Advancing solar steam generation for seawater desalination: Global research trends, photothermal materials, structural innovations, and future directions

Application of multi-criteria decision-making for seawater desalination: A review

Amidoxime modified polyacrylonitrile membrane for simultaneous seawater desalination and uranium extraction: molecular dynamics simulation and experiments

Interfacial solar evaporation offers a sustainable route for seawater desalination, addressing global freshwater scarcity by harnessing solar energy for efficient water evaporation. However, its performance is typically constrained by the availability and intensity of sunlight. Here, we report a novel evaporator design that overcomes this limitation by extracting substantial thermal energy from the bulk water to sustain high evaporation rates even in the absence of solar input. Through rational structural design and optimization of thermal conductivity of the evaporator support, the obtained evaporators harvest energy from the bulk water far exceeding the incident solar flux, enabling rapid evaporation under diverse weather conditions. The optimized evaporator achieves an exceptional evaporation rate of 11.15 kg m-2 h-1 under 1.0 sun. This design strategy expands the operational window of interfacial solar evaporation and offers a robust pathway toward continuous, high-efficiency desalination in real-world environments.

Integrated solid oxide fuel cell and air gap membrane distillation for efficient heat management and sustainable seawater desalination

Making waves: Conceptualization of seawater-augmented potable reuse.

Valorisation of seawater desalination brine via cultivation of a halotolerant microalga in bubble column photobioreactors.

Many tropical islands and coastal communities suffer from high energy costs, unreliable electrical supplies, poverty, and underemployment, which are all exacerbated by climate change. Multi-use Ocean Thermal Energy Conversion (OTEC) systems could align with the goals and values of these underserved and remote communities. Developing multi-use OTEC systems could help meet the United Nations’ Sustainable Development Goals #7 (Affordable and Clean Energy) and #13 (Climate Action). Multiple uses of OTEC water and power are explored in this study, including seawater air conditioning, desalination, support for aquaculture in tropical regions, and other uses. A use case for an onshore OTEC plant at the location of the existing OTEC plant in Kona, Hawaii, is examined to determine if sufficient thermal resources exist for OTEC power generation year-round, and to determine the potential for each value-added use. Potential environmental effects are evaluated using a new open-source numerical model for determining the risk from the discharge of large volumes of cold deep seawater in the ocean. Companies currently using the cold deep seawater pumped ashore at the Kona location were surveyed to determine their dependence on and interest in expanded OTEC and cold-water availability at the site. The analysis indicates that multi-use OTEC is feasible, with seawater air conditioning (SWAC), aquaculture, and desalination being the most compatible immediate additions, while future potential exists for adding extraction of critical minerals from seawater and e-fuel generation.

Framework materials offer abundant ion-intercalation sites; however, their desalination performance is often limited by structural instability and low site utilization due to water molecule cointercalation. Herein, we employ interface engineering by coating the framework material with a compact polymer mediator layer. This approach facilitates ion transport while blocking water molecules and synergistically introduces supplementary active sites. Exemplifying this strategy, a composite material (denoted PCN) is fabricated using NiHCF (a Prussian blue analogue) and polyaniline (PANI). PCN enables efficient dual-ion (Na+ and Cl-) extraction in symmetric flow-electrode capacitive deionization (FCDI) systems for seawater desalination. Mechanistic investigation reveals that the enhanced performance is not primarily attributed to improved electronic/ionic conductivity from PANI. Instead, the PANI layer forms a hydrophobic interface and introduces nitrogen sites, enabling synergistic dual-ion extraction. This compact mediator layer effectively prevents water molecule coinsertion, incorporates nitrogen-rich active sites, and ensures structural stability, thereby enhancing site utilization efficiency. This work demonstrates that modulating material interfaces to suppress H2O-induced side reactions and augment active site availability advances electrochemical ion extraction for water purification.

In recent years, the development of high-performance membranes for seawater desalination has attracted significant attention. This work proposes a novel model by employing a boron nitride nanotube (BNNT) as a support in lamellar boron nitride (BN) membranes. The effects of structural parameters as well as the role of nanotubes on seawater desalination performance are explored systematically via nonequilibrium molecular dynamics simulations (NEMD). In addition, the transport mechanism for water molecules and the separation mechanism for ions transmitted through the BN-BNNT membranes are elucidated at the molecular level. Simulation results indicate that the BN-BNNT membrane exhibits a higher water flux rate compared to the BN membrane. Additionally, reducing the gap width from 10 Å to 8 Å leads to a higher ion rejection rate but a significant decrease in water flux rate. The rejection rates for Na+ and Cl- ions are promoted by increasing the interlayer spacing to larger values. This phenomenon can be attributed to the trapping of water molecules and hydration ions in the interfacial regions formed between the BN and BNNT nanosheets. It is possible to simultaneously increase the water flux and interception by inserting nanotubes and adjusting the distance of the interlayer spacing. This study suggests that the stability of lamellar nanomembranes can be enhanced through the incorporation of nanotubes as a support. Simultaneously, it is possible to enhance the rejection rate in such membranes without decreasing the water flux rate by adjusting the relevant structural parameters.

Electrodialysis (ED) is a promising seawater desalination technology using electricity. However, the existing research studies on ED mainly focus on design of electrode materials and device structure. The ED is a multiscale and multi-physical process with multiple influencing parameters. Under these circumstances, the complicated ED process needs to be unified for understanding its physical essence and further optimization. In the current work, a similarity principle-based multiscale model is constructed to analyze ion migration mechanism inside ED device. The multiscale model is developed by correlating cation and anion concentration difference in a mesoscopic nanopore with macroscopic space charge density. On the basis of non-dimensionalization of Poisson-Nernst-Planck equations, the mesoscopic model of ED is unified with three dimensionless variables instead of eight-dimensional input parameters, which can be categorized as representative of ion absorption capability, ion transport characteristic, and nanopore characteristic. Then, the macroscopic model of ED is further unified using 6 dimensionless variables instead of 12-dimensional input parameters, and their physical meaning include ion absorption capability, ion transport characteristic, ion migration driving force, and desalination tank characteristic. The similarity principle of multiscale ED process is verified through nine dimensional different cases with identical dimensionless variables. The dimensionless cation-anion difference in nanopores of mesoscopic model varies within 0.25%, and the dimensionless outlet Na⁺ concentration of macroscopic model changes within 0.05%. Besides, a multi-physical sensitivity analysis is also carried out using the Taguchi method to clarify dominant parameters for ED. The Taguchi sensitivity analysis quantifies parameter contribution to seawater desalination rate in ED as seawater temperature 39.74%, initial ion concentration 15.94%, applied electric potential 15.91%, desalination tank length 11.45%, ion exchange membrane porosity 8.76%, and seawater flow velocity 8.19%. The current work lays a theoretical foundation for developing experimental correlations of ED, and it also contributes to rapid sampling generation in artificial intelligence prediction.

The Montreal Protocol established stringent international regulations concerning the production, consumption, and trade of ozone-depleting substances, including chlorofluorocarbons and hydrofluorocarbons, aimed at safeguarding the Earth's ozone layer. In this context, cyclopentane has emerged as an environmentally sustainable alternative owing to its zero-ozone depletion potential and low global warming potential. This review examines the physicochemical properties, industrial applications, and production methods of cyclopentane, with particular emphasis on its utilization as a refrigerant, a blowing agent in rigid polyurethane foams, and a hydrate-forming agent for seawater desalination. The primary applications are concentrated in refrigeration and thermal insulation, where cyclopentane-based foams demonstrate superior thermal conductivity and mechanical stability relative to conventional agents. However, the flammability of cyclopentane vapor presents operational challenges that necessitate the implementation of appropriate safety measures. Advances in catalytic reaction-distillation and extractive distillation processes may improve the efficiency of cyclopentane production and product purity in industrial settings. This review underscores cyclopentane’s efficacy as a substitute for compounds with higher ozone depletion potentials and emphasizes the importance of ongoing research into scalable, economically viable production technologies and safe industrial integration to fully realize its environmental and practical benefits.

Hydrogel-based solar-driven interfacial vapor generation is considered an effective method for freshwater production. However, traditional hydrogel evaporators suffer from weak mechanical strength and the trade-off between high evaporation rates and salt resistance, which limits their practical applications. Inspired by the unique water transport mechanism of natural reed, we construct a cellulose nanofiber-enhanced hydrogel evaporator with a hierarchical gradient pore structure. Microscale surface roughening design in hydrogel emulates leaf stomatal transpiration, enhancing light absorption while maintaining high vapor escape efficiency. Its bottom-to-top gradient pores enable rapid capillary-driven water transport and sustained interfacial supply, achieving efficient thermal-mass balanced evaporation. More importantly, the bilayered gradient hierarchical structure enables directional salt diffusion back to bulk water, effectively preventing salt crystallization. As a result, the hydrogel evaporator achieves an optimal evaporation rate of 2.61 kg m-2 h-1 under 1 sun. In a 20 wt% NaCl solution, a stable evaporation rate can be maintained without salt deposition. Moreover, the hydrogel evaporator is able to remove more than 99% of the primary metal ions from seawater and almost completely remove the dye ions from the dye solution. This work demonstrates a promising application in seawater desalination and dyeing wastewater treatment.

Water Resource Carrying Capacity (WRCC) plays a crucial role in promoting regional sustainable development. However, current studies on WRCC in coastal regions rarely consider marine-related indicators and future projections. To address these gaps, this study incorporates marine-related indicators to analyze the spatiotemporal evolution and key obstacles of WRCC in China’s coastal provinces from 2013 to 2022, and further predicts its trends over the next five years. The results indicate that from 2013 to 2022, WRCC in the region exhibited a fluctuating upward trend but remained at a relatively low level, showing a spatial distribution pattern of Southern > Eastern > Northern regions. A significant negative global spatial autocorrelation in WRCC was observed only in 2022. The spatial dispersion first expanded and then contracted, with the center gradually shifting northeastward each year. The main obstacles affecting WRCC in China’s coastal provinces include per capita coastline length, ecological water use ratio, per capita water resources, and the scale of seawater desalination projects. WRCC is expected to continue a modest increase over the next five years, though it will remain at Level III. These findings provide valuable insights for managing water resource challenges in coastal regions worldwide.

Nanofiltration (NF) membranes are critical for seawater desalination, wastewater treatment, and ion separation. However, conventional polyamide membranes suffer from irreversible damage, resulting in performance decline and increased operational costs. Developing self-healing PA-based NF membranes remains a major challenge. Herein, we fabricate a high-permeability, self-healing NF membrane via interfacial polymerization (IP) using thermally reversible Diels-Alder (DA) bonds to enable damage recovery. A furan-functionalized polyethylenimine was synthesized as the aqueous monomer, whereas 6-maleimidohexanoyl chloride and trimesoyl chloride served as organic monomers. During IP, acyl chloride formed robust amide bonds with amines, while DA reactions between maleimide and furan groups enabled self-healing. The membrane achieved a water flux of 36.5 L m-2 h-1, >95% Na2SO4 rejection, and with a molecular weight cutoff (MWCO) of 561 Da. After thermal repair, the damaged membrane recovered 88% Na2SO4 rejection, and the MWCO is maintained at 857 Da. This work presents a promising strategy to improve the performance and durability of PA NF membranes.

The intensifying global freshwater crisis has amplified the strategic importance of non-conventional water resources (NCWRs), particularly desalinated seawater (DSW) and potable reclaimed water (PRW). Effectively allocating these diverse NCWRs requires balancing ecological protection with economic development. However, the lack of a systematic method for quantifying their multicriteria value across economic-ecological nexuses hinders sound decision-making. Based on emergy theory, this study improves the comprehensive value assessment framework by adding ecological cost value, which is used to assess the multicriteria value of DSW and PRW. The results show that the ecological costs of DSW and PRW were 5.86 × 1010 and 2.44 × 1011 sej/m3, respectively, which indicates that the impact of emissions on the environment cannot be ignored. The environmental-economic values of DSW and PRW were 4.137 × 1012 and 4.80 × 1013 sej/m3, with cost-effectiveness ratios of 1:0.001 and 1:4.92, respectively. The assessment framework proposed in this study offers a comprehensive approach to water resource valuation, demonstrating the pronounced advantages of PRW over DSW. Additionally, the active promotion of NCWRs utilization and the continued refinement of the management system are crucial for advancing their development. These findings provide policymakers with a scientifically grounded tool to optimize water allocation strategies that balance economic and environmental objectives.

Water scarcity is a growing global issue, necessitating innovative and sustainable solutions for freshwater generation. Among the available technologies, reverse osmosis (RO) has become the primary method for seawater desalination due to its effective salt rejection and high energy efficiency. This study presents an integrated experimental and analytical investigation of a full-scale seawater reverse osmosis (SWRO) plant with a 2 MLD capacity at the Victoria and Alfred (V&A) Waterfront in Cape Town, South Africa. Operational data were collected over six months, including feedwater temperature (13.66 –16.78 °C), pressure (50–60 bar), total dissolved solids (32,883–38,387 mg/L), and pH (6.19–7.89). The plant consistently produced high-quality permeate with TDS around 500 mg/L, achieving a 31% recovery rate at an average energy consumption of 3 kWh/m³. Machine learning models, specifically multiple linear regression and decision trees, were used to predict RO performance and to explore the relationships between operational parameters. Results show that higher feed pressure improves permeate flux but raises energy use, increased feedwater temperature boosts flux and slightly reduces energy consumption, while deviations from near-neutral pH negatively impact product quality and efficiency. The novelty of this work lies in combining real plant operational data with predictive analytics to establish parameter-based performance relationships and identify optimal operating ranges (e.g., feed pressure ~52–55 bar, pH ~7). These insights provide a strong foundation for optimizing desalination processes, improving membrane efficiency, and guiding the design and operation of future RO desalination projects.

Water – energy – environment nexus in seawater desalination and cryptocurrency mining

Pyramidal array Janus hydrogel-based solar evaporator via broadband light trapping inspired by durian peel for efficient seawater desalination.

Performance of seabuckthorn (Hippophae rhamnoides Linn.) fruit residues derived biochars in the solar steam generation efficiency in seawater desalination and pollutant removal