Search Results (7,407)

Global water scarcity has intensified over recent decades, with projections suggesting that nearly six billion people may face limited access to clean water by 2050. Water reuse has emerged as a viable strategy to alleviate pressure on freshwater resources, particularly for non-potable applications. However, safe implementation requires wastewater to be treated to meet fit-for-purpose quality standards established through regional and national regulatory frameworks. Despite high levels of basic sanitation coverage in high-income countries such as the United States, persistent gaps remain in affordable and equitable wastewater management, particularly in small and underserved communities. This review focused on current knowledge of sustainable low-cost materials, including plant-based, clay, and clay-based ceramics; animal-derived products; and industrial by-products, used to remove a broad range of contaminants, including heavy metals, dyes, nutrients, emerging contaminants, and pathogens, from wastewater. The mechanisms governing their performance, such as adsorption, coagulation–flocculation, and filtration, were examined alongside contaminant-specific performance. The review further highlights the emerging role of 3D printing in developing customizable, efficient, and scalable treatment units using low-cost or waste-derived materials. Life cycle assessment (LCA) studies were evaluated to highlight their role as a flexible framework for assessing environmental impacts across life-cycle stages and for guiding the selection of sustainable materials and treatment systems. Together, these perspectives provide a comprehensive foundation for developing decentralized, community-oriented wastewater treatment solutions that support safe and effective water reuse, especially in rural and small communities. Full article

Increasing freshwater scarcity alongside growing irrigation demand poses a major challenge for agricultural production. One potential response is the use of drought adaptation amendments: materials of natural or synthetic origin that, when applied to soil or crops, either increase water availability or improve plant performance under water stress. Because these amendments range from minerals and microorganisms to polymers and plant-derived compounds, they are often studied in separate disciplinary literatures rather than as a single category of inputs. Here, we review drought adaptation amendments for agricultural use and evaluate them along three dimensions: effectiveness in mitigating drought stress, economic feasibility, and environmental and human-health implications. Across amendment classes, effectiveness is achieved through several recurring pathways, including reduced soil evaporation, altered canopy energy balance, improved infiltration and soil water retention, improved rhizosphere and root access to retained water, and enhanced physiological tolerance to water deficit. No single amendment consistently performs best across all three criteria. Materials that strongly modify soil water dynamics can be effective but may be costly or environmentally risky, while lower-risk options often have smaller or more context-dependent effects. Among the most promising lower-risk options identified in this review are microbial inoculants, certain mineral amendments, and water-based plant extracts, though their effectiveness remains context-dependent. Future research should prioritize amendments that combine drought-mitigating effects with economic feasibility and minimal environmental or health risks. Full article

Aquatic environments, whether freshwater, brackish, or marine, are increasingly disrupted, in terms of frequency, extent, geographic distribution, and duration, by the massive, worldwide proliferation of harmful and/or nuisance algae, the so-called Harmful algal blooms (HABs), which are a global phenomenon that poses a major threat to human and animal health and ecosystems [...] Full article

Freshwater scarcity is a major global issue faced by various regions, and the most common portable water sources globally are estuaries, canals, dams, lakes, and rivers. Existing water resources function as the best sinks for the frequent release of effluents from industrial and residential activities. This common practice often results in water pollution, a deterioration in marine biodiversity, and possible health risks for human populations. This study employed standard analytical methods in assessing the physicochemical and microbial characteristics of water samples collected from the Sundays River estuary in Eastern Cape Province (ECP), South Africa (SA). Microbiological assessment revealed that during the spring season, presumptive Escherichia coli (E. coli) colony counts were 1 cfu/100 mL, while total coliforms (TCs) and fecal coliforms (FCs) were recorded at 42.67 cfu/100 mL and 1 cfu/100 mL, respectively. In the summer season, fecal coliform (FC) counts reached 3.5 cfu/100 mL, while Enterococcus levels were higher, ranging up to 77.75 cfu/100 mL. Furthermore, the average standards of physicochemical parameters assessed in water obtained from both spring and summer seasons ranged as follows: pH (8.71–9.31), temperature (20.98–22.21 °C), turbidity (10–35.55 FNU), total alkalinity (22.25–94.00 mg/L), oxidation–reduction potential (ORP) (8.05–151.6 mV), electrical conductivity (EC) (13,915–40,260 uS/cm), salinity (8.07–25.78 psu), dissolved oxygen (DO) (6.79–7.39 mg/L), total dissolved solids (TDSs) (6960.6–20,125 mg/L), and biochemical oxygen demand (BOD) (0.11–2.94 mg/L). The levels of TDS, EC, turbidity, and salinity in the Sundays River estuary water exceeded the World Health Organization (WHO) guidelines of 2017, rendering the water unfit for even recreational purposes. Additionally, the bacterial levels identified in this study were above the values set by the South Africa Department of Water Affairs (SA-DWAF). The identified microorganisms are perceived as essential indicators of fecal contamination and have the potential to multiply in the environment. Possible pollution may be a result of various municipal effluents consistently discharged into the waterbody. Full article

Aquatic ecosystems worldwide are increasingly threatened by invasive species, with water hyacinth [Eichhornia crassipes (Mart.) Solms] being among the most destructive aquatic weeds. Despite numerous regional studies, a global assessment integrating climatic and hydrological drivers remains lacking. Here, we assessed current and future invasion risks across 55,945 freshwater lakes using the maximum entropy (MaxEnt) model. Climatic variables and key aquatic parameters, including biological oxygen demand (BOD), water depth, and discharge, were incorporated under two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5). Annual mean temperature, annual precipitation, and BOD were the strongest predictors of habitat suitability. Under current conditions, 5524 lakes, primarily in tropical and subtropical regions, were identified as being suitable habitats, with medium-sized lakes exhibiting the highest proportional suitability (16.54%). Although small lakes were most frequently classified as suitable due to their abundance, larger lakes showed higher suitability intensity. Future projections indicated marked habitat expansion, especially under SSP5-8.5, with suitable lake surface area increasing to 18.12% by 2061–2080. Moreover, 543 currently unsuitable lakes, including Lake Erie, Lake Huron, and Lake Ontario, were projected to face elevated invasion risk, particularly in Africa, South Asia, Southeast Asia, and North America. This global, lake-specific assessment supports early warning, targeted management, and climate-responsive policy planning. Full article

The Qingshankou Formation shales in the southeastern uplift of the Songliao Basin provide an ideal archive for constraining the controls of paleoenvironment on organic matter enrichment. Taking the shale succession at the Niaohexiang section of Binxian as the study object, we combined field sampling with TOC measurements, whole-rock X-ray diffraction, and major, trace, and rare earth element analyses. The strata are dominated by black shale and dark gray mudstone, with mineral assemblages composed mainly of clay, felsic, and carbonate minerals; argillaceous shale exceeds 60%. Normal alkanes display a post-peak distribution with C₂₇ as the dominant peak, low Pr/Ph ratios, and gammacerane index values of 0.18–0.26. Regular steranes are generally V-shaped, whereas some samples show high C₂₉ sterane contents and a reversed L-shaped pattern. Major elements are dominated by SiO₂ and Al₂O₃, trace elements such as Sr and Ba are relatively enriched, and rare earth elements show light REE enrichment with a pronounced negative Eu anomaly. These signatures indicate an upper-crustal felsic provenance and a continental island arc tectonic setting. Organic matter contents are low and derived mainly from terrestrial higher plants with minor aquatic input. Paleoenvironmental reconstruction suggests deposition in a freshwater to slightly brackish, semi-arid, anoxic-reducing shallow lacustrine setting with relatively low productivity, whereas dolostone formed under more saline, arid, and more productive conditions. Climatic fluctuations, salinity variations, and alternating redox states jointly controlled organic matter enrichment, and late-stage lacustrine salinization and anoxia associated with dolostone horizons enhanced organic matter preservation. Full article

Bottom sediments in anthropogenically impacted freshwater systems represent a dynamic and poorly constrained source of secondary pollution, where heavy metal mobility, rather than total concentration, controls the release of contaminants into the water column under changing physicochemical conditions. This issue is particularly pronounced in small and medium-sized freshwater systems subjected to sustained anthropogenic pressure, where local hydrochemical conditions and sediment composition strongly influence metal speciation and remobilization dynamics. This study aims to quantitatively assess heavy metal speciation, mobility, and associated ecological risk in bottom sediments of anthropogenically impacted freshwater systems using complementary analytical approaches. The data obtained indicate a pronounced spatial heterogeneity in the total metal content, due to varying degrees of anthropogenic impact on the water bodies. The highest level of pollution was recorded in the bottom sediments of the Chizhovskoye reservoir, where Zn concentrations reach 755 mg/kg, Cr—379 mg/kg, Ni—106 mg/kg, and Cu—158 mg/kg, indicating intense technogenic influence. The bottom sediments of the Loshitsa River are characterized by elevated, but less extreme values: the content of Cu is up to 77 mg/kg, Zn—up to 263 mg/kg, and Mn—up to 418 mg/kg. In contrast to urbanized water bodies, the background site—Lake Sergeevskoye—is characterized by significantly lower concentrations of heavy metals, which confirms its representativeness as a control object. Analysis of the fractional composition showed that Zn and Mn have the largest share of mobile forms, with their concentrations in the mobile phase reaching 12–92 mg/kg and 60–116 mg/kg, respectively, especially under conditions of increased anthropogenic load. A significant portion of Cu and Zn (up to 60–70% of the total content) is associated with organic matter, indicating the important role of the organic matrix in retaining metals and their potential mobilization under changing environmental conditions. Calculation of the geoaccumulation index showed that most of the studied bottom sediments belong to the from uncontaminated to moderately contaminated class, while for Cr and Ni in the Chizhovskoye reservoir, I_geo values up to 1.9 are characteristic, corresponding to a moderate level of pollution. The results obtained indicate a significant impact of anthropogenic load on the forms of occurrence and mobility of heavy metals and highlight the role of bottom sediments as an active factor in the secondary pollution of freshwater ecosystems. Full article

The once-extensive coastal forested wetlands (CFWs) of the Mississippi River Delta (MRD) are declining under the combined pressures of pervasive hydrologic change, unregulated harvesting, relative water level rise (due to the combination of geological subsidence and sea-level rise—SLR), and climate change. We synthesize here over 50 years of research conducted in the MRD to examine the history of the CFWs and their management, their ecosystem functions and services, and the nature, extent, and severity of ongoing changes. Seedling recruitment failure and increasing salinity levels are the most immediate threats to forest persistence, necessitating management that restores hydrologic function and sediment and nutrient supply to allow seedling survival and minimizes saltwater intrusion. Collectively, the evidence indicates that managed inflows can bolster accretion and sustain forest function, and long-term resilience requires hydrologic restoration at landscape scales coupled with site-level actions that secure recruitment and address local degradation trajectories. These include freshwater and sediment introduction, protection from herbivory, and, in some cases, planting. Our research findings have important implications for worldwide CFWs, and tidal freshwater ecosystems in general, which occur mainly in tropical deltas. Full article

Observations suggest that headwater streams have lower species diversity within a site than larger streams, but higher beta diversity, and thus gamma diversity, across a catchment. This pattern of diversity includes taxonomic richness and genetic diversity, as well as a high degree of endemism. I review several mechanisms that potentially contribute to the overall high diversity of freshwater organisms in headwaters, although these mechanisms are interdependent. These include the high numbers of headwater streams, heterogeneity of habitats and resources, founder effects, colonization dynamics, isolation, and strong selection, all leading to diversification of forms. However, riverscape diversity patterns vary across taxonomic and functional groups, highlighting that patterns of diversity are driven by different processes for different organisms. More explicitly structured sampling designs will better address patterns of taxonomic richness and for a broader range of taxa. It will be interesting to find ways to partition the relative importance of different mechanisms in contributing to the variation in diversity among headwaters. The great importance of headwater streams to global biodiversity conservation is clear, but will be more evident when better assessments of diversity patterns across these small systems are available. Full article

Sandstone of the Lower Cretaceous Luohe Formation is the main water inrush source in the Binchang Mining Area in the southwestern Ordos Basin. Its sedimentary environment and provenance features are critical for local coal development and safe mining. The Luohe Formation at Xiaozhuang Coal Mine comprises three vertical members: the lower member dominated by coarse- to medium-grained sandstones, the middle member mainly composed of fine-grained sandstones, and the upper member characterized by interbedded fine- to medium-grained sandstones and sandy conglomerates. This subdivision newly identifies a complete hydrodynamic evolutionary cycle of depositional environments from high-energy to low-energy and back to high-energy conditions. Integrated petrographic observations and analyses of major and rare earth elements first confirm that the tectonic affinity of the Luohe Formation progressively shifted from a passive continental margin to an active continental margin, accompanied by a corresponding transition in sediment provenance from the North China Craton to a magmatic arc source region. Trace element compositions precisely indicate that the Luohe Formation was deposited in a fluvial freshwater environment under hot, arid, and oxidizing conditions, thus providing new constraints on the paleoenvironmental evolution of the region. Full article

Currently, there are no data and studies from Lake Vaya, Burgas city, on the status and quantity of microplastic (MP) particles in fish. This is the first study on the abundance, morphotype, size, polymer type, and color of MP in Gambusia affinis and Liza saliens from the lake. In this study, we also investigated the distribution of MPs in different parts of the fish. Within each morphological group of MPs, three size classes were recognized: 25–100 µm, 100–200 µm, and 200–500 µm. Microplastics were found in all studied fish tissues except for caviar, but in different proportions of pellets, fibers, and fragments. In our study, fibers were the most isolated, followed by irregularly shaped MPs—fragments. Two types of polymers were found—PET and PA. There are currently no studies in Lake Vaya that assess the risk of ingestion of microplastics for fish health and human health. Research shows that almost all aquatic environments worldwide are at risk of MP contamination. Laboratory and field studies highlighted that fish are particularly susceptible to MP ingestion, although freshwater species have been studied less than marine ones. The results of our study suggest that consumption of fish from Lake Vaya may expose citizens to risk. Full article

Lake Erhai is an important plateau freshwater lake in China. It serves not only as a crucial drinking water source for the local region but also as the core area of the Cangshan Erhai National Nature Reserve. Consequently, Lake Erhai plays an extremely significant role in the local economy, society, and ecology. Since 2000, the water quality of Lake Erhai has continuously deteriorated, showing a eutrophic trend. To identify the primary driving forces behind these water quality changes, this study employed stepwise regression analysis. Climate conditions, socio-economic development within the basin, and implementation of environmental protection measures (IEPMs) were considered influencing factors for a comprehensive and systematic analysis of Lake Erhai’s water quality. The results indicate that rising air temperature may increase total phosphorus (TP) concentration, while rainfall may elevate both TP and total nitrogen (TN) levels. In contrast, higher wind speed may reduce chemical oxygen demand (COD_Mn), TP, and TN concentrations. Socio-economic development, meanwhile, may contribute to increased COD_Mn concentration. Based on these findings, this paper proposes recommendations focusing on formulating more effective non-point source pollution control measures and strengthening water quality monitoring in Lake Erhai during summer. By identifying the key natural and anthropogenic drivers of water quality changes in Lake Erhai, this study provides a scientific basis for the development of targeted pollution control strategies and directly contributes to the protection of clean water sources. Moreover, its revelation of the coupled impacts of climate change and socio-economic activities enhances understanding of plateau lake ecosystem resilience. This insight is critical for ensuring regional ecological security and serves as a model for advancing sustainable development goals in similar lake systems worldwide. Full article

Microplastic (MP) contamination has become a widespread environmental concern in coastal and freshwater wetlands, ecosystems that play a crucial role in hydrological regulation, nutrient cycling, and biodiversity conservation. Despite their ecological importance, research on MPs in wetlands remains fragmented and comparatively underexplored. This study presents a comprehensive bibliometric and visualization analysis of global research on MPs in coastal wetlands. A total of 17,523 publications were retrieved from the Web of Science Core Collection (2002–2025) using predefined search strings and screening criteria. Analytical tools, including VOSviewer version 1.6.20, were employed to examine co-authorship networks, country contributions, and keyword co-occurrence patterns. The results indicate a significant increase in MP-related publications after 2016, with China, the United States, and India emerging as leading contributors. However, wetland-specific studies constitute only a small fraction compared to marine-focused MP research, highlighting a substantial research gap. Key research themes identified include MP sources, transport pathways, sediment–water interactions, and ecotoxicological impacts. Additionally, there is growing attention to remediation approaches, particularly those involving TiO₂, ZnO, Fe₃O₄, and graphene derivatives, employing photocatalytic, magnetic, and adsorptive mechanisms. Overall, the findings underscore the limited focus on wetland ecosystems in MP research and emphasize the urgent need for integrated research efforts and management strategies to address MP contamination in these vulnerable ecosystems. Full article

Monosex all-male culture of the giant freshwater prawn (Macrobrachium rosenbergii) maximizes aquaculture yield due to a male growth advantage, but direct hormonal treatment of grow-out populations poses significant food safety risks. This study evaluated the efficacy of dietary 17β-estradiol (E2) in inducing functional neo-females from a fully all-male postlarval population to support an indirect monosex seed production strategy. All-male postlarvae were fed diets supplemented with E2 at concentrations of 0, 50, 100, 150, and 200 mg/kg for 36 days, followed by a 150-day hormone-free post-treatment period to assess growth performance, feminization rates, and gonadal histology. E2 administration successfully induced feminization across all treatments, reaching a peak rate of 35.5% at 150 mg/kg, whereas the control group remained entirely male. During the 36-day treatment period, E2 supplementation transiently enhanced specific growth and survival rates but concurrently reduced feed conversion ratios. Notably, these physiological differences disappeared completely over the 150-day post-treatment phase. Histological assessments confirmed that E2-induced neo-females exhibited normal oogenesis, with gonadosomatic index (GSI) values and oocyte diameters similar to those of wild-caught females. This establishes a definitive, physiologically safe, and non-surgical protocol for producing the neo-female broodstock necessary to sustain high-yield commercial monosex populations. Full article

This study presents the first cradle-to-gate life cycle assessment (LCA) of T-shirt production using viscose and Lyocell fibers, benchmarked against cotton and polyester under consistent system boundaries. The analysis covers spinning, knitting, wet processing, garment assembly, and regionalized energy supply. Results show that cotton T-shirts exhibit the lowest global warming potential (14.1 kg CO₂eq/kg) but the highest water demand (2.9 m³/kg) in China. Polyester garments, although less water-intensive, contribute significantly to plastic accumulation (1.0 kg/kg shirt) compared to cellulose-based fibers (0.1 kg/kg shirt). Within man-made cellulose fibers, Lyocell generally outperforms viscose in toxicity-related categories—reducing freshwater ecotoxicity by 35% and human non-carcinogenic toxicity by 62%—thanks to its closed-loop solvent recovery. However, Lyocell also shows the highest carbon footprint (21.6 kg CO₂eq/kg) unless produced in regions with cleaner energy mixes. Regional sensitivity analysis indicates that shifting production from China to Brazil could reduce global warming impacts by up to 38%. Overall, these results highlight the trade-offs across fiber types and demonstrate the importance of both material choice and production geography in driving sustainability within textile supply chains. Full article