medium, such as the surrounding soil. Such an outflow may result in the creation of suffosion holes. The appropriate management of the water supply network may contribute to reducing the number of failures, but due to their random nature, it is not possible to completely eliminate them. Therefore, alternative solutions are being sought to reduce the effects of the failures. This article presents a fragment of the results from a broader scope of the research, which attempted to determine the outflow zone in relation to the fractal characteristics of water outflows. The research included the analysis of the actual geometric structures created by the water outflows, which were simplified into linear structures using isometric transformations. The structures were analyzed in terms of the parameters characterizing them, including their fractal dimensions. As a result, it was found that there was no relationship between the analyzed fractal parameters and the leakage area or hydraulic pressure in the water pipe. However, the influence of the number of points forming each linear structure on the analyzed parameters was shown. This allowed for the determination of further research aimed at estimating the size of the water outflow zone after the unsealing of an underground water supply pipe.

Water scarcity affects at least 11% of the population and 17% of the territory of the European Union. Simultaneously in cities there is a problem of urban floods caused by violent and intense rainfalls. Decentralized drainage systems are designed to capture rainwater runoff at the place of precipitation and improve the hydrological conditions through the use of surface and subsurface infiltration, retention, and evapotranspiration techniques. The purpose of this paper was to evaluate the financial profitability of selected Low Impact Development (LID) methods for decentralized management of rainwater disposed from the roofs of two different buildings. In the presented conditions, the use of dual installations and infiltration tunnels turned out to be cost-effective solutions, whereas infiltration boxes were unprofitable for both buildings. The most unprofitable solution would become profitable if the investment costs were reduced by as much as 67% or if it was possible to generate 2.28 times more benefits. Although the research was carried out for specific conditions, the obtained results may be helpful in the implementation of similar investments. They are also a kind of contribution to the assessment of the cost-effectiveness of LID on a global scale due to the universality of the proposed research methodology.

One of the main tasks that water companies face is limiting water losses through the distribution network. This issue is becoming more and more relevant because of progressive climate changes and rising water resource deficiencies. The first step to reducing water losses is the proper detection of leakages, including their location and size. A common approach, called active leakage control, is to divide the water network into District Metered Areas (DMAs) to detect unreported leaks in the water distribution system (WDS). The operating flow meter device at the border of the DMA allows the determination of the number of water losses by balancing water inflows into the zone and billed water consumption. However, to precisely locate a water leak it is necessary to equip the DMA with an adequate number of pressure sensors. The aim of this paper is to evaluate the impact of water supply DMA formation on the sensitivity of the monitoring system in accordance with the number and location of the pressure sensors and the geometric structure of the water pipes in the DMA in order to successfully detect water leakage. The research was conducted on a model grid network with a constant node number but a differential pipe structure. Subsequently, results were verified in the conditions of a real water supply network. The obtained tests showed no clear relationship between the effectiveness of leak detection and the network complexity but confirmed a significant improvement in leak detection after equipping the monitoring system with an additional pressure gauge.

Designing of District metered areas (DMA) schemes is a key element in developing a technique for detecting and removing unreported leaks in a water distribution system (WDS) called active leakage control. The design of DMA is very specific to individual networks’ hydraulic and often constitutes one area with pressure managed zones. This paper presents the division of a selected water supply network zone into DMA areas. Based on the spatial distribution of the flow rate and the geometrical structure of the network (routes, pipe diameters, existing gate valves) in the analyzed water supply zone, the main transmission trunks were separated (DN150 ÷ DN500 diameter range) and were excluded from the division into metering areas. DMA areas were separated from the remaining parts of the network, using the district metered areas module, supporting the division of water supply networks into metering zones, available in the WaterGEMS software by Bentley. The number of nodes in the area was 200 as the main criterion for separating DMAs. The separated areas were combined into 3 main DMA zones, in which the sum of the pipe lengths varied between 2500 ÷ 3800 m. For each of the DMAs, the water supply route was determined individually, seeking a one-sided inflow to the isolated area. In two out of three cases, this goal has been achieved. In the third case, it turned out necessary to provide two-sided water inflow. The analysis of the correct operation of DMAs was based on the hydraulic modeling of WDS.