Search Results (1,087)

Energy consumption and environmental pollution pose significant challenges to sustainable development. This study develops a comprehensive coupled framework model that advances the quantitative integration of carbon (C), nitrogen (N), and phosphorus (P) cycles driven by multiple anthropogenic pollution sources. This paper used Panjin city as a case study to analyze the dynamic changes and interconnections among C, N, and P. Results indicated that net anthropogenic carbon inputs (NAI_C) increased by 33% from 2016–2020, while net anthropogenic nitrogen inputs (NAI_N) and net anthropogenic phosphorus inputs (NAI_P) decreased by 14% and 28%, respectively. The primary driver of NAI_C was energy consumption, while wetlands were the dominant carbon sequestration sink. Agricultural production was identified as the primary source of NAI_N and NAI_P, and approximately 4.5% of NAI_N and 2.9% of NAI_P were discharged into receiving water bodies. We demonstrate that human activities and natural processes exhibit dual attributes, producing positive and negative environmental effects. The increase in carbon emissions drives economic growth and industrial restructuring; however, the enhanced economic capacity also strengthens the ability to mitigate pollution through environmental protection measures. Similarly, natural ecosystems, including forests and grasslands, contribute to carbon sequestration and the release of non-point source pollution. The comprehensive environmental impact assessment of C, N, and P revealed that the comprehensive environmental index for Panjin city exhibited an improved trend. The factors of energy structure, energy efficiency, and economic scale promoted NAI_C growth, with the economic scale factor alone accounting for 93% of the total increment. Environmental efficiency factor and population size factor were the primary drivers in reducing NAI_N and NAI_P discharges into the receiving water bodies. We propose a novel management model, ecological restoration, clean energy utilization, resource recycling, and pollution source reduction to achieve systemic governance of C, N, and P inputs. Full article

This study evaluated age-related changes in nutrient digestibility in dogs and examined the effects of physiological development and dietary composition on digestive efficiency. Twenty Beagle dogs were assigned to three groups: puppies (<1 year; n = 8), adults (3–4 years; n = 8), and seniors (10–11 years; n = 4). All animals were fed diets formulated to contain identical nutrient levels that met or exceeded the minimum recommended nutrient requirements established by the Association of American Feed Control Officials. The digestibility of dry matter (DM), crude protein (CP), ether extract (EE), nitrogen-free extract (NFE), calcium (Ca), phosphorus (P), and amino acids were compared among the groups. The results showed that NFE digestibility was significantly higher in puppies, whereas CP digestibility was lower than that in adults and seniors, likely due to immature digestive function. In addition, EE digestibility was significantly lower in puppies, whereas P digestibility decreased with age. No significant difference was observed in Ca digestibility. Amino acid digestibility is lower in puppies, particularly for essential amino acids such as lysine, isoleucine, histidine, and arginine. These results indicate that age-related differences in digestive physiology and protein source affect nutrient utilization, providing a basis for developing life stage-specific nutritional strategies for companion animals. Full article

This research determines the techno-economic feasibility of valorizing as biofertilizer the nitrogen (N) and the phosphorus (P) from a municipal wastewater effluent using the microalgae Scenedesmus sp., contributing to phosphorus recycling, resource optimization, and diminishing eutrophication by capturing 74% of N, 97% of P, and 41% of chemical oxygen demand in effluents. The inoculum was conditioned in 20 L photobioreactors by weekly harvesting and refilling at room temperature (25 °C day, 12 °C night) with a 12:12 photoperiod and 4 L/min atmospheric air bubbling. The improved operational conditions were obtained using a Box–Behnken experimental design, establishing that 70% wastewater concentration (vol./vol.), 4.5% nutrient addition, and 3 days’ harvesting time were the best conditions. The estimated biomass production was 176 tons/year, and this represents a maximum net present value of 1.5 MUSD for a 6.8 Ha plant, capturing 10% of municipal wastewater effluent, which serves 64000 inhabitants. The representative operational costs (OPEX) were 32% for utilities, 30% labor costs, and 25% for raw materials, and the required capital expenditures (CAPEX) were 11 MUSD and are related to photobioreactors (64%) and land (21%). The findings demonstrate the potential of microalgae-based systems as a feasible and profitable approach to wastewater valorization, while also highlighting the need for scale-up validation and integration with existing treatment infrastructures, where land requirements and photobioreactor installation will be relevant for financial feasibility. Full article

Conventional separation methods often prove ineffective for complex, refractory high-phosphorus iron ores. Recent advances propose a coal-based direct reduction dephosphorization-magnetic separation process, achieving significant dephosphorization efficiency. This review systematically analyzes phosphorus occurrence states in high-phosphorus oolitic iron ores across global deposits, particularly within iron minerals. We categorize contemporary research and elucidate dephosphorization mechanisms during coal-based direct reduction. Key factors influencing iron mineral phase transformation, iron enrichment, and phosphorus removal are comprehensively evaluated. Phosphorus primarily exists as apatite and collophane gangue m horization agents function by: (1) inhibiting phosphorus-bearing mineral reactions or binding phosphorus into soluble salts to prevent incorporation into metallic iron; (2) enhancing iron oxide reduction and coal gasification; (3) disrupting oolitic structures, promoting metallic iron particle growth, and improving the intergrowth relationship between metallic iron and gangue. Iron mineral phase transformations follow the sequence: Fe₂O₃ → Fe₃O₄ → FeO (FeAl₂O₄, Fe₂SiO₄) → Fe. Critical parameters for effective dephosphorization under non-reductive phosphorus conditions include reduction temperature, duration, reductant/dephosphorization agent types/dosages. Future research should focus on: (1) investigating phosphorus forms in iron minerals for targeted ore utilization; (2) reducing dephosphorization agent consumption and developing sustainable alternatives; (3) refining models for metallic iron growth and improving energy efficiency; (4) optimizing reduction atmosphere control; (5) implementing low-carbon emission strategies. Full article

Biologically treated swine farm wastewater still contains high levels of refractory organics, humic substances and antibiotic residues, posing environmental risks and limiting opportunities for water reuse. Wastewater treatment by ozonation alone suffers from low mass transfer efficiency and selective oxidation. To overcome these limitations, a catalytic ozonation process (O₃/Fe²⁺/H₂O₂) was applied and optimized using Response Surface Methodology (RSM) based on single-factor experiments and Central Composite Design (CCD) for advanced swine farm wastewater treatment. The optimal conditions ([O₃] = 25.0 mg/L, [Fe²⁺] = 25.9 mg/L, [H₂O₂] = 41.1 mg/L) achieved a COD removal of 44.3%, which was 86.8% higher than that of ozonation alone, and increased TOC removal to 29.5%, indicating effective mineralization. Biodegradability (BOD₅/COD) of swine farm wastewater effluent increased from 0.01 to 0.34 after the catalytic ozonation treatment. Humic-like and fulvic-like substances were removed by 93.7% and 95.4%, respectively, and antibiotic degradation was significantly accelerated and enhanced. The synergistic process improved ozone utilization efficiency by 33.1% and removed 53.95% of total phosphorus through Fe³⁺-mediated coprecipitation. These findings demonstrate that with catalytic ozone decomposition and production of hydroxyl radicals, the O₃/Fe²⁺/H₂O₂ system effectively integrates enhanced ozone utilization efficiency, radical synergy, and simultaneous pollutant removal, providing a cost-effective and technically feasible strategy for advanced swine farm wastewater treatment and safe reuse. Full article

The escalating global challenge of waste production underscores the urgency for innovative waste management solutions. Sewage sludge, a byproduct derived from anaerobic digesters of wastewater treatment, was investigated as a flame-retardant synergist in Poly(Lactic Acid) (PLA). Micronized sludge was combined with ammonium polyphosphate (APP) at different ratios. The formulation containing (4:1) APP:Sludge exhibited enhanced flame retardancy compared to APP alone, achieving higher Limiting Oxygen Index (LOI) values and a V-0 rating in the UL-94 test. Cone calorimeter analysis further confirmed that the sludge contributed to reducing heat release and smoke generation. SEM–EDS analysis indicated that microcrystals, mainly composed of phosphorus and calcium oxides from APP and sludge, likely acted as protective barriers against heat transfer. In addition, filament extrusion demonstrated that sludge incorporation is compatible with 3D printing. This approach preserved structural integrity, sustainably utilized sewage sludge, and reduced reliance on commercial flame retardants. Integrating sludge as a synergist offers a promising solution for waste management and safer, more sustainable flame-retardant materials, supporting a circular economy. Full article

Background: Cardiovascular disease (CVD) is the leading cause of mortality in chronic kidney disease (CKD), driven by mechanisms distinct from the general population. Fibroblast Growth Factor 23 (FGF-23), a phosphaturic hormone elevated early in CKD, has been mechanistically linked to left ventricular hypertrophy, vascular dysfunction, and disordered mineral metabolism. This study examines the associations between FGF-23 and key renal, mineral, and cardiovascular parameters and its utility in risk stratification. Methods: We conducted a cross-sectional study of 60 adults with CKD stages 1–5. Serum FGF-23 was quantified using ELISA, alongside measures of iPTH, phosphorus, calcium, and eGFR (Estimated Glomerular Filtration Rate). Cardiovascular evaluation included transthoracic echocardiography and carotid intima-media thickness (CIMT). Associations were analyzed using Spearman correlations, ROC analysis, and multivariable logistic regression. Results: FGF-23 levels were significantly associated with declining eGFR (r = –0.288; p < 0.05), elevated iPTH (Intact Parathyroid Hormone) (r = 0.361; p < 0.05), and serum phosphorus (r = 0.335; p < 0.05). Patients with structural cardiac abnormalities (left atrial enlargement or left ventricular hypertrophy) exhibited higher FGF-23 concentrations (154 vs. 128 pg/mL; p = 0.027). FGF-23 alone predicted high cardiovascular risk with moderate accuracy (AUC 0.70; sensitivity 76%; specificity 67%). A composite model including iPTH and eGFR improved discriminatory power (AUC 0.76). Conclusions: FGF-23 correlates with subclinical cardiovascular remodeling and key mineral abnormalities in CKD. Its integration with iPTH and eGFR enhances cardiovascular risk stratification, supporting its potential as a multidimensional biomarker in early CKD. However, the cross-sectional design and modest correlation strengths limit causal inference and generalizability of the findings. Full article

Cadmium (Cd), a pervasive and highly phytotoxic metal pollutant, poses severe threats to agricultural productivity, ecosystem stability, and human health through its entry into the food chain. Plants have evolved intricate defense mechanisms, among which the strategic manipulation of nutrient elements emerges as a critical physiological and biochemical strategy for mitigating Cd stress. This comprehensive review delves deeply into the multifaceted roles of essential macronutrient elements (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur), essential micronutrient elements (zinc, iron, manganese, copper) and non-essential beneficial elements (silicon, selenium) in modulating plant responses to Cd toxicity. We meticulously dissect the physiological, biochemical, and molecular underpinnings of how these nutrients influence Cd bioavailability in the rhizosphere, Cd uptake and translocation pathways, sequestration and compartmentalization within plant tissues, and the activation of antioxidant defense systems. Nutrient elements exert their influence through diverse mechanisms: competing with Cd for root uptake transporters, promoting the synthesis of complexes that reduce Cd mobility, stabilizing cell walls and plasma membranes to restrict apoplastic flow and symplastic influx, modulating redox homeostasis by enhancing antioxidant enzyme activities and non-enzymatic antioxidant pools, regulating signal transduction pathways, and influencing gene expression profiles related to metal transport, chelation, and detoxification. The complex interactions between nutrients themselves further shape the plant’s capacity to withstand Cd stress. Recent advances elucidating nutrient-mediated epigenetic regulation, microRNA involvement, and the role of nutrient-sensing signaling hubs in Cd responses are critically evaluated. Furthermore, we synthesize the practical implications of nutrient management strategies, including optimized fertilization regimes, selection of nutrient-efficient genotypes, and utilization of nutrient-enriched amendments, for enhancing phytoremediation efficiency and developing low-Cd-accumulating crops, thereby contributing to safer food production and environmental restoration in Cd-contaminated soils. The intricate interplay between plant nutritional status and Cd stress resilience underscores the necessity for a holistic, nutrient-centric approach in managing Cd toxicity in agroecosystems. Full article

Nitrogen (N) and phosphorus (P) play vital roles in crop growth. However, conventional fertilizers exhibit low utilization efficiency, making them prone to causing resource wastage and water eutrophication. Although metal–organic frameworks (MOFs) have shown great potential for application in controlled-release fertilizers (CRFs), currently reported MOF-based CRFs suffer from low nutrient content, which limits their further application. To address this issue, this study synthesized a series of hierarchically porous MOFs, denoted as MIL-156(X), using sodium acetate as a modulator under hydrothermal conditions. These materials were subsequently loaded with urea and phosphate from aqueous solution to form MOFs-based CRFs (N-P-MIL-156(X)). Results indicate that MIL-156(X) retain microporous integrity while incorporating abundant mesopores. Increasing modulator content reduced particle size and average pore diameter but increased specific surface area and adsorption capacity for urea and phosphate. MIL-156-H (with a high modulator content addition) exhibited the highest adsorption capacity, conforming to Langmuir isotherm and pseudo-second-order kinetics. The adsorption mechanisms of urea and phosphate involved hydrogen bonding and the formation of Ca intra-spherical complexes, respectively. N-P-MIL-156-H contained 10.8% N and 16.3% P₂O₅, with sustained release durations exceeding 42 days (N) and 56 days (P₂O₅) in an aqueous solution. Pot trials demonstrated significantly higher nutrient use efficiency (N-44.8%, P₂O₅-16.56%) and a 12.22% yield increase compared to conventional fertilization (N-35.6%, P₂O₅-13.32%). Thus, N-P-MIL-156-H-based fertilization significantly promotes rice growth and N/P utilization efficiency, offering a promising strategy for developing controlled-release fertilizers and improving nutrient management. Full article

Ridge and furrow planting is a prevalent drought-resistant cultivation technique in dryland regions. Notably, the effects of this technology on crop grain yield and quality in dryland maize–wheat double-cropping systems remain limited. This study utilized a long-term positioning experiment initiated in 2004, which included five treatments: a permanent ridge and furrow with a border ridge of 133 cm row space (PRFBR); a ridge and furrow created each year with a border ridge of 133 cm row space (EYRFBR); a permanent ridge with a normal ridge of 100 cm row space (PRFNR); a ridge and furrow created each year with a normal ridge of 100 cm row space (EYRFNR), and a conventional flat planting pattern according to the local farmer (CF). The crop grain yield in 2015–2021, as well as the protein and phosphorus (P) and potassium (K) content in maize and wheat grains, and the protein components in winter wheat grains in 2020–2021 were investigated. The results showed that, compared to CF, all four ridge and furrow planting patterns significantly enhanced crop yield in dry and normal years, and the effects varied depending on crop species, with increases of 45.3–97.8% for wheat and 11.0–33.8% increases annually in dry years; and 24.5–51.6% increases for maize and 12.2–37.5% increases annually in the normal years. EYRFBR treatment increased wheat grain P and K content by 24.3% and 13.7%, as well as increasing the total protein, albumin, gliadin, soluble protein, and storage protein content by 9.7%, 22.3%, 9.6%, 14.5%, and 5.6%, whereas PRFNR reduced the glutenin content and glutenin/gliadin ratio in winter wheat grains by 5.1% and 10.9%, respectively. The yield achieved with a permanent ridge and furrow (PRF) surpassed that achieved when the ridge and furrow was created anew each year (EYRF), yet the normal ridge width (NR) outperformed the border ridge width (BR). However, the P, K, protein, and protein component content in wheat grains under EYRF was superior to that under PRF. Comprehensive evaluations through principal component analysis (PCA) and TOPSIS analysis consistently demonstrated that the EYRFBR treatment delivered optimal performance in yield and quality for winter and annual, while PRFNR achieved superior yield for summer maize. Consequently, in dryland maize–wheat double-cropping systems, an EYRFBR planting pattern should be recommended for high-yield and high-quality wheat production; however, the PRFNR planting pattern is more suitable for summer maize production. Full article

In Florida, many agricultural soils contain up to 600 mg/kg of Mehlich-3 extractable phosphorus (P), yet potato growers continue to apply P fertilizers, indicating complex P dynamics that remain underexplored. Previous studies have mainly focused on P fertilizer trials, overlooking crucial factors like phosphatase activity and P sorption isotherms in high-legacy P systems. This study aimed to address this gap by examining acid phosphatase activity (AcPA) and P sorption dynamics in a potato field in northeastern Florida. Utilizing a split-block design, 24 plots were subjected to two P application rates (0 and 49 kg/ha) and three management treatments: a multispecies cover crop (MSCC), MSCC with Telone-C35 (a nematicide), and an untreated control. Significant increases in AcPA were observed during the tuber bulking stage, suggesting that applied P was insufficient for plant needs. P sorption isotherms indicated that the soil had reached maximum P sorption capacity, with applied P primarily fixed through chemical processes. These findings underscore the need for revised P fertilizer strategies in high-legacy P soils and highlight the importance of monitoring AcPA and sorption phases for effective nutrient management. Full article

Overdosing an external carbon source can lead to its incomplete utilization. With this in mind, this study aimed to investigate the effect of carbon dosing on nutrient removal in a rotating electro-biological disc contactor (REBDC) treating hydroponic tomato wastewater and to evaluate its impact on effluent COD under a constant electric current (2.5 A/m²). In REBDC, discs served as the cathode, and an aluminum sheet placed in the tank served as the anode. Sodium acetate was added to provide carbon to nitrogen (C/N) ratios of 0.5, 1.0, 2.0, and 3.0. The HRT was 24 h. The phosphorus removal efficiency in the REBDC exceeded 90% at C/N ratios of 0.5, 1.0, and 2.0. A several-fold increase was observed in nitrogen removal efficiency at C/N = 2.0 and C/N = 3.0 compared to C/N = 0.5 (9 and 11 times higher, respectively). At C/N ratios of 2.0 and 3.0, the efficiency was 56.0% and 65%, respectively. Considerable amounts of unutilized organic carbon were found in the REBDC-treated wastewater. The rational solution would be to extend the HRT, which would enable greater substrate consumption and nitrogen removal. Full article

Background: Adherence to Medical Nutrition Therapy (MNT) is a key determinant of therapy success, particularly in chronic diseases like chronic kidney disease (CKD). MNT in CKD requires significant changes in patient’s dietary habits, which can affect long-term adherence. This study aims to evaluate the adherence to MNT in stage 5 CKD patients undergoing conservative kidney management (CKM), identifying potential challenges and strengths of nutritional intervention. Methods: We enrolled in 94 stage 5 CKD patients undergoing CKM at the University Hospital of Modena, Italy. We collect clinical data from medical and nutrition records. The inclusion criteria comprised patients of all genders, ages, and ethnicity with stage 5 chronic kidney disease (CKD), in pre-dialysis, enrolled in the nephrology and dietetics program, who had access to 24-h urine tests, anthropometric measurements, and dietary history records. Exclusion criteria included patients with CKD stages lower than 5, those who had not undergone at least one nutritional assessment, or lacked accessible 24-h urine data. The study utilized medical and dietary records from September 2017 to March 2025. The primary outcome was the assessment of adherence to medical nutrition therapy (MNT), comparing prescribed protein intake with actual intake, estimated from dietary history (DH). Protein intake was compared with normalized protein nitrogen appearance (nPNA) as stated by recent guidelines. Additional factors influencing adherence, such as age, gender, comorbidities, physical activity, and prior dietary interventions, were also evaluated. Anthropometric measurements and biochemical tests were collected, and dietary intake was assessed using a seven-day DH. Results: Data were analyzed using descriptive statistics, linear correlation models, univariate logistic regression, t-tests, paired t-tests, and chi-square tests, with significance set at p < 0.05. Most of the patients follow suggested energy and protein intakes limits; however, substantial individual variability emerged Bland–Altman analysis indicated a moderate bias and wide limits of agreement for energy intake (+116 kcal; limits of agreement –518.8 to +751.3 kcal), revealing frequent overestimation in self-reports. Protein intake showed less systematic error, but discrepancies between dietary recall and biochemical markers persisted. Protein intake decreased significantly over time (p < 0.001), while correlation with nPNA did not reach statistical significance (ρ = 0.224, p = 0.051). No significant associations were identified between adherence and most clinical or lifestyle factors, although diabetes was significantly associated with lower adherence to protein intake (p = 0.042) and a predominantly sedentary lifestyle showed a borderline association with energy intake adherence (p = 0.076), warranting further investigation. Longitudinal analysis found stable BMI and body weight, alongside notable reductions in sodium (p = 0.018), potassium (p = 0.045), and phosphorus intake (p < 0.001) over time. Conclusions: Assessing dietary adherence in CKD remains complex due to inconsistencies between self-reported and biochemical estimates. These findings highlight the need for more objective dietary assessment tools and ongoing, tailored nutritional support. Multifaceted interventions—combining education, personalized planning, regular monitoring, and promotion of physical activity—are recommended to enhance adherence and improve clinical outcomes in this vulnerable population. Full article

Morchella spp. is a type of valuable and rare edible fungi cultivated in soil. Optimization of the cultivation medium for Morchella spp. is key to obtaining high-efficiency production in an ecologically friendly manner. Recently, the sustainable resource utilization of agricultural waste has gathered attention. Specifically, reusing tomato substrate, mushroom residues, and coconut shells can lower the production costs and reduce environmental pollution, demonstrating remarkable ecological and economic benefits. To determine the soil microbial communities of Morchella spp. using different culture medias and influencing factors, this study analysed the relative abundance of bacterial and fungal communities in natural soil, soil with 5% tomato substrate, soil with 5% mushroom residues, and soil with 5% coconut shells using Illumina NovaSeq high-throughput sequencing. In addition, intergroup differences, soil physiochemical properties, and product quality were also determined. Results demonstrated that agricultural waste consisting of mushroom residues, waste tomato substrate, and coconut shells can improve the efficiency of Morchella spp. cultivation. When considering yield and quality, mushroom residue achieved the highest yield (soil nutrient enrichment), followed by tomato substrate (water holding + grass carbon nutrient). All three types of agricultural waste promoted early fruiting, significantly increased polysaccharide, crude protein, and potassium content, and lowered crude fat and fibre. In regard to soil improvement, the addition of different materials optimized the soil’s physical structure (reducing volume weight and increasing water holding capacity) and chemical properties (enrichment of nitrogen, phosphorus, and potassium, regulating nitrogen and medium trace elements). For microbial regulation, the added materials significantly increased the abundance of beneficial bacteria (e.g., Actinomycetota, Gemmatimonadota and Devosia) and strengthened nitrogen’s fixation/nitration/decomposition functions. In the mushroom residue group, the abundance of Bacillaceae was positively related to yield. Moreover, it inhibited pathogenic fungi like Mortierella and Trichoderma, and lowered fungal diversity to decrease ecological competition. In summary, mushroom residues have nutrient releasing and microbial regulation advantages, while tomato substrate and coconut shells are new high-efficiency resources. These increase yield through the “physiochemical–microorganism” collaborative path. Future applications may include regulating the function of microorganisms and optimizing waste preprocessing technologies to achieve sustainability. Full article

Phosphorus, a crucial yet nonrenewable resource, is essential for agriculture, life processes, and various industries. In this study, we employed co-pyrolysis of eggshells and peanut shells to prepare calcium-based biochar (EPB) with a high adsorption capacity and ecological non-toxicity, enabling effective phosphorus recovery from wastewater. EPB was characterized via X-ray diffraction, scanning electron microscopy, electron probe microanalysis, and Brunauer–Emmett–Teller analysis. Additionally, its phosphate adsorption characteristics were investigated under varying temperature, pH, and coexisting ion conditions. Phosphate adsorption followed the Langmuir isotherm with a maximum adsorption capacity of 178.08 mg/g, and the kinetics aligned with those of the quasi-second-order kinetic model. Phosphate adsorption by EPB was driven by electrostatic attraction and chemical precipitation. Moreover, we investigated the effects of phosphorus-enriched biochar on the growth and development of tobacco and soil microbial communities. Phosphorus-enriched biochar increased organic and inorganic phosphorus levels and promoted tobacco growth compared with conventional fertilizers. Phosphorus-enriched biochar reshaped tobacco rhizosphere microbial communities, promoting beneficial taxa, such as Nitrospira. Structural equation analysis showed that EPB enhanced microbial alpha diversity and key microbial communities, improving phosphorus availability and tobacco growth and development. Conclusively, this study provides a theoretical reference for phosphorus-containing wastewater treatment and reuse. Full article