Sustainable intensification of legume-based cropping systems requires innovative strategies that enhance nitrogen fixation and nutrient use efficiency while minimizing environmental impacts. This review examines the co-application of nitrogen-fixing bacteria and humic substances derived from agricultural waste as an integrated biotechnological approach to support sustainable soybean production. The review also summarizes key roles of microbial inoculants, such as Bradyrhizobium, Azospirillum, and Pseudomonas (Ps), and the agronomic functions of humic acids, fulvic acids, and humin compounds. When applied separately, these biostimulants improve nodulation, nutrient uptake, and soil health. When combined, they demonstrate synergistic effects—improving nitrogen-use efficiency, drought tolerance, and crop yield. Mechanisms driving these outcomes include enhanced microbial colonization, micronutrient chelation, hormonal modulation, and antioxidant activity. In addition, the review considers challenges including soil pH variability, native microbial competition, product standardization, and formulation compatibility. Recent advances in encapsulated inoculants and hydrothermal humification methods demonstrate promise for improving bioavailability and resilience. Environmental benefits include reduced nitrate leaching, increased soil organic matter, and alignment with circular bioeconomy principles through the valorization of organic waste. Despite barriers, such as formulation variability, limited precision delivery systems, and regulatory gaps, the integration of microbial and humic inputs offers a scalable, eco-friendly alternative to synthetic fertilizers. Future research should focus on molecular characterization, genotype-strain matching, and long-term field validation to ensure robust performance across agroecological zones. Finally, this review provides a comprehensive synthesis for researchers, agronomists, and policymakers seeking to improve the ecological and economic sustainability of soybean production through advanced biotechnological interventions.
Hydrocarbon contamination in marine environments poses a significant global environmental challenge, impacting ecosystems, human health, and economic activities. The present review provides a comprehensive overview of hydrocarbons in seawater, addressing their diverse sources, complex fate and transport mechanisms, ecological and toxicological impacts, and various remediation strategies. Both natural seepages from geological formations and a wide array of anthropogenic inputs are discussed as primary contributors to marine hydrocarbon burdens. Anthropogenic carbon inputs include large-scale accidental oil spills, chronic operational discharges from shipping and offshore platforms, industrial effluents, and diffuse urban runoff carrying petrogenic and pyrogenic hydrocarbons, during the past 50 years. In the sea, hydrocarbons undergo a series of interconnected physical, chemical, and biological transformations that mediate their persistence, bioavailability, and spatial distribution. The specific environmental conditions, such as temperature, nutrient availability, and microbial community composition, significantly influence the rate and extent of these natural attenuation processes. The ecological consequences range from acute lethal impacts causing immediate mortality in marine organisms to chronic sublethal effects on reproduction, growth, immune response, and behavior across a wide range of taxa, from plankton to marine mammals. Furthermore, long-term ecosystem disruptions, including habitat degradation of vital coastal areas, such as mangroves and coral reefs, and bioaccumulation within the food web, pose serious threats to ecosystem health and biodiversity. To mitigate these adverse effects, a range of remediation strategies has been developed and implemented; their mechanisms, effectiveness in various scenarios, inherent limitations, and potential secondary environmental considerations are explored in this review. Emphasis is placed on the importance of integrated approaches that combine rigorous prevention measures, rapid and effective response protocols during spill events, and sustainable, environmentally sound long-term remediation techniques. Understanding the intricate interplay between the sources, transformations, impacts, and potential solutions for hydrocarbon contamination is crucial for developing robust management plans and safeguarding the long-term health and resilience of marine ecosystems.
Wind plays a crucial role in various physical applications, including wind energy and pollutant transport and diffusion. Wind varies from both temporal and spatial perspectives. This paper presents a statistical analysis of wind energy potential in Mongo, the capital city of Guéra Province, Chad, using 11 years of data obtained from the local meteorological station. Using the Weibull distribution function, we analyzed the wind speed probability distributions based on the wind data obtained. The obtained results, based on average annual wind speed and energy generation, indicate that Mongo is suitable only for small-scale wind energy applications. The average wind speed within the chosen time interval is 3.2 m/s, which is classified as Class 1 according to the international system of wind classification. Wind rose plots illustrate that the wind directions vary across the years. The temperature data were also plotted, reporting an average temperature of 27.76°C over the 11-year study period. This indicates that Mongo has a relatively hot climate, which may contribute to the modest but consistent wind speeds observed in this city.
The valorization of forestry waste into densified biofuels is critical for sustainable energy development. This study investigates the optimization of the densification process for pine sawdust by examining the effects of key parameters on the final product quality, specifically focusing on the uniformity of the internal temperature field. A four-factor, mixed-level orthogonal experiment was designed, investigating forming pressure, moisture content, binder addition ratio, and heating temperature. The temperature mean square deviation (MSD) was utilized as the primary response variable to quantify thermal distribution uniformity. Analysis of variance (ANOVA) was performed to determine the statistical significance of each factor, and a multivariate regression model was established. Results from ANOVA indicated that the descending order of significance for factors impacting temperature MSD was: moisture content > forming pressure > heating temperature > binder addition ratio. A statistically significant interaction effect was identified between forming pressure and heating temperature. Response surface methodology was employed to optimize these two significant factors. The optimal conditions for minimizing temperature MSD, while maintaining constant moisture content and binder ratio, were determined to be a forming pressure of 10 MPa and a heating temperature of 190°C. By optimizing process parameters to achieve a more uniform temperature field, the quality and stability of the resulting pine sawdust densified fuel were significantly improved. This work provides a quantitative theoretical basis and key technical parameters for the scale-up and industrial application of biomass fuels in boilers and residential heating systems, thereby promoting the development of a low-carbon circular economy.
Weirs represent a frequently employed mechanism for regulating water surface elevations and managing flow within canals and hydraulic infrastructures. Among these, labyrinth weirs constitute a distinctive variant capable of accommodating a specific discharge while maintaining a reduced upstream water level compared to conventional linear weirs. The present investigation delved into the evaluation of the effectiveness of multilayer perceptron (MLP) networks, support vector machine (SVM), gene expression programming (GEP), and multivariate adaptive regression splines (MARS), aiming to predict the discharge coefficient (Cd) of a trapezoidal-arched labyrinth weir with an expanded central cycle. A dataset including 108 laboratory observations was utilized. The dimensionless parameters were obtained from the parameters including inside apex width of the middle cycle (w1), inside apex width of the end cycles (w2), weir height on the upstream side (B), unsubmerged total upstream head on the weir (Hd), and gravitational acceleration (g). The model was developed with the dimensionless parameters and Cd. Root mean square error (RMSE), determination coefficient (R2), mean absolute error (MAE), and developed discrepancy ratio (DDR) were used as performance assessment criteria. Based on these metrics, all four models exhibited the latent capacity to predict the Cd value. However, the MLP model demonstrated superior performance among the models during both training (RMSE = 0.024, MAE = 0.020, R2 = 0.816, and Cd[DDRmax] = 8.07) and testing (RMSE = 0.011, MAE = 0.006, R2 = 0.688, and Cd[DDRmax] = 11.32) phases. Sequentially, the subsequent standings were secured by the SVM, GEP, and MARS. MLP outperformed SVM, GEP, and MARS models in predicting Cd, achieving the highest R² and lowest RMSE/MAE values.
Y-zeolite is a promising adsorbent for removing organic sulfides from fuel. However, its application is limited by low adsorption capacity for refractory sulfur compounds. In this study, metal-modified Y-zeolite (MY) adsorbents, incorporating Ru³⁺, Bi³⁺, Zr⁴⁺, and Sb³⁺ ions, were successfully synthesized via a solid-state reaction method. X-ray diffraction analysis confirmed that metal ion incorporation did not alter the crystalline framework of Y-zeolite. Nitrogen adsorption-desorption isotherms revealed that the Ru-modified Y-zeolite (RuY) possessed a notably high specific surface area of 735.23 m²/g, whereas NH₃-temperature programmed desorption (NH₃-TPD) measurements showed that it also had the highest concentration of acidic sites (2.375 mmol/g). The effects of metal ion type, loading amount, and oxidation state on thiophene removal were systematically investigated via batch adsorption experiments. Sulfur removal efficiency increased in the following order: HY (43%) <BiY-1 (53%) <SbY-1(62%) <ZrY-1 (63%) <RuY-1 (68%). The RuY adsorbent exhibited the best adsorption performance, with Ru4+ ions acting as the primary active sites. The adsorption behavior followed the Langmuir isotherm model, indicating a monolayer adsorption process. Sulfur removal efficiency correlated positively with the sulfur-metal (S-M) bond strength in MY adsorbents. Compared to unmodified HY, MY adsorbents also showed improved selectivity for thiophene in the presence of competing toluene. The superior desulfurization performance of RuY is attributed to its smaller ionic radius (62 pm), higher charge (Ru⁴⁺), larger specific surface area, and abundance of Lewis acid sites.
Land use and land cover (LULC) change is a growing global concern, particularly in water-scarce regions, where it directly influences hydrological systems and groundwater sustainability. The Dire Dawa watershed in eastern Ethiopia exemplifies this challenge. This study investigates the impacts of LULC changes on groundwater recharge in the Dire Dawa watershed from 2000 to 2022. The LULC changes were analyzed using ERDAS IMAGINE 2015 and geographic information systems, while the effects on groundwater recharge were assessed using the Soil and Water Assessment Tool (SWAT) model. The performance of the SWAT model was evaluated using the sequential uncertainty fitting 2 technique, demonstrating good model performance, with R2 values of 0.84 (calibration) and 0.79 (validation), Nash-Sutcliffe efficiency values of 0.75 and 0.72, and percent bias values of −0.1 and −11, respectively. The results indicated that, over the 22 years, agricultural land expanded by 52.6%, while built-up areas increased by nearly 79.2%. In contrast, shrublands and forests declined by 23.7% and 62.8%, respectively. These shifts resulted in a 24.5% reduction in groundwater recharge (−48.8 mm/y) and a 19.9% increase in surface runoff (42.8 mm/y). These findings reflect broader regional patterns and emphasize the importance of integrated land and water resource management to support ecological stability and community resilience.
Chemical waste accumulates in the environment due to the improper disposal of laboratory wastewater. Wastewater generated after inorganic analysis typically contains hardness-causing substances, resulting in elevated oxygen demand. However, conventional wastewater treatment is often prohibitively expensive, especially in resource-limited settings. An eco-friendly method is therefore essential for recycling laboratory wastewater for washing purposes. In this study, laboratory wastewater was treated using a natural adsorbent—raw plantain pseudo-stem (RPPS)—and its powdered form (PPPS). Post-treatment analysis showed significant improvement in the physical and chemical parameters. Water quality indicators, such as pH, total dissolved solids (TDS), turbidity, conductivity, biological oxygen demand, chemical oxygen demand, and concentrations of heavy metals (lead, cadmium, mercury, iron, and copper), were assessed before and after treatment using inductively coupled plasma mass spectrometry. Results showed that both RPPS and PPPS were effective, eco-friendly, and cost-efficient for laboratory wastewater treatment, with PPPS exhibiting superior adsorption performance.
Activated carbon (AC) is widely used as an adsorbent in multiple sectors, including the pharmaceutical, chemical, beverage, and food industries. This study investigates the removal of organic materials from antibiotic fermentation effluents using powdered AC at various temperatures. Pristinamycin was synthesized by cultivating Streptomyces pristinaespiralis with date syrup as a glucose substitute. The fermentation effluent was treated with activated charcoal to reduce biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Optimal removal was achieved with 30 mg/L of activated charcoal at 25°C. Under these conditions, COD decreased by approximately 52%, and 5-day BOD decreased by approximately 9.1% compared to the untreated effluent. Increasing the AC dose enhanced the efficiency of COD removal. Based on these findings, AC adsorption of antibiotic pristinamycin from wastewater appears to be a viable treatment option.
Groundwater quality in rapidly urbanizing Bharatpur areas with unregulated industries remains a critical, understudied challenge. This study addresses this knowledge gap by comprehensively assessing the physicochemical and microbiological contamination of drinking water near the Bharatpur industrial area, Nepal, using a statistical approach. Twelve physicochemical and microbiological parameters were analyzed based on the Nepal Drinking Water Quality Standard (NDWQS) and the World Health Organization (WHO) guidelines. Statistical methods(correlation and regression) and an index-based assessment (water quality index [WQI]) were used to interpret contamination patterns. The results showed that the mean values of pH, conductivity, total dissolved solids, hardness, alkalinity, and Cl− were within the WHO/NDWQS guidelines. However, NO3−, PO43− (4.3-9.8 mg/L), NH3 (7-19.5 mg/L), free Carbon dioxide (CO2), and Escherichia coli (0-9 colony-forming unit/100 mL) exceeded the limits, indicating industrial and fecal contamination. The WQI values ranged from 560 to 663, indicating that all groundwater samples were unsuitable for drinking without treatment. Statistical analysis revealed strong positive correlations among key parameters. Conductivity was strongly associated with total dissolved solid, hardness, alkalinity, CO2, NH3, Cl−, PO43−, and E. coli. Hardness, alkalinity, and CO2 showed near-perfect intercorrelations, while additional strong associations were observed between Cl− and E. coli, PO43− and NO3−, and pH and NO3−. Further validation was performed using regression analysis with a first-degree linear equation. The findings indicate that groundwater near Bharatpur’s industrial zone is critically contaminated, necessitating the urgent need for policy interventions, such as wastewater treatment to safeguard public health.
A greenhouse pot experiment was conducted to evaluate the zinc (Zn) accumulation potential of Lupinus uncinatus Schldl. The effects of varying Zn concentrations on plant dry matter yield, metal tolerance, and Zn accumulation and distribution in roots, stems, and leaves were investigated. Zn was applied as ZnCl2 at rates of, 200, 400, and 600 mg/kg. One-way analysis of variance followed by Tukey’s multiple comparison test (p<0.05) revealed significant effects of Zn on root dry weight, Zn uptake in roots, stems, and leaves, and the shoot-to-root Zn ratio. Root dry weight was significantly reduced, with the highest Zn treatment (600 mg/kg) causing a 57% reduction compared to control plants. However, no significant differences were observed in overall plant dry matter yield. Metal tolerance declined with increasing Zn stress. Zn accumulation in leaves reached 9,632 mg/kg and 14,771 mg/kg at soil Zn application rates of 400 mg/kg and 600 mg/kg, respectively. The shoot-to-root Zn ratio exceeded one, and more than 64% of the total Zn absorbed by L. uncinatus was translocated to the shoots at 600 mg/kg. These results position L. uncinatus as a promising species for Zn phytoremediation, encouraging future studies under field conditions and with other toxic metals.
Modernizing street lighting through light-emitting diode (LED) retrofits and advanced controls is recognized as an effective strategy for reducing energy use and costs. While numerous studies confirm these benefits in Western Europe, little is known about their performance in Eastern European municipalities. This study addresses this knowledge gap by presenting a case study of municipal street lighting in Bulgaria. It presents the methodology, implementation, and evaluation of an energy-efficient modernization project for municipal street lighting systems in the Bulgarian cities of Pavlikeni and Byala Cherkva. He project involved a complete transition from outdated lighting technologies (e.g., high-pressure sodium, compact fluorescent, and mercury vapor lamps) to high-efficiency LED luminaires, integrated with an intelligent control and monitoring system. An energy audit, conducted in accordance with national regulations and European standards (EN 13201), revealed that over 90% of luminaires had exceeded their operational lifespan and no longer complied with photometric and technical requirements. Lighting design classifications were applied in accordance with EN 13201:2016 to ensure compliance with the standard’s requirements for luminance, uniformity, and glare control. An optimization problem was defined and solved using specialized software to determine the lowest luminaire power, minimum pole height, and smallest bracket tilt angle, with fixed pole spacing, while maintaining regulatory compliance. Using DIALux evo, multi-scenario photometric simulations and optimizations were performed, resulting in 47 optimized lighting models tailored to specific street segments. The upgraded system incorporates adaptive dimming features, enabling nighttime power reduction through pre-programmed driver settings. A centralized cloud-based management system was implemented for remote monitoring and control, enhancing reliability and reducing maintenance. Post-implementation analysis demonstrated 79.5% energy savings (549,082 kWh/year), along with carbon dioxide emission reductions of 1,349 t/year and a financial payback period of 6.2 years. This case study highlights the technical, economic, and ecological viability of large-scale LED retrofit projects with smart controls, offering a replicable model for municipalities across Central and Eastern Europe seeking improved energy efficiency and reduced environmental impact.
Globally, waste stabilization ponds (WSPs) in warm climates have demonstrated high treatment efficiencies for organic matter and suspended solids. This study evaluates the stage-wise performance and overall treatment efficiency of the Kalobe WSPs in Mbeya city, Tanzania, which treat approximately 15,000-18,000 m3/day of mixed domestic and industrial wastewater, compared with a design capacity of 28,800 m3/day. The system comprises anaerobic, facultative, and maturation ponds operating in parallel. Field sampling and laboratory analysis were conducted to determine pollutant concentrations across each treatment stage, focusing on key parameters including biochemical oxygen demand (BOD), 5-day, chemical oxygen demand (COD), total suspended solids (TSSs), ammonia, nitrite, and total dissolved solids (TDS). Results revealed that while the WSP system demonstrated high removal efficiencies for organic and solid pollutants, achieving reductions of 58.1% for BOD, 87.3% for COD, and 87.2% for TSS, its performance in nutrient and dissolved solids removal remained limited. Ammonia was moderately reduced (80.5%), whereas nitrite and TDS exhibited low removal efficiencies of 17.4% and 13.7%, respectively. The final effluent BOD (39 mg/L) and COD (78 mg/L) exceeded Tanzania’s national discharge standards, indicating partial non-compliance. The study also found that flow variations, particularly from industrial contributors such as Pepsi and Tanzania Breweries Limited, introduced intermittent hydraulic shocks, which may impair treatment consistency. The findings highlight the need for system upgrades, enhanced industrial pre-treatment enforcement, and the integration of post-treatment units to improve nutrient polishing. Overall, while Kalobe WSPs remain a cost-effective solution, strategic interventions are necessary to ensure sustained regulatory compliance and environmental protection.
The rapid urbanization of Ho Chi Minh City (HCMC) has led to an increasingly intense urban heat island (UHI) phenomenon, significantly impacting its environment and inhabitants. This study investigates the spatiotemporal dynamics of the surface UHI (SUHI) in HCMC by utilizing a 36-year time series of Landsat satellite imagery (1988, 1995, 2002, 2010, 2017, and 2024), processed within a geographic information system framework. Land surface temperature (LST) was derived to map and quantify UHI patterns. The results reveal a substantial and progressive intensification of the SUHI effect, with the citywide mean LST increasing from 25.4°C in 1988 to 28.7°C in 2024. Spatially, the SUHI has expanded from the urban core into peripheral suburban zones, particularly toward the east and northwest. A strong and consistent negative correlation (R2 > 0.7) was observed between LST and the normalized difference vegetation index, underscoring the critical role of green spaces in mitigating urban heat. These findings provide crucial, data-driven insights for urban planners and policymakers, highlighting the urgent need for sustainable development strategies—such as enhancing green infrastructure and adopting cool materials—to combat the adverse effects of urban warming in this rapidly expanding tropical metropolis.
The Yarkand River Basin, an ecologically fragile zone in arid northwest China, is critical for regional ecological management due to its sensitivity to environmental changes. This study examines the spatiotemporal dynamics of fractional vegetation cover (FVC) from 2000 to 2023 and its correlation with climatic factors, using the moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index data and climate observations (temperature and precipitation). FVC was estimated using the pixel dichotomy method, with Sen+Mann-Kendall trend analyses, and Pearson correlation was applied to assess temporal trends and climate-vegetation relationships. MODIS land use data were reclassified to evaluate FVC variations across forestland, grassland, farmland, bare land, and other ecological types. Results revealed significant spatiotemporal heterogeneity in FVC. Spatially, Yecheng County exhibited higher FVC than Bachu County, driven by favorable topography. Temporally, FVC showed a significant upward trend post-2000, particularly in grasslands and croplands, stabilizing between 2010 and 2023. Climate analysis indicated divergent responses: farmland and forest FVC were negatively correlated with temperature (ranging from 8°C to over 9°C). In contrast, grassland and forest FVC were positively associated with precipitation (increasing by ~14 mm). A 1-2-month lag effect was observed in precipitation’s impact on FVC. The Hurst index suggested a sustained FVC growth in most regions. These findings highlight the role of climate change in driving FVC dynamics, providing a scientific basis for ecological conservation and sustainable water resource management in arid regions.