Search

The paper industry wastewater even after bio-treatment at industrial scale is a major source of aquatic and soil pollution due to various unknown compounds. Hence, the study has focused on the detection of residual organic pollutants from the bleached and unbleached paper mill wastewater and both sources showed endocrine-disrupting compounds. The toxicity test with Phaseolus aureus seed germination showed inhibition of seed germination and alpha-amylase activity >25% in bleached and unbleached paper mill wastewater. The LC50 of Tubifex tubifex was noted of >50% after 48 hours incubation test. This revealed that the wastewater discharged from bleached paper mill is more toxic than unbleached paper mill waste this might be due to the use of more chemicals during bleaching and pulping process. This study has revealed that there is need to treat both paper mill wastewaters adequately prior to discharge. [ABSTRACT FROM AUTHOR]

Sanitary products (SPs) such as toilet paper and moist wipes are marketed as flushable products (FPs). SP manufacturers, wastewater authorities, and governmental agencies describe FPs in their own terms, and cause confusion about what is safe to flush with respect to sewer operations. To identify sewer-safe FPs, 11 toilet paper (TP) and 39 flushable wipe (FW) samples that were collected from around the world were examined to assess critical links between their fiber compositions, strength indicators, and disintegration performance. The findings illustrate that products that are made of primarily wood-pulp fibers have low strength, disintegrate rapidly, and are safe flushables. In contrast, products that contain strong and synthetic fibers (e.g. polyester) exhibit high strength, disintegrate slowly, and pose significant risk of accumulation in sewer systems. Suggestions are offered for product improvement and for long-term sustainability of FPs and wastewater infrastructures. [ABSTRACT FROM AUTHOR]

Variation in rates of sanitary hygiene products, toilet tissue and faeces occurring in sewers are presented for dry and wet weather from three steep upstream urban catchments with different economic, age and ethnic profiles. Results show, for example, that total daily solids per capita from the low income and ageing populations are almost twice that from high income or ethnic populations. Relative differences are verified through independent questionnaires. The relationship between solids stored in sewers prior to storms, antecedent dry weather period and the proportion of roof to total catchment area is quantified. A full solids’ flush occurs when storm flows exceed three times the peak dry weather flow. The data presented will assist urban drainage designers in managing pollution caused by the discharge of sewage solids. [ABSTRACT FROM PUBLISHER]

This paper presents a case study of the obstacles to green infrastructure implementation in the City of Vancouver. This case study has two aims, 1) to better understand the planning and decision-making processes hindering the widespread implementation of green infrastructure across the City of Vancouver, and 2) propose solutions to facilitate the uptake of GI. This paper begins by reviewing existing literature on barriers to green infrastructure implementation. Then, it investigates current perceptions of GI in the City of Vancouver, and what barriers exist to its implementation through document analysis and semi-structured interviews. Proposed solutions to green infrastructure implementation are reviewed and recommendations are provided for the City of Vancouver. It ends with a short discussion on the applicability of lessons learned from the study of Vancouver for other municipalities seeking to overcome barriers to green infrastructure implementation. [ABSTRACT FROM AUTHOR]

This research conducted a systematic literature review by taking into account bibliometric analysis of public—private partnership (PPP) studies published from 2001 to 2021 in the water sector. This study carried out a three-stage approach involving data collection, filtering, cleaning, and pattern and findings of research. The study generated 541 articles from 14 renowned international journals searched within Scopus database, and qualitative analysis was performed to produce 332 papers focusing on PPP studies in the water sector. The results showed that PPP studies in the water sector can be divided into five thematic areas including (1) risks, (2) sustainability, (3) success factors, (4) privatization, and (5) governance. The finding of this study reveals that scholars are interested in risk factors, risk allocation, risk mitigation and a number of success factors. On the other hand, the themes related to sustainability and typical governance models are found to remain limited. [ABSTRACT FROM AUTHOR]

The overlap of different fields has made it easy to introduce a real development of new technologies. New techniques used in the water sector are introduced; the importance of integration with each other will be increased to work as one unit with more efficiency and effectiveness. Integrating the real-time control of a supervisory control and data acquisition system (SCADA) and the data management and analysis capabilities of a geographic information system (GIS) can assist operators and decision-makers in disaster response and better system control. The objective of this paper is to evaluate the potential use of SCADA in conjunction with GIS to control and manage a water desalination plant network. The aid of the developed integrated system in the management of a water desalination system can be accessed on an interactive single dashboard for the network to simulate real situations through the data collected at each site that can be provided in real-time by SCADA, in addition to the results of analysis of these data that help to take the right decision and deliver the instructions thereon directly to the field devices to deal with any case of emergencies. In addition, this paper introduces an implementation approach of a new category of decision-support tools based on the integration of GIS and SCADA in implemented water desalination plants at the National Water Research Center (NWRC). A general review of both systems including their potentials in water desalination systems and the possibility of integration with each other has been introduced. This study demonstrates how integrating GIS and SCADA into a single dashboard can aid in data acquisition and provide a better understanding of the communication between the various sites and systems' facility administration, despite the fact that such integration is uncommon because both systems use different IT platforms. [ABSTRACT FROM AUTHOR]

Water distribution networks (WDN) are going towards more sophisticated management strategies to save water and energy and to improve users' service. The paper investigates experimentally the potentiality of a hydraulic device prototype that integrates the control ability of common pressure reducing valves with the energy recovery capability. The recovered energy is used to self-power the system for real-time monitoring and remote control, creating a useful tool to enhance water distribution networks management. The paper presents and discusses the experimental tests performed for a 2-inches prototype characterization. Tests reveal a maximum flow coefficient of 39 m3/h and a minimum required head of 4 m with 3 l/s. Because of the novelty of the device a procedure to verify the applicability of the system starting from working conditions has been set up. In the end the procedure is applied to the first on field test in a real WDN. [ABSTRACT FROM AUTHOR]

Catchment modelling is an effective approach to simulating the rainfall-runoff process. Estimating parameters is challenging in urban catchments with heterogeneous land use land cover (LULC). This paper describes a novel and reproducible approach to initialise the parameters for modelling catchment hydrology. The Alexandra canal catchment, Australia, was selected as the study catchment. A pixel-based LULC map was generated from the catchment's orbital image using the Deep Learning (DL) techniques. Integrate the LULC map with subcatchment delineation and hydraulic layout, group LULC attributes to compute the area and imperviousness fraction at pixel scale. The distance from each pixel to the subcatchment outlet was vectorised to estimate flow length. The cumulative likelihood and Kolmogorov–Smirnov (KS) were adopted to describe the parameter distributions, evaluate the goodness-of-fit and LULC effect. Results reflect a limited effect of LULC on flow length, and the approach can initialise the parameters for conceptual catchment modelling systems. [ABSTRACT FROM AUTHOR]

In this paper, we attempt to answer the following questions: Which factors determine college students' water-saving behaviors? The answer can enable colleges to take targeted water management measures to promote water-saving behaviors of students. Based on the theory of planned behavior and the combination of attitude-situation-behavior theory, this paper built a comprehensive theoretical model with sociodemographic characteristics, psychological characteristics as external dependent latent variables, situational factors as moderating variables, and water-saving behaviors as internal dependent latent variables. The research investigated 742 students in China colleges, and used corresponding methods to analyze the different types of the influencing factors of students' water-saving behaviors. The results show that the sociodemographic characteristics of college students have no significant impact on water-saving behaviors; the psychological characteristics have a significant impact on individual water-saving behaviors; the situational factors have a significant moderating effect on individual water-saving behaviors of students. [ABSTRACT FROM AUTHOR]

To mitigate urban drainage network pressures and seek sustainable solutions, novel tools like graph theory are presently being studied. This paper presents a systematic literature review of graph-based approaches through an intensive content analysis based on 144 published papers. Comparisons are drawn between water distribution networks and urban drainage networks in terms of convergence and divergence, revealing more divergence in network topological characteristics but more convergence in functional features. The findings provide convincing evidence for applications in UDNs, despite limited numbers and depth. Subsequently, a comparison between graph-based and hydraulic-based approaches is shown, demonstrating distinct advantages of graph-based methods in cases with limited data and time constraints. Based on these findings, the paper suggests several potential directions, including the improvement of parameter calculation formulas, the definition of parameter mathematical ranges and the popularization of recommended values. Finally, the paper examines its own shortcomings. [ABSTRACT FROM AUTHOR]

The paper proposes a spreadsheet-based model to simulate the hydrological response of a pilot installation of modular tray-based blue roof (BR). The BR is installed on the roof terrace of a building in the Campus of the University of Catania (Italy). The paper firstly describes the results of preliminary field experiments on the pilot aimed at evaluating hydrological parameters used in the model, i.e. the runoff coefficient and the initial abstraction of the terrace, and the evaporation from the BR. Then, the model was applied to 26 precipitation events recorded in the period from 2018 to 2020. Results of the application show a good ability of the model to reproduce the hydrological behaviour of the BR during precipitation events. Finally, the paper discusses limitations of the results obtained and potential for model improvement. [ABSTRACT FROM AUTHOR]

Urbanisation poses numerous challenges to fresh water biodiversity, and installation of above-ground rainwater tanks on private properties is one important tool for addressing these challenges. In this paper, we used an online survey targeting a representative sample of 1291 urban residents to investigate their underlying capabilities, opportunities, and motivations for installation of above-ground rainwater tanks on their properties. Only 221 (17%) of the 1,291 respondents already had an above-ground rainwater tank installed on their property. By segmenting on behavioural variables, we found that those urban residents who currently did not have a water tank on their property were not homogeneous. We identified three audience segments, ‘Supportive’ (19%), ‘Receptive’ (59%) and ‘Reluctant’ (22%), each with their own unique driver and barrier combination to rainwater tank installation. Suitable leverage points and behaviour change tools (e.g. education, enablement, incentivisation) and message framing (environmental, community, or functional benefits) are identified for each segment. [ABSTRACT FROM AUTHOR]

The prediction of tap water quality serves as a pivotal component in enhancing water resource management. The intricate nonlinearity and inherent instability in water quality data make this task challenging. In this paper, we present a Tap-Water Quality Temporal Prediction Network (TWQ-TPN) to accurately predict tap-water quality by focusing on the impact of temporal nonlinear patterns and long-term seasonal fluctuations. To achieve this, we design two modules, namely the Temporal Feature Extraction Module (TFEM) and the Feature Transformation and Prediction Module (FTPM). The TFEM learns complex dynamic nonlinear features in the temporal domain. The FTPM is to realize feature transformation in the high-dimensional features for long-term seasonal fluctuations. Thus, our TWQ-TPN can accurately predict tap water quality trends to help improve water management. We validate TWQ-TPN’s superiority using 5 years’ data from 33 major water facilities in South Korea, demonstrating excellence in pH, turbidity, and residual chlorine. Ablation experiments support TWQ-TPN’s rationale. [ABSTRACT FROM AUTHOR]

Traditional approaches devoted to upgrading the sewerage system functionality are highly costly and time demanding. Thus, the implementation of comprehensive modelling approaches can be intended as an effective and economically viable strategy to detect and outdo the critical issues of the networks. This paper presents an integrated procedure to monitor and simulate the network's performance, based on the coupling of Supervisory Control and Data Acquisition (SCADA) networks for data collecting and monitoring, with hydraulic simulations by the Storm Water Management Model 5.1 (EPA-SWMM) solver. The drawbacks of the network are then assessed by proposing several upgrades to improve the system. The proposed strategy was applied to the Nora-Noreña sewerage system, located in North Spain. Results show the potentiality of the methodology in reducing sewer network maximum filling degree requirements and overflows into the receiving water bodies. [ABSTRACT FROM AUTHOR]

Traditional engineering approaches are often inefficient and vulnerable, and cities face increasing challenges due to population growth, consumption rates and persistent inequalities. This paper aims to identify Nature-based Solutions (NbS) for water-sensitive European cities, categorising interventions according to their essential ecological functions for urban resilience. Through analysis of 77 projects in 46 cities, with interventions at three spatial scales, it examined a variety of actions that impact urban water management, addressing key challenges and their environmental impacts at the urban scale. The study concluded the importance of four categories of blue infrastructure and three categories of green infrastructure, highlighting their contribution to flood protection, water quality improvement and stormwater management. In Mediterranean regions facing water scarcity and extreme weather events, NbS represent a paradigm shift towards urban resilience and sustainability. [ABSTRACT FROM AUTHOR]

This paper investigates the shape and hydrodynamic characteristics of the sand bed at the junction of urban pipelines and their relationship with the flow ratio. Various hydrodynamic and morphological features, including shear layers, spiral cells, and scour pits. The dataset used for analysis consists of a three-dimensional time-averaged velocity field, turbulence, bed morphology, and confluence morphology of equilibrium phases obtained under controlled laboratory conditions. For large flow ratios (q*), significant local erosion occurs near the downstream shear plane at the junction. When the flow of tributaries surpasses that of the main stream, the strength and downstream extension of the spiral cell blocks increase. The max Reynolds number shear stress predominantly concentrates in the middle region of the water depth, aligning with the turbulent kinetic energy representation of the shear layer. Keeping the flow ratio constant, the velocity, turbulent kinetic energy, and absolute Reynolds shear stress all escalate with increased flow. [ABSTRACT FROM AUTHOR]

This paper proposes a novel method that integrates a tailored spectral graph metric and economic aspects within a coupled bi-objective optimization framework for the simultaneous pipe sizing and partitioning of water distribution networks (WDNs). Besides minimum pressure head and topological WDN connectivity, the telescopic diameter distribution criterion is applied through a new algorithm in the sizing phase to help the optimization converge towards sound engineering solutions. The application of the proposed method to a synthetic layout and a real Italian case study proves the superiority of the solutions obtained with the novel method from hydraulic and managerial/operational viewpoints in comparison with those obtained with a traditional decoupled method (separate pipe sizing and partitioning) in terms of i) compliance with service pressure constraints and ii) ease of management following WDN partitioning into district metered areas (DMAs). [ABSTRACT FROM AUTHOR]

This paper argues that enhancing the water conservation behavior of the urban population would provide an alternative solution by demand curtailment and behavior change, rather than traditional methods of increasing water supply. A structured, evidence-based approach to identify relevant research studies has been instrumental in this research. The paper provides a systematic review of 35 papers, narrowed down from 3089 papers, which have converged towards an integrated approach to water conservation behavior. The significant factors of water conservation behavior were classified under four broad themes: psychological, situational, demographic, and contextual. The review showed that the situational and contextual variables were understudied among these factors. Further, this study identifies research gaps in the models of water conservation behavior and highlights the need for future work. The issue of sustainability of water through a cogent argument based upon behavioral studies in water conservation has been carried out. Evidence-based systematic review for a comprehensive assessment of current literatures of water conservation behavior. Identification of four variable cluster themes: psychological, demographic, situational, and contextual variables. Provides insight into major theories used to predict water conservation behavior. Represents a knowledge map of theories and models to guide future researchers. Situational and contextual variables are understudied, with significant evaluation and population gap existing between developed and developing nations. Theoretical void exists in specific behavior theories, such as Identity Theory, in predicting water conservation behavior. Authors elaborated holistic model to predict water conservation behavior along with mediating effects of situational and contextual variables. Addressing issues of sustainability through cogent arguments in behavioral studies for water conservation. [ABSTRACT FROM AUTHOR]

The optimal location of pressure sensors is typicallysolved using heuristic algorithms. Non-dominated Sorting Genetic Algorithm II (NSGA-II) is one of the most used algorithms in the water industry, requiring a preliminary parameter tuning process. The lack of guidelines on how to tune model parameters generally limits the use of these algorithms by researchers or practitioners and, as such, fails to be used in real-life problems. The current paper explores different NSGA-II parameterizations for the optimal location of pressure sensors by using a multi-objective optimization methodology applied to a real distribution network. Results show that (i) both the uniform and simulated binary crossover operators (depending on the internal parameters) produce the best results, being the former recommended since it does not require further parameter tuning; (ii) polynomial mutation with lower probability value should be chosen; and (iii) the distribution indices of polynomial mutation have a minor effect on NSGA-II performance. [ABSTRACT FROM AUTHOR]

Cities and towns have developed stormwater systems to remove the runoff from developed areas. Although the systems are efficient in mitigating local drainage issues, they transfer pollutants and sediment to receiving waters, increase the flashiness of the flow regime and reduce ecological health. Water Sensitive Urban Design (WSUD) approaches are now being adopted to mitigate urbanisation and climate change impacts. This paper reports on the result of reviewing more than 200 papers leading to the conclusion that further investigation is vital to understand how WSUD systems can mitigate climate change impacts and rapid urban development due to the population growth and ongoing shift in populations to cities. Further, the importance of understanding the role of WSUD in increasing the liveability of urban areas. The paper also identifies both strengths and limitations of WSUD which is vital to promote realistic expectations and consequently appropriate designs, budgets, and maintenance regimes. [ABSTRACT FROM AUTHOR]

In flats where there are gas water heaters, there is waste of water at the beginning of a shower due to the large lengths of pipes between the showerheads and heater. This paper analyses the financial feasibility of implementing an automated system that saves such water. This paper also shows how the system prevents such waste. In six flats, by collecting cold water at the beginning of a hot shower, it was observed that 9.28 litres of water are wasted until the water temperature reaches 30°C. A financial analysis was performed based on costs and the amount of water that would be saved. It was considered the installation of the system in one or two showerheads per flat for multi-family buildings of different heights. The installation of one or two systems per flat would lead to savings of, respectively, at least 2.13 litres and 4.14 litres of water per shower. [ABSTRACT FROM AUTHOR]

In urban areas facing water stress, rainwater harvesting is essential. This paper proposes a passive rainwater harvesting system as a viable alternative for ensuring a clean water supply. The study introduces an innovative and original design for rainwater harvest. The presentation of the system is performed by analysis of efficiency and reliability of the system analytically. The optimal storage volume is determined through a 22-year precipitation data analysis using the mass balance method, ensuring high efficiency. Payback periods for various consumptions and tank sizes are calculated, showing shorter periods compared to active systems since the proposed system does not use electrical energy. The results demonstrate that 350 m3 of storage volume can assure 99% efficiency when potable water consumption is 0.01 m3/person/day. The payback period of the system was calculated to be between 5 and 10 years. The proposed system can be considered as an appropriate rainwater harvest alternative for existing buildings. [ABSTRACT FROM AUTHOR]

This paper proposes a methodology for the optimal design of series of sewer pipes including pumping stations. It employs a Shortest Path Algorithm to select the optimal combination of pipe diameters and invert elevations, as well as the optimal pumping features such as the number of pumps, location, and pumping head. The methodology is intended to be applied to the design of any sewer series. Although these are uncommon in real infrastructure, the study allows an analysis of the effect of pipe roughness, inflows, and pipe length on the total cost of the system and pumping features. The methodology was tested in theoretical series of 10 and 20 pipes as well as in a real series that is part of the sewer system of Bogotá, Colombia. The resulting designs suggested that using smooth pipes and reducing the pumping flow rate would decrease the cost of sewer systems in flat terrain. [ABSTRACT FROM AUTHOR]

This paper presents a holistic approach to address the challenges associated with deploying laboratory-derived hydraulic models in real operational conditions within Urban Water Systems (UWS). The underlying methods and tools are tested and validated using real-world data from the conveyance system serving the city of Athens, Greece. Initially, a novel data repair mechanism is developed, to rectify inconsistencies in time series. Subsequently, algorithmic techniques are applied to identify the most suitable datasets for calibration purposes. Furthermore, a grey-box procedure is developed to adjust key hydraulic modelling parameters, following a modular calibration procedure and aligning them with the specific characteristics of the UWS under study. The findings of this study provide valuable insights for effectively adapting and implementing laboratory-derived hydraulic models in real-world UWS scenarios, enabling better decision-making and management strategies for complex hydro-systems under challenging operational conditions. [ABSTRACT FROM AUTHOR]

This paper proposes a method for prioritizing sewer cleaning operations in the absence of historical data on failures. The method utilizes the Induced Ordered Weighted Averaging (IOWA) multi-criteria decision-making technique, incorporating experts' opinions to regulate subjective inferences and ascertain uncertainty. The study considers ten parameters categorized into three main focuses: structural, environmental, and operational to analyze sewer pipe conditions. As a case study, four small zones in Tehran city were prioritized using the proposed methodology. The findings reveal that (1) decision-makers' subjective priorities and evaluations do not significantly influence critical cleaning options, (2) pipe diameter is the most effective parameter for prioritizing since it allows pipes to be meaningfully categorized and compared, and (3) slope, age, depth, upstream manhole condition, and the number of connections and laterals are more important than other parameters. Overall, this study provides valuable insights into developing effective prioritization strategies for sewer cleaning operations. [ABSTRACT FROM AUTHOR]

This paper investigates emerging models of governance for shared water resources in decentralized urban regions in Indonesia and draws on a case of inter-local government collaboration for shared water resources in Cirebon region, Indonesia. The paper points to cooperation practice involving a mixed-model of governance for sharing water. by identifying a series of requirements for mixed governance. This model suits well not only because of the regional nature of water resource management in general, but also because such a model is likely to strengthen trust, increase transparency, and provide more equal positions among regions or stakeholders involved. Crucially, this model tends to decrease problematic levels of local autonomy and inter-local rivalry, which currently appears as a major challenge for shared water resource cooperation attempts in the decentralizing contexts of Indonesia and beyond. [ABSTRACT FROM AUTHOR]

Water management is concerned with action on the ground. The goal of this paper is to conduct a multi-voiced decision model for water resource management in the urban area of Mar de Plata city, Province of Buenos Aires, through the use of a multicriteria analysis tool. Using the Criterium Decision Plus system, criteria and subcriteria were integrated into a multi-voiced decision model for the prioritization of zones for water resource management. The criteria chosen were Potable Water Supply, Sanitation, Water Quantity, Potential Sources of Contamination, Flood Protection, and Equity. The model identified four of the seven zones as 'high' to 'very high' priority. Priority scoring ranged from 0.15 to 0.543. Regarding the criteria, "Potable Water Supply," "Water Quantity," and "Flood Protection" were identified as the main ones contributing to the final model results. The results show the starting point for generating proposals for water management actions in this urban area. [ABSTRACT FROM AUTHOR]

This paper aims to identify the potential barriers to municipal pipe renewal in Norway and the opportunities to mitigate these barriers. The research explores why the renewal rate on the pipe network is lower than the recommended through a research study of Norwegian municipalities, by gathering exploratory data as a base for a series of semi-structured interviews. The interviews were compiled into a data set and analysed to identify barriers to pipe renewal. The study found that the main barriers to pipe renewal were in the organizational and project implementation segments of the renewal projects. The most prominent groups of barriers were coordination and cooperation, followed by barriers to internal resources such as accessible human resources, time, and economics. Technical aspects during installation were less significant. The findings can impact project implementation by providing knowledge on the barriers and where to focus resources for optimising pipe renewal projects. [ABSTRACT FROM AUTHOR]

Many Ghanaian cities are increasingly becoming hotspots for floods with rising household vulnerabilities. However, research to understand the coping mechanisms of these households remains limited. This paper examines flood coping and adaptation strategies of flood community-dwelling households (n = 45) using a qualitative approach. Data gathering involved in-depth interviews using an interview guide. Data were analysed using the thematic analytical framework. The study revealed that households employed different coping and adaptation strategies to reduce the impact of floods and reduce their vulnerabilities to floods. While the coping strategies provided temporary relief, the over-reliance on structural methods of adaptation did not protect the participants well enough against the shocks of subsequent floods. A balanced use of structural and non-structural flood control mechanisms for effective adaptation is required. [ABSTRACT FROM AUTHOR]

The paper presents Fuzzy Inference System (FIS) -based approach to estimating probable flows for sizing building water supply pipes. Instead of calculating the design flow by estimating the number of fixtures operating simultaneously using probabilistic or deterministic approach utilizing a large amount of high-resolution field data, the proposed methodology uses Fuzzy logic to estimate demand characteristics of fixtures, unlike conventional fixture unit method. The developed methodology is based on FISs derived from users' socio-demographic characteristics, their diurnal activities and water use habits. A MATLAB program was developed to estimate the probable flows through the pipe using inputs-type of accommodation, connected fixture types and fixture flow rates. An imaginary 7-storey residential building with a gravity tank system was considered for pipe sizing. The design flows obtained by the proposed methodology were 50–70% of the those produced by the fixture unit approach leading to smaller pipe sizes. [ABSTRACT FROM AUTHOR]

Studies on the mixing of water storage tanks typically consider vertically oriented nozzles, however, not much consideration was given for horizontally oriented nozzles. This paper aims to employ computational fluid dynamics (CFD) to study the influence of horizontal nozzle configurations on the mixing within a typical circular water storage tank. The impact of the outlet locations and water depths on mixing time was also investigated. The results from the numerical simulations show that nozzle configuration with horizontal distance between the sets of nozzles of 0.71 tank diameters apart performed the best. An outlet located in the center of the circular storage tank encourages near-floor lateral movement of fluid and improved the velocity uniformity across the water column. The water depth was found to have a non-monotonic relationship with the mixing time and the depth to diameter ratio of 0.4 provides the best mixing in the studied tank with nozzles. [ABSTRACT FROM AUTHOR]

In this paper, a fluidized granular sand bed by a vertically upward water leak jet was studied experimentally. It was found that an increase in the size of sand particles decreases the height of the fluidized zone, and vice versa. By increasing the cover depth, the height and area of the fluidized and mobilized bed zones are reduced. Dimensions of the fluidized zone increase as the pressure increases. As the pressure inside the pipe increases 5-fold, the relative area of the fluidized zone increases approximately 3.5-fold, and the relative height increases 12-fold. By increasing ratio of the cover depth to mean particle size, the relative area and relative height of fluidization increases. New equations were obtained to determine the relative area and the relative height of the fluidized zone. [ABSTRACT FROM AUTHOR]

This paper examines the impact of anticipated duration for drinking water contamination on avoidance behavior. Differences in anticipated duration are based upon the type of public information provided to water customers: short-term boil water advisories (BWAs) versus long-term public notifications based upon Safe Drinking Water Act (SWDA) health-based violations. Avoidance behavior is measured by weekly bottled water sales at the county level in Kentucky. Our results confirm that BWAs have a much larger impact on bottled water sales than SWDA notifications. Bottled water sales increase by an estimated 3.8% in response to a 10-percentage point increase in population affected by BWAs during the week. This change in bottled water sales, however, represents a fraction of total avoidance behavior costs. Thus, bottled water purchases should be considered a very lower bound estimate for avoidance behavior cost estimates from contamination episodes of drinking water. [ABSTRACT FROM AUTHOR]

The use of machine learning solutions has been rising recently, and the water domain is reaping several benefits from its application. However, there is still room in the literature regarding machine learning applied to sewer systems. In this article, we study applied solutions to the predictive problem of four factors in the sewer: pipe defects, sedimentation, and failure and blockage events. Even with the number of publications available to solve each problem, there is still a need for improvement. This article aims to identify existing literature gaps through a bibliometric analysis based on data extracted from Scopus and Web of Science. Results show an increasing trend in published papers studying the domain and identify different knowledge gaps within the literature related to the correct use of data, the need for models capable of generalization, and the identification of novel techniques to be studied in the future. [ABSTRACT FROM AUTHOR]

Previous studies indicated that the population size would arrive at its upper limits under the intense water scarcity in Urumqi. However, these 'limits' have been repeatedly exceeded, and the population has grown from one million in the 1980s to four million in 2014. This phenomenon is viewed as a 'mystery of the population carrying capacity of water resources'. This paper investigates the mystery under an amplified framework of generalized water. The entropy of virtual water was 48.9, and 3.08 billion m3 of external virtual water flowed into Urumqi. External virtual water makes a main contribution to increase water supplies under acute water scarcity, and this contribution results from the characteristic of dissipative structure in an urban economy. It is proved that generalized water is one of the most essential answers to the mystery at least. Generalized water plays an important role and generalized water management is necessary in an urban economy. [ABSTRACT FROM AUTHOR]

Stormwater management systems rely on an acyclic network structure, making the network more vulnerable to failure. Existing stormwater resilience studies have predominantly focused on hydraulic and hydrological characteristics of the system with no robust frameworks to evaluate the resilience of the stormwater piped network in terms of network connectivity. This paper introduces a new index-based quantitative framework to characterise the resilience of acyclic stormwater network structure using graph theory and resilience theories. This includes an index developed to evaluate the overall independency of a pipe within an acyclic piped network. The framework was applied to various simple network structures, and an existing stormwater network demonstrating the influence of network structure, pipeline connectivity and number of outlets on the network resilience. This framework can be used to test different network layouts and structures in urban design and pipeline renewal projects to maximise the resilience of the structure of stormwater networks. [ABSTRACT FROM AUTHOR]

There is an urgent need for urban environments to be flood resilient due to increasing urbanization and climate change. This can be addressed by adopting sustainable drainage solutions (SuDS) in households. However, lack of knowledge and awareness among urban residents is a barrier. In this paper, we present an educational serious game called SuDSbury to overcome this barrier and a pre-/post-game survey-based evaluation to study whether the game can educate citizens (and to what degree). An exploratory study with 14 players across three game sessions suggests that playing SuDSbury induced changes in knowledge, comprehension, and personal norms regarding SuDS. However, comprehension of concepts related to urban drainage can be improved by increasing game realism. The game should be further tested with a larger sample and a diverse demographic of urban residents. The participants further found that SuDSbury is fun and engaging to play, making it suitable for broader public interventions. [ABSTRACT FROM AUTHOR]

This paper presents a novel decision support framework for water utilities to automatically create yearly pipeline rehabilitation plans while considering multiple parameters, including pipeline physical properties and other factors like transportation and urban space. The average age of urban water pipelines is growing, and the annual rehabilitation volumes are often lower than needed to improve or even preserve the level of service quality. The existing rehabilitation strategies range from simple pipe-age-based approaches to complex multiparameter strategies. The needed input of specific and detailed data, which are usually not available for water utilities, impedes a straightforward implementation of the latter strategies. Therefore, this study presents a two-step pipe rehabilitation strategy that enables the utility to automatically prioritise the pipes and related street areas/sections based on condition ranking. The strategy was validated on an operational water network in Tallinn, Estonia. [ABSTRACT FROM AUTHOR]

Water distribution networks (WDNs) require large capital investment and ongoing operational costs, resulting in their optimisation being a highly researched field. Despite the benefits tanks bring to networks, most optimisation models omit them as decision variables due to the complexity they can introduce to heuristic approaches. This paper addresses the least-cost optimisation of WDN design and operation through the development and application of the Small-network Configurator for Optimising Pump Energy consumption (SCOPE). The SCOPE algorithm incorporates pipes, pumps and tanks as decision variables and solves the optimisation problem through an iterative approach that pairs EPANET simulation results with subsequent hydraulic calculations to converge on the pumping and storage configuration which yields the lowest energy consumption. The SCOPE output can then be used to seed further optimisation techniques. This approach has been tested on the synthetic Nametown and real-life Dili networks and demonstrated annual cost savings of 10% and 25%, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a multi-criteria risk-based approach for managing urban flood hazards by using a combination of conventional measures and contemporary Sustainable Drainage Systems (SuDS). A multi-objective optimisation model coupled with a simulation model of UDS in the SWMM software is developed with the three objectives of minimising total costs, the risk of flooding and pollution discharged into receiving waters. K-means clustering technique is used to group the optimal solutions. A few optimal solutions and individual SuDS solutions are then ranked together by using the compromise programming (CP) method. The methodology is demonstrated by its application on a case study of the Golestan city UDS in Iran. The results obtained show there are indirect correlations between non-dominated solutions that minimise the risk of either flooding or pollution. The results also show the selected optimal solutions can provide cost-effective strategies that reduce both flood and pollution risks by at least 27% and 50%, respectively. [ABSTRACT FROM AUTHOR]

The need to develop sustainable stormwater management is intensifying due to climate impacts and urban densification. Such complex planning processes require insights into disparate issues, connecting heterogeneous actors. While many decision-support tools are developed to facilitate such planning, research assessing their usefulness is requested. This study introduces and assesses one such ICT-tool; the Visual Water platform, aiming to support sustainable stormwater planning in Swedish municipalities. The study aims to identify critical points to consider for developers of related decision-support tools and to detangle requirements and tradeoffs in making them relevant and user-friendly, building on test-sessions with Swedish practitioners. Results show that the platform responds to challenges within municipal planning as outlined by Swedish practitioners. However, though the platform content is considered relevant, its application in real-world planning is perceived as somewhat unclear. The paper discusses ideas for how sustainability-related decision-support tools better can respond to user demands. [ABSTRACT FROM AUTHOR]

The paper investigates per capita water consumption in Sirte city using a questionnaire survey data. The data captured included frequency, duration, flow rate, time of water use for each water end-use and household characteristics (demographic and socio-economic). The results show that the average daily per capita water consumption is 255 l/p/d. The per capita water consumption decreases with the increase in family size, while household income does not affect water consumption. Handwash basin tap accounts for the highest water consumption. The diurnal water consumption pattern is different from developed countries patterns and has multiple peaks. To predict the city's future water demand, three statistical models based on multiple linear regression technique (STEPWISE) were developed. The comparison of the developed models suggests that the models based on demographic variables can produce acceptable results and any further inclusion of additional variables (physical characteristics of households) do not necessarily improve the prediction accuracy. [ABSTRACT FROM AUTHOR]

Sydney Water owns approximately 450 kilometres of stormwater and waterway infrastructure spread across more than 70 catchments in Sydney, Australia. Improving waterway health and enhancing urban environments is an important part of Sydney Water's strategy to enhance the liveability of Sydney. This strategy can have a range of costs and benefits to the community. The costs of stormwater management can generally be estimated using market data. The benefits are not marketed directly, so estimation requires the use of nonmarket valuation methods. This paper reports the results of a choice modelling study that examined the willingness to pay of households in the catchments of Georges, Cooks and Parramatta rivers for improved stormwater management. The study found positive household values for improvements in waterway health, additional native vegetation plantings, including wetlands, additional recreation facilities in local open spaces used for stormwater management, and removal of rubbish and litter from the waterways. [ABSTRACT FROM AUTHOR]

Phthalates are plasticisers dangerous to ecosystems and humans.The paper aims to review the exposure of high-concern phthalates resulting from industrial and domestic activities to wastewater and analyse the advanced technologies used in European countries to remove phthalates from wastewater. We drew attention that many phthalates are not completely removed during the conventional wastewater treatment processes and often require an additional complex combination of technologies. Maximum wastewater cleaning efficiency (85–95%) depends on phthalates specificity and is achieved with advanced cleaning methods. However, the solutions to the problems of phthalate's presence and removal from wastewater are often addressed at the scientific research level. Because of the modernisation and operation of advanced technologies, the cost can increase by 5–25%. As a result, some European countries face financial difficulties implementing advanced technologies. To make progress in cleaning up phthalates, the EU is likely to continue maintaining and upgrading existing wastewater systems. [ABSTRACT FROM AUTHOR]

Trenchless methods for pipe rehabilitation have been increasing in popularity in recent years. Among the different advantages they have (e.g. less indirect costs) the paper deals with the environmental impact. In particular, the concept of carbon footprint is used to assess the environmental advantage in the use of CIPP and, among the different technologies presently available for this method, to indicate the more environmental friendly. The methods for calculation of carbon emissions are shown and then a simple analysis, for a theoretical case first, and then for a real case, are carried out. Critical considerations are finally presented. [ABSTRACT FROM AUTHOR]

Urban Evapotranspiration (ET) plays a crucial role in controlling irrigation water demand. The estimation of urban ET is difficult because of high spatial variability of urban surfaces. This paper reviews the two most commonly used approaches pertaining to advancements, limitations, and opportunities in arid regions. The two approaches include the landscape coefficient and surface energy balance approach. The key advancements include the standardization of the basic models and consideration of the spatial variability of the atmospheric advection effects. Two key limitations have been highlighted including oversimplification of microclimate effects in the models and lack of precise estimation of water requirement for mixed landscapes. Furthermore, several opportunities to address the existing limitations are discussed including the coupling numerical models, unmanned aerial vehicles (UAV)-based technologies for ET estimates, detection of mixed landscapes using various vegetation indices, and quantification of the atmospheric effects. This study highlights different dimensions and modeling techniques to estimate urban ET. [ABSTRACT FROM AUTHOR]

Stormwater Control Measures (SCMs) are increasingly applied to capture and utilise urban runoff to augment water supply, reduce flood risk, and to restore natural flow regimes in receiving waters. New advances in Real-Time Control (RTC) technology offer the potential to dynamically optimise SCM performance to meet multi-objectives, without the need for major structural upgrades. This paper reviews the application of RTC applied to different types of SCMs at a range of scales, revealing both the benefits and challenges. RTC can improve urban water management both now and into the future, and the applications are vast. SCM performance can be optimised at a single-site scale, but its real utility will be in larger collaborative systems, and its potential will increase with improved forecast capability and decreased costs of sensors and control elements. There is a critical need for creating new regulatory environments, governance and business models, to facilitate widespread implementation. [ABSTRACT FROM AUTHOR]

The paper discusses results of the long-term monitoring of a full-scale pilot installation of a modular tray-based blue roof (BR) system for the control of the runoff from the roof terrace of a building in the campus of the University of Catania (Italy). The BR was installed in one catchment of the rooftop while another symmetrical catchment was left unmodified and monitored to allow comparison. Results of the analysis have shown average 54% retention efficiency and 72% detention efficiency of the BR. Comparatively, the BR always overperformed the conventional roof, with mean 34% runoff reduction and mean 60% flow peak attenuation. The paper discusses also limitations of the results obtained and potential for improvement of the system efficiency, including comparison with some of the results from the literature. [ABSTRACT FROM AUTHOR]