Search Results (849)

Phosphorus (P) accumulation in intensively agricultural soils represents a growing environmental concern due to its potential mobilization and contribution to eutrophication. This study investigated the mechanisms controlling P availability and redistribution in agricultural soils from the Elota–Piaxtla Irrigation District (northwestern Mexico) during cropping and non-cropping periods. Soil P fractions were determined using the Hedley sequential extraction method and related to soil physicochemical properties through a correlation analysis. During the cropping period, P in Fe/Al hydroxides dominated (45–67% of total P), indicating strong adsorption and fixation in fine-textured soils. In contrast, the non-cropping period showed a significant increase in organic P in humic substances (up to 55%), suggesting enhanced biological transformation and residue recycling. Labile P fractions decreased from 60% to 44% of total P between sampling periods, while moderately labile fractions increased, indicating seasonal redistribution of P pools. Statistical analysis revealed that P dynamics were primarily governed by mineralogical characteristics and organic matter transformations rather than by individual soil properties. The accumulation of moderately labile and organic P fractions during fallow periods highlights a latent environmental risk, particularly in irrigated systems prone to runoff and erosion. These findings emphasize the need for fraction-based nutrient management strategies that integrate both agronomic efficiency and environmental protection in intensive agricultural soil. Full article

Background/Objectives: Obesity is a major public health problem associated with chronic inflammation and functional alterations in multiple organs and systems. Few studies have examined colostrum from obese mothers, particularly with respect to macrophage function, enzyme and cytokine concentrations, and the role of melatonin in immune modulation. This study aimed to evaluate melatonin levels and their effects on macrophage polarization, cytokine concentrations, nitric oxide synthase [iNOS], and arginase in colostrum from obese mothers. Colostrum samples were collected from eutrophic mothers [BMI: 18.5–24.9 kg/m²] and obese mothers [BMI: ≥30 kg/m²]. Methods: Macrophages were isolated by density gradient and treated with melatonin. The expression of M1 and M2 macrophages and cytokine concentrations were assessed by flow cytometry, while melatonin levels in colostrum supernatants, iNOS, and arginase in cell lysates were determined by ELISA. Results: An endogenous increase in melatonin was also observed in the colostrum of obese mothers. Maternal obesity has been shown to reduce M1 and M2 macrophage expression, increase nitric oxide synthase [NOS] activity, and elevate interleukin-6 [IL-6] and interleukin-17 [IL-17] levels. However, melatonin treatment restored M1 and M2 macrophage levels and reduced inducible nitric oxide synthase [iNOS] and arginase production to levels similar to those observed in mothers of healthy weight. Conclusions: these findings suggest that maternal obesity creates a pro-inflammatory environment in colostrum, characterized by altered macrophage polarization, altered cytokine secretion, and an imbalance in the enzymatic activities of iNOS and arginase within the L-arginine metabolic pathway. Both natural and supplemental melatonin exhibited immunomodulatory, antioxidant, and anti-inflammatory effects, helping to restore immune balance in colostrum. These results emphasize the potential benefits of melatonin as an immunometabolic modulator and its contribution to understanding immunometabolic regulation in obese mothers. Full article

Seasonal thermal stratification in deep reservoirs easily causes bottom hypoxia and a sharp decrease in oxidation–reduction potential (ORP), leading to the pulsed release of internal phosphorus from sediments. Under climate warming, this has become a hot issue for sustainable reservoir eutrophication control. Taking the Quanmin Reservoir in Southwest China as the research object, this study combined high-resolution profile monitoring and a Box–Behnken response surface experiment to construct a semi-empirical model coupling redox threshold effect and Arrhenius kinetics. Results showed that during thermal stratification, the water body below 18 m formed a significant redox gradient, resulting in a 21-fold vertical difference in phosphorus concentration. The response surface experiment confirmed that ORP dominates phosphorus release, and the temperature (T) effect is strictly redox-dependent: warming only promotes phosphorus release under anaerobic conditions (−50 mV), with a 26% increase in release amount when temperature rises from 10 °C to 30 °C, while temperature has a negligible effect under aerobic conditions (+30 mV). Model fitting yielded an ORP critical threshold of −17.2 ± 4.8 mV and a normalized steepness of 0.033 mV⁻¹, indicating joint control by diffusion and reaction. Based on these results, a synergistic regulatory mechanism of redox threshold and temperature was proposed, providing a quantitative basis for reservoir eutrophication management under climate warming. Maintaining ORP above −17 mV through bottom aeration can effectively block internal phosphorus release from the redox threshold perspective, though practical in situ application is constrained by aeration-induced water mixing and microbial variations, and such precise redox control may save energy, supporting the sustainability of reservoir ecosystems and long-term water quality security. Full article

Cyanobacteria inhabit ecosystems ranging from oligotrophic deserts to eutrophic lakes, yet it remains unclear whether distantly related species dominate in disparate habitats, share common genomic features, or show divergent specialization. Here, we established a comparative framework of Microcoleus vaginatus, the pioneer stabilizer of biocrusts, and Microcystis aeruginosa, a major cause of freshwater blooms worldwide. Our dataset comprises 504 high-quality cyanobacterial genomes, including 132 M. vaginatus, 148 M. aeruginosa, and 224 reference taxa, for analyses of genome architecture, functional repertoires, and genomic plasticity. Both focal lineages showed signatures of extensive horizontal gene transfer and shared a small set of conserved orthologous groups, annotated as FAD-dependent oxidoreductases, manganese efflux, and class II aldolases. Nevertheless, the two lineages followed distinct genomic strategies. M. vaginatus expands regulatory breadth and stress-resilience gene families, whereas M. aeruginosa shows evidence of genome streamlining and rapid nutrient exploitation. Notably, we hypothesize that aquatic M. vaginatus strains retain ancestral terrestrial genomic features while gradually acquiring potential aquatic-specific adaptations. Together, these results reveal a two-tier architecture associated with cyanobacterial dominance and provide a testable hypothesis for how cyanobacterial lineages may respond to global change pressures. Full article

Tofu wastewater (TWW), characterized as a high-strength organic effluent with elevated chemical oxygen demand (COD) and low pH, presents significant environmental challenges, including eutrophication, soil degradation, and greenhouse gas emissions. Conventional disposal methods have proven inadequate in mitigating these risks; however, thermophilic anaerobic digestion (TAD) has emerged as a viable technology for bioenergy recovery. Nonetheless, TAD is impeded by rapid acidification, ammonia and hydrogen sulfide inhibition, and the accumulation of volatile fatty acids (VFAs). This review introduces nano-calcium-peroxide-modified biochar (nano-CaO₂/BC) as a multifunctional additive designed to establish an integrated framework for intervention, risk mitigation, and resource recovery. The proposed amendment synergistically combines the adsorptive and microbial-supportive properties of biochar with the controlled oxidative and alkaline characteristics of nano-CaO₂. Under thermophilic conditions, the slow hydrolysis of nano-CaO₂ generates transient microaerobic zones that enhance polymer hydrolysis, suppress ammonia (NH₃) and hydrogen sulfide (H₂S) formation, and facilitate the oxidation of inhibitory VFAs, concurrently releasing calcium hydroxide (Ca(OH)₂) for sustained pH buffering. Utilizing failure mode and effects analysis (FMEA) as a semi-quantitative assessment tool, the results indicate that the composite significantly reduces risk priority numbers associated with acidification, ammonia toxicity, and sulfide inhibition when compared with conventional TAD methods. The resultant digestates, which are enriched in nutrients and recalcitrant carbon, possess the potential to serve as valuable soil amendments, thereby contributing to a circular bioeconomy. A techno-economic assessment grounded in unit cost analysis suggests that positive net benefits may be realized through enhanced biogas recovery and the mitigation of environmental penalties. However, empirical validation at the pilot scale is essential to substantiate the projected performance. This review underscores critical knowledge gaps and proposes a systematic experimental framework aimed at translating the conceptual risk mitigation strategy into practical applications. Full article

Conventional hydroponic systems, although resource-efficient, face significant sustainability challenges due to the discharge of nutrient-rich effluents, resulting in severe environmental pressures. In alignment with the European Union’s “Farm to Fork” strategy, innovative circular economy approaches are required to decouple crop production from environmental degradation. This study evaluates a novel Cascade Hydroponic System (CHS), designed to maximize resource utility by recovering and reusing the drainage from a primary salt-sensitive crop (cucumber) to a secondary, more salt-tolerant cultivation (melon). A comparative Life Cycle Assessment (LCA) is performed in accordance with the Product Environmental Footprint Category Rules (PEFCRs), utilizing primary operational data and direct monitoring of nutrient concentrations in the system’s effluent. The convergence of these elements establishes the novelty of this study. The CHS is benchmarked against a conventional Separated Hydroponic System (SHS) for a functional unit (FU) defined as “the simultaneous production of 1.0 kg of cucumber and 1.0 kg of melon”. The CHS demonstrated lower characterized impacts compared to SHS across all 16 assessed Environmental Footprint categories under the examined pilot-scale conditions. The key findings include reductions of 65.7%, 41.8%, and 30% in Water Use, Climate Change, and Freshwater Eutrophication scores, respectively. Based on the normalization results, the CHS revealed a 58% lower total environmental footprint score compared to SHS. Process contribution analysis indicates that the marked decrease in the environmental burden is associated with the use of fertilizers. While these inputs represent a significant share of the conventional system’s impact scores, their contribution was substantially lower in the CHS. Although based on pilot-scale operational data from a single crop cycle, the results highlight the considerable environmental potential of cascading nutrient reuse configurations, thus enhancing resource use efficiency and mitigating the associated environmental impacts while also contributing novel empirical knowledge to a field that has been limitedly studied. Full article

This study explores the application of a bioflocculant derived from poultry eggshell waste for the removal of Chlorella spp. and related contaminants from agricultural wastewater using a statistically guided experimental design. In accordance with circular bioeconomy principles, eggshell residues were repurposed as a low-cost and sustainable biomaterial for water treatment. Chlorella spp. was selected as the target microalga due to its rapid proliferation, tolerance to eutrophic environments, and frequent presence in agricultural effluents. A two-level factorial design with center points was applied to evaluate the individual and interactive effects of key operational parameters, including pH, temperature, initial biomass concentration, and bioflocculant dosage. The highest biomass removal efficiency (94%) was achieved at pH 10, a temperature of 18.5 °C, a bioflocculant dose of 100 mg L⁻¹, and an initial biomass concentration of approximately 3.76 × 10⁷ cells mL⁻¹, with a contact time of 360 min. Under these optimized conditions, notable reductions were also observed in chemical oxygen demand (78%), nitrates (87%), phosphates (21%), and coliform bacteria (99.6%). The developed regression model exhibited strong predictive capability (R² = 0.97), indicating high reproducibility within the investigated experimental conditions. Overall, the findings suggest that eggshell-derived bioflocculants may represent a promising alternative to conventional chemical flocculants for agricultural wastewater treatment. High removal efficiency was achieved at relatively low dosages under operational conditions, supporting the potential of this approach for improving microalgae harvesting and the wastewater treatment processes. Full article

Coal has been Malaysia’s primary energy source for electricity generation for the past few decades, resulting in increased greenhouse gas emissions and irreversible environmental damage. Solid Oxide Fuel Cells (SOFCs) have emerged as a viable clean-energy alternative to mitigate these environmental effects. There has been significant emphasis on developing pollution-free technology, with limited attention given to the environmental impact of SOFC. Research and development efforts have primarily focused on the design and technical aspects of SOFC. Prior to the introduction of SOFC to market, quantifying the environmental footprint of SOFC manufacturing is necessary to support a sustainable energy transition. This study conducts a comprehensive Life Cycle Assessment (LCA) of SOFC manufacturing in accordance with ISO 14040 and 14044 standards. The analysis focuses on a planar electrolyte-supported SOFC with a lifespan of 4.57 years, using a functional unit of 1 kWh electrical output. The Environmental Footprint (EF) 3.1 method implemented in GaBi Software was used for the impact assessment. Key environmental impact categories considered in the LCA include Climate Change (CC), Acidification Potential (AP), Eutrophication Potential (EP), Ozone Depletion Potential (ODP), Photochemical Ozone Formation (POF), and Human Toxicity Potential (HTP). The total climate change impact is approximately 19.674 kg CO₂ eq./kWh, with the Balance of Plant (BoP) phase contributing 91% of this impact, while the fuel cell stack phase contributes 1.25%. The study identifies key areas for improvement, primarily related to BoP and other high-impact processes, and emphasizes the importance of targeted measures to effectively reduce the environmental impacts associated with SOFC manufacturing. Full article

Cheese production generates large volumes of whey, and high-strength wastewater with elevated organic load, salinity, and nutrient content. Although whey contains valuable components including lactose, proteins, and minerals, approximately half of global production remains underutilized, contributing to eutrophication and oxygen depletion in aquatic ecosystems. Conventional physicochemical and biological treatment methods are limited by high operational costs, energy demands, and secondary waste generation. Microalgae-based bioremediation has emerged as a promising sustainable strategy for whey valorization, enabling simultaneous nutrient removal and biomass production. Through a focused review of the current literature, this study analyzes microalgal strains commonly applied in whey remediation, their cultivation modes (photoautotrophic, heterotrophic, and mixotrophic), nutrient uptake mechanisms, and operational conditions. The review highlights cultivation systems, biomass recovery techniques, and potential conversion of microalgal biomass into high value bioproducts, including biofuels, pigments, proteins, and biofertilizers. Critically, a major research gap exists: no studies systematically examine whey-grown microalgal biomass for bioplastic or film production, despite its elevated polysaccharide and protein content. Future development requires integrated biorefinery approaches, optimized cultivation strategies, and supportive policy frameworks to enable large-scale circular economy implementation within the dairy industry. Full article

Cyanobacterial harmful algal blooms are an increasing concern for wildlife health, particularly in eutrophic wetlands, yet well-documented avian cases supported by environmental, pathological, and toxicological evidence remain scarce. This study describes a sentinel case of probable microcystin toxicosis in a Red-gartered coot (Fulica armillata) from Laguna Petrel, a protected coastal wetland in central Chile, during a broader wildlife mortality event. Surface-water monitoring included nutrient analyses, in situ physicochemical measurements, phytoplankton assessment, and cyanotoxin quantification. The evaluated bird was documented alive with severe motor impairment, euthanized, and examined by gross necropsy, histopathology, and tissue toxicology. Water analyses showed elevated nutrients, persistently alkaline and highly productive conditions, marked dominance of Microcystis aeruginosa, and high concentrations of microcystin-LR, microcystin-RR, microcystin-YR, and nodularin. The bird showed marked hepatic lesions at necropsy, histopathological changes compatible with acute hepatotoxic injury, and detectable microcystin-LR in lyophilized liver tissue. Taken together, these findings support a diagnosis of probable microcystin toxicosis in this individual. This case highlights the value of waterfowl as sentinels of ecosystem health threats and underscores the importance of integrated monitoring in protected coastal wetlands potentially affected by toxic cyanobacterial blooms. Full article

Climate change represents one of the most critical challenges, especially in the Mediterranean area. Using organic and localized fertilization could be an effective agroecological strategy to help mitigate the environmental impacts of climate change. Our study was carried out in an experimental field over a three-year crop succession including broccoli, sweet pepper and barley. A randomized complete block design was adopted, with two factors: (i) fertilization method (100% broadcast and 40% localized) and (ii) fertilizer type by testing: on-farm compost, two types of commercial compost and a mineral fertilizer. Environmental impacts per hectare and marketable yield were quantified using Life Cycle Assessment (LCA), considering abiotic depletion (AD), acidification (AA), eutrophication (EU), global warming potential (GWP), and photochemical oxidation (PO). The localized application of fertilizers achieved marketable yields comparable to the broadcast method, despite lower fertilizer inputs, suggesting an optimal nutrient-use efficiency. The LCA demonstrated that localized fertilization also enhanced environmental sustainability, decreasing Global Warming Potential (GWP) by 20% per hectare, compared to broadcast treatments. Moreover, considering only the fertilization phase, we observed a 59% reduction in GWP under the localized strategy. Even though localized fertilization emerges as an effective climate-smart strategy without compromising productivity, future research is recommended to assess its long-term impacts in site-specific conditions. Full article

Against the backdrop of intensifying global climate change and water eutrophication, the increasing occurrence of Harmful Algal Blooms (HABs) poses a significant threat to aquatic ecosystems, human health, and socio-economic activities. The occurrence and development of HABs are complex processes governed by the interaction of physical, chemical, and biological factors. Therefore, timely and accurate monitoring is essential for early warning and scientific research. This paper comprehensively reviews recent advances in HAB monitoring technologies, with a focus on two core components: sensors and monitoring platforms. First, organized around key environmental parameters, it summarizes the principles, applications, and limitations of in situ sensors, such as multi-parameter water quality sondes, Imaging Flow Cyto-bots (IFCB), and Environmental Sample Processors (ESP), as well as laboratory-based analytical techniques such as HPLC-MS for measuring physical, chemical, and biological indicators. Second, it compares the technical characteristics of three major monitoring platforms (including field surveys, remote sensing, and autonomous systems) and discusses their potential for synergistic application. Finally, this review proposes a future framework for an integrated “Space–Air–Ground–Sea” intelligent monitoring network and explores possible pathways to address current challenges through cross-platform data fusion, sensor miniaturization, intelligentization, and artificial intelligence-driven decision support. This review aims to provide a comprehensive reference for the optimization and innovation of HAB monitoring technologies and to promote the development of the field toward greater integration, intelligence, and real-time monitoring capability. Full article

To alleviate the eutrophication in the Wuliangsuhai watershed and evaluate the pollutant reduction performance of ecological drainage ditches in the Hetao Irrigation District, a controlled field simulation experiment was conducted using synthetic agricultural return-flow water formulated from long-term monitoring data. Three leguminous plant treatments, two microbial substrate treatments, and one control were established to compare the migration and transformation of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) in overlying water, sediment, and plants under different hydraulic retention time intervals (0–6 h, 6–12 h, and 12–18 h). The results showed that plant treatments generally improved conventional water quality indicators, with increased pH and dissolved oxygen (DO) and decreased electrical conductivity, salinity, and total dissolved solids, whereas microbial substrate treatments tended to reduce DO. Pollutant reduction performance differed among treatments. Medicago sativa showed the strongest TN removal from overlying water, Microbial biological rope exhibited the best TP removal from overlying water, and Melilotus suaveolens performed best in COD reduction. Among all plant treatments, Astragalus laxmannii exhibited the most stable overall performance and a relatively strong integrated capacity for nitrogen and phosphorus retention. Most TN and TP reduction in overlying water and sediment occurred during the initial hydraulic retention time interval of 0–6 h, whereas TN plant uptake became more evident during 12–18 h. These findings suggest that ecological drainage ditches vegetated with locally adapted leguminous species have potential to mitigate agricultural non-point source pollution in arid irrigation districts. In particular, Astragalus laxmannii appears to be a promising candidate for ecological ditch design in the Hetao Irrigation District. However, this study was conducted under controlled synthetic return-flow conditions rather than with actual field drainage water, and no tracer-based hydrodynamic verification was performed; therefore, the reported hydraulic retention time effects and treatment efficiencies should be interpreted cautiously. Further field-scale validations under real drainage, seasonal variation, and long-term operation conditions are still needed. Full article

Although sedimentary zones in Lake Taihu differ in external inputs, hydrodynamic conditions, and sedimentary settings, the spatial differentiation of eukaryotic microbial communities and their assembly mechanisms remain insufficiently understood. This study analyzed sediment cores from four typical sedimentary zones of Lake Taihu: Dapu (DP), Gonghu (GH), the central lake area (HX), and Xuhu (XH). By integrating physicochemical measurements, 18S rRNA gene high-throughput sequencing, redundancy analysis, functional annotation, iCAMP, and co-occurrence network analysis, we characterized the composition, environmental associations, and assembly mechanisms of sedimentary eukaryotic microbial communities. The results showed that eukaryotic microbial communities in Lake Taihu sediments exhibited marked spatial heterogeneity, with dominant taxonomic groups including Chlorophyta, Intramacronucleata, and Diatomea. Alpha diversity was higher in the GH zone and lower in the HX zone, whereas beta diversity showed significant separation among lake zones. NH₄⁺-N, NO₃⁻-N, TN, TP, TOC, D50, MWC, and pH were associated with variation in community composition, but the main associated factors differed among zones. FunGuild annotation showed that annotated fungal functional groups exhibited distinct trophic distribution patterns across sedimentary zones. iCAMP analysis indicated that community assembly was generally dominated by stochastic processes, with dispersal limitation prevailing in the GH zone and ecological drift dominating in the DP, HX, and XH zones. Co-occurrence network analysis further revealed marked differentiation in potential biological associations among sedimentary zones. Overall, this study showed that nutrient conditions and sediment physical properties in different sedimentary environments of Lake Taihu jointly shaped the spatial patterns of eukaryotic microbial communities and their ecological associations, providing baseline information for understanding sedimentary ecological processes in eutrophic shallow lakes. Full article

Environmental impacts vary largely among different dairy production systems, and there is a lack of consensus on the sustainability of organic systems compared to conventional dairy systems internationally. This study aims to compare the two dairy systems to determine whether there is a difference in environmental sustainability and to synthesize life cycle assessment (LCA) findings in the context of Europe’s sustainability targets. A search was conducted using various databases and search terms, based on established criteria, to identify LCA studies comparing organic and conventional dairy farming in Europe. Information on LCA impact categories (global warming potential, GWP; acidification potential, AP; eutrophication potential, EP; land use, LU and energy use, EU) in addition to non-LCA parameters was retrieved. Methodological differences in LCA studies prevent direct comparisons; therefore, response ratios (Rr) were used to compare the different indicators, with a one-sample t-test assessing significance. Data from 18 papers from 10 European countries were analyzed. Farm characteristics showed that organic systems had significantly (p < 0.05) lower milk yield, stocking rate, concentrate input, diesel, and pesticide use compared to conventional systems. The results showed a non-significant lower mean Rrs for the GWP, AP, and EP impacts of the organic systems relative to the conventional system per unit product. Organic systems showed lower energy requirements (Rr = −0.29, p < 0.05), with a higher land use percentage (41%, p < 0.05) per unit product. When impacts were related to one hectare of occupied area, all impact categories (GWP, AP, EP, and EU) were significantly lower (p < 0.05) in organic systems. It remains challenging to draw conclusions about the best sustainable dairy management systems when both productivity and environmental impacts are considered. Land-based functional units focus on extensive, low-impact land-farming systems while largely overlooking productivity, thereby often indicating more favourable environmental performance than product-based metrics. Overall, this study highlights substantial differences in farm management practices between organic and conventional systems and demonstrates that variability in LCA methodological choices is a key driver shaping the magnitude and robustness of comparative environmental results. Full article