Inorganic scaling, governed by complex organic-inorganic interactions, presents a pervasive challenge in aqueous environments with broad implications for engineering systems. Using reverse-osmosis (RO) desalination as a model platform, we investigate how mixed organic foulants influence inorganic gypsum scaling at membrane-water interfaces. Representative proteins, humic substances, and polysaccharides are employed as model foulants to reveal their roles in modulating gypsum crystallization behavior. By integrating advanced in situ, time-resolved synchrotron X-ray scattering within the concentration polarization layer-a region typically inaccessible to conventional characterization techniques-with modelling, spectroscopic, and imaging analyses, we track the evolution of gypsum scaling from nanoscale precursors to mature crystals. Our findings reveal that different classes of organic foulants regulate gypsum crystallization through distinct mechanisms, ranging from inhibiting precursor aggregation in the bulk solution to altering interfacial physicochemical properties that govern the kinetics of heterogeneous nucleation and growth. These findings provide molecular-level insights into the coupled dynamics of organic fouling and inorganic scaling, advancing mechanistic understanding of crystallization at functional interfaces. Such insights offer guidance for the rational design of anti-scaling strategies in engineering systems.

Temporal insights into electromagnetic field-tuned scaling pathways of CaCO3 and CaSO4•2H2O during reverse osmosis desalination of real brackish water

Analysis of feed fluctuations on Ocean Wave-Powered Reverse Osmosis (WPRO) desalination using transient model

Desalination based on carbon nanomembranes offers high water permeance and salt rejection, making them promising for addressing global freshwater shortages and energy demands in reverse osmosis (RO) desalination. Enhancing ion rejection by modulating the energy barrier for ion transport through wide carbon nanotubes (CNTs) is a critical challenge for highly efficient desalination. We perform molecular dynamics simulations on water desalination using CNTs membranes, highlighting the key role of nanoconfinement coupled with an electric field. The results show that the electric field extends the threshold of CNT diameter required for complete ion rejection from 1.10 nm to 1.50 nm, achieving ∼100% ion rejection while maintaining water permeance of ∼97 L cm-2 day-1 MPa-1. The calculated energy barriers for ion transport demonstrate that the applied electric field significantly increases the inhibitory effect of wide CNTs on ion permeation. We elucidate that the molecular mechanism governing the free energy barrier of ion arises from the polarization of confined water induced by the coupling of the electric field and CNTs, leading to the stripping and reorganization of the ion hydration shell. This approach achieves water permeance that is up to three orders of magnitude higher than that of commercial RO membranes, enhancing the application potential of CNTs membranes coupled with external fields for water desalination. We expect this work to be valuable for understanding the thermodynamic and kinetic behaviors of solute transport and separation induced by molecular mechanisms.

Achieving both efficient water transport and complete salt rejection in synthetic water channels continues to pose a significant challenge for reverse osmosis (RO) desalination. In this study, we design a series of functional porous organic cages (POCs) by grafting fluorine (-F), hydroxyl (-OH), amino (-NH2), and methyl (-CH3) into the interior of a prototypical CC3 cage to construct CC3-F, CC3-OH, CC3-NH2, and CC3-CH3 channels, respectively. Subsequently, molecular dynamics simulations are conducted to explore how different chemical functional groups influence the desalination performance of these CC3-based channels embedded in a lipid bilayer. It is revealed that water transports through the channels in a single-file manner, and all the channels exhibit complete salt rejection. Water fluxes follow the order: CC3-F > CC3-OH > CC3 > CC3-NH2 > CC3-CH3, as attributed to the steric hindrance and hydrogen bonding of functional groups that affect water-channel interaction and alter the dynamic configuration of confined water molecules in the channels. Furthermore, wetting-dewetting transition is found to be largely suppressed in the hydrophilic channels. From temperature-dependent water flux, activation energies are estimated to range from 12 to 20 kJ/mol in CC3-based channels, lower than those in polyamide RO membranes. From bottom-up, this simulation study reveals molecular-level mechanisms of the role of functionalization in tuning water transport in one-dimensional subnanometer channels and provides a theoretical basis for designing high-performance synthetic water channels toward next-generation desalination technologies.

This research focuses on synthesizing a novel antiscalant and exploring the inhibition of CaSO4 and CaCO3 scaling in reverse osmosis desalination technology. The antiscalant bearing residues of aspartic and maleic acid (MA) has been synthesized via alternate cyclopolymerization of N,N-diallylaspartic acid [(H2CCH-CH2)2NH+CH-(CO2 -)-CH2CO2H] and MA. The performance of the antiscalant and several commercial ones was evaluated against supersaturated CaSO4 and CaCO3 solutions. At a 2.5 ppm concentration, the antiscalant imparted percent scale inhibition (PSI) of ≈100% for CaSO4 until 820 min [i.e., induction time (IT) after which scaling starts]. The superior performance of the antiscalant was ascertained at 0.5 and 1 ppm concentrations at 40 °C, where it showed ITs of 40 and 60 min, respectively, which are sufficient to mitigate scaling during the 15 min residence time of the reject brine in the osmosis chamber. The antiscalant was also examined for the mitigation of CaCO3 scaling.

Abstract Water scarcity poses major constraints to sustainable rural development, particularly in arid regions. In Egypt, limited freshwater resources are increasingly prioritized for domestic use, compelling proposed large-scale land reclamation projects to rely on brackish groundwater. However, marginal water quality restricts cultivation to salt-tolerant crops, undermining the long-term profitability of ongoing agribusiness activities. This study is the first to evaluate the techno-economic viability of integrating decentralized desalination systems into the Moghra development area. A systematic hydrochemical assessment of 73 wells, using the Irrigation Water Quality Index (IWQI), classified 49 as “Severe Restriction” and 24 as “High Restriction”, confirming widespread concerns about groundwater suitability. A two-stage reverse osmosis (RO) desalination system powered by photovoltaic (PV) energy was designed to achieve a 70% recovery rate. An optimization model identified blending ratios that maximize post-treatment water quality while minimizing the desalinated water volume. Results showed substantial improvements: the average sodium adsorption ratio (SAR) decreased by 66%, and IWQI increased from 34 to 77. Consequently, 68 wells were reclassified as “Low Restriction” and 5 as “Moderate Restriction”, enabling a shift from salt-tolerant olives to higher-value crops (e.g., wheat–maize rotation). A cost–benefit analysis assessed trade-offs between desalination costs and resulting economic returns. Under the abstraction limit, the proposed RO–PV blending strategy yielded a 35% higher net present value (NPV) and a 15.7% internal rate of return (IRR), demonstrating both technical and financial viability. These findings provide actionable insights for policymakers, stakeholders, and investors to enhance water productivity and agricultural sustainability in arid regions.

Machine learning-driven process design and performance prediction for small-scale seawater reverse osmosis desalination

Hydrogen-integrated power management for hybrid renewable energy-driven reverse osmosis desalination: Enhancing water and energy sustainability in remote areas in Egypt

Multi-objective optimisation of a seawater reverse osmosis desalination system driven by vertical axis wind turbines: technical, economic, and environmental perspectives

Maximizing CO2 mineralization for a concurrent treatment and resource recovery system of seawater reverse osmosis desalination waste brine through electrochemical generation of alkali.

Abstract Integration of renewable energy sources and desalination systems can offer potential solutions to face global freshwater scarcity in a clean and sustainable approach. In this work, a standalone system constructed from a reverse osmosis desalination unit powered by a wind turbine through a hydromechanical drivetrain is designed and evaluated in a simulation environment. The adoption of a continuously variable hydromechanical drivetrain enhances the isolation of reverse osmosis operation from the effects of wind speed variations. An adaptive real-time optimal control system, based on the extremum seeking control algorithm, is adopted to ensure freshwater availability under a wide range of operating conditions. The adopted controller maintains the highest efficiency of the reverse osmosis process under different wind speed profiles. The simulation results using realistic wind speed profiles showed the ability of the proposed system to desalinate seawater and produce freshwater with a salinity level below 600 ppm, which is suitable for human consumption.

Synthesis of 2D nickel MOF nanosheets incorporated in thin film nanocomposite membranes for efficient reverse osmosis desalination.

Freshwater scarcity remains a critical challenge in small island regions, particularly in archipelagic countries such as Indonesia, where seawater is abundant but access to clean freshwater is limited. Tunda Island, located in Serang Regency, Banten Province, exemplifies this condition, as local communities primarily depend on rainwater harvesting and shallow groundwater sources to meet daily water demands. This study aims to evaluate a modified reverse osmosis (RO) desalination system integrated with coconut shell–based activated carbon as an adsorptive pretreatment medium for seawater desalination. The coconut shell adsorbent was employed to enhance pretreatment efficiency and improve the overall performance of the RO system. Seawater samples collected from Tunda Island were processed through the integrated system, and the quality of the treated water was evaluated according to the Indonesian Ministry of Health standards. Key parameters analyzed included Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), pH, color, and temperature. The results demonstrated that the treated water achieved COD of 120.10 mg/L, BOD of 10.5 mg/L, TSS of 3.76 mg/L, TDS of 117.245 ppm, pH of 7.30, clear color, and a temperature of 27°C, indicating compliance with applicable water quality standards. These findings confirm that the integration of coconut shell–based activated carbon with reverse osmosis effectively improves desalination performance and produces freshwater suitable for domestic use.

At present, the global shortage of water resources has led to serious challenges, and traditional water production technologies such as seawater desalination and atmospheric water harvesting have certain limitations due to inflexible operation and environmental conditions. This study proposes a novel water production system (called “NeWater” system in this paper), which combines saline water desalination with atmospheric water-harvesting technologies to simultaneously produce freshwater from brackish water or seawater and ambient air. To evaluate its performance, an integrated thermodynamic and mathematical model of the system was developed and validated. The NeWater system consists of a vapor compression refrigeration unit (VRU), a direct evaporation unit (DEU), up to four heat exchangers, some valves, and auxiliary components. The system can be applied to areas and scenarios where traditional desalination technologies, like reverse osmosis and thermal-based desalination, are not feasible. By switching between different operating modes, the system can adapt to varying environmental humidity and temperature conditions to maximize its freshwater productivity. Based on the principles of mass and energy conservation, a performance simulation model of the NeWater system was developed, with which the impacts of some key design and operation parameters on system performance were studied in this paper. The results show that the performances of the VRU and DEU had a significant influence on system performance in terms of freshwater production and specific energy consumption. Under optimal conditions, the total freshwater yield could be increased by up to 1.9 times, while the specific energy consumption was reduced by up to 48%. The proposed system provides a sustainable and scalable water production solution for water-scarce regions. Optimization of the NeWater system and the selection of VRUs are beyond the scope of this paper and will be the focus of future research.

Conventional thin-film composite (TFC) reverse osmosis (RO) membranes experience irreversible performance loss at high temperatures, restricting their use in industries with high-temperature streams, including oil and gas, pharmaceuticals, electronics, power generation, food production, and hybrid desalination plants. However, the mechanisms driving the performance decline of TFC membranes at high temperatures remain poorly understood. Herein, we combine controlled experiments, molecular dynamics simulations, and micromechanical modeling to elucidate TFC failure mechanisms and to evaluate thermally resilient thin-film cross-linked (TFX) composite membrane. Upon exposure to elevated temperatures (>60°C), salt rejection of TFC dropped from ~99 to <90%, with irreversible structural damage in the polysulfone layer, confirmed by scanning electron microscopy. In contrast, the TFX membrane maintained ~99% salt rejection and showed no signs of physical degradation up to 80°C. Our combined analyses revealed that TFC membrane failure arises from irreversible pore expansion in the thermoplastic polysulfone support, leading to polyamide film rupture and delamination. TFX membranes resist thermal deformation, enabling ultrahigh-temperature RO desalination and water reuse.

Objective: To evaluate, from technical, economic, and socio-environmental perspectives, two structural alternatives designed to mitigate water scarcity scenarios in the Camboriú River Basin and adjacent watersheds (Santa Catarina, Brazil): a seawater reverse osmosis desalination plant and a multipurpose floodable park. Theoretical framework: The study is grounded in the concepts of water security, water governance, Nature-Based Solutions, grey infrastructure, and multicriteria decision-making approaches applied to water resources planning in coastal basins under anthropogenic pressure and climate variability. Method: A multicriteria analysis model was applied, integrating technical, economic, and socio-environmental indicators. Variables were weighted by experts and local water governance stakeholders using ordinal scales and a magnitude–importance matrix for environmental impact assessment. Results and discussion: Results indicate that the floodable park shows better economic performance and relevant socio-environmental benefits but faces significant territorial constraints and structural interferences. The desalination plant achieved superior technical performance and a more homogeneous socio-environmental profile, particularly due to continuous water production and reduced pressure on freshwater sources. The integrated assessment identified desalination as the most strategic alternative under severe scarcity scenarios. Research implications: The findings support regional water planning processes and provide decision-making support for public managers responsible for water security in urbanized coastal basins. Originality/value: The study advances knowledge by comparatively assessing green and grey infrastructure within a single, replicable multicriteria framework, contributing to hybrid decision-making strategies in water resource management.

Desalination powered by renewable energy is still not widely applied. Its developmentis limited to pilot plants and small units, mainly located in remote areas. This paperproposes the Water Higher Technical Institute (WHTI) – Al-Egailat city fortheoretical study of such a system to desalinate brackish water using RO systempowered by solar PV on small scale. All the data used are based on a statistical solarenergy available from historical charts and the proposal data of a PV-powered ROsystem suited for such design purpose from trusted manufactured company.Al-Egailat city (South Mediterranean coast) is highly qualified for testing of suchsystems since it has a huge water aquifer and several water well of a salinity of (2500)ppm., the paper presents the design of the PV-powered RO water desalination system.Based on the climate conditions in Al-Egailat, the paper presents a comprehensivedesign and simulation of a standalone solar-powered reverse osmosis (RO)desalination system for brackish water producing 20 m³/day of freshwater. Thestudy covers:• System sizing (PV, battery, RO units).• Energy-water nexus optimization.• Simulation results (PVsyst, HOMER Pro).• Economic and environmental benefits(health and social conditions).M.I.K. and AlMishriqy 38926• Building up of local capabilities and expertise in the field of waterdesalination by solar electric systems.The proposed system uses 18 KWp solar PV, 138 kWh LiFePO₄ storage, and fourparallel 5 m³/day RO units, achieving a Levelized Cost of Water (LCOW) of $0.50–0.80/m³, making it viable for off-grid communities.

Biofouling is a significant operational challenge in seawater reverse osmosis (SWRO) desalination, particularly in biologically active environments like the Arabian Gulf. This study assesses the operational and economic impacts of implementing SpectroMarine, an autonomous real-time monitoring system, in a 100,000 m 3 /day SWRO facility. SpectroMarine leverages in-situ fluorescence and UV-visible absorbance measurements to detect early-stage biological activity in feedwater, enabling predictive maintenance and proactive fouling control. An economic model was constructed using literature-based operational baselines, including membrane lifespan, cleaning frequency, specific energy consumption, chemical dosing, and downtime. Implementation of SpectroMarine is projected to reduce energy consumption by 3%, cleaning-in-place (CIP) frequency by 50%, membrane replacement costs by 20%, and pretreatment chemical usage by 25%. Furthermore, unplanned downtime may be reduced by up to 50%. The model estimates annual savings of approximately 2.89 million SAR, with a payback period of less than 2 months under Gulf-specific operating conditions. The presented results are based on a literature-derived economic model incorporating sensitivity analysis, and no site-specific field validation has been conducted at this stage.

Sustainable water management in urban environments requires exploring alternatives that reduce pressure on conventional water resources. Among other options, this study analyzes the technical and economic feasibility of wastewater reuse versus reverse osmosis desalination for urban water supply in coastal cities, using Spanish cases such as Madrid, Barcelona, Seville, and Bilbao as a reference. In areas such as the Cantabrian coast, traditionally well-supplied, resource pressure and climate change raise the need for resilient alternatives for water supply. Reuse requires adding advanced tertiary treatment to existing WWTPs. Total costs (investment and operation) are estimated at €0.780/m³, also considering the need to build a secondary distribution network for non-potable uses, which represents a structural limitation. The main operating costs of regeneration are related to energy, reagents, waste management, and maintenance, while investment costs in transport networks represent a considerable burden. This option is economically advantageous compared to desalination, especially where existing infrastructure exists and the climate favors a significant demand for reused water. Reverse osmosis desalination, on the other hand, has higher costs, with an estimated total cost of €1,271/m³. However, its main advantage is that the water produced is suitable for human consumption and can be directly integrated into the main water supply network without the need for additional secondary networks. This makes it a more robust option in contexts where increased resilience to droughts or meeting drinking water demands are required. However, its higher energy consumption and operating costs make it less economically competitive compared to reuse, except in cases where urban or climatic characteristics make the latter difficult to implement. The study concludes that the most appropriate option depends on the local context and allows decision-making to be guided toward context-adapted solutions based on both technical and economic criteria. Key Words: water, reuse, desalinization, urban, cities, economy