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In the context of sustainable development and global challenges such as climate change and energy security, this paper conducts a bibliometric analysis of scientific journals on multi-criteria decision-making (MCDM) methods with an emphasis on their applications in environmental and energy engineering. The study used the CiteSpace software program 6.2.R6 Advanced to analyze citation networks and identify key publications, authors, and research topics. The simulations carried out made it possible to identify the main research centers and patterns of international cooperation, pointing to the key countries and institutions involved in MCDM research. The results of the analysis reveal the research areas of greatest interest and the main directions for future research. These results can support scientists, researchers, and policymakers in making more informed and sustainable decisions, contributing to the achievement of the Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

Groundwater-dependent cultivation is imperative to meet the ever-increasing food demands in Egypt. To explore the Moghra aquifer's potential, where a large-scale rural community is being established, a finite element groundwater flow (i.e., FEFLOW®) model was invoked. The developed model was calibrated against the observed water levels. GRACE-based groundwater storage was incorporated into the tuning procedure of the developed model. Eight abstraction rates from 1000 wells, changing from 800 to 1500 m3/day/well, were simulated for a 100-year test period. The maximum resulting drawdown values, respectively, ranged from 59 to 112 m equating to about 20–40% of the aquifer's saturated thickness. The implications of the climate change from gradual sea level rise and an increase in crop consumptive water use were investigated. Extending seawater invasion into the aquifer caused a slight increase in the piezometric levels within a narrow strip along the seaside. Applying a chronologically increasing withdrawal rate to meet the projected increment in crop water requirements raised the maximum resulting drawdown by about 7.5%. The sustainable exploitation regime was defined as a time-increasing withdrawal rate adequate to reclaim 85,715 acres (34,688 ha). The recommended development scheme is compatible with the withdrawal rationing rule, aiming to maintain that the resulting drawdown does not exceed one meter a year. [ABSTRACT FROM AUTHOR]

The main results highlighted in this article underline the critical significance of hydrogen technologies in the move towards carbon neutrality. This research focuses on several key areas including the production, storage, safety, and usage of hydrogen, alongside innovative approaches for assessing hydrogen purity and production-related technologies. This study emphasizes the vital role of hydrogen storage technology for the future utilization of hydrogen as an energy carrier and the advancement of technologies that facilitate effective, safe, and cost-efficient hydrogen storage. Furthermore, bibliometric analysis has been instrumental in identifying primary research fields such as hydrogen storage, hydrogen production, efficient electrocatalysts, rotary engines utilizing hydrogen as fuel, and underground hydrogen storage. Each domain is essential for realizing a sustainable hydrogen economy, reflecting the significant research and development efforts in hydrogen technologies. Recent trends have shown an increased interest in underground hydrogen storage as a method to enhance energy security and assist in the transition towards sustainable energy systems. This research delves into the technical, economic, and environmental facets of employing geological formations for large-scale, seasonal, and long-term hydrogen storage. Ultimately, the development of hydrogen technologies is deemed crucial for meeting sustainable development goals, particularly in terms of addressing climate change and reducing greenhouse gas emissions. Hydrogen serves as an energy carrier that could substantially lessen reliance on fossil fuels while encouraging the adoption of renewable energy sources, aiding in the decarbonization of transport, industry, and energy production sectors. This, in turn, supports worldwide efforts to curb global warming and achieve carbon neutrality. [ABSTRACT FROM AUTHOR]

Renewable energy sources, encompassing wind, solar, hydro, and geothermal options, are assuming an increasingly crucial role in the global energy landscape. They present a sustainable substitute for fossil fuels, effectively reducing greenhouse gas emissions and significantly contributing to the ongoing efforts against climate change. The widespread adoption of renewable energy technologies has undergone rapid expansion on a global scale, propelled by governmental policies, technological advancements, and decreasing costs. Despite their numerous advantages, renewable energy sources encounter challenges such as intermittent energy supply, storage solutions, and integration into existing power grids. Nevertheless, with sustained investment and innovation, renewable energy sources have the potential to become the predominant energy source of the future. This article conducts a bibliometric analysis of research on renewable energy sources in Poland and Germany. The analysis is grounded in publications catalogued in the Web of Science database, spanning the years from 1990 to 2023. The investigation delves into research topics related to renewable energy sources and scrutinizes the most frequently cited publications authored by individuals from these two countries. This bibliometric analysis stands out through its unique value proposition compared to other similar studies by placing a distinctive emphasis on critical research gaps, such as energy storage, smart grid technologies, and renewable energy in transportation. Additionally, the study's focus on the specific trajectories of Poland and Germany in renewable energy adoption, coupled with the identification of key institutions with the highest centrality index, provides unparalleled insights into the evolving landscape of sustainable energy research. The findings from this study can serve as a valuable source of information for policymakers, researchers, and other stakeholders interested in promoting the advancement and utilization of renewable energy sources. [ABSTRACT FROM AUTHOR]

The restoration of aging sewer networks is a fundamental remediation approach with the aim of renewing or improving existing systems. Remediation methods include repair, renovation, and replacement (renewal). The restoration of a sewer network itself can be performed using either excavation or trenchless technologies. While these technologies offer various advantages, they also present disadvantages. The choice of a restoration technology depends on numerous parameters, including economic factors and local conditions (such as the construction of the existing sewage network, available working space, traffic load, and environmental safety restrictions). In addition to the parameters influencing the choice of restoration technology, recent considerations have been given to constraints related to greenhouse gas emissions and the corresponding carbon footprint. Carbon footprint serves as an indicator of the restoration activity's dependence on fossil fuels, both during implementation and operation. In the 21st century, concerns regarding carbon footprints have rapidly escalated. The reduction in carbon footprints is a crucial objective from both an economic and an ecological point of view. This article specifically addresses the prospects of monitoring the carbon footprint concerning the partial restoration of a sewer network within the historical core of the city of Brno, located in the Czech Republic. This aspect constitutes the unique and innovative contribution of the paper. The intensity of the energy demand of excavation and trenchless technologies is utilized as a direct measure of the carbon footprint of each technology. The comparative assessment demonstrates that the trenchless technology used achieves a reduction of 59.2% in CO2 emissions compared to the excavation technology. The carbon footprint of Variant 1 (trenchless technology) is 9.91 t CO2 eq., while the carbon footprint of Variant 2 (excavation technology) is 24.29 t CO2 eq. The restoration of open pipelines produces more emissions due to the higher energy consumption, making it more expensive in terms of fuel costs, waste disposal costs, and the corresponding environmental hazards. [ABSTRACT FROM AUTHOR]

The main goal of this work is to show the new approach to determining safety technological levels (SLs) in terms of water quality and its chemical stability, as well as issues of water corrosion properties in water distribution systems (WDSs), due to the fact that water supply pipes are prone to corrosion. In the paper the methodology of determining the risk associated with threat to technical infrastructure was considered. The concept was studied on the basis of real operational data from the water treatment plant. The probability of exceeding the individual parameters for WTPI is slightly larger than for WTPII, which means that this water treatment process may cause lack of chemical stability in the water supply network. Operators should anticipate in the process of designing water distribution system, using proper materials, as to ensure an adequate level of safety from the water source to the water recipient. It should be noted that it is necessary to adjust the material of internal installation of water supply networks to the parameters of the water. At present, there are no correlations between the designing step and water parameters. It was concluded that to protect the water supply infrastructure, which belongs to critical infrastructure, water company should put more emphasis on distribution of stable water that has not potentially corrosion properties. Some suggestions were made for the protection of WDS and to ensure safety of system functioning and long-term usability of water pipes.

"Water, Resources, and Resilience: Insights from Diverse Environmental Studies" is a collection of research articles that explore various water-related topics. The articles cover subjects such as water allocation, soil substrates, energy generation, and public health. The collection emphasizes the challenges posed by population growth, climate change, and pollution, and highlights the use of advanced technologies and analytical tools in understanding and managing water resources. The articles aim to provide knowledge that can drive positive change and promote sustainable water management. The collection is intended for researchers, policymakers, environmentalists, and anyone interested in water-related issues. [Extracted from the article]

The primary objective of this work is to introduce a novel approach that modifies the method for analyzing and assessing the risk of water supply network failure. The approach aligns with recommendations from the World Health Organization and the European Union regarding the reliability and safety of water supply to consumers. The presented method for assessing the risk in the water distribution subsystem was based on the vulnerability identifying method (VIM) and involves the determination of the vulnerability index (VI). The VIM vulnerability factors considered encompass the failure rate, chemical stability of water, and issues related to water corrosion properties in water distribution subsystems. The obtained risk assessment includes parameters such as the probability of hazard occurrence, the consequences of these hazards, and vulnerability to them. This concept was evaluated using real operational data from the water distribution subsystem. The estimated risk level, under the given operating conditions, indicates its acceptability. [ABSTRACT FROM AUTHOR]

Focusing on renewable energy sources (RES), this article examines their comprehensive impact on society and the economy. This publication goes beyond traditional approaches by introducing bibliometric analysis using CiteSpace. By identifying key research trends in the scientific literature, it contributes to a better understanding of areas of research interest in the field of renewable energy. Bibliometric analysis serves to systematize knowledge and identify the main research trends - a valuable contribution to the development of this important field of science. As a research tool, it highlights the dynamics and evolution of the field of renewable energy research; this can support the further development of this important branch of science and serve as a platform for identifying potential areas for further research and practical activities. Through a detailed analysis of trends in the scientific literature, the article contributes to a deeper understanding of areas of interest in the field of renewable energy. The results are a valuable starting point for future scientific research and practical initiatives, supporting the development of this key field. [ABSTRACT FROM AUTHOR]

Despite studies focusing on soil substrates (carbon and nitrogen) and heavy metal availability, the impact of diversified parent materials in arid alkaline regions has received little attention. To reveal the influence of parent material, we investigated four different parent materials: fluvio-marine, Nile alluvial, lacustrine, and aeolian deposits. We assessed the effect of soil parent materials through selected soil physical and chemical properties, such as clay content, bulk density, pH, and available phosphorus (AP). The Tukey HSD test (SPSS ver. 23) was used to assess the soils derived from these different sediments. Using the R "glmulti" package, we examined this effect in a model of mixed-effects meta-regression. The sum of Akaike weights for models that contained each element was used to estimate the importance of each factor. The average contents of soil organic carbon (SOC) and total N in alluvial deposits were greater (p < 0.001) than those of marine, aeolian, and lacustrine deposits. A multivariate analysis in arid regions revealed that parent material, soil pH, and the availability of P had the greatest effects on SOC concentration, whereas clay content, available P, soil pH, parent material, and bulk density had the greatest effects on soil total nitrogen. The average content of Fe in the aeolian deposits was greater (p < 0.001) than those of marine, alluvial, and lacustrine deposits, without any significant differences between the latter two deposits. We found that the highest average contents of zinc (Zn), manganese (Mn), and copper (Cu) were recorded in alluvial deposits, with significant differences between other deposits. Soil parent material was the major factor impacting soil iron (Fe) content, along with clay content and soil pH. However, soil bulk density was the most important factor controlling soil Zn and Mn contents, while SOC drove Cu content. This study will help in developing a more accurate model of the dynamics of soil substrates and availability of heavy metals by considering readily available variables, such as parent materials, soil pH, soil bulk density, and clay content. [ABSTRACT FROM AUTHOR]

Vertical-flow constructed wetlands (VFCWs) are an innovative and sustainable nature-based technology for wastewater treatment in rural areas. This work aimed to evaluate the treatment performance of VFCWs using real wastewater, which can provide more accurate and reliable results compared with field-based experiments, and to investigate the use of Paulownia trees in VFCWs for wastewater treatment. To compare the efficiency of the plants based on the treatment performance of the VFCWs, three units were prepared and composed of Paulownia, the commonly used Phragmites Australis, and an unplanted unit used as a control during the experimental program. The results show significant reductions in both the chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) levels for both planted units, with removal ratios for COD and BOD5 of 60% to 98%, respectively. Both Paulownia and Phragmites Australis significantly reduced the levels of COD and BOD5 in the effluent, with removal percentages ranging from 57.1% to 98% for COD and 49.1% to 98% for BOD5. The control unit, without plantings, showed a lower but still significant removal percentage for both COD (from 55.1% to 96.1%) and BOD5 (from 48.3% to 97.8%). Thus, the results reveal that the efficiency of constructed wetlands can be significantly enhanced by the presence of suitable plant species, such as Paulownia and Phragmites Australis, and constructed wetlands can be a viable and cost-effective option for the treatment of wastewater in various settings, with the added benefit of using the relevant biodiversity. [ABSTRACT FROM AUTHOR]

A novel two-hybrid optimization model of particle swarm optimization (FAPSO) and firefly algorithm with genetic algorithm (FAGA) are introduced to improve the performance of the conventional firefly algorithm for the least cost design of water distribution networks. The performance of the models is tested through application to three of the well-known benchmark networks available in the literature and also to the real case study of the El-Mostakbal City network, Ismailia, Egypt. The performance of the different algorithms was determined by evaluating the minimum, maximum, mean and standard deviation of costs, the function evaluation number, the consumed computational time for 1000 evaluations and the success rate calculated using the fuzzy logic concept for different optimal solutions slightly greater than the known optimal solution (by about 1.0% and 2.0%) were utilized for testing the convergence and search capabilities of the models. It was found that the FAGA model is superior to the standard firefly and FAPSO models in exploring the search space, exploiting the promising areas and convergence to the optimal solution and can be considered as a reasonable optimization technique for the management of water distribution networks. [ABSTRACT FROM AUTHOR]

Dams are built for different purposes, but failure of a dam could result in extreme disasters such as floods. The Grand Ethiopian Renaissance Dam (GERD) was mainly built for power generation, but concerns about its safety, location and site conditions have led the downstream countries to investigate the GERD's stability. This paper aims to investigate the impact of the failure of the dam on the downstream countries using the Hydrologic Engineering Center River Analysis System (HEC-RAS). Outflow hydrographs and flood inundation maps were provided through a hypothetical dam break scenario. An unsteady flow hydrodynamic routing with a 2D model was used to simulate the failure of the dam. A sensitivity analysis study of the output's findings against breach parameters was also performed. The breach outflow discharge increases as the breach dimension increases. However, the peak discharge decreases with increasing breach formation time. Moreover, to prepare emergency action plans, it is important to predict the inundation depth, levels, arrival of flood waves, flood coverage area and water velocity. Furthermore, the results showed that Khartoum would turn into lakes within about 10 days and flood water depth would exceed 11 m at some locations in residential areas. Moreover, the flood waves overtopped the Roseires, Sennar and Merowe dams by 11, 7 and 20 m, respectively. In addition, the level of Lake Nasser would reach 188 m above sea level and the Aswan High Dam might be in great danger. [ABSTRACT FROM AUTHOR]

The operation of a water supply system (WSS) is inextricably linked with the possibility of different types of failure. It is very common for these failures to be random in nature. The results of reliability studies carried out in many water supply systems revealed, for example, the possibility of incidental water pollution, power supply issues, failure in machinery, damage to water plants, or natural disasters. As a result of the WSS failure, we deal with a state of threat to safety (TSS) or a state of loss of safety (LSS). Using Markov processes, we developed a failure model of the WSS to determine the possibility that the system may find itself in different states of safety. As a result, a mathematical model using Markov processes has been proposed for each of these distinct states of safety (complete safety state—CSS; threat to safety state—TSS; and loss of safety state—LSS). The proposed approach in the water supply system will limit emergency states by optimizing working and repair times. Reducing losses in the water supply system is crucial to reduce and optimize energy consumption for water production and distribution. [ABSTRACT FROM AUTHOR]

The paper assumes that the measure of the loss of safety in water distribution is the risk related to the occurrence of some undesired events such as the failure to meet certain (required) water quality conditions (that may have negative impacts on the consumer health), or a severe disruption of the water supply services. In this aspect, risk is assessed using the expected value of losses (hazardous effects) that may occur as a result of the occurrence of the undesirable events. A comparison of the determined values with the risk acceptability criteria is the basis for the safety assessment. The analysis was made based on the available operational data of the water supply subsystem. The analysis covered the period from 2011 to the third quarter of 2021 and was prepared on the basis of available physicochemical and microbiological analyses of water performed at the water and microbiology laboratory of the considered water supply system in Poland’s Subcarpathian Province. A novel approach to risk analysis of the loss of safety in water supply system taking into account the occurrence of some undesired events was achieved. The estimated value of the risk level, under the given operating conditions, indicates that there is no real threat to water consumers. [ABSTRACT FROM AUTHOR]

One of the factors limiting the possibility of the development of urban agglomerations is access to drinking water. Due to progressive climate change, the available water resources are limited. The paper proposes new indicators of limiting the development of agglomerations related to the availability of water resources and the production capacity of water treatment plants, a method for assessing the diversification of water resources (using the Pielou index), and a water loss balance was prepared based on International Water Association (IWA) standards. On the basis of the obtained results, the potential increase in the number of inhabitants indicators (∆PR, ∆PP) and the time for the development of agglomeration indicators (TR, TP), the directions of development of the studied agglomerations in terms of the possibility of water supply were indicated. The main problems were reducing the amount of water losses, appropriate management of the migration policy of the population, and the necessity to look for alternative sources of water. [ABSTRACT FROM AUTHOR]

The subject of the work is the analysis and assessment of the risk of biological instability of water. The lack of water stability causes the increased susceptibility of the distribution system to secondary microbial contamination of water and constitutes a hazard for consumers’ health. The risk is expressed as the loss of water supply safety and distinguishes a failure of not meeting certain water quality parameters that can influence physico-chemical parameters and the bacteriological quality of the water supplied to the consumers. In the paper the method of analysing and evaluating the risk of loss of biostability of tap water is presented. The presented analysis was performed on the basis of the operating data from the water treatment plant.

Photovoltaic installations (PVs) are currently one of the fastest-growing sources of renewable energy. Expanded forms of financial support and higher electricity prices have resulted in a large increase in its installed capacity. PV installations are increasingly being ordered by industry and privates, often for installations capacity of several hundred kilowatts. In addition to the advantages, photovoltaic installations also have drawbacks. One of these is that the increase in the voltage in the power grid leads to the exclusion of individual installations from the grid. An important issue in the operation of photovoltaic installations is also their reliability during their lifetime. The reliability of photovoltaic installations depends on the random nature of the cloud cover as well as the material's mechanical degradations. This paper presents a literature analysis using Citespace software in terms of reliability. A detailed bibliometric analysis has been performed to outline the main drawbacks of the PV installations cited by researchers. This literature review forms the basis for further analysis. The paper also presents a new approach to implementing the Multiple-Criteria Decision Analysis (MCDA) method for assessing the risk of failure of PV panels. The obtained results showed the main interests of scientists in the field of failure analysis of photovoltaic installations and countries having the largest share in research on this issue. The applied Analytic Hierarchy Process (AHP) analysis enables supporting the process of managing photovoltaic installations by analyzing installation operations in terms of reliability as reliability impacts the profitability of investments and operating costs. The proposed method can be used by the operators of photovoltaic installations or farms. [ABSTRACT FROM AUTHOR]

The lack of biochemical stability in drinking water increases the secondary contamination risk in water supply systems and hence represents a sanitary threat to consumers. The work presented here assesses the likelihood of such risk. The assessment is based on data obtained from one of the water treatment plants. The assessment of the bio-chemical instability risk combines both approaches: fault and event trees. Additional consideration was naturally given to the events that initiated the contamination at the outlet of the water treatment plant. It is concluded that if it is to protect the water-supply infrastructure representing a kind of critical infrastructure, a water-supply company needs to put more emphasis on the distribution of stable water in terms of its properties and composition, thus having no potentially corrosive properties. The assessment underlines the importance that water supply utilities should equally consider both the supplied water sanitary quality and the water supply service continuity. [ABSTRACT FROM AUTHOR]

The continuity of gas-supply service is a major concern for all gas-supply operators. A safety review of a gas-supply system could help to mitigate the potential repercussions of supply disruptions. Disruptions occur at random due to systemic failures in gas distribution networks. Assessing the operational safety of gas distribution networks is challenging and complex, especially when operational data are limited or associated with high uncertainty. This paper focuses on gas leak incidents. Natural gas leaks disrupt the production process and endanger the ecosystem. Mechanically originated damage in pipelines is found to be the major cause of leaks, according to our investigations. This paper proposes a three-parameter risk matrix to be used in the safety analysis of gas-supply systems. This paper then raises the possibility of using grey-system theory. Grey-system theory has been used to overcome the limitations of the conventional matrix method. This choice is motivated by two facts: our data are heterogeneous with a high level of uncertainty, and some of the data are based on experts' judgement and maintenance reports using qualitative metrics. It is underlined how GST provides insight for the decision-making process, even in the absence of complete information sets. The method developed here is advocated in the context of procedures ensuring the safety and the supply continuity of gas-supply systems. [ABSTRACT FROM AUTHOR]

Turbidity impacts, not only on the aesthetic properties of water but also on many features capable of affecting health. This leaves the parameter in question as a very important indicator of the quality of surface water (due to a large amount of information on potential threats), and one capable of serving as a basis for risk analysis. Information on the turbidity of raw water was obtained from the water-supply company, with the focus being on data from the years 2010–2015. This reflects a research focus on the period following modernization of a treatment plant, completed in late 2009. Variation in the turbidity of raw water through the annual cycle was analyzed, with the finding that no cessation of delivery of water to the city on account of inadequate quality was necessitated. This further denotes a positive assessment regarding the efficiency of the water-treatment technology installed in 2009, which proved to be very effective at treating water whose turbidity changed rapidly from time to time, to reach several thousand NTUs. The paper also details attempts to determine the “a posteriori” probability of occurrence of turbidity of a certain value, in line with Bayesian theory. [ABSTRACT FROM AUTHOR]

The consequence of the lack of water stability is increased susceptibility in the distribution system to secondary microbial contamination of water and thus a threat to the health of consumers. In this study, three different water quality parameters including BDOC (biodegradable dissolved organic carbon), ΣNinorg, and PO43– were employed to assess and evaluate the risk of loss of biostability of tap water. The analysis was based on the operating data obtained from the water treatment plant (WTP) prior to the final disinfection process for which water is supplied from intake of drilling wells, what constitute the new approach in comparison with other study. In this work, two technological schemes in the WTP were analyzed, one conventional, which is represented as WTPc, and the other using a biologically active carbon filter (BAF), which is represented as WTPcf. The modified Kaplan and Newbold method was used in determining the BDOC content by using for this purpose colonized by autochthonous bacteria bioreactor with granular activated carbon. Results show that conventional water purification processes do not provide the effective elimination of biogenic substances and, in particular, BDOC and assimilable organic carbon, therefore it is recommended to apply BAFs, as its effectiveness in removal of various impurities and the ability to stop waterborne microorganisms is very high. [ABSTRACT FROM AUTHOR]

In the thesis failure analysis and assessment of water supply system in considered city was presented. The analysis was prepared on the basis of the exploitation data obtained from water company. The characteristic of water distribution system was presented. Indicators of failure rates were calculated. Data were presented in division to diameter, material, type, season and month of failure. [ABSTRACT FROM AUTHOR]

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The aim of the study is to analyse and assess the water supply network failure frequency in last ten years, with particular emphasis on the last year of the analysis. The analysis is based on actual data obtained from the water company. The study contains the analysis of the network failure with division into used material, the type of network and place of failure occurrence. Also the failure rate was calculated. Continuous changes in the age and material structure of the water network cause the need for conducting failure frequency research because data on failure rate are the key indicators for operational policy of water supply systems. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess the risk of failure of group water network in case of raw water contamination. The analysis was based on qualitative simulation performed in hydraulic water network model developed in the EPANET software. It was focused on the quantitative description of the consequences of chemically contaminated water. The methodology of risk assessment relies in determining the consequences of the supply water containing contamination threatening the health and lives of water consumers. The research methodology is as follows: development of a hydraulic model of the water pipeline and it's hydraulic verification, computer simulations of contamination propagation, calculating the dose delivered to the i-th section of the water supply system supplying water to Ni recipients and the mass of a substance that enters the body li. The simulation results indicate the spread of contamination that after 24 h covered most of the area supplied with water. The load delivered to the resident obtaining water from the i-th section of the water supply network, Li/Ni, was up to 18 g⋅d-1, at least 15 g⋅d-1 was received by 34.9% of the population, 10-15 g⋅d-1 by 12.5% of the residents, 5-10 g⋅d-1 by 10.7% of the residents, 0-5 g⋅d-1 by 41.7% of the residents and uncontaminated water was delivered to only 13.3% of the consumers. The dose taken by the statistical consumer (calculated as for adults) l is up to 0.8 g for Li/Ni = 18 g⋅d-1 and is proportional to Li/Ni. [ABSTRACT FROM AUTHOR]

The paper presents issues related to risks associated with the operation of small water supply systems on the background of water consumer safety assessment made on the basis of risk analysis. Definition of water consumer safety loss as a risk associated with the water consumption of poor quality or water lack was proposed. For this purpose, a three-parameter matrix is implemented with the parameters of the probability of a representative accident scenario, the losses of the water consumers and their protection. Risk management, together with the implementation of protective barriers of small water supply system against threats is a fundamental condition for the continued operation of the system. [ABSTRACT FROM AUTHOR]

The paper presents the concept of safety in water distribution systems, which is an important issue connected with its functioning in crisis situations. The research undertaken is directed towards methods of safety assessment relating closely to current world trends, aiming to ensure safety of water supply and use. The paper pays special attention to water consumer safety. Safety levels were assumed on the basis of failure intensity, exposure of water consumers and a number of undesirable event groups. Individual values of the immediate risk index were presented and three categories were distinguished as permissible, tolerable, or unacceptable risk categories, according to presumed action. The risk index can characterize the safety of the functioning of technical systems. The risk index definition is considered as the product of threat ranking. The paper contains the original proposal for a new method of risk analysis and assessment. [ABSTRACT FROM AUTHOR]

The important and crucial issue concerning water supply functioning in terms of conducting failure analysis were discussed. In the work failure indicators, water losses and availability of water services, that define standards of quality water services and their values were determined based on data from exploitation. In order to understand the current situation of water supply infrastructure it is necessary to perform periodic analyzes of water supply network failure, which was proposed in this paper. A detailed analysis of the failure and the water loss of the water supply network should be the main element of the urban management water supply network, particularly in the strategic plans for its modernization. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present the novel approach to risk assessment in combination with failure and consequence analysis, depending on two parameters defined by the fuzzy functions: the repair time of water pipe and the cost of water pipe repair, what allow to determine particular risk levels. The presented methodology can be used to describe the functioning of the public water supply in terms of its renewal. [ABSTRACT FROM AUTHOR]

Increasing restrictions on the emission of greenhouse gases by the standards and the European Union's policy aims at increasing the share of renewable energy sources in the energy mix of the Member States. Subsequently, we observe a rapid increase in the installed capacity of the renewable energy sources. Renewable energy sources are currently the fastest growing sectors of energy generation, specifically the photovoltaic sector. In 2005, the total installed capacity in photovoltaic installations in the European Union was about 2.17 GW, while in 2019 it was already over 130 GW. Currently, due to many forms of incentive governmental measures the construction of photovoltaic installations is rapidly increasing with installations mounted on private houses and buildings. The article presents selected issues concerning the failure modes of photovoltaic installations and a comparative assessment of the estimated and the real measured electrical production of an operational photovoltaic installation. The Solar-PV power plant design approach proposed in the paper considers the failure modes to enhance the plant's reliability. [ABSTRACT FROM AUTHOR]

Initiated by a case study to assess the effectiveness of the modernisation actions undertaken in a water supply system, some R&D activities were conducted to construct a global predictive model, based on the available operational failure and recovery data. The available operational data, regarding the water supply system, are the pipes' diameter, failure modes, materials, functional conditions, seasonality, and the number of failures and time-to-recover intervals. The operational data are provided by the water company responsible of the supply system. A predictive global model is proposed based on the output of the operational data statistical assessment. It should assess the expected effectiveness of decisions taken in support of the modernisation and the extension plan. [ABSTRACT FROM AUTHOR]

For reliable pressure-driven analysis (PDA) results, it is necessary to reasonably determine an objective head-outflow relationship (HOR) and the required head for each node. So far, no methodology has been proposed to objectively determine two factors based on data of real block. In this study, the HOR was defined using the water supply method, residential environment, and water consumption data within real blocks. The standard minimum residual pressure criteria were reviewed to quickly and rationally determine the required head for each node. To validate the proposed methodology, the HOR and required head application conditions were configured for different scenarios; the available flow rate of nodes and the water supply capacity of the entire block were evaluated based on PDA results. Through the results for each scenario, the HOR definition method was able to provide a reasonable result reflecting the actual block's conditions, unlike the conventional orifice-type HOR, and the standard minimum residual pressure criteria as the required head was evaluated to be more efficient than the conventional time-consuming method. The HOR uncertainty and the lack of rationality in the selection of the required heads affected the reliability of PDA results; these problems can be solved using the proposed methodology. [ABSTRACT FROM AUTHOR]

Within the frame of upgrading and modernisation of the Water Supply System (WSS), our work is focussing on the safety systems/devices implemented or that should be implemented in the WSS. The implementation of safety systems is supposed to reduce hazard occurrence and hazardous consequences in case of a WSS unsafe disruption. To assess this reduction, we preconise the use of the safety integrity levels standards. The implementation of the safety systems/devices is undertaken on the ground of the multi-barriers safeguard approach. The "Water Contamination Hazard" is considered in the paper. A case study is presented, assessed and conclusions are drawn. The methodology presented in the paper and the results of the case study assessment will contribute to the decision-making regarding the upgrading of the safety and the performance of the WSS. [ABSTRACT FROM AUTHOR]

The proper operation of a water supply system (WSS) requires constant investment. The priority is to provide residents with high quality potable water, in the required quantity and pressure, in accordance with the applicable regulations. The paper presents an assessment of the potential inherent operational risk of a WSS in support of the risk-based investment management process. It is of high importance to invest in the operational safety as it concerns both producers and consumers. The investment engenders additional costs that should partially be supported by the consumers. Thus, the paper presents a methodology to analyse consumers' readiness to accept water supply services' additional costs. The proposed methods may underpin a comprehensive program for risk-based investment management and operational decision-making. The case study and the approach in this article concern one particular regional WSS, based on information collected from water consumers. The assessment suggests a willingness to tolerate additional costs in view of enhancing the performance of the water supply services. [ABSTRACT FROM AUTHOR]

This paper first presents the results of polling on the subject of potable water in crisis situations, with respondents from south-eastern Poland's Subcarpathian region asked for their opinions on the level of nuisance associated with water supply interruptions and water quality, levels of consumption and water companies' quality of service. Among the respondents 53% regard the quality of the water they receive as satisfactory, while a quarter see it as only average. However, respondents are relatively satisfied with the corporate response when supplies are interrupted, as methods and means of notification are judged effective by 60%. Continuing with work to assess possibilities for water companies to improve their performance in crisis situations, the present study generates an Analytical Hierarchy Process allowing recipients to determine importance criteria where quality of service is concerned. This could facilitate management by water companies, providing for centralised control and comparison that help secure services of appropriate quality. The process can also help protect different groups of recipients, as safety is evaluated through analysis of functioning, and of failures and losses. [ABSTRACT FROM AUTHOR]

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association's Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the "mean time between failures." The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of natural mineral waters recognized by EU member states (on the basis of being announced in the Official Journal of the European Union) and originating in Polish territory. For each of these waters, calculations were made in relation to the Langelier saturation index, Ryznar stability index, and indices S1 (effect of chloride and sulfate ions on iron and steel), S2 (effect of nitrate ions on zinc), and S3 (effect of bicarbonate/sulfate ratio on copper). The impact of mineral waters on copper, hot-dip galvanized iron, stainless steel, acid-resistant steel, cast iron, low-alloy steel, and nonalloy steel was assessed on the basis of the indices calculated. The analysis allowed determination of the possibility of these measures being used in assessing the performance of mineral water installations. [ABSTRACT FROM AUTHOR]

Given that a consequence of a lack of stability of the water in a distribution system is increased susceptibility to secondary contamination and, hence, a threat to consumer health, in the work detailed here we assessed the risk of such a system experiencing quality changes relating to the biological and chemical stability of water intended for drinking. Utilizing real operational data from a water treatment station, the presented analysis of the stability was performed based on the fault tree method. If they are to protect their critical-status water supply infrastructure, water supply companies should redouble their efforts to distribute stable water free of potentially corrosive properties. To that end, suggestions are made on the safeguarding of water distribution systems, with a view to ensuring the safety of operation and the long-term durability of pipes. [ABSTRACT FROM AUTHOR]

The development of appropriate methods by which to assess the functioning of gas pipelines helps limits the consequences of disasters, in that way protecting users better. Assessment methods of this kind are presented in this paper, which advocates the integrated risk area identification method. The risk taken account of is understood to be a function of the probability or frequency of occurrence of undesirable events, and comes with parameters defining the consequences of these events, should they arise, in terms of their magnitude. The level of system vulnerability to events of these types is a factor considered, and the risk calculation is of a kind that encompasses both quantitative and qualitative aspects. The approach taken is regarded as a quick and simple risk-assessment tool applicable to the daily operation of gas networks for a gas company. Specifically, the framework of the research carried out extends to: (1) Estimation of the average cost of failure of gas pipelines in the case of an urban agglomeration in SE Poland; (2) assessment of the level of integrated risk facing the gas-supply subsystem, by reference to the risk area identification method; (3) failure forecasting by way of regressions with delay; and (4) conclusions regarding failure risk assessment in a gas-supply network, as well as a consideration of prospects. The framework referred here, thus constitutes the basis for both analysis and assessment of the safety of a gas-supply system. [ABSTRACT FROM AUTHOR]

In accordance with the water quality standard, the safe functioning of the water treatment system operation is considered. This paper alludes to extreme situations, which arise where there is periodic deterioration of the quality of raw water, for which the technological process of water treatment is not prepared. A conception method is presented by which to assess indices of risk vis-à-vis drinking water, on the basis of a probability estimation methodology. The categorisation of water pipes in line with quality-reliability as regards the physical and chemical composition of drinking water or water intended for business purposes is proposed. An example of the method being put to use is also offered, and it is recognised how the approach being proposed could be the basis for further analysis that takes different conditions of functioning of water-supply systems into account. [ABSTRACT FROM AUTHOR]

Analysis and assessment of the reliability and safety of a gas-supply system is a key issue, given its status as critical infrastructure. A gas-supply system is characterised by continuous operation and a consequent need to achieve a high level of operating reliability and safety. Such a system has its unique aspects, with particular elements having their different functions while also simultaneously interacting in the context of the integral whole. In such circumstances, risk analysis can prove useful in planning activity to prevent damage, and also in the devising of rescue scenarios. Thus, the purpose of the analysis presented here has been to supply the information that is necessary in decision-making relating to risk reduction. One of the most comprehensive assessment methods is based on the expected value of gas shortage. Basic formulae with which to determine a generalised indicator of system reliability are also presented, with risk viewed as synonymous with the unreliability of gas supply. This paper then proposes a method by which an indicator of the expected efficiency of operation may also be determined as the quotient of chance and absolute risk. The thinking in this article has been developed on the basis of data from a real gas-supply system, while the computational methods deployed allowed applications to draw conclusions regarding possible modification of the expected gas shortages method. [ABSTRACT FROM AUTHOR]

This article presents results of research which aimed to assess the impact of biofiltration processing on the biological stability of water. Effectiveness of biogenic substances removal (C, N, P) and bacteriological quality of water after the biofiltration process were discussed. The research was carried out on a semi-technical scale on natural underground water rich in organic compounds. A filter with a biologically active carbon (BAC) bed was used for the research. Despite the low water temperature of between 9–12 °C, there was a high efficiency of organic matter removal—33–70%. The number of mesophilic and psychrophilic bacteria in the water before and after the biofiltration process was comparable (0–23 CFU/mL) and met the requirements for drinking water. No E. coli was detected in the water samples. The biological material washed out of the filter bed did not cause deterioration of water quality which proved that the operating parameters of the biofilters were properly chosen, i.e., contact time of 30 min, filtration speed up to 3 m/h. Reduction of the content of nutrients in the treated water limits the risk of microbial growth and thus the emergence of biological growth in the distribution system. [ABSTRACT FROM AUTHOR]