Search Results (3,044)

Rapid urbanisation and climate-induced extreme weather events have intensified urban stormwater runoff challenges. Biofiltration systems have emerged as effective, sustainable urban drainage solutions for mitigating these impacts. A total of 78 peer-reviewed studies were assessed to synthesise findings on how design parameters influence pollutant removal performance in biofiltration systems treating urban stormwater runoff. Peer-reviewed articles published from 1 January 1995 to 3 June 2025 were retrieved from Scopus and Web of Science (WoS). Non-peer-reviewed, non-empirical, incomplete, or non-relevant studies were excluded. Rigorous application of a standardised review protocol and predefined criteria was employed to mitigate bias. The findings reveal high removal efficiencies for certain trace metals, ammonium, Escherichia coli (E. coli), hydrocarbons, and microplastics, with inconsistent removal for total nitrogen, nitrates, and phosphorus. The primary pollutant removal mechanisms were adsorption, ion exchange with select media, and denitrification in saturated zones. Only 22% of the reviewed studies incorporated a saturated zone, while 18% included a protective surface layer, despite both design elements being associated with improved pollutant removal performance. Variations in media composition and stormwater quality limit comparability across studies. This review highlights the need for context-specific design guidance and further exploration of multi-functional media to enhance multi-pollutant removal. Full article

Optimizing nitrogen form under drip fertigation may improve wheat productivity by regulating the root-zone inorganic N environment during early vegetative growth. A two-year field experiment evaluated nitrate-dominant (N1), balanced ammonium–nitrate (N2), and ammonium-enriched nitrogen strategies (N3) during GS13–GS31, with conventional farmer practice (CK) and a zero-N control (N0) for comparison. Nitrogen-form regulation markedly altered the soil NH₄⁺-N ratios, especially in the 0–20 cm soil layer, with N3 highest, N1 lowest, and N2 intermediate. Compared with the nitrate- or ammonium-dominant strategy, the balanced treatment N2 improved spike formation rate and maintained relatively higher N accumulation at GS31 and GS65, and showed greater N translocation and contribution of translocated N to grain N than N1. Correlation analyses indicated that spike formation rate was closely related to spike number (R² = 0.764) and N accumulation at GS31 was positively related to Ntrans (R² = 0.588). N2 showed the most favorable overall performance, with the highest numerical values for grain yield, nitrogen recovery efficiency, irrigation water use efficiency, and net profit among the fertigation treatments. However, the advantages of N2 over N3 in grain yield and SPAD-AUC were modest and not consistently significant. These results indicate that balancing ammonium and nitrate supply during GS13–GS31 under drip fertigation can improve root-zone N conditions and support better overall agronomic performance in winter wheat under the alkaline soil conditions of the North China Plain. Full article

To identify the sources and driving mechanisms of nitrate contamination in pore water around Nansi Lake, 54 pore water samples were analyzed via hydrogeochemical analysis, Gibbs diagrams, ionic ratios, and principal component analysis (PCA). The pore water is predominantly slightly alkaline, with dominant cations Ca²⁺ and Na⁺, and anions HCO₃⁻ and SO₄²⁻. Nitrate-nitrogen (NO₃⁻-N) concentrations range from 0.82 to 54.31 mg·L⁻¹, with a coefficient of variation of 1.41 and an exceedance rate of 18.52%, indicating significant external inputs. A positive correlation between NO₂⁻ and NO₃⁻ suggests denitrification in some areas. Nitrate concentrations exhibit distinct spatial heterogeneity: high concentrations occur in agricultural/aquaculture lakeside plains and urban areas, low concentrations near coal mining subsidence zones, and transitional zones showing outward diffusion. Nitrate sources are predominantly anthropogenic. High Cl⁻ and low NO₃⁻/Cl⁻ ratios indicate domestic and aquaculture wastewater infiltration, whereas low Cl⁻ and high NO₃⁻/Cl⁻ ratios indicate agricultural fertilizer input. Industrial and natural sources are minor. PCA identified three controlling factors (cumulative variance 69.81%): coal mining and industrial/domestic pollution (39.82%), carbonate rock weathering (19.44%), and agricultural activities (10.55%). Health risk assessment shows no significant risk for adults (hazard quotient (HQ) < 1), but children face localized risks at nine sites (HQs of 1.25–2.26) in intensive farming, urban, and transitional zones. Excessive fertilizer application and sewage leakage are the primary causes, posing methemoglobinemia risks to infants. This study provides a scientific basis for nitrate pollution control and sustainable water management in the Nansi Lake Basin and offers methodological insights for similar lacustrine plain regions. Full article

Asparagus (Asparagus officinalis L.) represents a high-value horticultural crop in Thailand with significant export potential; however, optimizing productivity in tropical environments requires a precise understanding of how cultivation practices and harvest seasons influence marketability. Here, a split-plot experiment arranged in a completely randomized design with three replications was conducted to examine how different crop methods and harvest seasons affect asparagus yield and quality in Lopburi Province, Thailand. The main plots were categorized by harvest season—summer, rainy, and winter—while the subplots included three crop methods: conventional, GAP, and organic. Summer produced the highest yield and asparagus with the greatest levels of total chlorophyll, phenolics, and DPPH radical scavenging activity compared to other seasons. Although the conventional methods yielded the most spears per plant, these spears contained higher levels of contaminants, including cadmium, lead, and nitrate. In contrast, spears from GAP and organic methods had higher phosphorus levels. However, no pesticide residues were found in any spear samples. Economically, the organic method had the shortest payback period, owing to lower production costs; despite a lower annual yield, stable market prices kept it profitable. In addition, organic soils had the highest levels of organic matter, nitrogen, and phosphorus. Overall, while conventional methods enhance the yield and certain qualities, organic farming, particularly when harvested in summer, yields the highest economic returns and the most sustainable system among those tested. Full article

Pea (Pisum sativum L.) is a multifunctional legume of growing importance in sustainable cropping systems. This study presents an integrative assessment of a forage pea variety across multiple agronomic functions under temperate continental conditions. Results from three environmentally comparable field trials were synthesized to evaluate (i) grain yield and protein traits, (ii) biomass production and nutrient accumulation in cover cropping systems, and (iii) effects on soil nitrate dynamics and maize (Zea mays L.) yield. Compared with vegetable- and dry-seed-type genotypes, the forage-type cultivar exhibited greater plant height and lodging tendency, moderate grain yield, and elevated protein content (28.8%), characterized by a legumin-dominated protein profile. As a winter cover crop grown in mixture with oat (Avena sativa L.), pea produced lower total biomass than rye (Secale cereale L.) but showed substantially higher nitrogen concentrations (2.93–3.01%), indicating enhanced nitrogen input potential. In crop rotation, pea-based treatments significantly affected soil nitrate distribution and maize productivity. Complementary resource use in pea-based systems enhanced biomass production, supporting forage and green manure functions while contributing to soil fertility and system stability. Its morphological and physiological adaptability enables integration into diverse production models, from intensive to regenerative systems. Overall, pea should be regarded not merely as a single crop, but as a strategic component of diversified farming systems aimed at increasing protein yield, optimizing inputs, improving soil quality, and strengthening the long-term sustainability of agroecosystems. Full article

Phenolic compounds contribute to the color, flavor, and functionality of foods but are often degraded during conventional heat treatments, prompting interest in non-thermal techniques. Thermal methods produce heat-driven changes that are more directly interpretable, whereas non-thermal methods require compound-resolved interpretation because higher post-treatment signals may reflect release from bound pools rather than true preservation. This review evaluates liquid chromatography–mass spectrometry (LC–MS) evidence on how ultrasound, high-pressure processing, pulsed electric fields, and cold plasma reshape polyphenol fingerprints across food matrices (2021–early 2026). Ultrasound and high-pressure processing preserve constitutive structures while increasing measurable phenolics through cell disruption and bound-pool release. Pulsed electric fields show similar release behavior but may shift toward oxidative losses when electroporation increases enzyme contact or downstream operations amplify degradation. Cold plasma introduces reactive oxygen and nitrogen species, with the clearest LC–MS/MS evidence for oxidation and nitration. In fresh-cut tissues, stress responses elevate phenylpropanoid products. Bulk assays such as total phenolic content (TPC) cannot separate preservation from release or true chemical conversion alone. LC–MS offers the compound-level detail needed to understand how each non-thermal technique changes polyphenol structure and functionality across food matrices. Full article

This study focused on alfalfa (Medicago sativa cv. Xinmu No. 4) as the experimental material, and a two-year field plot controlled experiment was conducted to compare the effects of different co-application ratios of organic and chemical fertilizers on alfalfa yield, soil nutrient status, and soil biological characteristics. The six fertilization treatments were as follows: CM0 (100% cattle manure), CM1 (75% cattle manure + 25% chemical fertilizer), CM2 (50% cattle manure + 50% chemical fertilizer), CM3 (25% cattle manure + 75% chemical fertilizer), CM4 (100% chemical fertilizer), and CK (no fertilizer application). The results showed that alfalfa hay yield was highest under the CM3 treatment in both 2024 and 2025, representing increases of 38.03% and 40.85%, respectively, compared with the control (CK). Relative to the other treatments, CM3 significantly increased soil total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, readily available potassium, and organic matter contents. In addition, CM3 markedly enhanced the activities of soil nitrate reductase (NR), nitrite reductase (NiR), and the root enzymes glutamate synthase (GOGAT) and glutamine synthase (GS). The combined application of organic and chemical fertilizers significantly reshaped the soil bacterial community structure associated with alfalfa. Under the CM3 treatment, Chao1, Shannon, and ACE indices of soil bacterial diversity increased, whereas the Simpson index decreased. Moreover, the CM3 treatment was associated with higher relative abundances of several key bacterial phyla and genera. The 25% cattle manure plus 75% chemical fertilizer (CM3) treatment exhibited the strongest overall effects, significantly increasing total alfalfa hay yield, enhancing soil macronutrient availability and key enzyme activities, improving soil microbial α-diversity, and optimizing soil bacterial community structure. This treatment consistently outperformed the no-fertilizer control (CK) and all other organic–inorganic fertilizer combinations. Collectively, these findings provide robust scientific evidence supporting strategies to increase forage productivity, mitigate environmental impacts, and promote the sustainable development of the grassland industry. Full article

Although it is well established that nitrate exerts an inhibitory effect on nodulation and biological nitrogen fixation in soybean, the underlying mechanism remains unclear. In soybean plants, nitrate is assimilated into asparagine (Asn) and glutamine (Gln); their systemic circulation within the plant may contribute to the reduced N-fixation capacity of nodules. To investigate the effects of nitrate, Asn, and Gln on soybean nodulation and biological N fixation, a unilateral nodulated double-root soybean system was used. The non-nodulated side roots were supplied with nitrate (14 mM), Asn (20 mM), or Gln (20 mM), while the nodulated side roots were not supplied with N. Changes in nodule number, nodule dry weight, nitrogenase activity, and N compound content were analyzed after 4 and 10 days of treatment. The results showed that all three exogenous N sources significantly reduced nodule number, nodule dry weight, and nodule nitrogenase activity after both 4 and 10 days of treatment, while promoting the accumulation of ureides, Asn, and Gln in leaves. Nitrate and Asn treatments increased the accumulation of ureides and Asn in nodules, whereas Gln had no significant effect on nitrogenous compounds in nodules. These results suggest that nitrate inhibits nodulation and biological N fixation primarily through its conversion to Asn in soybean plants. The accumulation of Asn in shoots and nodules may suppress nodulation and biological N fixation by promoting ureide accumulation. Full article

This research explored how dietary supplementation of calcium nitrate influences methane emissions, nitrogen excretion, ruminal fermentation parameters, and microbiota in Liuyang black goats. A total of twelve male goats from this breed were divided into two groups: one serving as a control group (CON), while the other received a treatment of 3% calcium nitrate (CAL). The research was conducted over a period of 40 days and comprised two separate trial phases. A 10-day adaptation period and a 5-day sampling period (days 11–15) for each stage. Results showed that incorporating calcium nitrate significantly reduced the emissions of methane (CH₄) (p < 0.05) and carbon dioxide (CO₂) (p < 0.05). Moreover, the use of calcium nitrate modified the trends in ruminal fermentation, resulting in an increase in pH (p < 0.05). Moreover, the ratio of acetate to propionate (A:P) was notably reduced in the CAL group (p < 0.05), indicating a shift toward enhanced production of propionate. At the microbial level, an increased presence of Bacteroidota and Prevotella was observed in the CAL group (p < 0.05). In contrast, the CON group exhibited elevated levels of Firmicutes and Methanobrevibacter (p < 0.05). This finding suggests that calcium nitrate plays a significant role in reducing methane emissions and also affects the fermentation processes in the rumen along with the microbiota of Liuyang black goats. Further research is needed to examine the long-term implications of calcium nitrate supplementation on the health and productivity of these goats. Full article

Characterizing surface runoff and the transport process of non-point source pollutants (NSPs) carried by this runoff is crucial for identifying key source areas, estimating pollution loads entering water bodies, and implementing pollution control, which is particularly important in regions dominated by smallholder farming in China. Currently, most of the commonly used NSP models originated from international countries and have shortcomings such as high data requirements, high generalization degrees, and requiring the calibration of numerous parameters in the application process. Therefore, a distributed non-point source pollution model based on the time-varying gain and stormwater runoff response was constructed, designed for application at the watershed scale. This study describes the construction of the model, introducing its principles and structure through three key modules: a rainfall–runoff module, a soil erosion module, and a pollutant migration and transformation module. The proposed model was used to simulate the rainfall–runoff, soil erosion, and nutrient migration and transformation processes at different spatiotemporal scales. Although it achieved the best performance at the monthly and annual scales, its simulation results at the daily and hourly scales still met the relevant requirements, with relative errors within 20% and Nash–Sutcliffe Efficiency (NSE) coefficients of approximately 0.7. The annual sediment delivery ratios for the Yangliu Small Watershed and the basin above the Ankang section in 2022 were determined to be 0.445 and 0.36, respectively. The pollutant processes corresponding to different runoff events in the Yangliu Small Watershed were simulated, and the average NSE for total nitrogen (TN), ammonia nitrogen (NH₃-N), nitrate nitrogen (NO₃-N), total phosphorus (TP), and soluble reactive phosphorus (SRP) were determined to be 0.69, 0.74, 0.79, 0.71, and 0.71, respectively. For the basin above the Ankang section, the NSE coefficients for the simulation of NH₃-N and TP pollutant processes were 0.78 and 0.83, respectively. The model demonstrated robust applicability across various spatial (ranging from small to large watersheds) and temporal (hourly−daily−monthly−annual) scales, and exhibited stability across different basins in a semi-humid region of China. The model is characterized by a parsimonious parameter set, ease of calibration, and strong spatiotemporal versatility, thus providing an efficient and reliable tool for non-point source pollution simulation. Full article

To address ammonium nitrogen (NH₄⁺-N) and nitrite accumulation in intensive marine shrimp aquaculture, a marine recirculating aquaculture system (RAS) for Penaeus vannamei centered on a moving bed biofilm reactor (MBBR) was constructed to investigate the microbial basis of nitrogen removal. The results showed that the MBBR contributed most to NH₄⁺-N removal, demonstrating favorable nitrification potential under marine conditions (0.513 mg·L⁻¹·h⁻¹). The biofilm carrier formed a complete attached layer and developed a mature biofilm structure. Microbial community analysis revealed clear differentiation between the biofilm and sediment. The biofilm community was dominated by norank_f__Caldilineaceae (9.89%). Linear discriminant analysis effect size identified the nitrifying genus Nitrospira to be significantly enriched on the biofilm side (α = 0.05, linear discriminant analysis > 2.0). In addition, PICRUSt2-based functional prediction suggested a higher potential in biofilm than in sediment for ammonia oxidation and downstream nitrogen transformation, involving ammonia monooxygenase (EC:1.14.99.39), hydroxylamine dehydrogenase (EC:1.7.2.6), nitrate reductase (EC:1.7.99.4), and nitrite reductase (EC:1.7.2.1). Thus, this study provides a microbial basis and process strategy for P. vannamei RAS. Full article

Root-zone nitrogen fertilization (RZF) can increase crop N uptake and yield, yet the underlying rhizosphere N-cycling functional mechanisms remain insufficiently resolved. In a field experiment with winter oilseed rape (Brassica napus L.), RZF was compared with conventional fertilization (CF) under the same N input rates, alongside a zero-N control (N0). Compared with CF, RZF significantly increased seed yield (by 0.44 t ha⁻¹) and aboveground N uptake (by 20.45 kg ha⁻¹), while simultaneously enriching rhizosphere mineral N pools (NH₄⁺–N and NO₃⁻–N by 54.50% and 56.02%, respectively). Shotgun metagenomics revealed that RZF reprogrammed rhizosphere N-cycling functional potential, characterized by enhanced nitrogen fixation, reduced nitrification and denitrification, and a tendency toward increased assimilatory nitrate reduction. These module-level shifts were supported by concordant changes in key functional genes, indicating greater genetic potential for N retention and assimilation (nifD, glnA, gltB, nasA, napB, nrfA) and reduced potential for nitrification- and denitrification-driven N losses (amoB/C, narI, nirK, norB). Taxonomic composition analysis showed enrichment of Bradyrhizobium and suppression of key nitrifier taxa (Nitrosospira and a Nitrososphaeraceae-affiliated taxon) under RZF. Rhizosphere pH exhibited the strongest Mantel correlation with multiple N-cycling modules, and rhizosphere available N (AN; sum of NH₄⁺–N and NO₃⁻–N) was positively associated with plant N traits and yield. Structural equation modeling supported a pathway in which a functional balance index (retention/assimilation vs. loss/oxidation) increased AN (0.22), and AN strongly promoted yield (0.90). Collectively, these results elucidate a rhizosphere-centered mechanism whereby localized N placement strengthens soil–plant N coupling and enhances crop productivity through reprogramming microbial N-cycling functional potentials, positioning rhizosphere N processes as a key mechanistic bridge for microbiome-informed optimization of root-zone fertilization. Full article

Aquaculture wastewater (AWW) contains elevated concentrations of nitrogen, phosphorus, and salts, in addition to many micropollutants that may cause environmental pollution if discharged untreated. This study evaluated the potential of the halophilic microalga Dunaliella salina for simultaneous phycoremediation of AWW and production of biodiesel-oriented biomass. Microalgal growth and biochemical composition were compared between AWW and synthetic f/2 medium under controlled laboratory conditions. Results showed that AWW supported efficient microalgal growth, showing a biomass yield of 1.32 g L⁻¹ with a productivity of 0.09 g L⁻¹ d⁻¹, representing 40.88% and 18.42%, respectively, over that obtained in f/2 medium. Cultivation in wastewater also enhanced the volumetric productivity of lipids, proteins, and carbohydrates by 26.20%, 12.46%, and 26.38%, respectively. Significant nutrient removal from AWW was achieved, with high reduction efficiencies for nitrate, nitrite, ammonium, phosphate, and sulfate within the range 76.80–94.10%, along with a decrease in salinity by 29.70%. The lipid fraction was dominated by fatty acid methyl esters suitable for biodiesel production, representing 94.10% of the total lipids. Biodiesel properties met the international fuel standards and were even improved when the microalga was cultivated in AWW. These findings demonstrate that AWW can serve as an effective culture medium for halophilic microalgae, enabling simultaneous wastewater treatment and sustainable biofuel feedstock production. Full article

Coal-fired power plants can adversely affect aquatic ecosystems through wastewater discharge, waste landfills, and the atmospheric deposition of toxic substances released during coal combustion. These processes degrade the water quality of nearby surface and underground water bodies. The study presents the impact of the coal-fired power plant Contour Global Maritza East 3 on the ecological status of the Sokolitsa River, reflected by changes in the composition and structure of the sensitive phytobenthos and macrozoobenthos communities and supporting environmental variables, including water temperature, pH, dissolved oxygen, conductivity, nutrients, sulfates, calcium, and calcium carbonate hardness. Methods for monitoring and assessing the ecological status of surface water bodies compliant with European and national legislation were applied to the studied biological quality elements and key physicochemical variables. Historical monitoring data from a ten-year period, 2013–2022, together with data collected during the study in 2023 and 2024 were analyzed and evaluated. The results indicated a significant increase in most physicochemical variables downstream of the CFPP compared with the upstream site, including water temperature, conductivity, calcium carbonate hardness, calcium, sulfates and nitrogen (N) nutrients (ammonium N, nitrite N, nitrate N, total N). The ecological status of the river deteriorated, as indicated by the negatively affected aquatic habitats and the changes in the taxonomic richness and abundance of the studied organism groups. Full article

Understanding how landscape structure affects nutrient pollution is essential for contemporary effective river basin management. This study examined the influence of landscape composition and configuration on concentrations of nitrate (NO₃⁻), nitrite (NO₂⁻), and ammonium (NH₄⁺) in 30 small lowland catchments of central–eastern Poland during the cold period. Water samples were collected monthly from September 2021 to April 2022, and land-use patterns were quantified using landscape metrics derived from high-resolution spatial data at the catchment scale and within riparian buffer zones. The results showed that the impact of land use on nitrogen concentrations was strongly dependent on both landscape type and spatial scale. Forests, meadows, wetlands, and water bodies generally acted as sink landscapes, reducing nitrate and nitrite levels. The effect was more pronounced in catchments where forest patches (mainly coniferous) covered a larger area, had greater total Edge Length, and were more complex in shape. It was advantageous when meadow patches were large, cohesive, and weakly fragmented. In contrast, arable land and built-up areas consistently functioned as source landscapes, contributing to higher nitrogen concentrations when characterized by a larger share, size (both), and aggregation degree of patches (arable land). Higher landscape diversity at the catchment scale was associated with lower nitrate and nitrite concentrations. Overall, land-use effects were best explained at larger spatial extents, especially the entire catchment and the 500 m buffer zone. These findings emphasize the need to integrate landscape structure and appropriate spatial scale into nutrient management strategies for lowland agricultural catchments. Full article