Water Systems Research Articles

Cu- and Ag-mediated inactivation of L. pneumophila in bench- and pilot-scale drinking water systems.

Legionella pneumophila (Lp) is an opportunistic drinking water pathogen that can cause infections through the inhalation of Lp-containing aerosols and can occur in premise plumbing systems. In this work, the use of copper (Cu) and silver (Ag) ions was evaluated at the bench and pilot scale to determine (i) the effective independent concentrations of copper and silver that are efficacious in inactivating Lp, (ii) the impact of various water quality parameters on the efficaciousness of copper and silver ions, and (iii) the effectiveness and practicality of using dissociation to produce ions at the pilot scale. At the bench scale, it was determined that 0.3 ppm and 0.03 ppm of Cu and Ag, respectively, achieved 6-log inactivation of Lp in 5 h in experimental buffer. But, in dechlorinated filter-sterilized tap water, the same concentrations of Cu were not effective, and the effectiveness of Ag was slower. pH and dissolved inorganic carbon content were found to be important parameters in determining if the use of Cu and Ag ions is appropriate. At the pilot scale, dissociation was successfully used to produce Cu and Ag ions. Target levels of ions were met at the pilot scale but were difficult to achieve, and no impact was observed on Lp concentrations. Results from this study suggest that there are important caveats in the application of this technology when applied in a drinking water matrix and prior understanding of a system's water chemistry may be important to determine the effectiveness of Lp disinfection using Cu and Ag.IMPORTANCEThis work sheds light on the effectiveness of using Cu and Ag ions to inactivate (or kill) Legionella pneumophila. Legionella is an opportunistic drinking water pathogen of public health concern. This work demonstrates that there are important caveats in the application of using Cu and Ag ions to inactivate Legionella pneumophila.

Water is the vessel through which we ride the waves of changing climates

Acting through water, climate change may affect livelihoods, societal structures, and political conflicts, hindering progress toward poverty reduction. Expanding on themes from the WEST Water Conference, this perspective paper considers how water insecurity from changing climates has unequal impacts within societies, water and gender roles, changing livelihoods, and shifting cultural norms. Opportunities are shared to build resilience into our future water systems. First, technologies are considered for tracking water availability, quality, and usage. Second, collaborating with nature to manage water builds into the idea of blue-green cities. And third, the route to community participation in managing resilient water systems is with an empowered population, made possible through a three-step process of Awareness, Education, and Resources.

Diversity of Lignicolous Freshwater Fungi from Yuanjiang River in Yunnan (China), with the Description of Four New Species

Yuanjiang River (Red River) is one of the six major water systems in Yunnan Province, which originates from western Yunnan Province. This river system features numerous tributaries, complex terrain, and abundant natural resources. During the investigation on the diversity of lignicolous freshwater fungi in the Yuanjiang River, nine species were collected and identified, five belonging to Dothideomycetes and four to Sordariomycetes. Based on morphology and multigene phylogenetic analyses, four species, namely, Aquadictyospora aquatica, Dictyosporium fluminicola, Myrmecridium submersum, and Neomyrmecridium fusiforme, are described as new species. Dictyocheirospora aquadulcis is reported as a new national record, and Myrmecridium hydei is reported as a new habitat record. Dictyocheirospora rotunda, Halobyssothecium aquifusiforme, and Pseudohalonectria lutea were known earlier from freshwater habitats, but we described them in detail in this paper. This study contributes significantly to the understanding of the diversity of lignicolous freshwater fungi in southwestern China.

The Role of Reclaimed Water in Urban Flood Management: Public Perception and Acceptance

Water management is a significant issue for Kathmandu, the capital of Nepal, due to rapid urbanization, a lack of freshwater sources, and inadequate infrastructure. In order to solve the dual issues of urban flood risks and water scarcity that the city faces due to rapid population growth and restricted freshwater supply, our research explores the implementation of reclaimed water systems in Kathmandu, Nepal. This study collects respondents from 400 residents of Kathmandu using a systematic survey. It investigates their attitudes, preparedness, and concerns about using recovered water for home and municipal purposes. The outcomes indicate a high level of public knowledge, with a significant percentage (about 80%) acknowledging the value of recycled water. Nevertheless, only around one-third of respondents are amenable to home usage of such systems for drinkable purposes, primarily because of worries about the health and safety of the water. The study also finds that the acceptability of reclaimed water consumption positively correlates with higher educational attainment, which is essential information for policymakers concerned with urban sustainability.

Assessment of Possibilities of Using Local Renewable Resources in Road Infrastructure Facilities—A Case Study from Poland

The rising demand for water and energy is driving the overuse of natural resources and contributing to environmental degradation. To address these challenges, the focus has shifted to low- and zero-emission technologies that utilize alternative sources of water and energy. Although such systems are commonly applied in residential, commercial, and industrial buildings, facilities along transportation routes generally depend on grid connections. This study aimed to enhance operational independence and reduce environmental impacts by modernizing the Rest Area Stobierna (RAS) along Poland’s S19 expressway, part of the Via Carpatia road. A comprehensive technical, economic, and environmental analysis was conducted using HOMER Pro software (3.18.3 PRO Edition) and a simulation model based on YAS operating principles. The proposed Hybrid Renewable Energy System (HRES) incorporates photovoltaic panels, battery storage, and a rainwater harvesting system (RWHS). Two configurations of the HRES were evaluated, a prosumer-based setup and a hybrid-island mode. Optimization results showed that the hybrid-island configuration was most effective, achieving a 61.6% share of renewable energy in the annual balance, a 7.1-year return on investment, a EUR 0.77 million reduction in Net Present Cost (NPC), and a 75,002 kg decrease in CO2 emissions over the system’s 25-year lifecycle. This study highlights the potential of integrating renewable energy and water systems to improve sustainability, reduce operational costs, and enhance service quality in road infrastructure facilities, offering a replicable model for similar contexts.

Hydrochemical characteristics of water quality of the Bystrytsia River basin (Lviv region)

The article investigates the hydrochemical composition of water in the Bystrytsia River basin. The ratio of the main water ions was determined and it was found that along the flow the hydrochemical facies of water changes from HCO3-–Ca2+ to HCO3-–Ca2+–Mg2+. River water has an average mineralization, which increases from 391 mg/l to 463 mg/l. The reaction of the environment in the Bystrytsia River basin is mostly slightly alkaline (pH=8.15) and changes to neutral (pH=7.2) in the village of Hrushiv. Permanganate oxidation of river water in the village of Velyka Ozymyna is higher than in other areas and is associated with the presence of lowland peatlands in this area, which are a source of humic acids. A tendency for a gradual increase in phosphates P–PO43- from the river source to its mouth and sudden changes in the concentration of nitrates N–NO3- has been noted. The contamination coefficients of such biogenic elements are less than 1. Ammonium ions, nitrites and many heavy metals (Zn, Mn, Cu, Co, Ni, Pb) were not detected in the river water of the Bystrytsіa river basin. The water in the Bystrytsia River basin corresponds to class 1 according to the water pollution index (very clean, IW=0.02-0.16) and this indicator is 1.8 times lower than in the Dniester River. The increase in the water pollution index along the river is due to increases in the multiplicity of phosphates in the water. The ecological state of water in the Bystrytsia River basin using the complex indicator СPES was determined to be stable with features of instability (CPESmin=-0.61 and CPESav=0.87), instability was detected in the Novoshytska HPP reservoir, in the villages of Zalokot and Urizh. The negative complex indicator of the ecological state of water in these areas corresponds to the sanitary and toxicological indicators (CPES 3) and is due to the influence of magnesium ions, which dominate over Ca2+ ions in river water, form the HCO3- – Mg2+ or HCO3- – Mg2+ – Ca2+ hydrochemical facies and exceed the permissible content. A stable water state with features of instability has been established in the Dniester and Cherkhavka rivers. According to the IZV, the waters are very clean, but have increased mineralization (>500 mg/l), higher hardness (5.8 and 4.7 mmol-eq/l), stronger acidity (pH=7.2 especially in the Dniester), higher permanganate oxidation (4.2 mg O/l mostly in the Dniester), higher concentration of Fe3+ ions (4.9 μg/ml mostly in the Dniester). The hydrochemical composition of the water is different: HCO3- – Ca2+ – Mg2+ in the Dniester and Ca2+– HCO3- – Na+ in the Cherkhavka. These analytical results would be useful for building a hydrological conceptual model that ensures better use of the natural water system in the Bystrytsia River basin. Key words: Bystrytsia River basin; main ions; biogenic components; chemical oxygen demand; water pollution index; water quality assessment by a complex indicator.

The Horizon of the Third Pole: Mapping future scenarios and strategic responses

The Third Pole region, comprising the vast glaciers and water systems of the Hindu Kush Himalayas (HKH), is emerging as a key indicator of global climate change. Often referred to as the “Water Tower of Asia,” it sustains nearly 2 billion people through its water resources, yet the region is experiencing unprecedented changes. This review examines the region's evolving climate dynamics, focusing on key climate scenarios and potential strategic responses. The paper synthesizes data from the latest climate models, regional governance frameworks, and international climate policy developments to explore future pathways for the Third Pole. It also delves into the region's socio-economic vulnerabilities, water security challenges, and the geopolitical complexities of transboundary environmental governance. Our findings emphasize the need for proactive adaptation strategies, transboundary cooperation, and innovative policy mechanisms to mitigate climate risks. The review provides a roadmap for policymakers, scientists, and regional stakeholders to navigate the looming environmental crises, highlighting pathways that could forge a resilient future for the Third Pole.

Problem of Waterborne Diseases in African Countries

The diseases, considered waterborne or associated with poor sanitary conditions, pose a serious problem for health sector in the majority of African countries. The above-mentioned illnesses include infectious and parasitic ones, namely, cholera, typhoid fever, hepatitis A, amebic and bacillary dysentery, trachoma, ascariasis, trichuriasis, ancylostomiasis, and schistosomiasis. Their proliferation is conduced by hot climate, as well as lack of access to safe water and sewage systems for population. African countries may be classified into 3 groups by spread of the diseases in question: with steadily dangerous, difficult and relatively safe sanitary and epidemiologic situation. Capacity of vaccination against waterborne diseases faces several limitations. An important target for African countries is to provide clean water and adequate sanitation for all in order to eliminate waterborne diseases or reduce their proliferation to acceptable levels. It requires modern technologies that take into account local conditions and resilience of pathogens to chemical disinfectants.

Characterization of PFAS Residuals: A Case Study on PFAS Content in a Firefighting Foam Delivery System of an Aircraft Rescue and Firefighting Vehicle.

When fire suppression systems that held aqueous film forming foams (AFFF) are transitioned to per- and polyfluoroalkyl substance (PFAS)-free firefighting formulations, PFAS can dissolve from the wetted surfaces of the systems and release into the new firefighting formulations. The overall objective of this work was to characterize PFAS residual mass on the wetted surfaces of aircraft rescue and firefighting (ARFF) vehicle on-board fire suppression system components from the water, mixed fire water, and foam concentrate systems with various geometries, materials of construction, and locations within the fire suppression system. The ARFF vehicle components were dismantled from the system after a triple water rinse procedure which removed 19,600 mg total measured PFAS post-TOP assay from the foam concentrate system and 23 mg total measured PFAS post-TOP assay from the water system. Results for total mass of PFAS on each part indicate most of the residuals were present on parts which have large surfaces areas or the rubber or brass parts. For large surface area plastic parts (i.e., foam and water tanks), the overall mass on these parts was greater than other parts even though the PFAS residual concentrations were lower compared to other material types due to larger surface areas for accumulation. Parts constructed of rubber or brass appeared to have higher measured PFAS surface residual concentrations as compared to parts constructed of plastic or stainless steel.

Microplastics in China's surface water systems: Distribution, driving forces and ecological risk.

Comprehensively understanding the distribution, driving forces and ecological risk of microplastics (MPs) in China's surface water systems is crucial for future prevention and control of MPs pollution, particularly in the context of regional differences. Nevertheless, traditionally localized investigation and the limited MPs data availability hinder more comprehensive estimation of MPs pollution in surface water systems of China. This study presents a robust dataset, which consists of 14285 samples from 32 provincial districts, describing the MPs pollution characteristics using a data mining method combined with a machine learning model. The results show that the developed model has high accuracy in predicting the abundance, colors, shapes, and polymer types of MPs, with the coefficient of determination (R2) ranging from 0.825 to 0.978. MPs abundance varied greatly in China's surface water systems, ranging over 1-5 orders of magnitude due to the complex influence of anthropogenic activities and natural conditions. Human activities and natural conditions mutually impact the dynamics of MPs in China's surface water systems. Watersheds in almost all provinces of China are contaminated by high and extremely high ecological risk levels, highlighting the urgency for sustainable MPs management.

Problems of Monitoring Surface Waters in the Dnipro Basin

In Ukraine, the qualitative state of surface waters is unsatisfactory, especially in major water accumulation facilities of national importance, such as the Dnipro reservoirs. This situation necessitates changes in the state monitoring mission and regulatory policies in water use. Particular public importance lies in the objective assessment of the ecological and hydrological state of Ukraine's water bodies and waters, especially under the conditions of ecological-economic and military aggression, with respect to water bodies of national significance, such as the Dnipro reservoirs, primarily the Kremenchuk Reservoir. The study employs scientific methods of systemic analysis, including GIS analysis, generalization, and systematization, while considering synergistic approaches in the development of structural-logical schemes for monitoring systems in hydrology using the abduction method. The necessity of correlation analysis and the integration of surface water and soil monitoring systems has been investigated. For example, soil contamination with free nitrogen has led to a tenfold increase in nitrate concentrations in well water in the Poltava region over recent years. The analysis revealed insufficient observation points for surface water and a lack of systematic soil contamination surveys. It was demonstrated that monitoring of the Kremenchuk Reservoir should encompass not only the water quality of the reservoir itself but also the water-bearing streams, tributaries, and parts of the basin forming the reservoir, in accordance with the proposed structural-logical schemes. It was identified that only 0.1% of the 35 billion UAH allocated over the past 12 years to the Dnipro River rehabilitation program was spent on water monitoring, while water rental payments account for only 20% of state and municipal water management expenditures. A structural-logical scheme for the development of hydro-ecological monitoring of the water environment in part of the Dnipro basin has been proposed. Structural-logical schemes for the development of a spatial monitoring framework for the integral system of the Kremenchuk Reservoir's components have been suggested. The need to establish an information-analytical center for state water monitoring in Ukraine has been identified.

Exploring the Microbial Ecology of Water in Sub-Saharan Africa and the Potential of Bacteriophages in Water Quality Monitoring and Treatment to Improve Its Safety

Access to safe water and food is a critical issue in sub-Saharan Africa, where microbial contamination poses significant health risks. Conventional water treatment and food preservation methods have limitations in addressing water safety, particularly for antibiotic-resistant bacteria and other pathogenic microorganisms. This review explores the potential application of bacteriophages as an innovative solution for water treatment and food preservation in the region. Bacteriophages specifically infect bacteria and offer a targeted approach to reducing bacterial load, including multidrug-resistant strains, without the drawbacks of chemical disinfectants. This review highlights the advantages of phage bioremediation, including its specificity, adaptability, and minimal environmental impact. It also discusses various case studies demonstrating its efficacy in different water systems. Additionally, we underscore the need for further research and the development of region-specific phage applications to improve water quality and public health outcomes in sub-Saharan Africa. By integrating bacteriophage-based strategies, water treatment processes, food production, and preservation can be enhanced to reduce the spread of antimicrobial resistance and contribute to the global effort to secure safe water for all.

Resource Optimization for Grid-Connected Smart Green Townhouses Using Deep Hybrid Machine Learning

This paper examines Connected Smart Green Townhouses (CSGTs) as a modern residential building model in Burnaby, British Columbia (BC). This model incorporates a wide range of sustainable materials and smart components such as recycled insulation, Photovoltaic (PV) solar panels, smart meters, and high-efficiency systems. The CSGTs operate in grid-connected mode to balance on-site renewables with grid resources to improve efficiency, cost-effectiveness, and sustainability. Real datasets are used to optimize resource consumption, including electricity, gas, and water. Renewable Energy Sources (RESs), such as PV systems, are integrated with smart grid technology. This creates an effective framework for managing energy consumption. The accuracy, efficiency, emissions, and cost are metrics used to evaluate CSGT performance. CSGTs with one to four bedrooms are investigated considering water systems and party walls. A deep Machine Learning (ML) model combining Long Short-Term Memory (LSTM) and a Convolutional Neural Network (CNN) is proposed to improve the performance. In particular, the Mean Absolute Percentage Error (MAPE) is below 5%, the Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) are within acceptable levels, and R2 is consistently above 0.85. The proposed model outperforms other models such as Linear Regression (LR), CNN, LSTM, Random Forest (RF), and Gradient Boosting (GB) for all bedroom configurations.

Unveiling heavy metal removal mechanisms in mulberry and rice husk biochars via sacrificial mineral descriptors.

Rice husk biochar (RBC) and mulberry biochar (MBC) have gained significant attention in the removal of heavy metals in aquatic environments. Their easy affordability and eco-friendly nature make these biochar's a powerful adsorbent for sustainable water remediation applications. Although their heavy metal adsorption characteristics of individual biochar's have been widely studied, a clear understanding of how the inherited mineral composition in RBC and MBC influences Pb2+, Cd2+, and Zn2+ removal in both deionized water (DIW) and Organization for Economic Co-operation and Development (OECD) water is currently lacking. In this study, heavy metal removal mechanisms of RBC and MBC in these water systems were investigated using various kinetic models and correlated them with their mineral composition. With the highest correlation coefficient of modified two-compartment first-order kinetic model (MTCFOKM), the measured qe values highlight MBC as a promising candidate for heavy metal removal in both acidic and alkaline conditions. pH edge experiments revealed significant differences in metal removal efficiency between these biochars, despite their similar specific surface areas and surface charges (pHpzc). XRD and FTIR characterization provided a strong support in explaining the high heavy metal removal ability of MBC stem from calcite mineral that inherited from biomass. Furthermore, the pH edge experiment combined with MINEQL+ speciation profiles revealed that heavy metal removal by MBC at low pH is linked to calcite leaching, shift in system pH, and heavy metal precipitation.

Comparative Study of Water and Fertilizer Regimes on Water Potential, Phenolic Substances, and Photosynthetic Characteristics of Pistacia weinmannifolia

Effective water and fertilizer management is crucial for the forestry production of Pistacia weinmannifolia. This experiment employed an orthogonal design to measure the water potential, anthocyanins, chlorophyll, and photosynthetic parameters of Pistacia weinmannifolia under different water and fertilizer regimes. The effects of different water and fertilizer regimes on the water potential, phenolic compounds, and photosynthetic characteristics of Pistacia weinmannifolia were analyzed. A comprehensive analysis method was used to evaluate and establish the best water and fertilizer regimes system. The results showed that the water and fertilizer regimes increased the water potential, anthocyanins, chlorophyll content, flavonoids, and photosynthesis (p < 0.05). During the mid-growth stage and late mid-stage growth of Pistacia weinmannifolia, the fertilizers with the most significant effects on water potential, chlorophyll, and anthocyanins were nitrogen (N) and phosphorus (P). The supply of a certain amount of N and P had positive effect on water potential, chlorophyll, and anthocyanins. Increasing N content was more effective in improving carboxylation efficiency than increasing P content. The effect of N content on photosynthetic efficiency was greater than that of P content Analyses using the TOPSIS model demonstrate that Pistacia weinmannifolia exhibits superior comprehensive efficiency in water potential, chlorophyll, flavonoid, and anthocyanin content. When applying 0.54 g·plant−1 of pure P and 0.67 g·plant−1 of pure N, with the relative soil moisture content maintained at 85%, the optimal comprehensive benefit for photosynthetic indicators is achieved with 0.34 g·plant−1 of pure P and 0.77 g·plant−1 of pure N, while maintaining the relative soil moisture content at 46.66%. These findings indicate that the water–fertilizer coupling treatment group exhibited improved growth status and photosynthesis. Therefore, the cultivation of Pistacia weinmannifolia should prioritize maintaining a balanced water–fertilizer ratio to optimize resource utilization.

Equity Assessment of Groundwater Vulnerability and Risk in Drinking Water Supplies in Arid Regions

Groundwater is a vital drinking water source, especially in arid regions, sustaining both urban and rural populations. Its quality is influenced by natural (hydrogeological) and human-driven (demographic, policy) factors, which may pose significant public health risks, especially for communities relying on unregulated water supplies. This study addresses critical gaps by examining groundwater vulnerability and contamination disparities, emphasizing their implications for public health and equitable resource management. It analyzes the impact of socio-hydrogeological factors on arsenic and nitrate levels in groundwater-supplied systems in Arizona, U.S. Methods include spatial analysis, ANOVA, multivariate regression, and cluster analysis. Significant disparities in arsenic and nitrate contamination, including exceedances of regulatory limits, were observed across supply types, aquifer characteristics, jurisdictional oversights, and groundwater management areas. Domestic wells and community water systems showed distinct contamination risks. Groundwater vulnerability was influenced by geological differences (karst vs. alluvial aquifers) and regulatory oversight, with Tribal and State systems facing unique challenges and resource needs. Socioeconomic disparities were evident, with minority communities, institutional facilities, rural areas, and specific housing types disproportionately exposed to higher contaminant levels. These findings unveil the intersection of race, socioeconomic status, and public health risks, offering an adaptable framework for addressing similar groundwater challenges in arid and semi-arid regions globally. This study is innovative in its focus on policy distinctions between private and regulated wells, karst and alluvial aquifers, and State and Tribal jurisdictions. It emphasizes the need for targeted vulnerability assessments and remediation strategies that integrate geological, hydrological, and regulatory factors to address risk disparities in vulnerable communities. These environmental inequities underscore the urgent need for stronger regulations and strategic resource allocation to support marginalized communities. The study recommends enhancing monitoring protocols, prioritizing resource distribution, and implementing targeted policy interventions to ensure equitable and sustainable access to safe drinking water in arid regions.

Use of the microalgae Tisochrysis lutea in a "green water" system increases the absorption area in the intestine of larvae of the seahorse Hippocampus reidi Ginsburg, 1933.

The study aimed to investigate the influence of different microalgae used in green water culture on the intestinal morphology of the seahorse Hippocampus reidi during the first 15days of life. Four treatments were tested in triplicate, consisting of two microalgae (Tisochrysis lutea-ISO and Chaetoceros muelleri-CHO), used either individually (TISO and TCHO) or combined (TIC 1:1) in larval rearing water, and a treatment without microalgae (TWM). Larvae (6.68 ± 0.55mm) were fed copepods (Parvocalanus crassirrostris; 2 ind mL-1) and rotifers (Brachionus rotundiformis; 8 ind mL-1) from the first to the seventh day, and from the eighth day onwards, with Artemia sp. nauplii (2 ind mL-1). For the analysis of intestinal histomorphometry, histological analysis of the tissue was performed on day 0 (initial) and after 7 and 15days. The results demonstrate a significant increase in weight and weight gain of the larvae on the 15th day in the treatments with the addition of the microalgae T. lutea, whether alone or combination with other microalgae, compared to TWM. In relation the intestinal histomorphometry of larvae, the ANCOVA revealed that, on the 7th and 15th day, only the treatments with microalgae significantly affected the surface area of the intestinal villi. The intestinal histomorphometry of larvae from TISO showed higher values of villus height (85.29 ± 1.23 µm2) compared to TWM (69.42 ± 2.82 µm2) and TCHO (76.92 ± 2.23 µm2) (P < 0.05) but did not show significant differences compared to TIC (80.127 ± 2.08 µm2), which reflected on the villi surface area. Therefore, larvae from TISO (3603.43 ± 151.31 µm2) and TIC (3550.29 ± 120.99 µm2) showed significantly higher values of this parameter compared to TWM (3026.79 ± 147.64 µm2) and TCHO (3069.09 ± 126.18 µm2) (P < 0.05). In conclusion, the protocol for H. reidi larvae rearing in a green water system with the addition of the microalgae T. lutea resulted in an increase in the intestinal absorption area, resulting in improved performance of the larvae.

Review of Climate Change Impacts on Water Quantity and Quality in the Murray–Darling Basin, Australia

Climate change is a global phenomenon that significantly affects water quality and quantity, with implications observed across various regions worldwide. In the Murray–Darling Basin (MDB), Australia’s largest and most vital river system, climate change is exacerbating environmental and public health challenges, particularly through its impact on water resources. This review assesses the historical, current, and potential future impacts of climate change on both water quantity and quality in the MDB. The study involved a systematic review of 126 reputable sources, including peer-reviewed journals, government reports, and relevant books. A particular focus was given to the increasing frequency of blue-green algae (BGA) and blackwater events, which are key indicators of climate change’s impact on the basin’s water systems. The findings underscore the critical importance of integrating climate adaptation measures into existing water quality management policies to mitigate these adverse effects. The review concludes that proactive adaptation measures are essential for enhancing the resilience of the MDB’s water resources against the ongoing and future impacts of climate change, with lessons that may be applicable to other regions facing similar challenges.

Disaster resilience of household-level food-energy-water nexus

This study examines the resilience and sustainability of household-level Food-Energy-Water (FEW) systems in the face of increasing natural disasters exacerbated by climate change. With the backdrop of escalating natural hazards and heightened vulnerabilities, this research explores innovative approaches to enhancing household resilience through the implementation of sustainable FEW systems such as rainwater harvesting, sand filtration, solar energy, geothermal energy, gas-powered and solar generators, hydroponic food production, and small greenhouses. Three primary scenarios, food disruption, energy scarcity, and water shortage are analyzed to evaluate the effectiveness of various household-level FEW systems within a residential context. These systems are compared in terms of cost-effectiveness and performance, highlighting their capacity to supply essential needs during crises. The paper also introduces an integrated nexus approach, considering the interdependencies among food, energy, and water systems, and evaluates the compounded impact of simultaneous disruptions. This comprehensive analysis aims to provide actionable insights into the development of resilient infrastructures at a micro-scale, which can significantly mitigate the adverse effects of global environmental changes on local scales.

Mechanisms of Low Temperature Thickening of Different Materials for Deepwater Water-Based Drilling Fluids

During deepwater drilling, the low mudline temperatures and narrow safe density window pose serious challenges to the safe and efficient performance of deepwater water-based drilling fluids. Low temperatures can lead to physical and chemical changes in the components of water-based drilling fluids and the behavior of low temperature gelation. As a coarse dispersion system, water-based drilling fluid has a complex composition of dispersed phase and dispersing medium. Further clarification of low temperature gelation would be helpful in developing technical approaches to enhance the flat rheology performance of deepwater water-based drilling fluids. In this paper, different components are separated in order to comprehensively analyze the gelation behavior of different materials in water-based drilling fluids at low temperatures. In the first place, the rheological and hydrodynamic radius alterations of inorganic salts, bentonite, and additives in aqueous solutions were examined at low temperatures. The effects of inorganic salts, bentonite, and additives on the purified water system were investigated at low (4 °C)–normal (25 °C)–high (75 °C) temperatures. The low temperature gelation of different materials in pure water systems are fully clarified. The mud containing 4% bentonite with weak low temperature gelation commonly used in deepwater water-based drilling fluids was selected as the basic test system. Inorganic salts, additives, and solid-phase materials were added to the mud containing 4% bentonite. The effects of the interactions between different materials and bentonite particles on the low temperature gelation behavior of mud were analyzed. The higher the bentonite dosage, the stronger the low temperature gelation behavior of mud. The higher the addition of inorganic salts, the more serious the low temperature gelation behavior of mud. Inorganic salts should be avoided as much as possible to add too much. The low temperature gelation behavior of mud with low-viscosity additives is weak. However, the viscosity of mud with high-viscosity additives has a small change in viscosity with increasing temperature. The low temperature gelation of mud with the addition of solid-phase particulate materials with reactive groups on the surface is strong, and the low temperature gelation with the addition of inert particles is weak. This paper elucidates the low temperature gelation mechanism of bentonite, inorganic salts, additives, and solid-phase materials in deepwater water-based drilling fluids. The conclusion can also be used to guide the construction of a drilling fluid system, which is of great significance for the research and development of deepwater water-based drilling fluid additives and the safe and efficient performance of deepwater drilling fluids.