Search Results (630)

Growing pressure from shrinking freshwater supplies and worsening pollution has heightened the demand for more effective water treatment solutions, especially those that promote reuse. This review synthesizes findings from 235 peer-reviewed papers examining plant-, mineral-, and other naturally derived coagulants used in surface water purification. Overall, these materials demonstrate turbidity reduction performance on par with conventional chemical coagulants across a wide range of initial turbidity levels (roughly 50–500 NTU). They are generally inexpensive, biodegradable, low in toxicity, and produce smaller volumes of residual sludge. Most function through mechanisms such as polymer-chain bridging or charge neutralization. However, their deployment at scale is still constrained by limited commercialization pathways, technical integration issues, and uneven public acceptance. Continued cross-disciplinary work is required to refine their performance and broaden their use, particularly in regions with limited resources or rural infrastructure. Full article

Water scarcity continues to challenge arid regions such as Egypt, where growing population demands, climate change impacts, and increasing agricultural pressures intensify the need for sustainable water management. Treated wastewater has emerged as a viable alternative resource, provided that the effluent meets stringent quality standards for safe reuse. The purpose of this study was to develop a comprehensive model of the Khorshed Wastewater Treatment Plant (KWWTP) to depict the processes used for biological nutrient removal. Operational data was gathered and examined over a period of 18 months to describe the quality of wastewater discharged by the Advanced Sequencing Batch Reactor (ASBR) of the plant, using specific physicochemical parameters like TSS, COD, BOD₅, and N-NO₃⁻. A process flow diagram integrating the Activated Sludge Model No. 1 (ASM1) for biological nutrient removal was created using the GPS-X. The study determined the parameters influencing the nutrient removal efficiency by analyzing the responsiveness of kinetic and stoichiometric parameters. Variables related to denitrification, autotrophic growth, and yield for heterotrophic biomass were the main focus of the calibration modifications. The results showed that the Root Mean Square Error (RMSE) for the dynamic-state was COD (0.02), BOD₅ (0.07), N-NO₃⁻ (0.75), and TSS (0.82), and for the steady state was COD (0.04), BOD₅ (0.11), N-NO₃⁻ (0.67), and TSS (0.10). Since the model’s accuracy was deemed acceptable, it provides a validated foundation for future scenario analysis and operational decision support that produces a trustworthy model for predicting effluent data for the concentrations of TSS, COD, BOD₅, and N-NO₃⁻ in steady state conditions. Dynamic validation further confirmed model reliability, despite modest discrepancies in TSS and nitrate predictions; addressing this issue necessitates further research. Full article

Poultry farming ranks among the most rapidly expanding sectors of global agriculture, significantly contributing to food availability, improved dietary quality, and economic stability in rural areas. The sector’s efficiency stems from short production cycles and the ability to convert agricultural by-products into high-quality protein, energy, and essential nutrients. Despite these benefits, the growing scale of poultry production raises serious environmental concerns, including intensive use of land and water, high feed demand, and impacts on greenhouse gas emissions, soil nutrient balance, and water quality. This study examines the poultry industry in the Republic of Moldova, where it forms a crucial component of the agricultural economy. Drawing on recent statistical data and scientific literature, the article reviews production dynamics, farm structures, and technological adoption, offering a comprehensive overview of the sector’s current state. The findings highlight both the sector’s essential role in strengthening food security and rural livelihoods and its susceptibility to resource limitations and environmental pressures. The analysis emphasizes the importance of implementing precision livestock farming technologies, improving biosecurity, and promoting environmentally sustainable practices as key strategies for long-term sector resilience. These insights aim to support policymakers and stakeholders in developing effective strategies to ensure a competitive and sustainable poultry industry in Moldova. Full article

Climate challenges, along with a projected global population increase of 2 billion by 2080, are intensifying pressures on agricultural systems, leading to biodiversity loss, land use constrains, soil fertility declining, and changes in water cycles, while crop yields struggle to meet the rising food demand. These challenges, coupled with evolving legislation and rapid technology advancements, require innovative sustainable agricultural solutions. By reshaping farmers’ daily operations, real-time data acquisition and predictive models can support informed decision-making. In this context, smart farming (SM) applied to plant breeding can improve efficiency by reducing inputs and increasing outputs through the adoption of digital and data-driven technologies. Examples include the investment on common ontologies and metadata standards for phenotypes and environments, standardization of HTP protocols, integration of prediction outputs into breeding databases, and selection workflows, as well in building multi-partner field networks that collect diverse envirotypes. This review outlines how AI and machine learning (ML) can be integrated in modern plant breeding methodologies, including genomic selection (GS) and genetic algorithms (GAs), to accelerate the development of climate-resilient and sustainably performing crop varieties. While many reviews address smart farming or smart breeding independently, herein, these domains are bridged to provide an understandable strategic landscape by enhancing breeding efficiency. Full article

This study presents an integrated Life Cycle Sustainability Assessment (LCSA) of the Natural gas-to-methanol (NGTM) and methanol-to-gasoline (MTG) pathways using Aspen HYSYS process modeling, Environmental Life Cycle Assessment (LCA), Social Life Cycle Assessment (SLCA), and Life Cycle Costing (LCC). The results reveal significant variability in sustainability performance across process units. The DME and MTG Reactors Section generates the highest direct greenhouse gas (GHG) emissions at 0.86 million tons CO₂-eq, representing 54.9% of total global warming potential, while the Compression Section consumes 2717.5 TJ/year of energy, making it the dominant source of electricity-related indirect emissions. Distillation and Purification withdraws 31,100 Mm³/year of water—approximately 99% of total demand—yet delivers 86.6% of the overall economic surplus despite high operating costs. Social impacts concentrate in the Methanol Reactor Looping and DME and MTG Reactors Sections, with human health burdens of 305.79 and 804.22 DALYs, respectively, due to catalyst handling and high-pressure operations. Sensitivity results show that methanol purity rises from 0.9993 to 0.9994 with increasing methane content, while gasoline output decreases from 3780 to 3520 kg/h as natural gas flow increases. The findings provide process-level evidence to support sustainable development of natural gas-based fuel conversion industries, aligning with Qatar National Vision 2030 objectives for industrial diversification and lower-carbon energy systems. Full article

The effects of global change on the planet are undeniable, especially in terms of climate change, which is alarming in regions with water resource deficiencies, such as arid and semi-arid territories. One such territory is the Region of Murcia (Spain), in the southeast of which lies the Campo de Cartagena region. It is place where rainwater has historically been essential for settlement and traditional agricultural and livestock farming, giving rise to a valuable, now-forgotten water heritage. Through historical, spatial, climatic, and statistical analysis, we aim to demonstrate the significant implementation of these infrastructures in the study area and identify the causes of their abandonment, despite the continued increase in demand for water by all economic sectors, especially the agricultural, urban and tourism sectors. The results demonstrate the existence of five traditional runoff management infrastructures (cisterns, dams, runoff water channels, terracing and benching), and that the effects of global change have been decisive in their neglect, especially those related to climate change and land use modifications, in addition to increased demographic and socioeconomic pressure. Full article

Under the dual pressures of global climate change and anthropogenic activities, enhancing the ecological functions of hydraulic structures has become a critical direction for sustainable watershed management. While traditional spur dike designs primarily focus on bank protection and flood control, current demands require additional consideration of river ecosystem restoration. Numerical simulations were performed using the RNG k-ε turbulence model to solve the three-dimensional Reynolds-averaged Navier–Stokes equations, a formulation that enhances prediction accuracy for complex flows in curved channels, including separation and reattachment. Following a grid independence study and the application of standard wall functions for near-wall treatment, a comparative analysis was conducted to examine the flow characteristics and ecological effects within a 180° channel bend under three configurations: no spur dikes, a single-side arrangement, and a staggered arrangement of non-submerged, flow-aligned, rectangular thin-walled spur dikes. The results demonstrate that staggered spur dikes significantly reduce the lateral water surface gradient by concentrating the main flow, thereby balancing water levels along the concave and convex banks and suppressing lateral channel migration. Their synergistic flow-contracting effect enhances the kinetic energy of the main flow and generates multi-scale turbulent vortices, which not only increase sediment transport capacity in the main channel but also create diverse habitat conditions. Specifically, the bed shear stress in the central channel region reached 2.3 times the natural level. Flow separation near the dike heads generated a high-velocity zone, elevating velocity and turbulent kinetic energy by factors of 2.3 and 6.8, respectively. This shift promoted bed sediment coarsening and consequently increased scour resistance. In contrast, the low-shear wake zones behind the dikes, with weakened hydrodynamic forces, facilitated fine-sediment deposition and the growth of point bars. Furthermore, this study identifies a critical interface (observed at approximately 60% of the water depth) that serves as a key interface for vertical energy conversion. Below this height, turbulence intensity intermittently increases, whereas above it, energy dissipates markedly. This critical elevation, controlled by both the spur dike configuration and flow conditions, embodies the transition mechanism of kinetic energy from the mean flow to turbulent motions. These findings provide a theoretical basis and engineering reference for optimizing eco-friendly spur dike designs in meandering rivers. Full article

Failures in clean water service lines can disrupt supply, increase operational costs, and reduce customer satisfaction. This study develops a machine learning framework to predict such failures, providing a proactive tool for utility asset management. A case study was conducted on a water distribution network in Tehran, serving approximately 205,000 customers, with 11 years of service line data and over 88,000 recorded failures. Service line attributes, including length, diameter, material, age, demand, and pressure, were combined with historical failure data to train Random Forest, Extreme Gradient Boosting, and Long Short-Term Memory models. Model performance was assessed using F1-score, AUC-ROC, and AUC-PRC. A novel metric was introduced to quantify failure reduction when prioritising replacements. The results demonstrate that machine learning can effectively capture complex relationships between service line features and failures, offering significant benefits for tactical maintenance planning. This research underscores the potential of predictive approaches to improve reliability and reduce costs. Full article

This paper proposes a novel framework for embedding the Fixed And Variable Area Discharge (FAVAD) equation into the software EPANET 2.2 for the simulation of water distribution networks (WDNs). This framework yields a realistic model of leakage outflows that accounts for the expansion of the leak area as a function of service pressure. Without altering the source code of EPANET, this is accomplished by using node emitters and by iteratively adjusting emitter coefficients in the Matlab^® (R2023a) environment to mimic the effects of the FAVAD equation along WDN pipes. An additional benefit consists of preventing backflow occurring under negative pressure conditions in EPANET 2.2. The application to two benchmark WDNs under various leakage configurations demonstrates the robustness and the numerical efficiency of the framework, as well as the impact and benefits of the FAVAD formulation. For instance, for pipes with higher elasticity, omitting the expansion of the leak area leads to an underestimation of the total leakage rate that exceeds 30% for one of the studied cases. Furthermore, the algorithm successfully prevents leakage backflow under both demand-driven and pressure-driven analyses. Full article

Food systems operate as socio-ecological systems (SES) in which governance, markets, and biophysical constraints interact through feedback. However, how resilience capacities accumulate across sequential shocks, particularly in hyper-arid, import-dependent rentier states, remains under-traced. We analyze Qatar’s food-system SES across three distinct stress tests: the 2017–2021 blockade, the COVID-19 pandemic (multi-node logistics and labor shock), and the post-2022 Russia–Ukraine war (global price and agricultural input-cost shock). Using a qualitative longitudinal case-study design, we combine documentary review with process tracing and a two-layer coding scheme that maps interventions to SES components (actors, governance system, resource systems/units, interactions, outcomes/feedback) and to predominant resilience capacities (absorptive, adaptive, transformative). The results indicate path-dependent capability building: the blockade activated rapid buffering and rerouting alongside early adaptive investments; COVID-19 accelerated adaptive reconfiguration via digitized logistics, e-commerce scaling, and targeted controlled-environment agriculture; and the Russia–Ukraine shock validated an institutionalized portfolio (fiscal buffering, reserves, procurement diversification, and upstream linkages). Across episodes, supply continuity was maintained, but resilience gains also generated water–energy–food tradeoffs, shifting pressures toward energy-intensive cooling/desalination and upstream water demands linked to domestic buffers. We conclude that durable resilience in eco-constrained, import-dependent systems requires explicit governance of these tradeoffs through measurable performance criteria, rather than crisis-driven expansion alone. Full article

Worldwide, carbon fiber (CF) demand has been rising over the last decade, which contrasts with the fact that up to 30–50% of composite materials in aircraft production are scrapped. This situation highlights the increasing need for recycling methods to reduce fabrication costs and global warming potential. Emerging technologies focus on recovering long CFs, as they represent the most valuable form but are also the most difficult to reclaim using conventional recycling methods. Hydrothermal treatments offer a promising alternative to valorize this waste by decomposing the polymer matrix under subcritical and supercritical conditions without significantly damaging the fibers. Water, isopropanol, and mixtures of water/isopropanol or water/acetone were tested as solvents, with and without the addition of zinc chloride (ZnCl₂) as a homogeneous catalyst. The influence of temperature, pressure, and solvent composition on resin degradation was evaluated. In this work, degradation rates of up to 92% were achieved at 415 °C, 233 bar, 120 min, 5 wt.% IPA, and ZnCl₂ 0.1 M. It should be noted that ZnCl₂ caused reactor corrosion. Furthermore, the recovered fibers retained their morphology, including the sizing layer, and showed mechanical properties similar to the original material, while a small H₂-rich gaseous fraction was generated as a byproduct of the hydrothermal degradation. Using water–isopropanol solutions resulted in the reactor being significantly cleaner than when using water alone, which can be advantageous for future scale-up and for reducing maintenance requirements. These results confirm the potential of hydrothermal processing as an efficient and selective method for the recycling and valorization of carbon-fiber-reinforced composites from the aeronautical industry. Full article

Industrial whey dewatering via membrane processes remains challenging due to the rapid increase in viscosity, strong fouling tendencies from proteins and minerals, and the steep rise in osmotic pressure during concentration. These effects restrict operating windows and complicate energy-efficient process control. This study addresses the application of forward osmosis (FO) technology for industrial-scale dewatering of sweet whey using an Aquaporin Inside^® HFFO14 module. Various feed- and draw-side cross flow velocities (0.0397 to 0.0524 m s⁻¹ and 0.0127 to 0.0190 m s⁻¹, respectively) and draw solution (DS) osmotic pressures of 20 bar and 60 bar were investigated using a production-scale prototype plant. Sweet whey had an initial osmotic pressure of 7 bar and an electrical conductivity of 5.7 mS cm⁻¹. DS pressures of 20 bar and 60 bar resulted in a total recovery of 50% and over 80%, respectively. Water flux rates initially ranged from 10.1 to 11.6 L m⁻² h⁻¹ (LMH) and ceased at 3.3 LMH. Specific energy demand ranged from 0.15 to 1.1 kWh m⁻³. These findings support the feasibility of industrial-scale FO technology and underscore the potential of FO as an energy-efficient, sustainable solution for the dairy industry. However, frequent rinsing and cleaning routines are crucial to maintain membrane performance. Full article

Arid zones, such as the MENA regions and the Sahara countries, are experiencing significant water stress. To address this global challenge, desalination technologies provide a crucial solution, particularly the reverse osmosis (RO) technique, which is widely used to treat Seawater or Brackish water. Mauritania is among the countries facing a scarcity of potable water resources and relies on desalination technologies to meet its water demand. In this work, a numerical and experimental study was carried out on the functional and productive parameters of the Nouadhibou desalination plant in Mauritania using MATLAB/Simulink (R2016a). The study considered two operating scenarios: with and without the energy recovery unit. The objective of this paper is to perform an analytical study of the operating procedures of the Nouadhibou RO desalination plant by varying several parameters, such as the pressure exchanger, and the feed water mixing ratio in the pressure exchanger unit, etc., in order to determine the system’s optimal operating point. This paper analyzes the system’s performance under different conditions, including recovery rate, feed water temperature, and PEX splitter ratio. In Case No. 1 (without a pressure recovery unit), and with a recovery rate of 20%, doubling the plant’s productivity from 400 to 800 m³/d requires 400 kW of power. In contrast, in Case No. 2 (with a pressure recovery unit), achieving the same productivity requires only 100 kW, with a 75% of energy saving. When the desalination plant operates at a productivity of 400 m³/d@40%, the SPC decreases from 6 kWh/m³ (Case No. 1) to 2.7 kWh/m³ (Case No. 2), resulting in a 55% specific power consumption saving. The results also indicate that power consumption increases with both feed water temperature and PEX splitter ratio, while variations in these parameters have a negligible effect on permeate salinity. Full article

To enhance the abrasion resistance of TC4 titanium alloy and meet the demand for wear-resistant and corrosion-resistant friction pair materials for water-hydraulic components of marine equipment, the tribological properties of the material subsequent to ultrasonic rolling extrusion surface strengthening under seawater-lubricated conditions were investigated. The process of ultrasonic rolling machining was simulated and analyzed by the finite element method. The influence of process parameters on surface residual stress and surface roughness of TC4 was studied, and the appropriate range of process parameters was determined. The effects of key process parameters such as rolling times, static pressure, amplitude, and rotational speed on the surface properties of TC4 were investigated by the single-factor test method. Based on the response surface methodology, a prediction model of surface hardness and roughness of TC4 was constructed, and the process parameters were optimized and analyzed. The friction coefficient, wear amount, and wear rate of TC4 and CFRPEEK under seawater lubrication before and after strengthening were studied by wear tests. The wear morphologies of the specimens prior to and subsequent to strengthening were analyzed, and the friction and wear mechanisms were explored in depth. The results indicate that ultrasonic rolling extrusion surface strengthening process facilitates grain refinement in the surface layer of TC4, enhances surface hardness, and optimizes surface roughness, thereby improving its wear resistance. This is of guiding significance to the design and use of hydraulic components in seawater and has a promoting effect on the development of marine equipment. Full article

Amidst rapid urbanization, balancing ecological protection with development demands has become a critical challenge for sustainable planning. This article collected data on the natural geography and socio-economic aspects of Fuzhou City and quantified five key ecosystem services—crop production, water yield, carbon sequestration, soil conservation, and habitat quality—using the InVEST model. By using SOFM to identify different ESBs and combining sensitivity analysis to form different ecological functional zones, and using geographic detectors to detect their driving factors, this aims to provide a framework for urban green space management. The results indicate that ecosystem services have a significant northwest southeast spatial gradient and can be divided into five types of ESBs. Among them, the core ecological clusters account for 59.36% of the study area and are mainly distributed in the forest-covered northwest region. Based on different service bundles and sensitivity levels, it is divided into five ecological functional zones. Geographic detector analysis shows that the interaction effect between natural factors (such as altitude and precipitation) and socio-economic factors (such as GDP density and land use) significantly enhances the explanatory power of ESB distribution. This study provides a transferable model for ecological management in global coastal cities facing similar terrain complexity and urbanization pressures. The framework demonstrates how understanding ecosystem service packages and their driving factors can effectively guide urban ecological planning decisions and provide valuable insights into coordinating ecological protection and urban development through targeted green space management methods. Full article