Water

16 pages, 3069 KB

Open AccessEditor’s ChoiceArticle

Source-Oriented Health Risks and Distribution of BTEXS in Urban Shallow Lake Sediment: Application of the Positive Matrix Factorization Model

by Ivana Trajković, Milica Sentić, Jelena Vesković, Milica Lučić, Andrijana Miletić and Antonije Onjia

Water 2024, 16(16), 2302; https://doi.org/10.3390/w16162302 - 15 Aug 2024

Cited by 4 | Viewed by 1929

Abstract

The degradation of sediments in urban environments worldwide is driven by population growth, urbanization, and industrialization, highlighting the need for thorough quality assessment and management strategies. As a result of these anthropogenic activities, benzene, toluene, ethylbenzene, xylenes, and styrene (BTEXS) are persistently released [...] Read more.

The degradation of sediments in urban environments worldwide is driven by population growth, urbanization, and industrialization, highlighting the need for thorough quality assessment and management strategies. As a result of these anthropogenic activities, benzene, toluene, ethylbenzene, xylenes, and styrene (BTEXS) are persistently released into the environment, polluting sediment. This study employed self-organizing maps (SOMs), positive matrix factorization (PMF), and Monte Carlo simulation of source-oriented health risks to comprehensively investigate sediment in an urban shallow lake in a mid-sized city in central Serbia. The results indicated a mean ∑BTEXS concentration of 225 µg/kg, with toluene as the dominant congener, followed by m,p-xylene, benzene, ethylbenzene, o-xylene, and styrene. Three contamination sources were identified: waste solvents and plastic waste due to intensive recreational activities, and vehicle exhaust from heavy traffic surrounding the lake. Both non-carcinogenic and carcinogenic health risks were below the permissible limits. However, children were more susceptible to health risks. Benzene from vehicle exhaust is the most responsible for non-carcinogenic and carcinogenic health risks in both population groups. The results of this study can help researchers to find a suitable perspective on the dynamics and impacts of BTEXS in lake sediments. Full article

(This article belongs to the Special Issue Fate, Transport, Removal and Modeling of Pollutants in Water)

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21 pages, 13626 KB

Open AccessEditor’s ChoiceArticle

Numerical Simulation Study of Factors Influencing Ultrasonic Cavitation Bubble Evolution on Rock Surfaces during Ultrasonic-Assisted Rock Breaking

by Jinyu Feng, Tie Yan and Zhaokai Hou

Water 2024, 16(16), 2234; https://doi.org/10.3390/w16162234 - 8 Aug 2024

Cited by 7 | Viewed by 2539

Abstract

With the increasing demand for deep oil and gas exploration and CCUS (Carbon Capture, Utilization, and Storage) engineering, improving rock-crushing efficiency stands as a pivotal technology. Ultrasonic vibration-assisted drilling has emerged as a novel rock-breaking technology. The high-frequency vibrations of ultrasonic waves impact [...] Read more.

With the increasing demand for deep oil and gas exploration and CCUS (Carbon Capture, Utilization, and Storage) engineering, improving rock-crushing efficiency stands as a pivotal technology. Ultrasonic vibration-assisted drilling has emerged as a novel rock-breaking technology. The high-frequency vibrations of ultrasonic waves impact rocks, inducing resonance and accelerating their fragmentation. At the same time, ultrasonic waves generate cavitation bubbles in the liquid near rock surfaces; the expansion and collapse of these bubbles further contribute to rock damage, thereby improving crushing efficiency. Therefore, investigating the dynamics and failure characteristics of cavitation bubbles near rock surfaces under ultrasonic influence is crucial for advancing ultrasonic-assisted rock-breaking technology. This study treats the liquid as compressible flow and investigates the movement and rupture of bubbles near rock surfaces under varying ultrasonic parameters, rock properties, characteristics of the circulating medium, and other relevant factors. The findings show that ultrasonic waves induce the oscillation, translation, collapse, and rebound of bubbles near rock surfaces. Higher ultrasonic frequencies correspond to larger collapse pressures and amplitudes near surrounding rocks, as well as longer expansion times and shorter collapse durations. In addition, bubble movement and collapse lead to rock material deformation, influenced by the rheological properties of the liquid medium. The study outcomes serve as a foundation for optimizing engineering parameters in ultrasonic-assisted rock breaking and provide theoretical support for the advancement of this technology. Full article

(This article belongs to the Special Issue Hydrodynamic Science Experiments and Simulations)

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38 pages, 1050 KB

Open AccessEditor’s ChoiceReview

Sludge Composting—Is This a Viable Solution for Wastewater Sludge Management?

by Elena Elisabeta Manea and Costel Bumbac

Water 2024, 16(16), 2241; https://doi.org/10.3390/w16162241 - 8 Aug 2024

Cited by 13 | Viewed by 6958

Abstract

Wastewater treatment plants generate significant amounts of sludge, a residual product that is rich in nutrients, usually considered waste, and traditionally eliminated by storage or incineration, methods that are expensive, environmentally damaging, and often unsustainable. Composting is increasingly recognized as an ecological and [...] Read more.

Wastewater treatment plants generate significant amounts of sludge, a residual product that is rich in nutrients, usually considered waste, and traditionally eliminated by storage or incineration, methods that are expensive, environmentally damaging, and often unsustainable. Composting is increasingly recognized as an ecological and durable solution for managing biodegradable waste, including sludge resulting from wastewater treatment. The composting of residual sludge usually requires mixing with bulking agents, such as green waste or agricultural residues, to ensure a well-balanced carbon–nitrogen ratio. This mixture undergoes a controlled aerobic decomposition, sometimes followed by post-treatment, resulting in a stabilized final product that is nutrient-rich and pathogen-free and can be used as soil amendment or fertilizer in different agricultural or landscaping applications. By using composting, communities can reduce elimination costs, reduce greenhouse gas emissions, and minimize the environmental impact of sludge management. This paper reviews recent reported experiences in the laboratory regarding full-scale sludge composting, highlighting the particularities of the processes, the influence factors, the quality of the final product, and the environmental and regulatory constraints. Composting is a sustainable and ecological solution for managing wastewater sludge, contributing to nutrient circularity, and minimizing the environmental impact. Full article

(This article belongs to the Special Issue Resource Use of Sewage Sludge for Soil Application)

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18 pages, 3055 KB

Open AccessEditor’s ChoiceArticle

Projected Climate Change Impacts on the Number of Dry and Very Heavy Precipitation Days by Century’s End: A Case Study of Iran’s Metropolises

by Rasoul Afsari, Mohammad Nazari-Sharabian, Ali Hosseini and Moses Karakouzian

Water 2024, 16(16), 2226; https://doi.org/10.3390/w16162226 - 6 Aug 2024

Cited by 5 | Viewed by 8286

Abstract

This study explores the impacts of climate change on the number of dry days and very heavy precipitation days within Iran’s metropolises. Focusing on Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz, the research utilizes the sixth phase of the Coupled Model Intercomparison Project [...] Read more.

This study explores the impacts of climate change on the number of dry days and very heavy precipitation days within Iran’s metropolises. Focusing on Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz, the research utilizes the sixth phase of the Coupled Model Intercomparison Project (CMIP6) Global Circulation Models (GCMs) to predict future precipitation conditions under various Shared Socioeconomic Pathways (SSPs) from 2025 to 2100. The study aims to provide a comprehensive understanding of how climate change will affect precipitation patterns in these major cities. Findings indicate that the SSP126 scenario typically results in the highest number of dry days, suggesting that under lower emission scenarios, precipitation events will become less frequent but more intense. Conversely, SSP585 generally leads to the lowest number of dry days. Higher emission scenarios (SSP370, SSP585) consistently show an increase in the number of very heavy precipitation days across all cities, indicating a trend towards more extreme weather events as emissions rise. These insights are crucial for urban planners, policymakers, and stakeholders in developing effective adaptation and mitigation strategies to address anticipated climatic changes. Full article

(This article belongs to the Special Issue Impacts of Climate Change on Water Resources: Assessment and Modeling, 2nd Edition)

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24 pages, 6681 KB

Open AccessEditor’s ChoiceArticle

A Machine Learning Approach to Monitor the Physiological and Water Status of an Irrigated Peach Orchard under Semi-Arid Conditions by Using Multispectral Satellite Data

by Pasquale Campi, Anna Francesca Modugno, Gabriele De Carolis, Francisco Pedrero Salcedo, Beatriz Lorente and Simone Pietro Garofalo

Water 2024, 16(16), 2224; https://doi.org/10.3390/w16162224 - 6 Aug 2024

Cited by 14 | Viewed by 4427

Abstract

Climate change is making water management increasingly difficult due to rising temperatures and unpredictable rainfall patterns, impacting crop water availability and irrigation needs. This study investigated the ability of machine learning and satellite remote sensing to monitor water status and physiology. The research [...] Read more.

Climate change is making water management increasingly difficult due to rising temperatures and unpredictable rainfall patterns, impacting crop water availability and irrigation needs. This study investigated the ability of machine learning and satellite remote sensing to monitor water status and physiology. The research focused on predicting different eco-physiological parameters in an irrigated peach orchard under Mediterranean conditions, utilizing multispectral reflectance data and machine learning algorithms (extreme gradient boosting, random forest, support vector regressor); ground data were acquired from 2021 to 2023 in the south of Italy. The random forest model outperformed in predicting net assimilation (R² = 0.61), while the support vector machine performed best in predicting electron transport rate (R² = 0.57), Fv/Fm ratio (R² = 0.66) and stomatal conductance (R² = 0.56). Random forest also proved to be the most effective in predicting stem water potential (R² = 0.62). These findings highlighted the potential of integrating machine learning techniques with high-resolution satellite imagery to assist farmers in monitoring crop health and optimizing irrigation practices, thereby addressing the challenges determined by climate change. Full article

(This article belongs to the Special Issue Water Resources, Environment, and Ecosystems: Application of New Technology)

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14 pages, 3414 KB

Open AccessEditor’s ChoiceArticle

Trimethoprim Removal from Aqueous Solutions via Volcanic Ash-Soil Adsorption: Process Modeling and Optimization

by Roberto Lavecchia, Antonio Zuorro, Oussama Baaloudj and Monica Brienza

Water 2024, 16(15), 2209; https://doi.org/10.3390/w16152209 - 5 Aug 2024

Cited by 5 | Viewed by 2215

Abstract

Antibiotic contamination of water sources is a significant environmental and public health concern. This contamination is classified among the most dangerous types of pollution currently because of their harmful effects. Therefore, it is essential to identify effective and environmentally friendly ways to deal [...] Read more.

Antibiotic contamination of water sources is a significant environmental and public health concern. This contamination is classified among the most dangerous types of pollution currently because of their harmful effects. Therefore, it is essential to identify effective and environmentally friendly ways to deal with those dangerous compounds. Within this context, this work looked into whether soils made from volcanic ash could be used as cost-effective adsorbents to remove the antibiotic trimethoprim (TRM) from aqueous solutions. To examine the impacts of the main operating parameters on TRM removal, which are the initial antibiotic concentration (C), contact time (t), stirring speed (S), and solid-to-liquid ratio (R), a Central Composite Design (CCD) based on the Response Surface Methodology (RSM) was employed. Full quadratic polynomial models were used to correlate the experimental data, allowing for the estimation of each factor’s influence. With a predicted removal efficiency of 77.59%, the removal process optimization yielded the following set of optimal conditions: C = 4.5 mg/L, t = 45.5 min, S = 747 rpm, and R = 0.04 g/mL. Experiments conducted under predicted ideal conditions supported both the result and the previously developed model’s capacity for prediction. Additionally, the adsorption mechanism was also proposed based on the characterization of the adsorbent before and after the treatment. The study’s findings provide the possibility of using soils formed from volcanic ash as a cost-effective adsorbent material for the removal of TRM and likely other similar pollutants from contaminated waters. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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18 pages, 1133 KB

Open AccessEditor’s ChoiceReview

A Review of Drip Irrigation’s Effect on Water, Carbon Fluxes, and Crop Growth in Farmland

by Hui Guo and Sien Li

Water 2024, 16(15), 2206; https://doi.org/10.3390/w16152206 - 4 Aug 2024

Cited by 14 | Viewed by 14674

Abstract

The substantial depletion of freshwater reserves in many pivotal agricultural regions, attributable to the dual pressures of global climate change and the excessive extraction of water resources, has sparked considerable apprehension regarding the sustainability of future food and water security. Drip irrigation, as [...] Read more.

The substantial depletion of freshwater reserves in many pivotal agricultural regions, attributable to the dual pressures of global climate change and the excessive extraction of water resources, has sparked considerable apprehension regarding the sustainability of future food and water security. Drip irrigation, as an efficient and precise irrigation method, reduces water loss caused by deep percolation, soil evaporation, and runoff by controlling the irrigation dosage and frequency, thus improving the efficiency of water resource utilization. Studies have shown that compared with traditional irrigation methods, drip irrigation can significantly decrease water consumption, optimize the water–energy relationship by reducing soil evaporation, increase the leaf area index, and promote crop growth, thereby enhancing plant transpiration. Although more wet and dry soil cycles from drip irrigation may increase soil CO₂ emissions, it also enhances crop photosynthesis and improves crop net ecosystem productivity (NEP) by creating more favorable soil moisture conditions, indicating greater carbon sequestration potential. The advantages of drip irrigation, such as a short irrigation cycle, moderate soil moisture, and obvious dry and wet interfaces, can improve a crop’s leaf area index and biomass accumulation, improve root dynamics, promote the distribution of photosynthetic products to the aboveground parts, and thus enhance crop yields. This study highlights the potential for the application of drip irrigation in arid regions where resource optimization is sought, providing strong technical support for the achievement of sustainable agricultural development. Future research needs to consider specific agricultural practices, soil types, and environmental conditions to further optimize the implementation and effectiveness of drip irrigation. Full article

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24 pages, 2913 KB

Open AccessEditor’s ChoiceArticle

Applying Machine Learning Methods to Improve Rainfall–Runoff Modeling in Subtropical River Basins

by Haoyuan Yu and Qichun Yang

Water 2024, 16(15), 2199; https://doi.org/10.3390/w16152199 - 2 Aug 2024

Cited by 12 | Viewed by 3873

Abstract

Machine learning models’ performance in simulating monthly rainfall–runoff in subtropical regions has not been sufficiently investigated. In this study, we evaluate the performance of six widely used machine learning models, including Long Short-Term Memory Networks (LSTMs), Support Vector Machines (SVMs), Gaussian Process Regression [...] Read more.

Machine learning models’ performance in simulating monthly rainfall–runoff in subtropical regions has not been sufficiently investigated. In this study, we evaluate the performance of six widely used machine learning models, including Long Short-Term Memory Networks (LSTMs), Support Vector Machines (SVMs), Gaussian Process Regression (GPR), LASSO Regression (LR), Extreme Gradient Boosting (XGB), and the Light Gradient Boosting Machine (LGBM), against a rainfall–runoff model (WAPABA model) in simulating monthly streamflow across three subtropical sub-basins of the Pearl River Basin (PRB). The results indicate that LSTM generally demonstrates superior capability in simulating monthly streamflow than the other five machine learning models. Using the streamflow of the previous month as an input variable improves the performance of all the machine learning models. When compared with the WAPABA model, LSTM demonstrates better performance in two of the three sub-basins. For simulations in wet seasons, LSTM shows slightly better performance than the WAPABA model. Overall, this study confirms the suitability of machine learning methods in rainfall–runoff modeling at the monthly scale in subtropical basins and proposes an effective strategy for improving their performance. Full article

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24 pages, 2321 KB

Open AccessEditor’s ChoiceArticle

Legionnaires’ Disease Surveillance and Public Health Policies in Italy: A Mathematical Model for Assessing Prevention Strategies

by Vincenzo Romano Spica, Paola Borella, Agnese Bruno, Cristian Carboni, Martin Exner, Philippe Hartemann, Gianluca Gianfranceschi, Pasqualina Laganà, Antonella Mansi, Maria Teresa Montagna, Osvalda De Giglio, Serena Platania, Caterina Rizzo, Alberto Spotti, Francesca Ubaldi, Matteo Vitali, Paul van der Wielen and Federica Valeriani

Water 2024, 16(15), 2167; https://doi.org/10.3390/w16152167 - 31 Jul 2024

Cited by 9 | Viewed by 4725

Abstract

Legionella is the pathogen that causes Legionnaires’ disease, an increasingly prevalent and sometimes fatal disease worldwide. In 2021, 97% of cases in Europe were caused by Legionella pneumophila. We present a mathematical model that can be used by public health officials to [...] Read more.

Legionella is the pathogen that causes Legionnaires’ disease, an increasingly prevalent and sometimes fatal disease worldwide. In 2021, 97% of cases in Europe were caused by Legionella pneumophila. We present a mathematical model that can be used by public health officials to assess the effectiveness and efficiency of different Legionella monitoring and control strategies to inform government requirements to prevent community-acquired Legionnaires’ disease in non-hospital buildings. This simulation model was built using comprehensive data from multiple scientific and field-based sources. It is a tool for estimating the relative economic and human costs of monitoring and control efforts targeting either L. pneumophila or Legionella species and was designed to analyze the potential application of each approach to specific building classes across Italy. The model results consistently showed that targeting L. pneumophila is not only sufficient but preferable in optimizing total cost (direct and economic) for similar human health benefits, even when stress-tested with extreme inputs. This cost–benefit analytical tool allows the user to run different real-life scenarios with a broad range of epidemiological and prevalence assumptions across different geographies in Italy. With appropriate modifications, this tool can be localized and applied to other countries, states, or provinces. Full article

(This article belongs to the Special Issue Legionella: A Key Organism in Water Management)

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19 pages, 10941 KB

Open AccessEditor’s ChoiceArticle

Assessment and Driving Factors of Wetland Ecosystem Service Function in Northeast China Based on InVEST-PLUS Model

by Xiaolin Zhu, Ruiqing Qie, Chong Luo and Wenqi Zhang

Water 2024, 16(15), 2153; https://doi.org/10.3390/w16152153 - 30 Jul 2024

Cited by 11 | Viewed by 4068

Abstract

Wetland ecosystem service function provides and maintains the Earth’s life system, which supports human and social development. However, in recent years, with the intensification of human social activities, the wetland area in northeast China has been reduced, and wetland ecosystem service function has [...] Read more.

Wetland ecosystem service function provides and maintains the Earth’s life system, which supports human and social development. However, in recent years, with the intensification of human social activities, the wetland area in northeast China has been reduced, and wetland ecosystem service function has been damaged. This paper evaluates the ecosystem service function of wetlands in northeast China based on the InVEST model, taking 40 prefecture-level cities as the evaluation unit, calculating the carbon stock, soil retention, and habitat quality of the wetlands in the study area and analyzing the drivers of changes in ecosystem service function using the PLUS model. The following results were obtained: temporally, the wetland carbon stock decreased from 754 Tg in 2000 to 688 Tg in 2020; the wetland soil retention increased from 24,424 Tg in 2000 to 33,160 Tg in 2010, and then decreased to 28,765 Tg in 2020; and the quality of wetland habitats was roughly unchanged. The wetland habitats in the study area were categorized into 5 types, classified as I, II, III, IV, or V, and the spatial changes in the 40 prefecture-level cities in northeast China were analyzed. The driving factors affecting the change in the wetland ecosystem service function were further analyzed, mainly focusing on changes in the wetland area itself. The influence of other land-use types and the influence of related policies were analyzed in three aspects, among which the GDP and spatial density of the population are social factors, and the elevation and slope are natural factors that provide larger contributions to the change in wetland area. The reduction in forest and grassland areas and the increase in cultivated land and construction land areas have a negative effect on the ecosystem service function of wetlands, and the implementation of relevant wetland protection policies promotes the ecosystem service function of wetlands. According to the problems faced by wetlands in different regions, the government formulates strategies that are in line with local development, with a view to implementing wetland ecological development in the northeast region in the new context, which will help to realize intensive land use and stimulate the vitality of the region. Full article

(This article belongs to the Section Ecohydrology)

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18 pages, 1518 KB

Open AccessEditor’s ChoiceArticle

Solar-Powered Desalination as a Sustainable Long-Term Solution for the Water Scarcity Problem: Case Studies in Portugal

by Rita Apolinário and Rui Castro

Water 2024, 16(15), 2140; https://doi.org/10.3390/w16152140 - 29 Jul 2024

Cited by 9 | Viewed by 11743

Abstract

The challenge of global water scarcity, exacerbated by population growth, pollution, and uneven resource distribution, demands innovative solutions. Seawater desalination, particularly Reverse Osmosis (RO) desalination technology, offers a promising remedy due to its efficiency, economic attractiveness, and enduring durability. This study explores the [...] Read more.

The challenge of global water scarcity, exacerbated by population growth, pollution, and uneven resource distribution, demands innovative solutions. Seawater desalination, particularly Reverse Osmosis (RO) desalination technology, offers a promising remedy due to its efficiency, economic attractiveness, and enduring durability. This study explores the potential of solar-powered desalination to replace grid-imported electricity as a cost-effective solution to water scarcity, emphasizing economic and environmental aspects. We delve into the economic viability of desalination by developing a model that considers desalination capacity, input electricity prices, and specific energy consumption. Applying this model to case studies in Portugal (Porto Santo Island in the Madeira Archipelago and Algarve in the southern mainland) demonstrates that integrating photovoltaic (PV) solar energy systems to supply the electricity required in the desalination process can reduce the unit production costs of desalinated water by about 33%. The obtained unit production cost of desalinated water using solar PV input is lower than current water tariffs, underscoring the economic feasibility of this approach. The proposed solution is in line with the United Nations Sustainable Development Goals (SDGs), contributing to Goal 6 (Clean Water and Sanitation), Goal 7 (Affordable and Clean Energy), and Goal 8 (Decent Work and Economic Growth). Full article

(This article belongs to the Special Issue Membrane Separation Technology for Water Purification and Power Generation Using Water)

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29 pages, 9301 KB

Open AccessEditor’s ChoiceArticle

Baffle-Enhanced Scour Mitigation in Rectangular and Trapezoidal Piano Key Weirs: An Experimental and Machine Learning Investigation

by Chonoor Abdi Chooplou, Ehsan Kahrizi, Amirhossein Fathi, Masoud Ghodsian and Milad Latifi

Water 2024, 16(15), 2133; https://doi.org/10.3390/w16152133 - 27 Jul 2024

Cited by 16 | Viewed by 5425

Abstract

The assessment of scour depth downstream of weirs holds paramount importance in ensuring the structural stability of these hydraulic structures. This study presents groundbreaking experimental investigations highlighting the innovative use of baffles to enhance energy dissipation and mitigate scour in the downstream beds [...] Read more.

The assessment of scour depth downstream of weirs holds paramount importance in ensuring the structural stability of these hydraulic structures. This study presents groundbreaking experimental investigations highlighting the innovative use of baffles to enhance energy dissipation and mitigate scour in the downstream beds of rectangular piano key weirs (RPKWs) and trapezoidal piano key weirs (TPKWs). By leveraging three state-of-the-art supervised machine learning algorithms—multi-layer perceptron (MLP), extreme gradient boosting (XGBoost), and support vector regression (SVR)—to estimate scour hole parameters, this research showcases significant advancements in predictive modeling for scour analysis. Experimental results reveal that the incorporation of baffles leads to a remarkable 18–22% increase in energy dissipation and an 11–14% reduction in scour depth for both RPKWs and TPKWs. Specifically, introducing baffles in RPKWs resulted in a noteworthy 26.7% reduction in scour hole area and a 30.3% decrease in scour volume compared to RPKWs without baffles. Moreover, novel empirical equations were developed to estimate scour parameters, achieving impressive performance metrics with an average R² = 0.951, RMSE = 0.145, and MRPE = 4.429%. The MLP models demonstrate superior performance in predicting maximum scour depth across all scenarios with an average R² = 0.988, RMSE = 0.035, and MRPE = 1.036%. However, the predictive capabilities varied when estimating weir toe scour depth under diverse circumstances, with the XGBoost model proving more accurate in scenarios involving baffled TPKWs with R² = 0.965, RMSE = 0.048, and MRPE = 2.798% than the MLP and SVR models. This research underscores the significant role of baffles in minimizing scouring effects in TPKWs compared to RPKWs, showcasing the potential for improved design and efficiency in water-management systems. Full article

(This article belongs to the Section Water Erosion and Sediment Transport)

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34 pages, 10129 KB

Open AccessFeature PaperEditor’s ChoiceArticle

Meteorological Drought Analysis and Regional Frequency Analysis in the Kızılırmak Basin: Creating a Framework for Sustainable Water Resources Management

by Gaye Aktürk, Hatice Çıtakoğlu, Vahdettin Demir and Neslihan Beden

Water 2024, 16(15), 2124; https://doi.org/10.3390/w16152124 - 26 Jul 2024

Cited by 22 | Viewed by 4844

Abstract

Drought research is needed to understand the complex nature of drought phenomena and to develop effective management and mitigation strategies accordingly. This study presents a comprehensive regional frequency analysis (RFA) of 12-month meteorological droughts in the Kızılırmak Basin of Turkey using the L-moments [...] Read more.

Drought research is needed to understand the complex nature of drought phenomena and to develop effective management and mitigation strategies accordingly. This study presents a comprehensive regional frequency analysis (RFA) of 12-month meteorological droughts in the Kızılırmak Basin of Turkey using the L-moments approach. For this purpose, monthly precipitation data from 1960 to 2020 obtained from 22 meteorological stations in the basin are used. In the drought analysis, the Standard Precipitation Index (SPI), Z-Score Index (ZSI), China-Z Index (CZI) and Modified China-Z Index (MCZI), which are widely used precipitation-based indices in the literature, are employed. Here, the main objectives of this study are (i) to determine homogeneous regions based on drought, (ii) to identify the best-fit regional frequency distributions, (iii) to estimate the maximum drought intensities for return periods ranging from 5 to 1000 years, and (iv) to obtain drought maps for the selected return periods. The homogeneity test results show that the basin consists of a single homogeneous region according to the drought indices considered here. The best-fit regional frequency distributions for the selected drought indices are identified using L-moment ratio diagrams and ZDIST goodness-of-fit tests. According to the results, the best-fit regional distributions are the Pearson-Type 3 (PE3) for the SPI and ZSI, generalized extreme value (GEV) for the CZI, and generalized logistic distribution (GLO) for the MCZI. The drought maps obtained here can be utilized as a useful tool for estimating the probability of drought at any location across the basin, even without enough data for hydrological research. Full article

(This article belongs to the Section Hydrology)

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26 pages, 5275 KB

Open AccessEditor’s ChoiceArticle

Adsorption of a Multicomponent Pharmaceutical Wastewater on Charcoal-Based Activated Carbon: Equilibrium and Kinetics

by Mina Asheghmoalla and Mehrab Mehrvar

Water 2024, 16(15), 2086; https://doi.org/10.3390/w16152086 - 24 Jul 2024

Cited by 10 | Viewed by 7220

Abstract

The treatment of pharmaceutical wastewater is a critical environmental challenge, necessitating efficient removal methods. This study investigates the adsorption of a synthetic multicomponent pharmaceutical wastewater (SPWW) containing methanol, benzene, methylene chloride, 4-aminophenol, aniline, and sulfanilic acid onto charcoal-based activated carbon (AC). Batch experiments [...] Read more.

The treatment of pharmaceutical wastewater is a critical environmental challenge, necessitating efficient removal methods. This study investigates the adsorption of a synthetic multicomponent pharmaceutical wastewater (SPWW) containing methanol, benzene, methylene chloride, 4-aminophenol, aniline, and sulfanilic acid onto charcoal-based activated carbon (AC). Batch experiments were conducted to study the effects of pH, contact time, and initial concentrations of the adsorbates. The results show that longer contact time and higher initial concentrations increase the adsorption capacity, whereas pH shows no significant effect on the adsorption capacity at a value of less than 10, eliminating the need for pH adjustment and reducing process costs. The pseudo-second order (PSO) kinetic model best describes the adsorption process, with intraparticle diffusion playing a key role, as confirmed by the Weber and Morris (W-M) model. Six models describing the adsorption at equilibrium are applied to experimental data, and their parameters are estimated with a nonlinear regression model. Among isotherm models, the Langmuir-Freundlich model provides the best fit, suggesting multilayer adsorption on a heterogeneous granular activated carbon (GAC) surface. The maximum adsorption capacity is estimated to be 522.3 mgC/gAC. Experimental results confirm that GAC could effectively treat highly concentrated pharmaceutical wastewater, achieving up to 52% removal efficiency. Full article

(This article belongs to the Topic Wastewater Treatment by Physical, Chemical, Photochemical, and Biological Processes, and Their Combinations)

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16 pages, 1663 KB

Open AccessEditor’s ChoiceArticle

Crop Water Use and a Gravity Model Exploration of Virtual Water Trade in Ghana’s Cereal Agriculture

by Alexander Sessi Kosi Tette, Golden Odey, Mirza Junaid Ahmad, Bashir Adelodun and Kyung-Sook Choi

Water 2024, 16(15), 2077; https://doi.org/10.3390/w16152077 - 23 Jul 2024

Cited by 3 | Viewed by 2370

Abstract

Agricultural water productivity is crucial for sustainability amidst the escalating demand for food. Cereals are pivotal in providing nutritious food at affordable prices. This study was based on Ghanaian data spanning from 1992 to 2021 to evaluate water usage in the cultivation of [...] Read more.

Agricultural water productivity is crucial for sustainability amidst the escalating demand for food. Cereals are pivotal in providing nutritious food at affordable prices. This study was based on Ghanaian data spanning from 1992 to 2021 to evaluate water usage in the cultivation of major cereals. It also examined the virtual water losses or gains in cereal trade alongside influencing factors. The analysis utilized secondary data encompassing the virtual water content, production quantity, export and import quantities, distance, GDP per capita, population, and land per capita of Ghana and its 75 trade partners. In the last 5 years, crop water use (CWU) reached an average of 7.08 billion m³/yr for maize, 3.48 billion m³/yr for rice, 1.08 billion m³/yr for sorghum, and 0.63 billion m³/yr for millet production. Ghana’s major partners for exported virtual water (EVW) were Niger, Burkina Faso, South Africa, and Togo. Major partners for imported virtual water (IVW) were Argentina, South Africa, Ukraine, Togo, Russia, Burkina Faso, Canada, Senegal, Nigeria, Portugal, UK, Niger, and the USA. The Panel Least Squares Method of regression was used to apply the Gravity Model principle in assessing influencing factors. The findings indicate that Ghana is a net importer of virtual water in the cereal trade, with significant influences from geographical distance, GDP per capita, population, land per capita, and cereal water use. Full article

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19 pages, 4611 KB

Open AccessEditor’s ChoiceArticle

Anaerobic Digestion of Dye Wastewater and Agricultural Waste with Bio-Energy and Biochar Recovery: A Techno-Economic and Sustainable Approach

by Albert Tumanyisibwe, Mahmoud Nasr, Manabu Fujii and Mona G. Ibrahim

Water 2024, 16(14), 2025; https://doi.org/10.3390/w16142025 - 17 Jul 2024

Cited by 9 | Viewed by 5291

Abstract

While several researchers have investigated the anaerobic digestion (AD) of textile wastewater for dye degradation, their studies suffer from lower biogas productivity due to substrate inhibition and the occurrence of secondary pollution from digestate disposal. Hence, this study focuses on using the extract [...] Read more.

While several researchers have investigated the anaerobic digestion (AD) of textile wastewater for dye degradation, their studies suffer from lower biogas productivity due to substrate inhibition and the occurrence of secondary pollution from digestate disposal. Hence, this study focuses on using the extract of wheat straw (WS) as a co-substrate to facilitate the dye AD process, followed by recycling the digestate sludge for biochar production. In the first study, the batch digesters were operated at different dye wastewater (DW)/WS ratios (0–50% v/v), substrate-to-inoculum ratio of 0.28–0.50 g/g, pH 7.0 ± 0.2, and 37 °C. The digester operated at a DW/WS fraction of 65/35% (v/v) showed the best chemical oxygen demand (COD) removal efficiency of 68.52 ± 3.40% with bio-CH₄ of 270.52 ± 19.14 mL/g COD_removed. About 52.96 ± 3.61% of the initial COD mass was converted to CH₄, avoiding inhibition caused by volatile fatty acid (VFA) accumulation. In the second experiment, the dry digestate was thermally treated at 550 °C for 2 h under an oxygen-deprived condition, yielding 0.613 ± 0.031 g biochar/g. This biochar exhibited multiple functional groups, mineral contents, and high stability (O/C = 0.193). The combined digestion/pyrolysis scenario treating 35 m³/d (106.75 kg COD/d) could maintain profits from pollution reduction, biogas, biochar, and carbon trading, obtaining a 6.5-year payback period. Full article

(This article belongs to the Topic Advanced Processes and Technologies for Wastewater: Collection, Treatment, and Resource)

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18 pages, 1949 KB

Open AccessEditor’s ChoiceReview

Unraveling the Potential of Microbial Flocculants: Preparation, Performance, and Applications in Wastewater Treatment

by Yang Yang, Cancan Jiang, Xu Wang, Lijing Fan, Yawen Xie, Danhua Wang, Tiancheng Yang, Jiang Peng, Xinyuan Zhang and Xuliang Zhuang

Water 2024, 16(14), 1995; https://doi.org/10.3390/w16141995 - 14 Jul 2024

Cited by 12 | Viewed by 5048

Abstract

Microbial flocculants (MBFs), a class of eco-friendly and biodegradable biopolymers produced by various microorganisms, have gained increasing attention as promising alternatives to conventional chemical flocculants in wastewater treatment and pollutant removal. This review presents a comprehensive overview of the current state of MBF [...] Read more.

Microbial flocculants (MBFs), a class of eco-friendly and biodegradable biopolymers produced by various microorganisms, have gained increasing attention as promising alternatives to conventional chemical flocculants in wastewater treatment and pollutant removal. This review presents a comprehensive overview of the current state of MBF research, encompassing their diverse sources (bacteria, fungi, and algae), major categories (polysaccharides, proteins, and glycoproteins), production processes, and flocculation performance and mechanisms. The wide-ranging applications of MBFs in removing suspended solids, heavy metals, dyes, and other pollutants from industrial and municipal wastewater are critically examined, highlighting their superior efficiency, selectivity, and environmental compatibility compared to traditional flocculants. Nonetheless, bioflocculants face significant challenges including high substrate costs, low production yields, and intricate purification methodologies, factors that impede their industrial scalability. Moreover, the risk of microbial contamination and the attendant health implications associated with the use of microbial flocculants (MBFs) necessitate thorough evaluation. To address the challenges of high production costs and variable product quality, strategies such as waste valorization, strain improvement, process optimization, and biosafety evaluation are discussed. Moreover, the development of multifunctional MBF-based flocculants and their synergistic use with other treatment technologies are identified as emerging trends for enhanced wastewater treatment and resource recovery. Future research directions are outlined, emphasizing the need for in-depth mechanistic studies, advanced characterization techniques, pilot-scale demonstrations to accelerate the industrial adoption of MBF, and moreover, integration with novel wastewater treatment processes, such as partial nitrification and the anammox process. This review is intended to inspire and guide further research and development efforts aimed at unlocking the full potential of MBFs as sustainable, high-performance, and cost-effective bioflocculants for addressing the escalating challenges in wastewater management and environmental conservation. Full article

(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment III)

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29 pages, 4994 KB

Open AccessEditor’s ChoiceReview

A Systematic Literature Review for Addressing Microplastic Fibre Pollution: Urgency and Opportunities

by Carmen Ka-Man Chan, Chris Kwan-Yu Lo and Chi-Wai Kan

Water 2024, 16(14), 1988; https://doi.org/10.3390/w16141988 - 13 Jul 2024

Cited by 18 | Viewed by 6191

Abstract

Microplastic fibre (MPF) pollution is a pressing concern that demands urgent attention. These tiny synthetic textile fibres can be found in various ecosystems, including water and air, and pose significant environmental risks. Despite their size (less than 5 mm), they can harm aquatic [...] Read more.

Microplastic fibre (MPF) pollution is a pressing concern that demands urgent attention. These tiny synthetic textile fibres can be found in various ecosystems, including water and air, and pose significant environmental risks. Despite their size (less than 5 mm), they can harm aquatic and terrestrial organisms and human health. Studies have demonstrated that these imperceptible pollutants can contaminate marine environments, thereby putting marine life at risk through ingestion and entanglement. Additionally, microplastic fibres can absorb toxins from the surrounding water, heightening their danger when consumed by aquatic organisms. Traces of MPFs have been identified in human food chains and organs. To effectively combat MPF pollution, it is crucial to understand how these fibres enter ecosystems and their sources. Primary sources include domestic laundry, where synthetic textile fibres are released into wastewater during washing. Other significant sources include industrial effluents, breakdown of plastic materials, and atmospheric deposition. Additionally, MPFs can be directly released into the environment by improperly disposing of consumer products containing these fibres, such as non-woven hygienic products. A comprehensive approach is necessary to address this pressing issue, including understanding the sources, pathways, and potential risks of MPFs. Immediate action is required to manage contamination and mitigate MPF pollution. This review paper provides a systematic literature analysis to help stakeholders prioritise efforts towards reducing MPFs. The key knowledge gaps identified include a lack of information regarding non-standardised test methodology and reporting units, and a lack of information on manufacturing processes and products, to increase understanding of life cycle impacts and real hotspots. Stakeholders urgently need collaborative efforts to address the systematic changes required to tackle this issue and address the proposed opportunities, including targeted government interventions and viable strategies for the industry sector to lead action. Full article

(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment III)

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13 pages, 1163 KB

Open AccessEditor’s ChoiceArticle

Application of Low-Pressure Nanofiltration Membranes NF90 and NTR-729HF for Treating Diverse Wastewater Streams for Irrigation Use

by Charith Fonseka, Seongchul Ryu, Sukanyah Devaisy, Jaya Kandasamy, Lee McLod, Harsha Ratnaweera and Saravanamuthu Vigneswaran

Water 2024, 16(14), 1971; https://doi.org/10.3390/w16141971 - 11 Jul 2024

Cited by 4 | Viewed by 2630

Abstract

The application of low-pressure nanofiltration (NF) was investigated for three different applications: water reuse from acid mine drainage (AMD), surface water containing natural organic matter (NOM) and agricultural reuse of microfiltered biologically treated sewage effluent (MF-BTSE). AMD contains many valuable rare earth elements [...] Read more.

The application of low-pressure nanofiltration (NF) was investigated for three different applications: water reuse from acid mine drainage (AMD), surface water containing natural organic matter (NOM) and agricultural reuse of microfiltered biologically treated sewage effluent (MF-BTSE). AMD contains many valuable rare earth elements (REEs) and copper (Cu) that can be recovered with fresh water. The NF90 membrane was investigated for recovery of fresh water from synthetic AMD. A steady permeate flux of 15.5 ± 0.2 L/m²h was achieved for pretreated AMD with over 98% solute rejection. NF90 achieved a high dissolved organic carbon (DOC) rejection of 95% from surface water containing NOM where 80% of the organic fraction was hydrophilic, mainly humics. The NF process maintained a high permeate flux of 52 LMH at 4 bars. The MF-BTSE was treated by NTR-729HF for agricultural reuse. NTR-729HF membranes were capable of rejecting DOC and inorganics such as sulfates and divalent ions (SO₄²⁻, Ca²⁺ and Mg²⁺) from MF-BTSE, with less than 20% rejection of monovalent (Na⁺ and Cl⁻) ions. The sodium adsorption ratio (SAR) was significantly reduced from 39 to 14 after treatment through NTR-729HF at 4 bar. The resulting water was found to be suitable to irrigate salt-sensitive crops. Full article

(This article belongs to the Special Issue Application of Membrane Separation Technology in Water and Wastewater Treatment)

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19 pages, 984 KB

Open AccessEditor’s ChoiceReview

Assessing International Transboundary Water Management Practices to Extract Contextual Lessons for the Nile River Basin

by Mekdelawit M. Deribe, Assefa M. Melesse, Belete B. Kidanewold, Shlomi Dinar and Elizabeth P. Anderson

Water 2024, 16(14), 1960; https://doi.org/10.3390/w16141960 - 11 Jul 2024

Cited by 8 | Viewed by 6473

Abstract

Transboundary waters account for a significant portion of global freshwater resources, yet their management is often challenging. The Nile River basin faces significant challenges owing to the complex history and unique context of the basin. Examining the experience of other transboundary basins can [...] Read more.

Transboundary waters account for a significant portion of global freshwater resources, yet their management is often challenging. The Nile River basin faces significant challenges owing to the complex history and unique context of the basin. Examining the experience of other transboundary basins can offer insights for the effective management of the Nile waters. This paper aims to extract contextual lessons for the Nile from global transboundary water management practices. To that end, we performed a scoping literature search to identify well-researched transboundary water management practices from across the world, selected key case studies, and analyzed their management practices. We discussed the context of the Nile and organized the unique challenges of the basin in five themes, and we discussed how global experiences could provide valuable insights for the Nile basin within each theme. Trust building, the need for equitable water use frameworks, a strong river basin organization, the nuanced role of external actors, and the impact of broader political context were major themes that emerged from the analysis of the Nile context. Within each theme, we presented experiences from multiple basins to inform transboundary water management in the Nile basin. Full article

(This article belongs to the Special Issue Conflict and Cooperation: The Duality of Cross-Border Water Governance)

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16 pages, 1280 KB

Open AccessEditor’s ChoiceArticle

Are Harmful Algal Blooms Increasing in the Great Lakes?

by Karl R. Bosse, Gary L. Fahnenstiel, Cal D. Buelo, Matthew B. Pawlowski, Anne E. Scofield, Elizabeth K. Hinchey and Michael J. Sayers

Water 2024, 16(14), 1944; https://doi.org/10.3390/w16141944 - 10 Jul 2024

Cited by 5 | Viewed by 2851

Abstract

This study used satellite remote sensing to investigate trends in harmful algal blooms (HABs) over the last 21 years, focusing on four regions within the Laurentian Great Lakes: western Lake Erie, Green Bay, Saginaw Bay, and western Lake Superior. HABs in the water [...] Read more.

This study used satellite remote sensing to investigate trends in harmful algal blooms (HABs) over the last 21 years, focusing on four regions within the Laurentian Great Lakes: western Lake Erie, Green Bay, Saginaw Bay, and western Lake Superior. HABs in the water column were identified from remote sensing-derived chlorophyll concentrations, and surface HAB scums were classified based on the Normalized Difference Vegetation Index (NDVI) band ratio index. Using imagery from the Moderate Resolution Imaging Spectroradiometer sensor on the Aqua satellite (MODIS-Aqua) from 2002 to 2022, we generated daily estimates of the HAB and surface scum extents for each region, which were then averaged to generate mean annual extents. We observed a significant decline in the Saginaw Bay mean annual HAB extents over the 21-year study period. Otherwise, no significant changes were observed over this period in any region for either the HAB or surface scum mean annual extents, thus suggesting that HABs are not increasing in the Great Lakes. Despite the lack of increasing trends, the blooms are still recurring annually and causing a negative impact on the nearby communities; thus, we believe that it is crucial to continue studying Great Lakes HABs to monitor the impact of current and future abatement strategies. Full article

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21 pages, 4041 KB

Open AccessEditor’s ChoiceArticle

Application of Dynamic Programming Models for Improvement of Technological Approaches to Combat Negative Water Leakage in the Underground Space

by Sérgio Lousada, Svitlana Delehan and Andrii Khorolskyi

Water 2024, 16(14), 1952; https://doi.org/10.3390/w16141952 - 10 Jul 2024

Cited by 5 | Viewed by 1941

Abstract

The article solves an urgent problem, which is to develop a new approach to finding solutions to improve technological methods to combat negative water leakage in underround spaces. We propose the use of dynamic programming methods to select the optimal technology to secure [...] Read more.

The article solves an urgent problem, which is to develop a new approach to finding solutions to improve technological methods to combat negative water leakage in underround spaces. We propose the use of dynamic programming methods to select the optimal technology to secure such spaces. In accordance with the algorithm proposed in this paper, the problem was broken into a number of stages. At each stage, an optimal solution was sought (organisation of transport, delivery of materials to the destination, selection of materials, etc.). Thus, we applied a decomposition approach that allowed us to take into account the variety of parameters that affect the efficiency of the process. All these stages and their corresponding technological solutions were formalised by building network models. In these network models, vertices corresponded to solutions, and the distances between vertices (edges) corresponded to the value of the optimisation parameter. Thus, the shortest route from the initial to the final vertex corresponded to the optimal technological solution to combat negative water leakage in underground spaces. Based on the systematisation of data on technologies to combat water inflow into underground spaces, basic and refined models were developed. These models allowed us to take into account the risks associated with water breakthroughs into underground spaces. To minimise the risks, additional measures to combat water inflows are envisaged. In the practical part of this study, the results of the selection of a method with which to control water inflows are presented. This method involves the use of anchoring to reduce water filtration. According to the results of field observations, no water breakthroughs into the underground space were recorded. Full article

(This article belongs to the Special Issue Water-Related Geoenvironmental Issues, 2nd Edition)

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21 pages, 3527 KB

Open AccessEditor’s ChoiceArticle

Quantifying Predictive Uncertainty and Feature Selection in River Bed Load Estimation: A Multi-Model Machine Learning Approach with Particle Swarm Optimization

by Xuan-Hien Le, Trung Tin Huynh, Mingeun Song and Giha Lee

Water 2024, 16(14), 1945; https://doi.org/10.3390/w16141945 - 10 Jul 2024

Cited by 8 | Viewed by 2281

Abstract

This study presents a comprehensive multi-model machine learning (ML) approach to predict river bed load, addressing the challenge of quantifying predictive uncertainty in fluvial geomorphology. Six ML models—random forest (RF), categorical boosting (CAT), extra tree regression (ETR), gradient boosting machine (GBM), Bayesian regression [...] Read more.

This study presents a comprehensive multi-model machine learning (ML) approach to predict river bed load, addressing the challenge of quantifying predictive uncertainty in fluvial geomorphology. Six ML models—random forest (RF), categorical boosting (CAT), extra tree regression (ETR), gradient boosting machine (GBM), Bayesian regression model (BRM), and K-nearest neighbors (KNNs)—were thoroughly evaluated across several performance metrics like root mean square error (RMSE), and correlation coefficient (R). To enhance model training and optimize performance, particle swarm optimization (PSO) was employed for hyperparameter tuning across all the models, leveraging its capability to efficiently explore complex hyperparameter spaces. Our findings indicated that RF, GBM, CAT, and ETR demonstrate superior predictive performance (R score > 0.936), benefiting significantly from PSO. In contrast, BRM displayed lower performance (0.838), indicating challenges with Bayesian approaches. The feature importance analysis, including permutation feature and SHAP values, highlighted the non-linear interdependencies between the variables, with river discharge (Q), bed slope (S), and flow width (W) being the most influential. This study also examined the specific impact of individual variables on model performance by adding and excluding individual variables, which is particularly meaningful when choosing input variables for the model, especially in limited data conditions. Uncertainty quantification through Monte Carlo simulations highlighted the enhanced predictability and reliability of models with larger datasets. The correlation between increased training data and improved model precision was evident in the consistent rise in mean R scores and reduction in standard deviations as the sample size increased. This research underscored the potential of advanced ensemble methods and PSO to mitigate the limitations of single-predictor models and exploit collective model strengths, thereby improving the reliability of predictions in river bed load estimation. The insights from this study provide a valuable framework for future research directions focused on optimizing ensemble configurations for hydro-dynamic modeling. Full article

(This article belongs to the Special Issue Application of Machine Learning in Hydrologic Sciences)

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21 pages, 4849 KB

Open AccessEditor’s ChoiceArticle

Leak and Burst Detection in Water Distribution Network Using Logic- and Machine Learning-Based Approaches

by Kiran Joseph, Jyoti Shetty, Ashok K. Sharma, Rudi van Staden, P. L. P. Wasantha, Sharna Small and Nathan Bennett

Water 2024, 16(14), 1935; https://doi.org/10.3390/w16141935 - 9 Jul 2024

Cited by 6 | Viewed by 5034

Abstract

Urban water systems worldwide are confronted with the dual challenges of dwindling water resources and deteriorating infrastructure, emphasising the critical need to minimise water losses from leakage. Conventional methods for leak and burst detection often prove inadequate, leading to prolonged leak durations and [...] Read more.

Urban water systems worldwide are confronted with the dual challenges of dwindling water resources and deteriorating infrastructure, emphasising the critical need to minimise water losses from leakage. Conventional methods for leak and burst detection often prove inadequate, leading to prolonged leak durations and heightened maintenance costs. This study investigates the efficacy of logic- and machine learning-based approaches in early leak detection and precise location identification within water distribution networks. By integrating hardware and software technologies, including sensor technology, data analysis, and study on the logic-based and machine learning algorithms, innovative solutions are proposed to optimise water distribution efficiency and minimise losses. In this research, we focus on a case study area in the Sunbury region of Victoria, Australia, evaluating a pumping main equipped with Supervisory Control and Data Acquisition (SCADA) sensor technology. We extract hydraulic characteristics from SCADA data and develop logic-based algorithms for leak and burst detection, alongside state-of-the-art machine learning techniques. These methodologies are applied to historical data initially and will be subsequently extended to live data, enabling the real-time detection of leaks and bursts. The findings underscore the complementary nature of logic-based and machine learning approaches. While logic-based algorithms excel in capturing straightforward anomalies based on predefined conditions, they may struggle with complex or evolving patterns. Machine learning algorithms enhance detection by learning from historical data, adapting to changing conditions, and capturing intricate patterns and outliers. The comparative analysis of machine learning models highlights the superiority of the local outlier factor (LOF) in anomaly detection, leading to its selection as the final model. Furthermore, a web-based platform has been developed for leak and burst detection using a selected machine learning model. The success of machine learning models over traditional logic-based approaches underscores the effectiveness of data-driven, probabilistic methods in handling complex data patterns and variations. Leveraging statistical and probabilistic techniques, machine learning models offer adaptability and superior performance in scenarios with intricate or dynamic relationships between variables. The findings demonstrate that the proposed methodology can significantly enhance the early detection of leaks and bursts, thereby minimising water loss and associated economic costs. The implications of this study are profound for the scientific community and stakeholders, as it provides a scalable and efficient solution for water pipeline monitoring. Implementing this approach can lead to more proactive maintenance strategies, ultimately contributing to the sustainability and resilience of urban water infrastructure systems. Full article

(This article belongs to the Special Issue Advances in Management of Urban Water Supply System)

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31 pages, 2593 KB

Open AccessEditor’s ChoiceReview

Advancing Hydrology through Machine Learning: Insights, Challenges, and Future Directions Using the CAMELS, Caravan, GRDC, CHIRPS, PERSIANN, NLDAS, GLDAS, and GRACE Datasets

by Fahad Hasan, Paul Medley, Jason Drake and Gang Chen

Water 2024, 16(13), 1904; https://doi.org/10.3390/w16131904 - 3 Jul 2024

Cited by 17 | Viewed by 12540

Abstract

Machine learning (ML) applications in hydrology are revolutionizing our understanding and prediction of hydrological processes, driven by advancements in artificial intelligence and the availability of large, high-quality datasets. This review explores the current state of ML applications in hydrology, emphasizing the utilization of [...] Read more.

Machine learning (ML) applications in hydrology are revolutionizing our understanding and prediction of hydrological processes, driven by advancements in artificial intelligence and the availability of large, high-quality datasets. This review explores the current state of ML applications in hydrology, emphasizing the utilization of extensive datasets such as CAMELS, Caravan, GRDC, CHIRPS, NLDAS, GLDAS, PERSIANN, and GRACE. These datasets provide critical data for modeling various hydrological parameters, including streamflow, precipitation, groundwater levels, and flood frequency, particularly in data-scarce regions. We discuss the type of ML methods used in hydrology and significant successes achieved through those ML models, highlighting their enhanced predictive accuracy and the integration of diverse data sources. The review also addresses the challenges inherent in hydrological ML applications, such as data heterogeneity, spatial and temporal inconsistencies, issues regarding downscaling the LSH, and the need for incorporating human activities. In addition to discussing the limitations, this article highlights the benefits of utilizing high-resolution datasets compared to traditional ones. Additionally, we examine the emerging trends and future directions, including the integration of real-time data and the quantification of uncertainties to improve model reliability. We also place a strong emphasis on incorporating citizen science and the IoT for data collection in hydrology. By synthesizing the latest research, this paper aims to guide future efforts in leveraging large datasets and ML techniques to advance hydrological science and enhance water resource management practices. Full article

(This article belongs to the Special Issue Water Resource Management in Artificial Intelligence and Big Data Analytics)

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41 pages, 10492 KB

Open AccessEditor’s ChoiceReview

Water Dams: From Ancient to Present Times and into the Future

by Andreas N. Angelakis, Alper Baba, Mohammad Valipour, Jörg Dietrich, Elahe Fallah-Mehdipour, Jens Krasilnikoff, Esra Bilgic, Cees Passchier, Vasileios A. Tzanakakis, Rohitashw Kumar, Zhang Min, Nicholas Dercas and Abdelkader T. Ahmed

Water 2024, 16(13), 1889; https://doi.org/10.3390/w16131889 - 1 Jul 2024

Cited by 18 | Viewed by 10676

Abstract

Since ancient times, dams have been built to store water, control rivers, and irrigate agricultural land to meet human needs. By the end of the 19th century, hydroelectric power stations arose and extended the purposes of dams. Today, dams can be seen as [...] Read more.

Since ancient times, dams have been built to store water, control rivers, and irrigate agricultural land to meet human needs. By the end of the 19th century, hydroelectric power stations arose and extended the purposes of dams. Today, dams can be seen as part of the renewable energy supply infrastructure. The word dam comes from French and is defined in dictionaries using words like strange, dike, and obstacle. In other words, a dam is a structure that stores water and directs it to the desired location, with a dam being built in front of river valleys. Dams built on rivers serve various purposes such as the supply of drinking water, agricultural irrigation, flood control, the supply of industrial water, power generation, recreation, the movement control of solids, and fisheries. Dams can also be built in a catchment area to capture and store the rainwater in arid and semi-arid areas. Dams can be built from concrete or natural materials such as earth and rock. There are various types of dams: embankment dams (earth-fill dams, rock-fill dams, and rock-fill dams with concrete faces) and rigid dams (gravity dams, rolled compacted concrete dams, arch dams, and buttress dams). A gravity dam is a straight wall of stone masonry or earthen material that can withstand the full force of the water pressure. In other words, the pressure of the water transfers the vertical compressive forces and horizontal shear forces to the foundations beneath the dam. The strength of a gravity dam ultimately depends on its weight and the strength of its foundations. Most dams built in ancient times were constructed as gravity dams. An arch dam, on the other hand, has a convex curved surface that faces the water. The forces generated by the water pressure are transferred to the sides of the structure by horizontal lines. The horizontal, normal, and shear forces resist the weight at the edges. When viewed in a horizontal section, an arch dam has a curved shape. This type of dam can also resist water pressure due to its particular shape that allows the transfer of the forces generated by the stored water to the rock foundations. This article takes a detailed look at hydraulic engineering in dams over the millennia. Lessons should be learned from the successful and unsuccessful applications and operations of dams. Water resource managers, policymakers, and stakeholders can use these lessons to achieve sustainable development goals in times of climate change and water crisis. Full article

(This article belongs to the Section Soil and Water)

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14 pages, 3512 KB

Open AccessEditor’s ChoiceArticle

Behavioral and Biochemical Effects of Glyphosate-Based Herbicide Roundup on Unionid Mussels: Are Mussels Good Indicators of Water Pollution with Glyphosate-Based Pesticides?

by Agnieszka Drewek, Jan Lubawy, Piotr Domek, Jan Polak, Małgorzata Słocińska, Aleksandra Dzięgelewska and Piotr Klimaszyk

Water 2024, 16(13), 1882; https://doi.org/10.3390/w16131882 - 1 Jul 2024

Cited by 5 | Viewed by 2767

Abstract

The behavioral (filtration activity) and biochemical (oxidative stress) effects of Roundup 360 Plus (active substance glyphosate) herbicide on two species of unionid mussels, Unio tumidus (Philipsson, 1788) and Anodonta anatina (L.), were evaluated at concentrations ranging from 15 to 1500 μg L⁻¹ [...] Read more.

The behavioral (filtration activity) and biochemical (oxidative stress) effects of Roundup 360 Plus (active substance glyphosate) herbicide on two species of unionid mussels, Unio tumidus (Philipsson, 1788) and Anodonta anatina (L.), were evaluated at concentrations ranging from 15 to 1500 μg L⁻¹ of glyphosate for five days. During all experiments, we did not record the mortality of the studied mussel species. Exposure to Roundup herbicide induced dose-dependent filtration disruptions in both U. tumidus and A. anatina. Exposure of the mussels to a low and environmentally relevant concentration 15 µg glyphosate L⁻¹ resulted in a slight (<20%) and temporary decrease in mean valve dilation. Exposure of the mussels to Roundup at relatively high concentrations caused drastic and prolonged shell closure and a reduction in the mussel shell opening rate. Exposure of both mussel species to herbicide resulted in oxidative stress; an increase in superoxide dismutase enzymatic activity was detected. The most significant increase in SOD activity was observed after the exposure to the highest Roundup concentration. However, no correlation between the Roundup concentration and enzymatic activity was found. The use of unionid mussels to detect environmentally relevant concentrations of Roundup, as a part of biological early warning system for pollution, is limited, but they can serve to detect the incidental pollution of aquatic ecosystems with high concentrations of this herbicide. Full article

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31 pages, 4116 KB

Open AccessEditor’s ChoiceReview

Innovations in Solar-Powered Desalination: A Comprehensive Review of Sustainable Solutions for Water Scarcity in the Middle East and North Africa (MENA) Region

by Mohammad Al-Addous, Mathhar Bdour, Shatha Rabaiah, Ali Boubakri, Norman Schweimanns, Nesrine Barbana and Johannes Wellmann

Water 2024, 16(13), 1877; https://doi.org/10.3390/w16131877 - 30 Jun 2024

Cited by 44 | Viewed by 22033

Abstract

Water scarcity poses significant challenges in arid regions like the Middle East and North Africa (MENA) due to constant population growth, considering the effects of climate change and water management aspects. The desalination technologies face problems like high energy consumption, high investment costs, [...] Read more.

Water scarcity poses significant challenges in arid regions like the Middle East and North Africa (MENA) due to constant population growth, considering the effects of climate change and water management aspects. The desalination technologies face problems like high energy consumption, high investment costs, and significant environmental impacts by brine discharge. This paper researches the relationships among water scarcity, energy-intensive desalination, and the development of renewable energy in MENA, with a particular focus on the Gulf Cooperation Council (GCC) countries. It examines innovations in solar-powered desalination, considering both solar photovoltaic (PV) and solar thermal technologies, in combination with traditional thermal desalination methods such as multi-effect distillation (MED) and multi-stage flash (MSF). The environmental impacts associated with desalination by brine discharge are also discussed, analyzing innovative technological solutions and avoidance strategies. Utilizing bibliometrics, this report provides a comprehensive analysis of scientific literature for the assessment of the research landscape in order to recognize trends in desalination technologies in the MENA region, providing valuable insights into emerging technologies and research priorities. Despite challenges such as high initial investment costs, technical complexities, and limited funding for research and development, the convergence of water scarcity and renewable energy presents significant opportunities for integrated desalination systems in GCC countries. Summarizing, this paper emphasizes the importance of interdisciplinary approaches and international collaboration by addressing the complex challenges of water scarcity and energy sustainability in the MENA region. By leveraging renewable energy sources and advancing desalination technologies, the region can achieve water security while mitigating environmental impacts and promoting economic development. Full article

(This article belongs to the Special Issue Water Sustainability and High-Quality Economic Development)

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16 pages, 2517 KB

Open AccessEditor’s ChoiceArticle

Enhancing Water Management: A Comparative Analysis of Time Series Prediction Models for Distributed Water Flow in Supply Networks

by Carlos Pires and Mónica V. Martins

Water 2024, 16(13), 1827; https://doi.org/10.3390/w16131827 - 27 Jun 2024

Cited by 9 | Viewed by 4027

Abstract

Water scarcity poses a significant challenge to social integration and economic development, necessitating efficient water management strategies. This study compares time series forecasting models, both classical, Holt–Winters and ARIMA, and modern, LSTM and Prophet, to determine the most accurate model for predicting water [...] Read more.

Water scarcity poses a significant challenge to social integration and economic development, necessitating efficient water management strategies. This study compares time series forecasting models, both classical, Holt–Winters and ARIMA, and modern, LSTM and Prophet, to determine the most accurate model for predicting water flow in public supply networks. Data from four rural Portuguese locations were used, with preprocessing ensuring quality and uniformity. Performance metrics were evaluated for both medium-term (10 days) and long-term (3 months) forecasts. Results indicate that classical models like Holt–Winters and ARIMA perform better for medium-term predictions, while modern models, particularly LSTM, excel in long-term forecasts by effectively capturing seasonal patterns. Future research should integrate additional variables and explore hybrid models to enhance forecasting accuracy. Full article

(This article belongs to the Topic Application of Smart Technologies in Water Resources Management)

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13 pages, 14176 KB

Open AccessEditor’s ChoiceArticle

A CFD Study on Optimization of Mass Transfer and Light Distribution in a Photocatalytic Reactor with Immobilized Photocatalyst on Spheres

by Qasim Jamil, Khush Bakhat Rana and Lev Matoh

Water 2024, 16(13), 1828; https://doi.org/10.3390/w16131828 - 27 Jun 2024

Cited by 8 | Viewed by 2624

Abstract

This study explores the influence of flow velocity, sphere size, and inter-sphere distance on hydrodynamics and mass transfer in a photocatalytic reactor. The effects of two different light configurations on light distribution and degradation were also evaluated. A 2D computational fluid dynamics (CFD) [...] Read more.

This study explores the influence of flow velocity, sphere size, and inter-sphere distance on hydrodynamics and mass transfer in a photocatalytic reactor. The effects of two different light configurations on light distribution and degradation were also evaluated. A 2D computational fluid dynamics (CFD) model was developed to simulate the continuous flow photocatalytic reactor with TiO₂-coated spheres and validated with experimental measurements by observing the degradation of methyl orange. The experimental setup consists of a tube containing an equal number of TiO₂-coated glass spheres. The case with radiation from one wall shows a non-uniform light distribution compared with the case with radiation from both walls. The CFD simulations focused on analyzing the velocity streamlines and turbulence characteristics (turbulent kinetic energy (TKE) and turbulence dissipation rate (TDR)). These parameters showed significant variations in each studied case. The case with larger spheres reached the highest velocity of 38 m/s of the pollutant solution. The highest TKE and TDR values of 0.47 m²/s² and 12.2 m²/s², respectively, were also observed in the same case, indicating enhanced mixing and mass transfer to the catalyst surfaces, ultimately leading to a more efficient degradation process. The results show that an optimized design of photocatalytic reactors can significantly improve mass transfer and, thus, degradation efficiency. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment: Recent Advances and Prospects for Sustainable Clean Water Supply)

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14 pages, 1877 KB

Open AccessEditor’s ChoiceArticle

Graph Neural Networks for Sensor Placement: A Proof of Concept towards a Digital Twin of Water Distribution Systems

by Andrea Menapace, Ariele Zanfei, Manuel Herrera and Bruno Brentan

Water 2024, 16(13), 1835; https://doi.org/10.3390/w16131835 - 27 Jun 2024

Cited by 9 | Viewed by 3900

Abstract

Urban water management faces new challenges due to the rise of digital solutions and abundant data, leading to the development of data-centric tools for decision-making in global water utilities, with AI technologies poised to become a key trend in the sector. This paper [...] Read more.

Urban water management faces new challenges due to the rise of digital solutions and abundant data, leading to the development of data-centric tools for decision-making in global water utilities, with AI technologies poised to become a key trend in the sector. This paper proposes a novel methodology for optimal sensor placement aimed at supporting the creation of a digital twin for water infrastructure. A significant innovation in this study is the creation of a metamodel to estimate pressure at consumption nodes in a water supply system. This metamodel guides the optimal sensor configuration by minimizing the difference between estimated and observed pressures. Our methodology was tested on a synthetic case study, showing accurate results. The estimated pressures at each network node exhibited low error and high accuracy across all sensor configurations tested, highlighting the potential for future development of a digital twin for water distribution systems. Full article

(This article belongs to the Special Issue Feasibility Evaluation and Sustainable Management of Water Infrastructure)

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13 pages, 20407 KB

Open AccessEditor’s ChoiceArticle

Flood Risk Assessment Using Multi-Criteria Spatial Analysis Case Study: Gilort River between Bălcești and Bolbocești

by Alexandru Giurea, Laura Comănescu, Robert Dobre, Alexandru Nedelea and Ioana Mirea

Water 2024, 16(13), 1760; https://doi.org/10.3390/w16131760 - 21 Jun 2024

Cited by 4 | Viewed by 2383

Abstract

Floods are the most widespread hazard globally and have a significant impact on local communities in terms of material damage and loss of life. Flood risk analysis is a complex process that needs to be addressed both physically and socially. This study provides [...] Read more.

Floods are the most widespread hazard globally and have a significant impact on local communities in terms of material damage and loss of life. Flood risk analysis is a complex process that needs to be addressed both physically and socially. This study provides a method for identifying the risk using Geographical Informational Systems techniques. Each indicator taken into account was analyzed, standardized, and weighted to obtain the final results. The case study was represented by the River Gilort (a tributary to Jiu River) in a hilly area (Getic Subcarpathians) between Bălcești and Bolbocești). In order to achieve reliable results, a series of natural and anthropic factors were used, such as elevation, slopes, geology, riparian vegetation, bank erosion, land use, groundwater depth, population density, vulnerable classes of the population, and density of houses. The flood risk assessment results show the distribution of flood risk in the study area, with a more significant impact on land use and only a few towns in the area presenting a significant flood risk. These results can be used by the competent local authorities to effectively manage flood risk. Full article

(This article belongs to the Special Issue Flood Risk Identification and Management)

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17 pages, 2841 KB

Open AccessEditor’s ChoiceArticle

Enhancing Oil–Water Separation Efficiency with WO₃/MXene Composite Membrane

by Abdelfattah Amari, Haitham Osman, Mohamed Boujelbene, Maha Khalid Abdulameer, Miklas Scholz and Saad Sh. Sammen

Water 2024, 16(13), 1767; https://doi.org/10.3390/w16131767 - 21 Jun 2024

Cited by 4 | Viewed by 2626

Abstract

In this study, a novel method for the high-performance treatment of oily wastewater was introduced using a tungsten (VI) oxide (WO₃)/MXene composite membrane based on poly (arylene ether sulfone) (PAES). Composite membranes were fabricated with superhydrophilic (SH) and superoleophobic (SO) characteristics, [...] Read more.

In this study, a novel method for the high-performance treatment of oily wastewater was introduced using a tungsten (VI) oxide (WO₃)/MXene composite membrane based on poly (arylene ether sulfone) (PAES). Composite membranes were fabricated with superhydrophilic (SH) and superoleophobic (SO) characteristics, which allow for the high-performance treatment of oily wastewater. The fabricated composite membrane can also photodegrade organic types of pollutants with just a short period of UV, enabling self-cleaning and anti-fouling properties. Moreover, the comprehensive characterization of the composite membrane through FTIR, SEM, and XRD analyses yielded valuable insights. The FTIR analysis revealed the characteristic peaks of WO₃, MXene, PAES, and the synthesized composite membrane, providing essential information on the chemical composition and properties of the materials. The XRD results demonstrated the crystal structures of WO₃, MXene, PAES, and the synthesized composite membrane, further enhancing our understanding of the composite membrane. Additionally, the SEM images illustrated the surface and cross-section of the fabricated membranes, highlighting the differences in pore size and porosity between the PAES membrane and the WO₃–MXene composite membrane, which directly impact permeate flux. The study showed that the composite membrane had a remarkable recovery time of only 0.25 h, and the efficiency of the separation process and water flux recovered to 99.98% and 6.4 L/m².h, respectively. The joint influence of WO₃ and MXene on composite membranes degraded contaminants into non-polluting substances after sunlight irradiation. This process effectively solves the treatment performance and decrease in permeate flux caused by contamination. The technology is membrane-based filtration, which is a simple and advanced method for treating polluted water. This innovative work offers promising solutions to address water pollution challenges and holds potential for practical applications from a self-cleaning and anti-fouling point of view. Full article

(This article belongs to the Special Issue Wastewater Treatment by Membrane)

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28 pages, 4868 KB

Open AccessEditor’s ChoiceReview

Hydrothermal Carbonization Technology for Wastewater Treatment under the “Dual Carbon” Goals: Current Status, Trends, and Challenges

by Guoqing Liu, Qing Xu, Salah F. Abou-Elwafa, Mohammed Ali Alshehri and Tao Zhang

Water 2024, 16(12), 1749; https://doi.org/10.3390/w16121749 - 20 Jun 2024

Cited by 15 | Viewed by 5978

Abstract

Hydrothermal carbonization (HTC) technology transforms organic biomass components, such as cellulose and lignin, into valuable carbon materials, gases and inorganic salts through hydrolysis, degradation and polymerization, with significant advantages over traditional methods by reducing energy consumption, lowering pollutant emissions and enhancing carbonization efficiency. [...] Read more.

Hydrothermal carbonization (HTC) technology transforms organic biomass components, such as cellulose and lignin, into valuable carbon materials, gases and inorganic salts through hydrolysis, degradation and polymerization, with significant advantages over traditional methods by reducing energy consumption, lowering pollutant emissions and enhancing carbonization efficiency. In the context of global climate change, HTC plays a critical role in water environment management by addressing industrial, agricultural, and domestic wastewater challenges. The application of HTC extends to wastewater treatment, where hydrochar effectively adsorbs heavy metals, organic compounds, and anions, thereby improving water quality. However, challenges remain, such as optimizing the process for diverse raw materials, managing economic costs, and addressing environmental and social impacts. Future research and policy support are essential for advancing HTC technology. By enhancing reaction mechanisms, developing catalysts, and promoting international cooperation, HTC can significantly contribute towards achieving carbon neutrality goals and fostering sustainable development. Full article

(This article belongs to the Special Issue Sustainable Wastewater Treatment and the Circular Economy)

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13 pages, 2818 KB

Open AccessEditor’s ChoiceArticle

Optimizing Flow Conditions and Fish Passage Success in Vertical Slot Fishways: Lessons from Fish Behavior Observations

by Damien Calluaud, Vincent Cornu, Philippe Baran, Gérard Pineau, Pierre Sagnes and Laurent David

Water 2024, 16(12), 1718; https://doi.org/10.3390/w16121718 - 17 Jun 2024

Cited by 4 | Viewed by 1885

Abstract

This study investigates the behavior of chubs (Squalius cephalus) of mid-body length (9.7–15.6 cm) with respect to turbulent flow conditions in a pool representing an experimental vertical slot fishway. Velocity and turbulence were characterized using PIV data. The influence of turbulent [...] Read more.

This study investigates the behavior of chubs (Squalius cephalus) of mid-body length (9.7–15.6 cm) with respect to turbulent flow conditions in a pool representing an experimental vertical slot fishway. Velocity and turbulence were characterized using PIV data. The influence of turbulent flow on fish behavior was assessed through the number of successful fish passage attempts, the associated passage times, and the spatial distribution of fish in the pool. Turbulence conditions were modified by the addition of one or three vertical rigid cylinders inside the pool. The results show that these adaptations may facilitate the passage of chubs. Results provide valuable insights and information to understand the relationship between fish behavior and hydraulic conditions, especially in the context of improving the design of fishways. Full article

(This article belongs to the Topic Advances in Environmental Hydraulics)

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19 pages, 4468 KB

Open AccessEditor’s ChoiceArticle

Water Use in Livestock Agri-Food Systems and Its Contribution to Local Water Scarcity: A Spatially Distributed Global Analysis

by Dominik Wisser, Danielle S. Grogan, Lydia Lanzoni, Giuseppe Tempio, Giuseppina Cinardi, Alex Prusevich and Stanley Glidden

Water 2024, 16(12), 1681; https://doi.org/10.3390/w16121681 - 13 Jun 2024

Cited by 20 | Viewed by 12371

Abstract

There is a growing concern about limited water supply and water scarcity in many river basins across the world. The agricultural sector is the largest user of freshwater on the planet, with a growing amount of water extracted for livestock systems. Here, we [...] Read more.

There is a growing concern about limited water supply and water scarcity in many river basins across the world. The agricultural sector is the largest user of freshwater on the planet, with a growing amount of water extracted for livestock systems. Here, we use data from the GLEAM model to advance previous studies that estimated livestock water footprints by quantifying water use for feed production, animal drinking water, and animal service water. We additionally account for the role of trade in accounting for feed water allocations to different animals in different countries and make use of a hydrologic model to estimate feed irrigation water requirements for individual crops at a high spatial resolution. Lastly, we estimate the contribution of livestock water abstractions to water stress at a small river basin scale for the entire globe. We find that feed production water accounts for the majority (>90%) of global livestock water withdrawals, though there is regional variation. Similarly, we find large regional variation in the water consumption per head by livestock species. Despite consuming >200 km³ of water per year, we find that reducing water use in the livestock system alone will rarely reduce water stress in high-stress basins. This study highlights the need for quantifying locally relevant water use and water stress metrics for individual livestock systems. Full article

(This article belongs to the Special Issue Assessment of Water Use in Livestock Production Systems and Supply Chains)

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14 pages, 3348 KB

Open AccessEditor’s ChoiceArticle

Enhanced Electricity Generation in Solar-Driven Photo-Bioelectrochemical Cells Equipped with Co₃(PO₄)₂/Mg(OH)₂ Photoanode

by Razieh Rafieenia, Mohamed Mahmoud, Mahmoud S. Abdel-Wahed, Tarek A. Gad-Allah, Anna Salvian, Daniel Farkas, Fatma El-Gohary and Claudio Avignone Rossa

Water 2024, 16(12), 1683; https://doi.org/10.3390/w16121683 - 13 Jun 2024

Cited by 6 | Viewed by 2071

Abstract

We developed a solar-driven photo-bioelectrochemical cell (s-PBEC) employing a novel anode photocatalyst material (Co₃(PO₄)₂/Mg(OH)₂) intimately coupled with electrochemically active bacteria for synergic electricity generation from wastewater. An s-PBEC was inoculated with a natural microbial community [...] Read more.

We developed a solar-driven photo-bioelectrochemical cell (s-PBEC) employing a novel anode photocatalyst material (Co₃(PO₄)₂/Mg(OH)₂) intimately coupled with electrochemically active bacteria for synergic electricity generation from wastewater. An s-PBEC was inoculated with a natural microbial community and fed with synthetic wastewater to analyze the performance of the system for electricity generation. Linear sweep voltammetry indicated an increase in power output upon light illumination of the s-PBEC after 1 h, rising from 66.0 to 91.5 mW/m². The current density in the illuminated s-PBEC exhibited a rapid increase, reaching 0.32 A/m² within 1 h, which was significantly higher than the current density in dark conditions (0.15 A/m²). Shotgun metagenomic analysis revealed a significant shift in the microbial community composition with a more diverse anodic biofilm upon illumination compared to the microbial communities in dark conditions. Three unclassified genera correlated with the enhanced current generation in illuminated s-PBEC, including Neisseriales (16.31%), Betaproteobacteria (7.37%), and Alphaproteobacteria (5.77%). This study opens avenues for further exploration and optimization of the solar-driven photo-bioelectrochemical cells, paving the way for integrative approaches for sustainable energy generation and wastewater treatment. Full article

(This article belongs to the Special Issue Application of Biotechnology in Water Purification)

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17 pages, 5704 KB

Open AccessEditor’s ChoiceArticle

Nutrient Recovery via Struvite Precipitation from Wastewater Treatment Plants: Influence of Operating Parameters, Coexisting Ions, and Seeding

by Andreia F. Santos, Luísa S. Mendes, Paula Alvarenga, Licínio M. Gando-Ferreira and Margarida J. Quina

Water 2024, 16(12), 1675; https://doi.org/10.3390/w16121675 - 12 Jun 2024

Cited by 14 | Viewed by 8831

Abstract

Phosphorus (P) is a critical element for life, and wastewater treatment systems can be strategic points for its recovery, thereby avoiding eutrophication pollution in nature. The aim of this research was to investigate P recovery via struvite, namely in terms of the influence [...] Read more.

Phosphorus (P) is a critical element for life, and wastewater treatment systems can be strategic points for its recovery, thereby avoiding eutrophication pollution in nature. The aim of this research was to investigate P recovery via struvite, namely in terms of the influence of operating parameters, coexisting interfering ions, and seeding. This paper focuses on synthetic solutions, although an assessment was performed on wastewater. The results of the assessment indicated that, in the synthetic solution, the minimum concentration for struvite precipitation is about 30 mg P/L, and that the Mg/P molar ratio of 1 promotes P removal efficiency with less contribution from other minerals. In order to assess the results in terms of real-world scenarios, the influence of coexisting ions (calcium and sodium) was investigated. Calcium was shown to have the greatest impact on the process, as 80% was removed for an initial concentration of 200 mg Ca/L. Indeed, these experiments generated an amorphous precipitate that did not contain struvite. The utilization of biomass ash (size < 63 µm) as seeding in crystallization increased the P removal efficiency compared to the sample without seed and helped to control the pH. The precipitation experiments with wastewater demonstrated good P removal efficiencies (over 90%) but indicated a reduction in the purity of the final product (struvite was a minor crystalline phase identified in XRD—15%wt). Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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15 pages, 4937 KB

Open AccessEditor’s ChoiceArticle

Mechanism of Crude Oil Biodegradation in Bioreactors: A Model Approach

by Carlos Costa and Nicolás Millán

Water 2024, 16(12), 1653; https://doi.org/10.3390/w16121653 - 10 Jun 2024

Cited by 3 | Viewed by 2742

Abstract

Oil-degrading bacteria have the ability to degrade alkanes present in crude oil because of a special enzymatic system, the alkane hydroxylase complex (AlkH). The mechanism for the transport and degradation of alkanes present in crude oil remains unclear, especially related to the first [...] Read more.

Oil-degrading bacteria have the ability to degrade alkanes present in crude oil because of a special enzymatic system, the alkane hydroxylase complex (AlkH). The mechanism for the transport and degradation of alkanes present in crude oil remains unclear, especially related to the first step in hydrocarbons oxidation. In this work, we present a novel model of the crude oil biodegradation mechanism by considering the contact between the oil drop and the cell and calculating the mass transfer coefficients in three oleophilic bacteria (B. licheniformis, P. putida and P. glucanolyticus). The mass transfer coefficients are evaluated under critical time conditions, when the kinetics and mass transport are in balance, and the difference in the values obtained (k_L α = 1.60 × 10⁻³, 5.25 × 10⁻⁴ and 6.19 × 10⁻⁴ m/d, respectively) shows the higher value of the mass transfer coefficient and higher biodegradation potential for B. licheniformis. Because the morphology of the cells has been analyzed by optical and electron microscopy, in the proposed model, the increase in the size of the cells in P. glucanolyticus compared to P. putida exhibits higher values of the mass transfer coefficients and this is attributed, as a novel statement, to a bigger window for alkanes transport (contact area) when the external area of the cell is bigger. Full article

(This article belongs to the Special Issue Biological Treatment of Water Contaminants: A New Insight)

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60 pages, 6757 KB

Open AccessEditor’s ChoiceReview

Recent Advances in Ball-Milled Materials and Their Applications for Adsorptive Removal of Aqueous Pollutants

by Pei Gao, Xuanhao Fan, Da Sun, Guoming Zeng, Quanfeng Wang and Qihui Wang

Water 2024, 16(12), 1639; https://doi.org/10.3390/w16121639 - 7 Jun 2024

Cited by 14 | Viewed by 6483

Abstract

Ball milling, as a cost-effective and eco-friendly approach, has been popular in materials synthesis to solve problems involving toxic reagents, high temperatures, or high pressure, which has the potential for large-scale production. However, there are few reviews specifically concentrating on the latest progress [...] Read more.

Ball milling, as a cost-effective and eco-friendly approach, has been popular in materials synthesis to solve problems involving toxic reagents, high temperatures, or high pressure, which has the potential for large-scale production. However, there are few reviews specifically concentrating on the latest progress in materials characteristics before and after ball milling as well as the adsorptive application for aqueous pollutants. Hence, this paper summarized the principle and classification of ball milling and reviewed the advances of mechanochemical materials in categories as well as their adsorption performance of organic and inorganic pollutants. Ball milling has the capacity to change materials’ crystal structure, specific surface areas, pore volumes, and particle sizes and even promote grafting reactions to obtain functional groups to surfaces. This improved the adsorption amount, changed the equilibrium time, and strengthened the adsorption force for contaminants. Most studies showed that the Langmuir model and pseudo-second-order model fitted experimental data well. The regeneration methods include ball milling and thermal and solvent methods. The potential future developments in this field were also proposed. This work tries to review the latest advances in ball-milled materials and their application for pollutant adsorption and provides a comprehensive understanding of the physicochemical properties of materials before and after ball milling, as well as their effects on pollutants’ adsorption behavior. This is conducive to laying a foundation for further research on water decontamination by ball-milled materials. Full article

(This article belongs to the Topic Sustainable Technologies for Water Purification)

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27 pages, 32827 KB

Open AccessEditor’s ChoiceArticle

Dynamic Hazard Assessment of Rainfall-Induced Landslides Using Gradient Boosting Decision Tree with Google Earth Engine in Three Gorges Reservoir Area, China

by Ke Yang, Ruiqing Niu, Yingxu Song, Jiahui Dong, Huaidan Zhang and Jie Chen

Water 2024, 16(12), 1638; https://doi.org/10.3390/w16121638 - 7 Jun 2024

Cited by 12 | Viewed by 2366

Abstract

Rainfall-induced landslides are a major hazard in the Three Gorges Reservoir area (TGRA) of China, encompassing 19 districts and counties with extensive coverage and significant spatial variation in terrain. This study introduces the Gradient Boosting Decision Tree (GBDT) model, implemented on the Google [...] Read more.

Rainfall-induced landslides are a major hazard in the Three Gorges Reservoir area (TGRA) of China, encompassing 19 districts and counties with extensive coverage and significant spatial variation in terrain. This study introduces the Gradient Boosting Decision Tree (GBDT) model, implemented on the Google Earth Engine (GEE) cloud platform, to dynamically assess landslide risks within the TGRA. Utilizing the GBDT model for landslide susceptibility analysis, the results show high accuracy with a prediction precision of 86.2% and a recall rate of 95.7%. Furthermore, leveraging GEE’s powerful computational capabilities and real-time updated rainfall data, we dynamically mapped landslide hazards across the TGRA. The integration of the GBDT with GEE enabled near-real-time processing of remote sensing and meteorological radar data from the significant “8–31” 2014 rainstorm event, achieving dynamic and accurate hazard assessments. This study provides a scalable solution applicable globally to similar regions, making a significant contribution to the field of geohazard analysis by improving real-time landslide hazard assessment and mitigation strategies. Full article

(This article belongs to the Special Issue Rainfall-Induced Landslides: Influencing, Modelling and Hazard Assessment)

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15 pages, 2842 KB

Open AccessEditor’s ChoiceArticle

Denitrification Mechanism of Heterotrophic Aerobic Denitrifying Pseudomonas hunanensis Strain DC-2 and Its Application in Aquaculture Wastewater

by Xinya Sui, Xingqiang Wu, Bangding Xiao, Chunbo Wang and Cuicui Tian

Water 2024, 16(11), 1625; https://doi.org/10.3390/w16111625 - 6 Jun 2024

Cited by 13 | Viewed by 4389

Abstract

A novel heterotrophic aerobic denitrifying Pseudomonas hunanensis strain DC-2 was screened from the sediments of Lake Dianchi and identified with high nitrification/denitrification ability. Within 30 h, the removal efficiency of ammonium-N and nitrate-N could reach 98.8% and 88.4%, respectively. The results of the [...] Read more.

A novel heterotrophic aerobic denitrifying Pseudomonas hunanensis strain DC-2 was screened from the sediments of Lake Dianchi and identified with high nitrification/denitrification ability. Within 30 h, the removal efficiency of ammonium-N and nitrate-N could reach 98.8% and 88.4%, respectively. The results of the single-factor experiments indicated that strain DC-2 exhibited excellent denitrification ability under the conditions of using sodium citrate as the nitrogen source, with an initial pH of 7, a C/N ratio of 10, and a temperature of 30 °C. Nitrogen balance experiments suggested that this strain removed N mainly via assimilation. Moreover, the N removal pathway was explored by genome and enzymatic assays, and a complex nitrogen metabolism pathway was established, including heterotrophic nitrification-aerobic denitrification (HN-AD), assimilatory reduction of nitrate (ANRA), and ammonia assimilation. Additionally, strain DC-2 was immobilized into particles for denitrification, demonstrating excellent efficacy in continuous total nitrogen removal (84.8% for TN). Hence, strain DC-2 demonstrated significant potential in treating real aquaculture wastewater. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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23 pages, 4708 KB

Open AccessEditor’s ChoiceArticle

Numerical Investigation of Different Stepped Spillway Geometries over a Mild Slope for Safe Operation Using Multi-Phase Model

by Binaya Raj Pandey, Megh Raj K C, Brian Crookston and Gerald Zenz

Water 2024, 16(11), 1635; https://doi.org/10.3390/w16111635 - 6 Jun 2024

Cited by 7 | Viewed by 3102

Abstract

The appropriate design and operation of spillways are critical for dam safety. To enhance design practices and gain insights into flow hydraulics, both experimental and numerical modeling are commonly employed. In this study, we conducted a numerical investigation of flow over a mildly [...] Read more.

The appropriate design and operation of spillways are critical for dam safety. To enhance design practices and gain insights into flow hydraulics, both experimental and numerical modeling are commonly employed. In this study, we conducted a numerical investigation of flow over a mildly sloping (1V:3H) stepped spillway with various step geometries using a multi-phase mixture model with dispersed interface tracking in ANSYS Fluent. The model was validated against experimental data from Utah State University, focusing on water surface profiles over the crest, velocities, and air concentrations. The validated numerical model was used to simulate flow over different step geometries (i.e., 0.2 m H uniform Step, 0.1 m H uniform step, non-uniform steps, adverse slope steps, and stepped pool) for a range of discharges from 0.285 m³/s/m to 1.265 m³/s/m. While flow depths over the crest and velocities in the chute compared well with experimental results, air concentrations exhibited some deviation, indicating numerical limitations of the solver. The shift in the location of the inception point was found to be mainly influenced by a higher flow rate than the different design configurations over an identical mild slope. The downstream non-linear flow velocity curve with different flow rates indicated less effectiveness of the step roughness over a high flow rate as a result of the reduction in relative roughness. The theoretical velocity ratio indicated the least reduction in downstream velocity with the stepped pooled spillway due to the formation of a “stagnant pool”. A higher negative-pressure region due to flow separation at the vertical face of the steps was obtained by adverse slope steps, which shows that the risk of cavitation is higher over the adverse slope step spillway. Turbulent kinetic energy (TKE) was found to be higher for uniform 0.2 m H steps due to the strong mixing of flow over the steps. The least TKE was found at the steps of the stepped pool spillway due to the formation of a “stagnant pool”. Uniform 0.2 m H steps achieved the maximum energy dissipation efficiency, whereas the stepped pool spillway obtained the least energy dissipation efficiency, introducing higher flow velocity at the stilling basin with a higher residual head. The adverse slope and non-uniform steps were found to be more effective than the uniform 0.1 m H steps and stepped pool spillway. The application of uniform steps of higher drop height and length could achieve higher TKE over the steps, reducing the directional flow velocity, which reduces the risk of potential damage. Full article

(This article belongs to the Special Issue CFD Modelling of Turbulent Free Surface Flows)

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20 pages, 7466 KB

Open AccessEditor’s ChoiceReview

Critical Review on Two-Stage Anaerobic Digestion with H₂ and CH₄ Production from Various Wastes

by Xinyi Zheng and Ruying Li

Water 2024, 16(11), 1608; https://doi.org/10.3390/w16111608 - 4 Jun 2024

Cited by 16 | Viewed by 9272

Abstract

Anaerobic digestion (AD) is a promising method for resource recovery from various wastes. Compared to the conventional single-stage AD process, a two-stage AD process with separate H₂ and CH₄ production provides higher energy recovery efficiency and enhanced operation stability. The stage [...] Read more.

Anaerobic digestion (AD) is a promising method for resource recovery from various wastes. Compared to the conventional single-stage AD process, a two-stage AD process with separate H₂ and CH₄ production provides higher energy recovery efficiency and enhanced operation stability. The stage separation makes it possible to apply optimal conditions for different functional microorganisms in their respective stages. This review elaborates the mechanisms of the two-stage AD process and evaluates recent research trends on this topic. A comprehensive comparison between single- and two-stage AD processes is made from the perspective of biogas production, organics degradation, energy recovery, and operation stability. The main influence factors on the two-stage AD process are discussed, including substrates, inoculum, and operation parameters, such as pH, temperature, etc. Upgrading technologies for the two-stage AD process are assessed. The microbial communities in the two-stage AD process for treating different substrates and the influence factors on microbial systems are also summarized. Furthermore, future research opportunities for enhancing the application of this technology are highlighted. Full article

(This article belongs to the Special Issue Application of Anaerobic Biological Technology for Wastewater Treatment)

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59 pages, 2880 KB

Open AccessEditor’s ChoiceReview

Use of Zero-Valent Iron Nanoparticles (nZVIs) from Environmentally Friendly Synthesis for the Removal of Dyes from Water—A Review

by Cristina Rodríguez-Rasero, Vicente Montes-Jimenez, María F. Alexandre-Franco, Carmen Fernández-González, Jesús Píriz-Tercero and Eduardo Manuel Cuerda-Correa

Water 2024, 16(11), 1607; https://doi.org/10.3390/w16111607 - 4 Jun 2024

Cited by 25 | Viewed by 8657

Abstract

This review article addresses the increasing environmental concerns posed by synthetic dyes in water, exploring innovative approaches for their removal with a focus on zero-valent iron nanoparticles (nZVIs) synthesized through environmentally friendly methods. The article begins by highlighting the persistent nature of synthetic [...] Read more.

This review article addresses the increasing environmental concerns posed by synthetic dyes in water, exploring innovative approaches for their removal with a focus on zero-valent iron nanoparticles (nZVIs) synthesized through environmentally friendly methods. The article begins by highlighting the persistent nature of synthetic dyes and the limitations of conventional degradation processes. The role of nanoparticles in environmental applications is then discussed, covering diverse methods for metallic nanoparticle production aligned with green chemistry principles. Various methods, including the incorporation of secondary metals, surface coating, emulsification, fixed support, encapsulation, and electrostatic stabilization, are detailed in relation to the stabilization of nZVIs. A novel aspect is introduced in the use of plant extract or biomimetic approaches for chemical reduction during nZVI synthesis. The review investigates the specific challenges posed by dye pollution in wastewater from industrial sources, particularly in the context of garment coloring. Current approaches for dye removal in aqueous environments are discussed, with an emphasis on the effectiveness of green-synthesized nZVIs. The article concludes by offering insights into future perspectives and challenges in the field. The intricate landscape of environmentally friendly nZVI synthesis has been presented, showcasing its potential as a sustainable solution for addressing dye pollution in water. Full article

(This article belongs to the Special Issue Novel Insights on Wastewater Treatment Processes for Sustainable Removal of Emerging Contaminants)

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20 pages, 20471 KB

Open AccessEditor’s ChoiceArticle

Rainfall-Triggered Landslides and Numerical Modeling of Subsequent Debris Flows at Kalli Village of Suntar Formation in the Lesser Himalayas in Nepal

by Diwakar KC, Mohammad Wasif Naqvi, Harish Dangi and Liangbo Hu

Water 2024, 16(11), 1594; https://doi.org/10.3390/w16111594 - 2 Jun 2024

Cited by 6 | Viewed by 2479

Abstract

Hazardous debris flows are common in the tectonically active young Himalayas. The present study is focused on the recurrent, almost seasonal, landslides and debris flows initiated from Kalli village in Achham District of Nepal, located in the Lesser Himalayas. Such geological hazards pose [...] Read more.

Hazardous debris flows are common in the tectonically active young Himalayas. The present study is focused on the recurrent, almost seasonal, landslides and debris flows initiated from Kalli village in Achham District of Nepal, located in the Lesser Himalayas. Such geological hazards pose a significant threat to the neighboring communities. The field survey reveals vulnerable engineering geological conditions and adverse environmental factors in the study area. It is found that a typical complete debris transport process may consist of two stages depending on the rainfall intensity. In the first stage, debris flows mobilized from a landslide have low mobility and their runout distance is quite modest; in the second stage, with an increase in water content they are able to travel a longer distance. Numerical simulations based on a multi-phase flow model are conducted to analyze the characteristics of the debris flows in motion, including the debris deposition profiles and runout distances in both stages. Overall, the numerical results are reasonably consistent with relevant field observations. Future debris flows may likely occur again in this area due to the presence of large soil blocks separated by tension cracks, rampant in the field; numerical simulations predict that these potential debris flows may exhibit similar characteristics to past events. Full article

(This article belongs to the Special Issue Rainfall-Induced Landslides: Influencing, Modelling and Hazard Assessment)

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27 pages, 9190 KB

Open AccessEditor’s ChoiceArticle

Isotope Hydrology and Hydrogeochemical Signatures in the Lake Malawi Basin: A Multi-Tracer Approach for Groundwater Resource Conceptualisation

by Limbikani C. Banda, Robert M. Kalin and Vernon Phoenix

Water 2024, 16(11), 1587; https://doi.org/10.3390/w16111587 - 31 May 2024

Cited by 10 | Viewed by 3282

Abstract

Reliance on groundwater is outpacing natural replenishment, a growing imbalance that requires detailed and multi-faceted water resource understanding. This study integrated water-stable isotopes and hydrogeochemical species to examine hydrogeochemical processes during groundwater recharge and evolution in the Lake Malawi basin aquifer systems. The [...] Read more.

Reliance on groundwater is outpacing natural replenishment, a growing imbalance that requires detailed and multi-faceted water resource understanding. This study integrated water-stable isotopes and hydrogeochemical species to examine hydrogeochemical processes during groundwater recharge and evolution in the Lake Malawi basin aquifer systems. The findings provide insights into groundwater source provenance, with non-evaporated modern precipitation dominating recharge inputs. Grouped hydrochemical facies exhibit five groundwater water types, prominently featuring Ca-Mg-HCO₃. Modelled hydrogeochemical data underscore dominant silicate dissolution reactions with the likely precipitation of calcite and/or high-Mg dolomitic carbonate constrained by ion exchange. Isotope hydrology reinforces water resource system conceptualisation. Coupled isotopic-hydrogeochemical lines of evidence reveal a discernible spatial-seasonal inhomogeneity in groundwater chemical character, revealing a complex interplay of meteoric water input, evaporative effects, recharge processes, and mixing dynamics. Findings show that measurable nitrate across Malawi highlights a widespread human impact on groundwater quality and an urgent need for detailed modelling to predict future trends of nitrate in groundwater with respect to extensive fertiliser use and an ever-increasing number of pit latrines and septic systems arising from rapid population growth. This study not only refined the Lake Malawi basin aquifer systems conceptualisation but also provided isotopic evidence of groundwater and lake water mixing. This study sets a base for groundwater management and policy decisions in support of the Integrated Water Resources Management principles and Sustainable Development Goal 6 objectives for groundwater sustainability in the transboundary Lake Malawi basin. Full article

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22 pages, 13590 KB

Open AccessEditor’s ChoiceArticle

Modelling Approach for Assessment of Groundwater Potential of the Moghra Aquifer, Egypt, for Extensive Rural Development

by Ahmed Shalby, Bakenaz A. Zeidan, Katarzyna Pietrucha-Urbanik, Abdelazim M. Negm and Asaad M. Armanuos

Water 2024, 16(11), 1562; https://doi.org/10.3390/w16111562 - 29 May 2024

Cited by 5 | Viewed by 3723

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Special Issue Groundwater Depletion: Current Trends and Future Challenges to Mitigate the Phenomenon)

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20 pages, 32280 KB

Open AccessEditor’s ChoiceArticle

Groundwater Depletion. Are Environmentally Friendly Energy Recharge Dams a Solution?

by Nerantzis Kazakis, Diamantis Karakatsanis, Maria Margarita Ntona, Konstantinos Polydoropoulos, Efthymia Zavridou, Kalliopi Artemis Voudouri, Gianluigi Busico, Kyriaki Kalaitzidou, Thomas Patsialis, Martha Perdikaki, Panagiotis Tsourlos, Andreas Kallioras, Nicolaos Theodossiou, Fotios-Konstantinos Pliakas, Panagiotis Angelidis, Theodoros Mavromatis, Olga Patrikaki and Konstantinos Voudouris

Water 2024, 16(11), 1541; https://doi.org/10.3390/w16111541 - 27 May 2024

Cited by 18 | Viewed by 4370

Abstract

Groundwater is a primary source of drinking water; however, groundwater depletion constitutes a common phenomenon worldwide. The present research aims to quantify groundwater depletion in three aquifers in Greece, including the porous aquifers in the Eastern Thermaikos Gulf, Mouriki, and the Marathonas basin. [...] Read more.

Groundwater is a primary source of drinking water; however, groundwater depletion constitutes a common phenomenon worldwide. The present research aims to quantify groundwater depletion in three aquifers in Greece, including the porous aquifers in the Eastern Thermaikos Gulf, Mouriki, and the Marathonas basin. The hypothesis is to reverse the phenomenon by adopting an environmentally acceptable methodology. The core of the suggested methodology was the simulation of groundwater using MODFLOW-NWT and the application of managed aquifer recharge (MAR) by using water from small dams after the generation of hydropower. Surface run-off and groundwater recharge values were obtained from the ArcSWAT simulation. The predicted future climatic data were obtained from the Coordinated Regional Climate Downscaling Experiment (CORDEX), considering the Representative Concentration Pathway (RCP) 4.5 and the climate model REMO2009. Groundwater flow simulations from 2010 to 2020 determined the existing status of the aquifers. The simulation was extended to the year 2030 to forecast the groundwater regime. In all three sites, groundwater depletion occurred in 2020, while the phenomenon will be exacerbated in 2030, as depicted in the GIS maps. During 2020, the depletion zones extended 11%, 28%, and 23% of the aquifers in Mouriki, the Eastern Thermaikos Gulf, and the Marathonas basin, respectively. During 2030, the depletion zones will increase to 50%, 42%, and 44% of the aquifers in Mouriki, the Eastern Thermaikos Gulf, and the Marathonas basin, respectively. The simulation was extended to 2040 by applying MAR with the water from the existing dams as well as from additional dams. In all sites, the application of MAR contributed to the reversal of groundwater depletion, with a significant amount of hydropower generated. Until 2040, the application of MAR will reduce the depletion zones to 0.5%, 9%, and 12% of the aquifers in Mouriki, the Eastern Thermaikos Gulf, and the Marathonas basin, respectively. Apart from over-pumping, climatic factors such as long periods of drought have exacerbated groundwater depletion. The transformation of dams to mini-scale hydropower facilities combined with MAR will benefit clean energy production, save CO₂ emissions, and lead to an economically feasible strategy against groundwater depletion. Full article

(This article belongs to the Special Issue Eye4water—Strengthening the Water Management Practices (in EMT-R) through the Development of Innovative ICT Methodologies and Improvement of Research Infrastructures)

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24 pages, 1285 KB

Open AccessEditor’s ChoiceReview

Leakages in Water Distribution Networks: Estimation Methods, Influential Factors, and Mitigation Strategies—A Comprehensive Review

by Athanasios V. Serafeim, Nikolaos Th. Fourniotis, Roberto Deidda, George Kokosalakis and Andreas Langousis

Water 2024, 16(11), 1534; https://doi.org/10.3390/w16111534 - 27 May 2024

Cited by 14 | Viewed by 12959

Abstract

While only a minimal fraction of global water resources is accessible for drinking water production, their uneven distribution combined with the climate crisis impacts leads to challenges in water availability. Leakage in water distribution networks compounds these issues, resulting in significant economic losses [...] Read more.

While only a minimal fraction of global water resources is accessible for drinking water production, their uneven distribution combined with the climate crisis impacts leads to challenges in water availability. Leakage in water distribution networks compounds these issues, resulting in significant economic losses and environmental risks. A coherent review of (a) the most widely applied water loss estimation techniques, (b) factors influencing them, and (c) strategies for their resilient reduction provides a comprehensive understanding of the current state of knowledge and practices in leakage management. This work aims towards covering the most important leakage estimation methodologies, while also unveiling the factors that critically affect them, both internally and externally. Finally, a thorough discussion is provided regarding the current state-of-the-art technics for leakage reduction at the municipal-wide level. Full article

(This article belongs to the Special Issue Water Supplies, Sewerage and Stormwater Networks: New Challenges and Advances in Modelling and Management)

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