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Amidst the escalating global water scarcity issues, finding better ways to sustainably treat brackish water and seawater while simultaneously recovering resources becomes increasingly important. In this work, we investigated the fabrication strategies to produce polyethersulfone hollow fiber membranes (PES HFMs) with robust characteristics and uniformly arranged shape. The presence of an air gap (AG) in the dry-wet spinning process facilitates the chain orientation due to the gravitational force and elongational stretch and moisture-induced early phase inversion, therefore preventing corrugations on the shell side. We extensively studied the correlation between HFM spinning parameters and the appearance and disappearance of buckling effects. Moreover, it was proven that the addition of N -methyl-2-pyrrolidone (NMP) to the bore fluid composition prolongs the demixing process, overcoming the HFMs' delamination issue. After optimizing the spinning conditions, a facile alkali-induced interfacial polymerization (IP) was employed to enhance the formation of a selective polyamide (PA) layer on PES HFM substrates. The final membrane made by this modification process, denoted as PES-IP-BOH, exhibits a Na 2 SO 4 rejection higher than 96 %, while maintaining low rejections for other monovalent salts. Accordingly, it achieved a high ideal selectivity of >23 for the selective separation of monovalent and divalent salts. • PES HFMs for the precise separation of monovalent and divalent salts were produced. • The transition to a dry-wet spinning process hindered the shell side's deformation. • An increase in air gap or take up speed led to a higher critical buckling pressure. • NMP incorporation in the bore fluid overcame the delamination issue. • A novel alkali-induced IP process enhanced the crosslinking degree of HPEI and TMC. [ABSTRACT FROM AUTHOR]

Interfacial water evaporation, powered by solar energy, holds great promise to extract freshwater from seawater on a global scale. It has the potential to address the world's water scarcity challenges using renewable energy. While the ideal design of evaporator materials is critical to the interfacial vaporization desalination, tailoring the structures and compositions of solar evaporators and figuring out the structure/composition-performance relationship of evaporators remains unexplored. Herein, 3D macroporous "brick-concrete" MXene/sodium alginate aerogel (MSA) evaporators were designed and fabricated with constant MXene content and varying polymer loading. The as-made MSAs show sodium alginate-dependent evaporating performance with an optimum evaporation rate of 3.28 kg m−2 h−1 (1 sun). This exceptional rate is attributed to several factors, including enhanced light absorption, optimized pore sizes, reduced enthalpy of evaporation and improved water transport. The water molecule states and hydrogen bonding network in the aerogels can be tuned by their compositions, resulting in the reduced evaporation enthalpy, the monolithic structures with controlled thermal conductivity facilitate the exploitation of environmental energy, leading to the high evaporation rate. Our study not only establishes design principles for achieving superior evaporation performance, but also sheds light on the relationship between structures, compositions, and performance of solar evaporators. • The "brick-concrete" structures were used to optimize the pore sizes of the 3D photothermal evaporators. • The functions of MSAs in water transport and hydrogen bond activization were systematically analyzed. • The as-prepared MSAs show excellent evaporation performance and reusability. [ABSTRACT FROM AUTHOR]

Water scarcity has become a global issue that needs to be addressed urgently. Solar steam generation (SSG) is a promising technology to alleviate the water crisis through desalination and condensation. However, the stability and efficiency of SSG can be seriously impacted by salt accumulation after prolonged operation. Common salt rejection schemes are only applicable for low-salinity (<10 wt%) desalination. In this work, inspired by the cactus's fog-capturing feature, the atmospheric water harvesting (AWH) function is integrated by an interlocked braided fibrous framework (IBFF) to absorb moisture for sustainable salt dilution during high salinity (20 wt%) desalination. The loop-pile density/height of IBFF is regulated to mimic the cactus roots/spines with different architectures, thus optimizing the water absorption/moisture harvesting performance. The excellent moisture-induced salt dilution ability ensures efficient and sustainable high salinity desalination performance over cyclic operation, with an exceptional evaporation rate of up to 3.11 kg m−2·h−1 under 1 sun radiation. Overall, this new approach offers a practical possibility for durable and competitive high salinity desalination with a continuous water/moisture supply. • A salt-rejection mechanism combined with advection-diffusion and moisture harvesting is proposed for sustainable salt dilution during high salinity SSG. • A scalable interlocked braided fibrous framework with tunable loop-pile density/height is fabricated for optimized water circulation and moisture harvesting • The indoor/outdoor long-term desalination and salt rejection process under various conditions and climates is recorded to demonstrate the self-recovering salt dilution ability. [ABSTRACT FROM AUTHOR]

Amid escalating water scarcity and rising energy prices, the scientific community strives to propose innovative and efficient water treatment solutions. In this context, solar passive technologies have attracted much attention. Furthermore, recent studies have experimentally revealed that the Marangoni effect, when leveraged in well-designed passive devices, may be a promising pathway towards long-term stable performance. This study presents a comprehensive numerical exploration of applying the Marangoni effect to mitigate salt accumulation, a challenge in long-term system operation. Through an extensive sensitivity analysis, we evaluate the solute molar outflow induced by the Marangoni effect, as different parameters vary. Specifically, the Marangoni effect induces enhanced mass transport, outperforming pure diffusive flow by over three orders of magnitude, under nighttime isothermal conditions. Furthermore, we provide a semi-empirical equation describing accurately the mass transfer versus the Marangoni number. Hence, nighttime brine discharge simulations show rapid salt reduction from the evaporator, reaching seawater-like salinity levels within two hours, setting stage for optimal daytime performance. To the best of our knowledge, this discharge time is the lowest reported in the literature under equivalent conditions. In conclusion we believe that the still poorly explored Marangoni effect may offer a durable mean of providing freshwater, particularly in emergencies. • Numerical investigation of Marangoni effect to mitigate salt accumulation • Marangoni effect leads up to 1000-fold mass transfer increase over diffusive flux. • Accurate semi-empirical equation for mass transfer vs. Marangoni number is provided. • Simulated time for passive brine disposal is less than 2 h. [ABSTRACT FROM AUTHOR]

Water scarcity has been proclaimed one of the biggest challenges in the 21st century. This study developed a novel compact solar desalination system based on a chamber (basin) and a chimney where water is evaporated and condensed, respectively. A transient numerical model based on fundamental principles was developed, which uses actual weather conditions to predict the performance of the solar tower desalination system. It was validated with the obtained experimental hourly water production and temperatures in the chimney in a city with a desert climate. A detailed thermal analysis with contours of temperature and mass fraction and streamlines is presented. Also, profiles of water evaporated/condensed are exhibited. Finally, the overall and condensation efficiencies were computed. The transient computational model could replicate experimental hourly water production and temperatures in the chimney with good agreement. The system in the actual state could produce up to 6052 mL of clean water under summer weather conditions. The increase in air velocity to 3.5 m/s improved clean water production by 19.82 % and condensation efficiency by 18.38 %. [Display omitted] • A solar chimney prototype was built and tested under actual ambient conditions. • A detailed transient mathematical model was developed and validated. • Transient simulations were conducted for an entire day in a city with an arid climate. [ABSTRACT FROM AUTHOR]

Addressing global water scarcity and achieving sustainable water management necessitates innovative solutions for handling reverse osmosis (RO) brine. This by-product, rich in high-value salts, poses environmental challenges due to its high salinity and chemical load. This study explores a novel approach for recovering valuable minerals from brine, focusing on Kainite, a mineral with substantial industrial applications and notorious for its nucleation difficulties. This research introduces a temperature-altering technique for Kainite crystallization, adjusting temperatures from 69 °C, 55 °C, 35 °C, and 25 °C, each subsequently reduced to 15 °C. Advanced characterization techniques were utilized to analyze the crystallized phases. The FREZCHEM model was used for a comparative analysis between isothermal evaporation and the experimental discontinuous evaporation results. Findings indicate that effective Kainite crystallization occurs only with discontinuous evaporation at specific temperature pairs: 55 °C to 15 °C and 69 °C to 15 °C. A novel application of Jänecke phase diagrams through the projection of crystallization path between 55 and 15 °C, and 69 and 15 °C, was instrumental in accurately predicting the crystallization sequence under these conditions. This study underscores discontinuous evaporation's potential for resource recovery from RO brine, contributing to sustainable water management. [Display omitted] • Kainite nucleation from RO bittern under discontinuous evaporation conditions • FREZCHEM simulated isothermal evaporation vs. propose discontinuous evaporation • Jänecke diagrams projection used to enhance discontinuous evaporation prediction • Discontinuous evaporation: competitive energy efficiency for RO brine Valorization [ABSTRACT FROM AUTHOR]

Utilizing solar energy for interfacial solar steam generation and wastewater remediation is regarded as one of the sustainable approaches for alleviating clean water shortage. However, it is still a great challenge to comprehend all the requirements of efficient evaporation, salt resistance and wastewater treatment as well as low cost in one evaporator, thus hindering its large-scale practical application. Herein, in this work, an environmentally friendly and low-cost hierarchical porous architecture (APC@TMF) was prepared by assembling potassium citrate activated poplar catkin derived porous carbon (APC) into the porous structure of thermalized melamine formaldehyde resin sponge (TMF) by a simple dipping method. The APC@TMF integrates the advantages of APC and TMF, thus leading to good light absorption, low thermal conductivity, high hydrophilicity and fast water transport. As expected, APC@TMF exhibits a high evaporation flux of 2.28 kg m−2 h−1 with energy conversion efficiency of 96.3 % in seawater, which outperforms TMF, PVA/TMF, PVA/APC and recently reported evaporators. Beyond that, it demonstrates good performance for seawater desalination and wastewater remediation as well as high cost-effectiveness. APC@TMF hierarchical porous architecture, assembled by filling poplar catkin (APC) derived carbon into the porous structure of thermalized melamine formaldehyde resin sponge (TMF), is successfully prepared by a simple dipping method, exhibits outstanding solar-driven interfacial seawater evaporation and wastewater purification performance. [Display omitted] • APC@TMF was prepared by assembling biomass-derived carbon into thermalized sponge. • APC@TMF shows good performance in seawater desalination and wastewater remediation. • The hierarchical porous structure of APC@TMF helps reduce the evaporation enthalpy. [ABSTRACT FROM AUTHOR]

Membrane modules for seawater desalination are becoming increasingly important for obtaining clean water with the rising global water scarcity. The productivity of membrane modules is compromised by biofouling on the membrane and feed spacer. Biofouling development can be mitigated by modification of the spacer or membrane surface. The purpose of the present study is to evaluate the impact of surface-modified feed spacers on the cleaning performance of spiral-wound membrane filtration systems. After cold-plasma treatment, the feed spacers were modified with various combinations of polydopamine (PDA) and silver nanoparticles (AgNP). To compare the cleaning performance of the modified and unmodified spacers, membrane fouling simulators containing nanofiltration membranes and feed spacers were tested under industrially representative conditions: two full cycles involving biofilm development followed by cleaning-in-place (CIP). The modified spacers significantly improved the CIP efficiency when compared with that of the unmodified feed spacer. The highest CIP efficiency was obtained for the PDA–AgNP-coated spacers, which removed >90 % of the biomass. The PDA layers remained undetached during the CIP process, and the amounts of AgNP decreased without affecting the CIP effectiveness during consecutive operational cycles. The results demonstrate that CIP should be included in biofouling tests to evaluate the full potential of surface modifications and suggest that hydrophilic and biocidal spacer surface coatings can significantly improve the CIP effectiveness, thereby considerably reducing the CIP frequency and operational costs. [Display omitted] • Cold-plasma treatment enables hydrophilic modification of hydrophobic feed spacers. • Hydrophilic and biocidal coatings were grafted onto cold-plasma-treated feed spacers. • Coatings were tested for biofouling control under industrial operating conditions. • Hydrophilic and biocidal coatings improved the cleaning-in-place effectiveness. • Improved cleaning effectiveness was maintained over several operational cycles. [ABSTRACT FROM AUTHOR]

Several countries face water scarcity problems, so they utilize water desalination. Reverse osmosis (RO) is the most popular desalination process, but it consumes high-grade energy and produces concentrated brine. Combining the RO with other desalination technologies can increase water recovery, reduce energy consumption, and reduce environmental impacts. The current study presents a comprehensive review of previous studies and techniques combining reverse osmosis with other desalination technologies to increase the overall system performance and/or treat RO brines. It analyzes and discusses the strengths and weaknesses of various desalination techniques, economic feasibility, and prospective developments. The discussion includes energy consumption and recovery ratio (RR) and the advantages and challenges of combining different desalination systems to overcome the limitations of standalone cycles. Findings include factors such as daily water production, energy consumption, and cost. While hybrid systems show promising performance metrics, they have potential drawbacks or challenges: increased complexity of system integration, higher maintenance requirements due to the combination of multiple technologies, and potential compatibility issues between different desalination processes. The hybrid RO-MD (Membrane desalination) systems have the highest daily water production, ranging between 26,000–50,000 m3/day, at a specific energy consumption of 3.572 kWh/m3 with energy cost ranging between 0.85 and 0.9 $/m3. The RO-MSF (Multi-Stage Flash) systems showed a daily water production ranging from 14.4 to 1000 m3/day at specific energy consumption ranging between 5.2 and 6.7 kWh/m3 with energy costs between 1.35 and 1.84 $/m3. Finally, hybrid systems can minimize the cost of producing freshwater and mitigate the environmental problems of waste brine. • Hybrid reverse osmosis with different desalination techniques is reviewed. • The hybrid RO and MD desalination systems present high-water production and economic feasibility. • Hybrid RO is superior to the standalone RO on various sides. • Hybrid RO is the future direction for desalination operations on a commercial scale globally. [ABSTRACT FROM AUTHOR]

Desalination is a response to water scarcity. Reverse osmosis is a popular method for desalination, but it has some weaknesses. These weaknesses include trade-offs between permeability and selectivity, susceptibility to oxidants, inefficient boron removal, and fouling. To address these issues, researchers have been exploring the use of graphene, a promising material with fine nanochannels, antibacterial properties, large surface area, unique properties, mechanical strength, and chemical stability. This review discusses the importance of reverse osmosis desalination membranes (RODMs) in addressing water scarcity, their limitations, the potential of graphene-based materials in RODMs, progress in reverse osmosis applications, and prospects for solving RODM challenges. Finally, it summarizes the current challenges and future directions for graphene-based RODMs. • Graphene's role in tackling water scarcity through RO • Graphene: solving RO membrane challenges • Graphene enhances RO's selectivity and permeability. • Graphene-based materials revolutionize RO technology • Future of graphene in addressing RO limitations [ABSTRACT FROM AUTHOR]

Facing the global challenge of water scarcity, solar-driven seawater desalination has been emerged as a green, non-polluting and sustainable technology, but the practical application of existing solar evaporators was hindered by their low evaporation efficiency and poor mechanical property. Inspired by the binding effect of cell walls, a novel and high-efficiency three-dimensional (3D) evaporator (CDs/CF/CS-LF) was constructed, in which loofah (LF) served as a natural 3D skeleton to support the hydrogel evaporator, resisted deformation, and created an efficient dual water supply mode with the chitosan (CS) hydrogel ensuring that the evaporator maintains high evaporation rate even under high salt environment. Additionally, the cellulose nanofibers (CF) filler enhanced the mechanical property of the hydrogel, ensuring shape stability under pressure impact, and carbon dots (CDs) facilitated the aggregation and cross-linking of chitosan chains through hydrogen bonds, further improving the mechanical property of the evaporator, while also enhancing the photothermal conversion capability of the 3D-CDs/CF/CS-LF evaporator as a photothermal material. The experimental results indicated that the 3D-CDs/CF/CS-LF evaporator could achieve an ultra-high solar vapor production rate of 8.08 kg m−2 h−1 under 1 sunlight intensity in 3.5 wt% NaCl solution. Outdoor seawater desalination experiments demonstrated the utility of 3D-CDs/CF/CS-LF evaporator for practical applications. This work provided a new approach for the improvement of CS-based evaporators and demonstrated their potential application in seawater desalination and purification. • LF with "binding effect" brings a directional water transport path in evaporator. • CF significantly improves the mechanical properties of 3D-CDs/CS/CF-LF evaporator. • CDs are immobilized in the hydrogel network to increase surface temperature. • 3D-CDs/CS/CF-LF exhibits an ultra-high solar evaporation rate of 8.08 kg m−2 h−1. [ABSTRACT FROM AUTHOR]

Water scarcity, an intensifying issue, has spurred extensive research into the development of sophisticated freestanding pseudocapacitive electrode materials. Characterized by their precise morphology, intricate mechanics, and superior desalination capabilities, these materials are revolutionizing water treatment technologies. However, their broad adoption is hampered by complex fabrication processes and the necessity for various unique components. Herein, the paper introduces a streamlined method combining electrospinning and carbonization to produce a freestanding nitrogen-doped carbon nanofiber encapsulating manganese cobalt oxide (MCO) nanoparticles for desalination purposes. The approach significantly enhances interfacial interactions, mitigates volume shifts during sodium ion adsorption and desorption, and strengthens interfacial stability. Benefiting from its structural and compositional merits, the optimal MCO-1.0 electrode showcases exceptional electrochemical attributes. It achieves an impressive desalination efficiency (34.68 mg g−1), swift capacitive deionization rate (0.58 mg g−1 min−1), and superior cyclic durability. The study enhances our understanding of freestanding carbon fibers encapsulated with metal oxide nanoparticles, a key step toward developing robust electrodes for industrial applications. [Display omitted] • Flexible hierarchical MnCo 2 O 4 @CNFs membrane electrode was fabricated for CDI. • Encapsulation structure alleviates volume expansion and facilitates ion diffusion. • A high electrosorption capacity and a rapid salt adsorption rate were achieved. [ABSTRACT FROM AUTHOR]

The number of desalination plants worldwide increased exponentially in the last decade. This is basically a consequence of fast population growth combined with the expansion of water scarcity zones, even though desalination processes are, comparatively, much more energy intensive than other freshwater membrane treatment processes. SeaWater Reverse Osmosis (SWRO) has gained preference among the most used desalination processes due to its compacity, flexibility and energetic efficiency. However, desalination processes produce a concentrated brine that needs to be disposed of and represents an environmental challenge to be tackled. Currently in the literature, the most explored solutions for brine treatment are based on the extraction of valuable resources from the concentrate, also called brine valorization. Late discussions have pointed out that other approaches such as reuse for energy production and disinfection products might also be a solution for the same challenge. This review presented the current state of the art of SWRO brine valorization including the following methods: disinfectant (chlorine) production and salinity gradient energy generation; expanding the possibilities for brine treatment and reuse. [Display omitted] • Disinfectant and energy production can be a solution for SWRO brine valorization. • SWRO brine valorization technologies are still at low technology readiness levels. • Nanofiltration is a promising pretreatment for brine mining and chlorine production. • A SWOT analysis of SWRO brine valorization solutions is presented. • To stimulate brine valorization, specific legislation is needed. [ABSTRACT FROM AUTHOR]

To face the challenges of global water scarcity and water pollution, membrane distillation (MD), represented by hydrophobic microporous membranes, has recently received considerable attention and has shown great potential in processes such as seawater desalination, production of potable water from poor quality water, and wastewater treatment. MD technology has only been implemented in a few pilot plants around the world, a gap that needs to be filled through research and development. The focus of this review is to provide an overview of the effects of operating conditions and the current state of research on the MD process. To further improve the performance of the MD process, three statistical optimization techniques including response surface methodology, evolutionary algorithms, and artificial neural networks for optimizing MD operating parameters are analyzed. Five externally assisted techniques for enhancing the MD process are then reviewed, including electric field, ultrasonic, electromagnetic field, micro bubble aeration, and two-phase flow techniques. Finally, important applications of MD in recent years are discussed, mainly including MD-coupled process applications and thermally positioned solar distillation systems, with the aim of providing new R&D ideas to advance MD technology from emerging to mature. [Display omitted] • Mechanism analysis and optimization methods of MD operating conditions • Process reinforcement methods of MD technology • Important applications and systems integration analysis of MD [ABSTRACT FROM AUTHOR]

Water-intensive industries face challenges due to water scarcity and pollution. In the management of these challenges, membrane processes play an important role. However, they produce significant amounts of reject waters, in which the separated salts and pollutants are concentrated. This study aims to develop a novel management concept for reject waters using alkali activation to immobilize salts in a solid phase using metakaolin, blast furnace slag (BFS), or their mixture as precursors and to create alkali-activated materials with sufficient properties to be potentially used in construction applications. Seven different waters were used to prepare the NaOH-based alkali activator solution: deionized water, three simulated seawaters with increasing salinity, and three reverse osmosis (RO) reject waters from mining or pulp and paper industries. Overall, BFS-based samples had the highest immobilization efficiency, likely due to the formation of layered double hydroxide phases (hydrotalcite, with anion exchange capacity) and hydrocalumite (chloride-containing mineral). Moreover, high-salinity water enhanced the dissolution of precursors, prolonged the setting time, and increased the compressive strength compared with nonsaline water. Thus, the obtained materials could be used in construction applications, such as backfilling material at mines where RO concentrates are commonly produced. [Display omitted] • Alkali-activated materials (AAMs) were prepared using high-salinity waters. • AAMs prepared using blast furnace slag immobilized salts effectively. • AAMs containing metakaolin had a higher level of salt leaching. • Immobilization involved both chemical and physical mechanisms. • High salt content enhanced the formation of high-strength material. [ABSTRACT FROM AUTHOR]

An increase in population leads to an increase in the water demand. Technological advancements are racing to address water shortages. Recent advances in deep learning (DL), machine learning (ML), and artificial intelligence (AI) have enabled us to effectively manage water scarcity as well as optimize, model, automate, and predict water treatment processes. Additionally, computer-assisted support to complicated problems related to water chemistry, and membrane applications. In the sector of water treatment and desalination processes, various models such as Support Vector Machines (SVM), Random Forest (RF), Genetic Algorithms (GA), K-Nearest Neighbors (KNN), time series models, and Multi-Layer Perceptron (MLP) have been applied to address the issues ranging from optimization of treatment processes to predictive modeling as well as failure/fault detection. Presently, water quality forecasting lacks the much-needed precision and accuracy. Thus, a highly versatile MLP is engineered and designed to approximate any continuous functions and may solve issues that are not linearly separable. Typically, MLPs are used for pattern classification, forecasting performance, and approximation. This review paper presents automatic forecasting of water quality and desalination processes efficiency which resolves the issue of missing values from the data sets. Moreover, this paper examines a wide range of peer-reviewed, vital water-based applications using DL, ML, and AI, including membrane separation, water quality, and performance efficiency. A thorough review of MLP applications in water treatment and seawater desalination is presented here. Furthermore, the conventional modeling approaches are compared with the MLP model. It will also highlight the drawbacks that hinder the implementation of real-world water treatment and desalination processes. In conclusion, the latest developments in membrane processes, seawater desalination, and MLP-based water treatment have been summarised. [Display omitted] • Revolutionizing water treatment and desalination using MLP. • MLP model is an engineered tool for self-monitoring and accurate prediction. • Comparative study of traditional models and MLPs. • Limitations of traditional and MLP modeling approaches. • Water quality forecasting using MLP models for water treatment and desalination processes. [ABSTRACT FROM AUTHOR]

Due to fossil fuels abundance at a relatively low cost of extraction, Kuwait relies heavily on non-conventional water resources, namely desalination and treated wastewater, to sustain its water sector. However, Kuwait finds itself balancing between the benefits of its rentier economy and the challenges posed by its reliance on fossil fuels, navigating a complex landscape of economic and environmental sustainability. This paper endeavors to explore the complex paradox surrounding Kuwait's water resources, examining the role of desalination, wastewater treatment, and groundwater extraction. It discusses into the barriers hindering efforts towards reform and mitigation strategies aimed at promoting sustainable water management practices. Including obstacles rooted in various socioeconomic and sociopolitical factors, such as low utility tariffs, heavy dependence on fossil fuels, and deficiencies in the country's water infrastructure. Through the application of a life cycle assessment and a detailed cost analysis, this research unveils the significant environmental and financial burdens associated with Kuwait's current water supply methods, prompting concerns regarding their sustainability and the nation's water security. While the primary focus of this study is on Kuwait, the analysis and findings hold broader implications and repercussions. • 78 % of Kuwait water demand is met through non-conventional sources. • Kuwait ranks among the top countries for water quality and sanitation services. • Yet, Kuwait water stress reached 3850 %, marking it worst among 177 nations. • Groundwater abstraction and transboundary cooperation requires governmental focus. • Water reuse policy for tertiary effluent need revision to expand irrigation end use. [ABSTRACT FROM AUTHOR]

A techno-economic assessment of electricity and freshwater cogeneration system powered by a standalone solar PV system is investigated under weather conditions of Al -Khobar City, Kingdom of Saudi Arabia. The excess electricity generated by the PV system is used to operate Reverse Osmosis (RO) desalination unit using three alternative storage types: Battery, Water-Tank, and hybrid Battery/Water-Tank storage system. The RO desalination plant is mathematically modeled, and its hourly specific energy consumption is predicted by taking into consideration variations in pressure and temperature for one full year using Engineering Equation Solver (EES) software. Then, a MATLAB code is developed and used to optimize the PV array with the three alternative storage options. A novel indicator called the Shortage of Water Supply Probability (SWSP) is introduced and used to optimize the storage size and to ensure satisfying water demand. Results showed that the lowest levelized cost of water (LCW = 1.874 $/m3) is obtained when operating the RO desalination plant with a hybrid Battery/Water-Tank storage system. However, LCW is 2.892 and 2.647 $/m3 when battery or water-tank storage systems are used, respectively. From an environmental point of view, utilizing renewable energy to run the cogeneration system saved 131 tons/year of CO 2 emissions. • Excess energy from standalone solar system operates a Reverse Osmosis desalination system. • Various storage types are considered and compared. • Mathematical models are developed for the system components. • A new indicator called shortage of water supply probability (SWSP) is introduced. • The Hybrid Battery/Water-Tank storage system is the most appropriate combination. [ABSTRACT FROM AUTHOR]

Interfacial solar steam generation (ISSG) is considered a green and inexpensive technology to solve water scarcity problems. Currently, it still needs to pursue a fast evaporation rate, high-quality fresh water production, and excellent mechanical properties. Herein, Janus aerogels with hydrophilic and hydrophobic structures were prepared by effective spraying of polydimethylsiloxane (PD on the upper surface of bacterial cellulose (BC) /carbon black (CB) /agar powder composites (named JBCA). After a series of experiments, the results showed that the obtained JBCA evaporator had a water evaporation rate of 1.83 kg m−2 h−1 under 1000 W m−2 solar radiation. Meanwhile, the same high evaporation rate (1.63 kg m−2 h−1) was obtained in high salinity (20 wt%) solution. More importantly, the ion removal rate for real seawater was more than 99 %. The results of outdoor evaporation experiments and sustainability analyses indicated that this low-cost material with Janus structure had great potential for practical applications. • A Janus aerogel (named JBCA) was prepared by spraying hydrophobic polydimethylsiloxane on a hydrophilic substrate. • The JBCA aerogel achieved an excellent evaporation rate of 1.83 kg m-2 h-1 in pure water. • In outdoeriments, daily freshwater production reached a maximum of 8.1 kg m-2 and a minimum of 4.82 kg m-2. • Low cost and environmental friendliness highlight the sustainability of JBCA aerogels. [ABSTRACT FROM AUTHOR]

Water desalination has become an important process to cope with water scarcity in the Mediterranean basin; however, the endemic seagrass Posidonia oceanica may be susceptible to high-salinity brines derived from this industry. To understand how brine affects metabolic processes in P. oceanica , transplantation experiments were performed in two sites exposed to a brine dilution plume derived from a desalination plant in Alicante (Spain). P. oceanica individuals were transplanted in three locations, i.e., a control site (∼37 psu), an intermediate influence site (IB, ∼39.5 psu), and a high-influence site (HB, ∼42 psu), and were monitored for 6 days. The metabolic endpoints of reactive oxygen species (i.e., H 2 O 2 , lipid peroxidation, and ascorbate cycle) and the regulation of genes involved in antioxidant and osmoregulation responses [ please complete sentence ]. The concentration of H 2 O 2 and thiobarbituric acid reactive substances (TBARS) increased, while that of ascorbate (ASC) decreased in HB, indicating excessive ROS production, lipid peroxidation, and antioxidant consumption. Genes related to osmoregulation (SOS1, SOS3 , AKT2/3) and antioxidant response (GR, APX, FeSOD, MnSOD , and STRK1) were upregulated in brine-exposed plants, especially at the early stages of the experiment. This novel approach has provided a battery of biomarkers that may serve as early warning tools for rapid action mitigation to avoid the negative effects of salinity on P. oceanica at the population and community levels. This approach can be also globally applied to relevant macrophytes in environmental monitoring programs to address other stressors and their isolated or combined contribution to marine pollution. [Display omitted] • Posidonia oceanica plants were transplanted next to a desalination brine discharge. • Brine exposure caused Reactive oxygen species production and oxidative damage. • Oxidative and osmoregulatory responses increased with brine influence. • Gene expression actively responded to increased salinities in the short term. • Metabolic descriptors can be used as early warning indicators of brine affection. [ABSTRACT FROM AUTHOR]

Inadequate access to clean water and wasteful resource consumption during production pose significant challenges in global development. To combat these issues, interfacial solar steam generation (ISSG) has emerged as an energy-efficient solution to mitigate the ongoing water scarcity crisis. However, the application of ISSG is hindered by high costs and intricate fabrication processes associated with synthetic functional materials. In response, this study introduces an innovative approach that repurposes abundant by-products generated from hemp fiber production. Hemp fiber noil are transformed into a nonwoven fabric substrate, onto which hemp stem-derived biochar is seamlessly integrated using a straightforward spray-coating technique, establishing an efficient solar-to-heat conversion evaporator. Leveraging the durability of hemp fibers, this system achieves an impressive seawater evaporation rate of 1.47 kg m−2 h−1 under 1 sun condition, making it highly competitive in seawater desalination research. This pioneering strategy combines waste green materials and their functional counterparts, unlocking practical applications, addressing resource scarcity, and mitigating environmental pollution. This research highlights the potential of sustainable material utilization to tackle pressing global challenges. [Display omitted] • Repurposing hemp fiber by-products for the creation of a nonwoven evaporator • Employing hemp stem-derived biochar as efficient solar-heat conversion material • Seawater evaporation rate reached 1.47 kg m−2 h−1 with hemp evaporation system. • Absence of noticeable salt sediment on the surface of evaporator • Utilizing scalable needle-punching and straightforward airbrush processing [ABSTRACT FROM AUTHOR]

The adoption of desalination processes for the production of fresh water is one of the main solutions to water scarcity. Desalination recovers fresh water from saline solutions, yet increasing their concentration during the process and producing a brine. The latter can have an environmental impact when discharged, thus requiring suitable disposal strategies or post-treatments. Among the processes reported in the literature, in this study, electrodialysis (ED) is studied as possible technology to be coupled to a standard desalination process in order to increase the global water recovery and produce hypersaline solution for subsequent brine-mining processes for the recovery of useful minerals. The performance in terms of Specific Energy Consumption (SEC), Total Recovery Ratio (RR TOT) and Additional Levelized Cost Of Treatment (ALCOT) are assessed by considering industrial ED unit equipped with standard membranes and high-performing membranes. The influence of operating conditions such as electric voltage, electric current and solutions residence time on the performance of the system is investigated. Results reveal that, in the best conditions, a RR TOT between 55 % and 78 % is achieved with SEC in the range of 0.5–1.9 kWh·m−3 P and with ALCOT in between 0.10 €·m−3 P and 0.21 €·m−3 P. The integration of electrodialysis into standard desalination processes improves the efficiency and the sustainability of desalination, minimizing waste (zero-liquid discharge) and increasing productivity. • Electrodialysis for brine minimization from desalination plants is investigated. • Integrated system has a higher recovery ratio (up to +36 %) than standard RO plant. • As valuable by-product high concentration brine for mining process is obtained. • Cost analysis of an integrated electrodialysis–reverse osmosis plant is performed. • Levelized cost of treatment and specific energy consumption are evaluated. [ABSTRACT FROM AUTHOR]

In recent years, graphene-based membranes are extensively explored for desalination process to fulfil the pure water scarcity. Still, there is a noticeable gap in the research on a technique that simultaneously deposits a membrane and also generates pores in the flake of membrane. In this work, we demonstrated a one-step and scalable protocol i.e. a conventional atmospheric plasma spraying (APS) to fabricate a graphene nanoplatelets (GNP) membrane for water desalination application. Various characterization tools: FE-SEM, Raman, and TEM etc. utilized to evaluate the deposition of GNPs flakes and induced sub-nanometer pores in the large area GNP membrane. Plasma-sprayed GNP membrane showed impressive desalination performance in terms of water flux, salt rejection, and permeability around ~67 Lm−2 h−1, ~99 %, and ~ 115 Lm−2h−1bar−1 respectively at 0.6 bar of transmembrane pressure (TMP). This performance of the GNP membrane was attributed to the critical role of graphene in terms of its structures, including induced pores within graphene sheets and its functions. Our deposited GNP membrane is cost-effective and showed the applicability of conventional plasma spraying in the design of nanomaterials-based membranes for various water purification protocols. [Display omitted] • A multilayer GNP membrane has been fabricated using a plasma spray technique for water desalination. • Sub-nanometer pores were generated in the deposited GNP membrane. • Water flux and salt rejection rate were 67 Lm−2 h−1 and >99 % respectively. [ABSTRACT FROM AUTHOR]

Water scarcity is a threat to crucial economic sectors, notably agriculture, which is a major concern in arid regions like Spain's Almería province, home to a substantial greenhouse industry. One of the possible solution for this fact is the use of alternative water sources, as desalination. This work offers a comprehensive characterization and economic evaluation of reverse osmosis desalinated water for greenhouse irrigation, exploring various scenarios, including photovoltaic electricity generation. To accomplish this, an economic model based on the energy hub methodology is proposed. This model provides a versatile framework that accounts for factors like variable electricity generation and water demand, allowing for accurate cost assessments. The results show that levelized cost of water between 2.51 and 3.69 €/m3 can be reached depending on the configuration of the system. Moreover, the cash flow analysis demonstrates that the investment in reverse osmosis systems for greenhouse irrigation can be recovered in less than three years in all the studied scenarios. These findings suggest that using reverse osmosis systems for greenhouse irrigation is a viable option particularly appealing to farmers and small associations in specific districts, promoting distributed desalination adoption in agriculture environments. • The combination of RO with greenhouse environments is studied. • The economic model based on energy hub methodology ensures precise cost assessment. • RO investment in greenhouse is recovered in under three years, promoting adoption. • Using PV-RO systems does not significantly disrupt cash flow dynamics. [ABSTRACT FROM AUTHOR]

As water scarcity intensifies, the quest for developing sophisticated electrode materials with adjustable configurations, complex structures, and developed desalination performance garners important interest. Prussian Blue (PB) and its analogs (PBAs), owing to their cost-effectiveness, uncomplicated synthesis, innate open framework, and modifiable composition, have elicited considerable recognition. Herein, the paper provides a comprehensive overview and analysis of the advances made in capacitive deionization electrodes based on PB and PBAs. It commences by detailing the synthesis techniques, post-treatment processes, and derivatives of standard PBs and PBAs. Subsequent sections propose strategies to minimize auxiliary reactions in electrochemical processes, encompassing structural design, protective coatings, substitution, and the confinement effect. Subsequently, emphasis is placed on structures that have potential as electrode materials in applications such as desalination, heavy metal removal, resource recovery, and water softening. A summary of current achievements in the field is provided, alongside a critique of prevailing limitations and emergent challenges. As advancements in electrode materials continue to unfold, it aims to stimulate innovative ideas for utilizing PB and PBAs in environmental research, thereby catalyzing additional investigation into the desalination area. [Display omitted] • The preparation methods of advanced PB/PBAs electrode are discussed in depth. • The versatile applications of PB/PBAs electrode are discussed extensively. • The future orientation development of PB/PBAs in CDI is provided. [ABSTRACT FROM AUTHOR]

Using solar energy for freshwater generation presents an effective and economical solution to address water shortages. Here, we introduced a structural strategy involving the incorporation of fixed-shape inverted pyramid-shaped grooves onto the evaporator surface. This innovation approach integrated delignified wood and MXene-based photothermal material to establish an interfacial solar steam generator (ISSG) dedicated to freshwater production. The carefully designed surface structure empowered the ISSG with remarkable heat localization capabilities, resulting in an exceptional steam generation capacity and resistance against salt deposition. The as-prepared sample, labeled MIDW-5, achieved an impressive evaporation rate of 1.927 kg m−2 h−1. Furthermore, the simulation results by COMSOL are in agreement with the experimental results. Therefore, the incorporation of MXene into delignified wood, complemented by the imprinted structure, yields a high-performance evaporator with substantial potential for low-cost freshwater production. • A MXene@wood evaporator with inverted pyramid-shaped grooves was constructed. • The evaporator has excellent thermal localization efficiency. • The evaporator shows splendid high light absorption and evaporate rate. • The evaporator is easy to prepare and environmentally friendly. • The evaporator performs outstanding desalting performance. [ABSTRACT FROM AUTHOR]

Global water scarcity has increased the demand for sustainable and affordable desalination solutions. Thermal desalination systems, such as solar stills, have been extensively studied for producing fresh water from saline sources. However, their efficiency is limited due to the low water vapor pressure inside the stills. To address this shortcoming, ultrasonic humidifiers have been proposed in recent years to increase the water vapor pressure inside solar stills and other thermal desalination systems, thereby enhancing their efficiency. This review aims to critically analyze current research on the use of ultrasonic humidifiers to improve the performance of these systems including solar stills, humidification-dehumidification systems, and membrane distillation systems. It examines the impact of various factors, including water temperature, salinity, placement of ultrasonic humidifiers, and the duration of ultrasonication, on the efficiency of these thermal desalination systems. Lastly, it compares the thermodynamic performance and economic viability of different desalination systems to identify the most promising ones. The findings of this review are expected to provide valuable insights for designing and optimizing desalination systems that incorporate ultrasonic humidifiers. • Ultrasonic humidifiers significantly boost freshwater yields in thermal desalination systems. • Solar stills with ultrasonic humidifiers show a reduction in desalination cost, attributed to high evaporation rates. • Ultrasonic humidification in HDH systems improves humidification efficiency, translating into higher distillate output. • Ultrasonic vibrations also enhance productivity in membrane distillation systems by mitigating inline fouling. • Future research should prioritize standardizing protocols, tackling fog formation in solar stills, and exploring scalability. [ABSTRACT FROM AUTHOR]

Recently, interfacial solar based desalination has gained large interest as a sustainable solution for global water scarcity. However, the poor water collection rate due to unfavorable weather conditions and unpredictable solar intensity makes it impractical in real operations. In this report, we proposed a novel joule-heating assisted heliotropic solar steam generator for all-day, all-weather solar desalination. For this, hydrophobic carbon fabric (CF) was first functionalized using thiol functionalization (t-CF) and then combined with melamine sponge to obtain t-CF-melamine solar steam generator (SSG). The heating properties of t-CF-melamine are examined, and the surface temperature reaches as high as 155°C in <5 min at an input voltage of 3 V. Under 1 sun irradiation condition, the evaporation rate of the t-CF-melamine SSG is increased dramatically to 11.2 kg m−2 h−1 at 3 V input voltage. This is attributed to the synergetic effect of photothermal and electrothermal effects of t-CF. Through desalination experiments, the heliotropic design was able to reject salt effectively while maintaining a stable evaporation rate of 11.57 kg m−2 h−1. In addition, t-CF also performed extremely well at low voltage (1–3 V) conditions demonstrating the capability of all-day, all-weather solar desalination. The present results of this work would inspire further research on electrically conductive materials for joule-heating assisted solar steam generation (SSG) devices for practical all-day, all-weather solar desalination. • A novel thiol functionalized carbon fabric (t-CF) based solar steam generator. • Low voltage joule heating assisted efficient solar steam generation in heliotropic model. • t-CF-melamine sponge could generate clean water in all-day all weather conditions with anti-salt fouling. [ABSTRACT FROM AUTHOR]

Global water scarcity continues to increase and water desalination is an increasingly important technological solution. This review presents a brief description of the synthesis, applications, and cost considerations associated with multifunctional advanced materials used in water desalination. Traditionally, desalination has been accomplished by using energy-intensive processes such as reverse osmosis and thermal distillation. The conventional techniques are incapable to address the desalination of water in proper way. As a result of these limitations, advanced materials have been developed and applied to enhance desalination processes. Examples of these materials include composite materials, nanomaterials (g-C 3 N 4 , graphene, etc.) and MXene based materials. Due to their improved performance, selectivity, and permeability, these materials may be used in membrane-based processes, such as nanofiltration and forward osmosis, as well as solar-driven desalination. In addition, advanced materials are used for water purification, wastewater treatment, and pollutant elimination, further addressing environmental concerns. However, cost remains a significant barrier to their widespread implementation, requiring an ongoing research and collaboration effort to render multifunctional advanced materials economically viable for water desalination. • In-depth Analysis: We offer a comprehensive analysis of the latest advancements in functionalized carbon nanomaterials and their specific roles in addressing the challenges of water desalination. • Synthesis Techniques: We discuss a variety of synthesis techniques employed to functionalize carbon nanomaterials, exploring their impacts on structural properties and desalination performance. • Applications Overview: The manuscript outlines the diverse applications of carbon 1D/2D nanomaterials in membrane-based and adsorption-based desalination processes, demonstrating their potential to enhance efficiency and selectivity. • Evaluation: Provides a critical evaluation of the cost-related aspects of integrating these nanomaterials into large-scale desalination operations, considering factors such as material production, system maintenance, and energy consumption. [ABSTRACT FROM AUTHOR]

The sustainable supply of freshwater resources is facing serious challenges due to the frequent occurrence of severe global weather, increasing environmental pollution and continuous population growth. Solar-powered interfacial evaporation systems for wastewater treatment and desalination are considered a hopeful freshwater acquisition strategy to solve water scarcity and energy crisis. Aerogel materials can promote water transmission and evaporation due to their porous structure and tunable surface wettability. In recent years, solar clean water technology based on aerogel has become a current research hotspot result from its advantages, for example high evaporation efficiency and simple preparation method. In this article, the study progress of aerogel materials for solar interface evaporation field is systematically presented. Three main sections are discussed: photothermal conversion materials, interface evaporator and applications. Eventually, the problems faced by the current solar interface evaporation technology in the development process are analyzed, and corresponding countermeasures are proposed. • The advance of aerogel based solar energy interfacial evaporators is reviewed. • Introduced the characteristics of different photothermal materials • The application of photothermal materials in aerogel interfacial evaporators is introduced. • Introduced the application progress of different types of interface evaporators • The multifunctional application of aerogel based interfacial evaporator was introduced. [ABSTRACT FROM AUTHOR]

Interfacial solar water evaporation (ISWE) technology provides a green, energy-saving and economical way to sustainably produce freshwater from various water sources for addressing the impending water shortage. However, the low evaporation rate, complex manufacturing process and harmful surface salt accumulation for ISWE are still challenging and considerably restricted the practical applications. Herein, we design and fabricate a robust ISWE based on the hierarchical Co 3 S 4 nanostructure as a photothermal absorber and three-dimensional (3D) nickel foam (NF) as a primary structure with macroporous networks. The as-fabricated Co 3 S 4 /NF not only introduces sufficient photothermal centers to convert solar energy into heat, but also provides abundant channels for water transportation and steam escape. The Co 3 S 4 /NF evaporator exhibits a high evaporation rate of 1.56 kg m−2 h−1 and a photothermal conversion efficiency up to 94.18 % under one-sun illumination. Moreover, such evaporator shows the long-term durability and good salt-resistant ability, which can sustainably produce freshwater from various water sources including seawater, saline water, lake water and other contaminated water. The photothermal Co 3 S 4 /NF evaporator would provide a promising platform for the production of drinkable water in a safe and sustainable manner. [Display omitted] • Hierarchical Co 3 S 4 nanostructures were in-situ grown on macroporous nickel foam. • The ISWE system based on Co 3 S 4 /NF was designed and fabricated for solar steam generation. • Co 3 S 4 /NF evaportor yields a high evaporation rate and efficiency under one-sun illumination. • Co 3 S 4 /NF evaportor addressed the robustness and versatility for various water sources. [ABSTRACT FROM AUTHOR]

Renewable solar energy meeting photothermal materials provides a promising approach for freshwater production via interfacial steam generation. The design and manufacture of high-performance evaporators are still highly anticipated for practical applications. Herein, the robust and durable solar evaporator is proposed and fabricated by integration of photothermal Cu-CuO x /NC (CNC) and three-dimensional porous structure heat-insulated polyurethane (PU) foam with polyvinyl alcohol (PVA)/sodium alginate (SA) modifications. The designed PVA-SA-CNC/PU simultaneously possesses fast water transmission, broadband light trapping, satisfactory mechanical robustness and effective heat confinement. When applied as a solar evaporator, the PVA-SA-CNC/PU exhibits a high evaporation rate of 1.99 kg m−2 h−1 and operates stably within ten consecutive cycles under one-sun illumination, which can also handle salt tolerant desalination of seawater and saline water to sustainably produce freshwater. In addition, the functional versatility of the fabricated evaporator is explored to purify various wastewater. This study establishes a highly efficient integrated evaporator with multitasking water purification towards the solution of water shortage. [Display omitted] • PVA-SA-CNC/PU evaportor was designed and fabricated. • PVA-SA-CNC/PU possesses excellent performance for solar water evaporation. • PVA-SA-CNC/PU evaportor achieves multitasking water purification. • PVA-SA-CNC/PU evaportor can handle salt tolerant desalination of seawater and saline water. [ABSTRACT FROM AUTHOR]

Lamellar graphene oxide (GO) membranes have received significant attention in desalination and water treatment due to their unimpeded permeation of water. Intercalation cross-linking is an effective way of improving the stability and perm-selectivity of GO membranes. This work reports a novel strategy to tune the nanostructure and morphology of GO membrane by combining highly oxidized GO nanosheets with borate cross-linking for desalination by pervaporation. The cross-linking processes covalent bonding of hydroxyl groups of GO membrane with sodium borate as the cross-linker, leading to formation of selective and stable three-dimensional GO-borate framework. The enrichment of hydroxyl groups on GO arising from high oxidation benefits the targeted cross-linking. Meanwhile, higher oxidation level of GO leads to higher content of carboxyl groups and improves the hydrophilicity of membrane. Consequently, the borate cross-linked GO membrane fabricated with fully oxidized GO simultaneously exhibits high water flux and enhanced structural stability. The results reveal that the interlayer spacing and swelling behavior of GO membranes are heavily influenced by the oxidation level and cross-linking, which are critical factors affecting the performance of the membranes in pervaporation desalination applications. The findings hold promise for the development of high-performance and stable GO membranes to address global water scarcity challenges. • GO oxidation level was exploited to tailor interlayer channel structure. • Ultrathin three-dimensional GO framework formed by borate cross-linking. • Increasing oxidation level intensifies cross-linking while maintains hydrophilicity. • Permeability, selectivity and stability were concurrently enhanced. [ABSTRACT FROM AUTHOR]

Nanofiltration (NF) membrane technology has become the most critical alternative to resolve fresh water resources shortage and water pollution. Preparing polyamide (PA) NF membrane with excellent water permeance and mono/multivalent salts selectivity is highly desired. Herein, we introduced 1-methylimidazole (1-MI) as a reactive additive into interfacial polymerization (IP) to prepare NF membrane and attempted to improve the NF membrane performance. 1-MI modified NF membranes exhibited enlarged pore size and thickness of PA layer, as well as a smooth and hydrophilic membrane surface, the water permeance improved from 7.7 L/(m2·h·bar) of Virgin-NF to 13.1 L/(m2·h·bar) of 1-MI-0.05-NF. The Na 2 SO 4 rejection was maintained at 95.01% while NaCl rejection dramatically reduced from 25.79% to 13.29%, and the Cl−/SO 4 2− selectivity slightly increased from 21.47 to 23 under the mixed salts solution as feed. The enhancement of water permeance was ascribed to the looser PA layer and enhanced hydrophilicity. The retaining Na 2 SO 4 rejection was attributed to electrostatic repulsion caused by more carboxylic acid groups, and the decreased NaCl rejection was ascribed to the looser PA layer. Besides, the modified membrane had an acceptable pH stability. In summary, 1-MI modified NF membrane was suitable for the separation of monovalent/divalent anionic salts. • 1-Methylimidazole (1-MI) as additive was utilized to prepare NF membrane. • The polyamide layer formation was regulated by the reaction and hydrolysis of 1-MI. • A looser and thicker polyamide layer structure was obtained. • 1-MI endowed the membrane with more amino and carboxylic acid groups. • The membrane prepared with 1-MI exhibited a higher water permeance and Cl−/SO42− selectivity. [ABSTRACT FROM AUTHOR]

Increasingly aggravated water scarcity and pollution lead to great challenges in humankind's survival and social advancement. Solar-driven interfacial evaporation, which separates the water and impurities by clean solar-driven evaporation, has been considered the most environmental-friendly and low-cost technology to solve water shortage and pollution. Low vaporization enthalpy hydrogel-based materials outperform all other potential materials as solar evaporators for photothermal conversion owing to their breakthrough evaporation rate, manufacturability, controllability, and multi-functionality. Firstly, we review the key concepts of hydrogels that demonstrate benefits in solar-driven interfacial evaporation systems, such as water transport and low evaporation enthalpy, as well as hydrogel evaporators created by incorporating various light absorber materials within the hydrogels. Secondly, we present the design strategies of metamaterials for overall hydrogel performance augmentation. Finally, some of the multiple functions of hydrogel evaporators are expanded, such as salt-blocking, photodegradation, sterilization, and electricity generation. Taking into account the benefits of the aforementioned hydrogel mechanisms and techniques, we further present design concepts and tactics for hydrogel evaporators required in practical applications. We anticipate the attainment of low-cost, high-efficiency operation and large-scale hydrogel development in solar water purification, which will establish a firm platform for addressing water resource scarcity and pollution. [Display omitted] • Low vaporization enthalpy hydrogels in solar-driven interfacial evaporation systems are reviewed. • Comprehensive design strategies for overall hydrogel are the key to highly efficient evaporation. • Highlight various multiple functions of hydrogel evaporators [ABSTRACT FROM AUTHOR]

Solar-powered water evaporation has been recognized as a potential water purification regeneration technology to alleviate the issue of global water shortage. Interfacial solar steam generation (ISSG) with a high rate of evaporation and high photo-thermal conversion efficiency is very desirable. Herein, a scalable, high-efficiency and surface tunable ISSG was developed by carbon nanotubes (CNTs) loaded on polydopamine (PDA) modified nickel foam (NF) with a honeycomb three-dimensional (3D) network structure. The surface of CNTs@PDA/NF (CPNF) solar evaporator was designed as the 3D wave-like for further improved water evaporation. The as-prepared solar steam generator has an evaporation rate of 1.61 kg m−2 h−1, and photo-thermal conversion efficiency of 91.0 % at 1.0 solar irradiance. Moreover, it displays efficient purification ability for heavy metal ions in seawater and lake water, and the concentration of Na+, Mg2+, K+ and Ca2+ in the desalinated condensate is in line with the World Health Organization's drinking water standards. Additionally, the dye-contaminated wastewater can also be purified and treated to be drinking water. Furthermore, it has a good salt self-melting function. In sum, this work provides some new insights for designing innovative solar evaporators with outstanding photothermal conversion capability. • A double-layer evaporator was designed with a moldable wavy surface form. • High evaporation rate (1.61 kg m−2 h−1) and evaporation efficiency (91.0 %) are achieved. • The resulting CPNF/PU shows excellent salt-resistant performance even in 20 wt% NaCl. [ABSTRACT FROM AUTHOR]

Harnessing graphene sheets' large surface area, catalytic effect, adsorption capacity, and reactivity, its use in composites for water treatment is on the rise. With ever-increasing newer pollutants in wastewater streams, treatment challenges are huge. Additionally, water scarcity puts an enormous demand on researchers to develop an integrated efficient system for desalination and wastewater purification. Can graphene-based composites and membranes meet water desalination and purification challenges? In this review, we provide a comprehensive report on the current graphene-based composites and membrane research. We laid out a systematic interrogation of present water purification techniques including desalination, shedding light on the prominent techniques that use graphene-based composites and their membranes. Not only are the fundamentals of the water purification mechanism, aspects of filtration device fabrication, and structural alteration parameters elaborated but how conditions affecting water filtration and use of eco-friendly graphene-based evaporators are emphasized. We also discuss underlying commercial aspects relating to the scale-up of the water treatment issues and highlight promising advances. Graphene's use provides cost-effectiveness and sustainability which are keys to its success. Our overall aim has been to connect the dots among the challenges of existing techniques, processability, scalability of graphene-based composites, and membranes for desalination and water purification methodologies. [Display omitted] • A comprehensive report on the current graphene-based composites and membrane research. • Can graphene-based composites effectively tackle ever-increasing nano-sized contaminants, overcoming the limitations of traditional separation methods – recent literature trends. • Insights into water purification mechanisms and factors affecting filtrations giving a wider picture of the water purification field. • Underlying commercial aspects to scale-up and promising commercial development are highlighted. • Future perspectives along with the environmental sustainability of these materials from the circularity standpoint are discussed. [ABSTRACT FROM AUTHOR]

Desalination methods have become more critical due to the worsening water scarcity problem. Reverse osmosis (RO), forward osmosis (FO), electrodialysis (ED), ion exchange (IX), membrane distillation (MD), multiple effect distillation (MED), and vapor compression distillation (VCD) are those standard desalination processes that are expensive and impose various environmental impacts. Using biological systems based on living microorganisms for seawater desalination is free of any environmental damage, and biodesalination processes using microalgae for producing portable water have recently become the cost-competitive option according to the progression of technology. Compared to other living organisms, microalgae offer unique advantages such as higher photosynthetic capability, shorter growth cycles, higher flexibility, and the ability to grow in seawater and wastewater. They can also absorb carbon dioxide through photosynthesis during their growth, making them appropriate candidates for more eco-friendly water desalination. Light intensity, temperature, pH, saline water nutrients, and the selected microalgae species are different operating parameters affecting desalination efficiency. This review paper thoroughly investigates biodesalination methods using various microalgae species in various conditions, and additional suggestions for future studies and process optimization are recommended. [Display omitted] • The global status of desalination processes and their drawback were studied. • The biodesalination process by using various species of microalgae was thoroughly investigated. • Several aspects of salt-resistive microalgae cultivation and their ability in removing salt from saline water were studied. • The operating conditions of PBR systems for cultivation of microalgae and desalination of seawater were reported. • Additional suggestions for future studies and process optimization are provided. [ABSTRACT FROM AUTHOR]

Purification of seawater and wastewater by solar-driven interfacial evaporation is a promising way to alleviate water scarcity. However, the high cost, complex fabrication methods, and short service life of the materials limit their practical application. Herein, a novel three-dimensional (3D) photothermal aerogel composited of vermiculite nanosheets and polyvinyl alcohol (PVA) precursors have been prepared via freeze-drying and treated by quick pyrolysis for highly efficient solar-driven interfacial evaporation. The vermiculite nanosheets exfoliated from natural clay were used as the skeletal support of the composite aerogels, which are cheap and abundant natural materials. The introduced PVA improves the mechanical properties and produces carbon derivatives after pyrolysis, enhancing the light absorption capacity. The as-prepared aerogels have hierarchical porous structures, impressive mechanical properties, great light absorption capacity, and outstanding salt-rejection ability. The optimized aerogel not only exhibits a high evaporation rate of 2.64 kg m−2 h−1 (normalized to top and side surfaces) under 1.0 sun irradiation with excellent cost-effectiveness at 361.64 g h−1 $−1 but also shows superior performance in treating high-salt (15.0 wt%) brine water and organic dye-contained wastewater. The proposed method provides an attractive and effective way to prepare photothermal aerogels for efficient solar steam generation for mitigating water scarcity issues. • 3D clay-based solar evaporators for desalination were made. • Scalable and low-cost PVPA was prepared via a simple and quick pyrolysis strategy. • The as-prepared PVPA shows excellent evaporation performance and reusability. • The PVPA can treat different concentrations of brine and dye-contained wastewater. [ABSTRACT FROM AUTHOR]

The thin film composite (TFC) polyamide (PA) nanofiltration (NF) and reverse osmosis (RO) membranes are the two of the most robust technologies for the removal of organic micropollutants (OMPs) for (waste) water treatment, and improving sodium chloride (NaCl) rejection for sea water desalination to tackle water scarcity. However, the neutral, smaller and polar OMPs are often ineffectively removed by commercial NF/RO membranes. In-situ NF and RO membrane surface modification is a promising and viable option for improving the rejection of OMPs in existing membrane-based treatment plants without changing the production process. However, there is a research gap in the retention of different groups of OMPs by in-situ modified NF and RO membranes. To fill the research gap in recent years, this current review comprehensively analyzed the impact of reported in-situ NF and RO membranes modification strategies on water permeability, the retention of OMPs grouped by size, hydrophobicity, and charge, and NaCl rejection, where the tradeoff between water/OMPs permeability and water/NaCl permeability received special emphasis. Furthermore, optimal modification strategies to improve OMPs rejection in different groups by NF and RO have been suggested. [Display omitted] • The effects of different groups of OMPs on OMPs removal are presented. • The impact of different polymer materials on OMPs and NaCl rejection is illustrated. • Performance of the modified membranes by various polymers is analyzed. • Optimal strategies for NF/RO membrane performance are evaluated. • Guidelines and perspectives for future NF/RO membrane modification are provided. [ABSTRACT FROM AUTHOR]

The utilization of solar vapor generation for water purification plays a pivotal role in addressing the severe water scarcity crisis. However, it poses challenges due to inefficient light trapping and absorption limitations in solar thermal energy conversion. Here, we have strategically developed an array structured light trapping system with vertically grown, leaf-like zeolitic imidazolate framework (ZIF-L) nanosheets on flexible air-laid paper, accompanied by the catalytic effect of Co ions that result in oxidative polymerization of dopamine (DA) into pleated polydopamine (PDA) layers. This novel solution extends the propagation path of light in the trapping system through multiple scattering. Upon optimization, the P/ZIF-L@PDA-3 evaporator boasts an evaporation rate of 1.48 kg m−2 h−1 at 1 sun (1 kW m−2) irradiation and achieves an impressive solar vapor conversion efficiency of 94.5 %. In practical settings, the evaporation rate can reach 2.22 kg m−2 h−1 after 9 h with an average outdoor light intensity of 0.995 kW m−2. Our study presents an innovative approach to constructing a flexible evaporator with a light-trapping structure, providing immense potential for practical solar applications. [Display omitted] • Flexible evaporator with array light trapping system for solar steam generation • The modification of polydopamine on ZIF-L to boost scattering and absorption • The evaporator shows superhydrophilic properties for self-dissolution of salts. • The evaporator shows excellent desalination and wastewater treatment capabilities. [ABSTRACT FROM AUTHOR]

Decision-makers in the Middle East and North Africa (MENA) region are looking for ways to recycle wastewater to meet the demand for water amidst scarcity. Reusing treated wastewater is crucial for managing water resources sustainably, particularly in water-stressed nations in arid regions of the world that rely on desalination and groundwater to meet their water needs. This study looks into how socio-demographic factors affect how the general public feels about utilizing wastewater for various purposes. A structured questionnaire was used to collect data from 1206 respondents throughout the MENA region, and descriptive and inferential statistics were used to analyze the results. The MENA region is found to recognize the environmental benefits of reuse, but prefers applications that have less direct human interaction such as flushing toilets, non-food industries, car washes, home cleaning, and firefighting. The public is open to reuse as long as it is approved by professionals such as medical experts, university professors and experts. Gender and wealth did not significantly influence the confidence to use treated wastewater for most reuse applications. Still, age and education level did not have a major impact. All respondents agreed to use treated wastewater for non-food business, car washing, home cleaning, and firefighting. Study findings provide insight into the attitudes and perceptions of individuals toward treated wastewater reuse, and can inform future efforts to promote the acceptance and implementation of these applications. • The reuse of wastewater for both potable and non-potable purposes • Recycle wastewater to meet the demand for water amidst scarcity In Mena region • General attitudes or conceptions of recycling and reusing wastewater • Socio-demographic factors affect how the general public feels about utilizing wastewater for various purposes. • How religious beliefs have influenced wastewater treatment practices in different cultures. [ABSTRACT FROM AUTHOR]

The solar interfacial evaporation is considered as an innovate and promising technology to overcome the water scarcity crisis. However, an army of problems are being presented in evaporator applicate on open water, which formats and deposits of salt crystallization at its surface during long-term evaporation and permanents damage causing by wave impact. In this study, a self-floating and durable Janus interfacial solar evaporator (ISE) based on self-healing hydrogel with salt-rejecting was demonstrated for the efficiency production of clean water. Benefiting from the decrease of water evaporation enthalpy in hydrogel-based ISE, water evaporation rates over 2.096 kg·m−2·h−1 and solar efficiency of 85.50 % are attained under 1 sun. Additionally, the evaporator of Janus structure effectively avoids the format and deposition of salt at photothermal layer, exhibiting positive salt-rejecting and purification in various wastewater for long-term evaporation. What is more, the performance and appearance of self-healing hydrogel-based ISE can be easily restored. An encouraging and cheering Janus evaporator was proved via integrating self-healing and damage-tolerant hydrogels for solar desalination and water purification, which exhibits exciting durability and lifetime. • The evaporation rate of water under one sunlight is 2.096 kg·m−2·h−1. • solar efficiency of 85.50 % are attained under 1 sun. • The obtained Janus-ISE has excellent salt resistance. • The obtained Janus-ISE has self-healing properties. • The obtained Janus-ISE can be applied to open water bodies in different environments. [ABSTRACT FROM AUTHOR]

The increasing worldwide demand for freshwater production requires new and sustainable processes to overcome the shortage of clean water. Reverse osmosis (RO) is regarded as the most efficient type of desalination technology and proper knowledge of mathematical modeling of the RO system can help in developing advanced RO systems. Currently, with high computational capability, it is possible to predict how a system will behave in specific conditions without testing experimentally. This article provides a comprehensive assessment of current developments in the RO modeling. To the best of our knowledge, there is no review paper published so far which has covered the modeling in overall RO processes. The study includes basic theories for RO processes and different models based on the membrane configurations like spiral wound, hollow fiber, and tubular. The paper also discusses different mathematical models of RO concerning the solvent flux, solute flux, membrane fouling, energy consumption, nanomaterial incorporation in membrane, hybrid technologies with RO, and zero liquid discharge to enhance the performance of RO system. It is observed that these models could assist in optimizing the design as well as the operation of the systems to increase efficiency, decrease the consumption of energy and enhance the quality of water obtained. Further, predictive models could be developed for forecasting the performance of systems and contribute early warning of possible problems like scaling, fouling, and membrane degradation. [Display omitted] • Comprehensive assessment of current developments in the RO modeling presented. • Mathematical models of RO related to solvent flux and solute flux discussed. • Models based on membrane fouling, energy consumption, and membrane materials analyzed. • Zero liquid discharge (ZLD) and hybrid technology models examined. [ABSTRACT FROM AUTHOR]

Solar-powered desalination is an attractive solution to the problem of water scarcity, but the practical applications of three-dimensional (3D) interfacial solar steam generators have been limited by their complex production methods, low water generation rates, and durability issues. This study proposes a low-cost, easy-to-produce 3D solar steam generator with a popsicle design that employs diesel soot coated on polyvinyl alcohol sponges and plant transpiration-inspired chopsticks wrapped in airlaid paper for efficient water transport. The effects of various design factors are investigated, and it is found that the DSp-PVA-3D-6 configuration achieved an impressive evaporation rate of 3.81 kg m−2 h−1 under one sun illumination. The generator also demonstrated anti-salt fouling ability and sustained high evaporation performance over an extended period. Indoor seawater desalination studies yielded positive outcomes, while outdoor experiments showed that the DSp-PVA-3D array efficiently produced fresh water (2 L m−2 h−1) meeting daily human fresh water requirements. This proposed design is a significant step towards creating practical, inexpensive steam generators for real-world solar-powered saltwater desalination, offering a promising solution to global water scarcity. • A novel plant transpiration inspired 3D popsicle design. • A cost effective and facile 3D design for highly efficient steam generation. • DSp-PVA-3D ISSG generator gains latent energy from the hotter surrounding environment. • DSp-PVA-3D-6 generator desalinates sea-water with anti-fouling property in long term operations. [ABSTRACT FROM AUTHOR]

Desalination technology has been recognized as a promising solution for mitigating the pressure caused by water shortage. In order to help the decision-makers to select the most sustainable desalination process/technology, a multi-criteria decision analysis method under hybrid information was proposed for sustainability ranking of alternative desalination processes. The interval AHP (Analytic Hierarchy Process) method was employed to determine the weights of the evaluation, and the TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) under hybrid information was employed to determine the sustainability ranking of the alternative desalination processes. Comparing with the previous studies about desalination process selection, the proposed method can achieve desalination selection based on the decision-making matrix composed by multiple types of data (i.e. crisp numbers, interval numbers and fuzzy numbers). Accordingly, the challenges of uncertainties and the quantification on the soft criteria can be successfully solved. The results based on the developed model can facilitate the decision-makers to select the most sustainability desalination technology with the considerations of economic, environmental. Technological and social pillars simultaneously. Four alternative desalination processes including multi-stage flash system (MSF), low temperature multi-effect distillation (LT-MED), reverse osmosis (RO), and vapor compression distillation (VCD) were studied by the proposed method in this study, and the closeness degree (CD) of LT-MED which represents its integrated sustainability performance is 0.6984, followed by the CDs of MSF (0.5602), VCD (0.5381) and RO (0.4116), respectively. Thus, the sustainability ranking from the best to the worst is LT-MED, MSF, VCD and RO. The results were validated by the sum weighted method, and sensitivity analysis was also carried out. The results reveal that the selection of LT-MED as the most sustainable is robust. • A sustainability ranking method for desalination process selection was proposed. • The interval AHP was used to determine the weights of the criteria. • The TOPSIS method was used to rank the desalination processes under hybrid information. • The decision-making matrix with multiple types of data can be addressed. [ABSTRACT FROM AUTHOR]

Water scarcity is viewed as the top global risk for the next decade. One way to resolve water shortage is desalination which expends energy to derive fresh water from the vast amount of saline water. While the current desalination technologies are matured and reliable, desalinating seawater is still an energy intensive process, necessitating research for new generation desalination technology with lower energy consumption. Previously, our group proposed an innovative hydrate based desalination utilizing LNG cold energy (ColdEn-HyDesal) which reported a low specific energy consumption of 0.84 kWh/m3. In this work, we further evaluate the economic feasibility of ColdEn-HyDesal in Singapore. With a regasification rate of 200 t/h, the ColdEn-HyDesal facility simulated in this study produces 260 m3 water per hour. Through a comprehensive evaluation of the capital and operating costs, we observed significant reduction in the levelized cost of water (LCOW) from $9.31/m3 to $1.11/m3 with cold energy integration. The effect of water recovery rate, plant capacity and geological locations were analysed. Finally, the costs of water via the ColdEn-HyDesal process at various scales were benchmarked with matured desalination technologies, revealing that ColdEn-HyDesal technology is economically favourable at larger scale. • The economic feasibility of hydrate-based desalination (HyDesal) process with LNG cold energy utilization is evaluated • The FCI for HyDesal process with and without LNG cold integration are $42.4 million and $9.6 million, respectively • The levelized cost of water for HyDesal process decreased from $9.31/m3 to $1.11/m3 through LNG cold utilization. • The coupling of HyDesal with LNG cold utilization is economically favourable at higher plant capacity. [ABSTRACT FROM AUTHOR]

Abstract Water scarcity is a grand challenge that has always stimulated research interests in finding effective means for pure water production. In this context, reverse osmosis (RO) is considered the leading and the most optimized membrane-based desalination process that is currently dominating the desalination market. In this review, various aspects of RO desalination are reviewed. Theories and models related to concentration polarization and membrane transport, as well as merits and drawbacks of these models in predicting polarization effects, are discussed. An updated review of studies related to membrane modules (plate and frame, tubular, spiral wound, and hollow fiber) and membrane characterization are provided. The review also discusses membrane cleaning and different pre-treatment technologies in place for RO desalination, such as feed-water pre-treatment and biocides. RO pre-treatment technologies, which include conventional (e.g., coagulation-flocculation, media filtration, disinfection, scale inhibition) and non-conventional (e.g., MF, UF, and NF) are reviewed and their relative attributes are compared. As per the available literature, UF, MF and coagulation-flocculation are considered the most widely used pre-treatment technologies. In addition, this review discusses membrane fouling, which represents a serious challenge in RO processes due to its significant contribution to energy requirements and process economy (e.g., flux decline, permeate quality, membrane lifespan, increased feed pressure, increased pre-treatment and membrane maintenance cost). Different membrane fouling types, such as colloidal, organic, inorganic, and biological fouling, are addressed in this review. Principles of RO process design and the embedded economic and energy considerations are discussed. In general, cost of water desalination has dropped to values that made it a viable option, comparable even to conventional water treatment methods. Finally, an overview of hybrid RO desalination processes and the current challenges faced by RO desalination processes are presented and discussed. Highlights • An updated review of RO desalination is provided. • Concentration polarization and transport models are discussed. • Design, energy, and economic factors are discussed. • Hybrid RO processes are reviewed. • Technological challenges are addressed. [ABSTRACT FROM AUTHOR]

Abstract Zero liquid discharge desalination (ZLDD) is a sustainable solution to the global water scarcity problem. It provides high water recovery, zero waste generation and valuable salt production. In this work, a mathematical model of a novel ZLDD system that consists of freeze desalination (FD) and membrane distillation-crystallization (MD-C) has been developed based on the theories of heat and mass transfer as well as experimental results. To improve the energy efficiency of the system, effects of important parameters, such as (1) the feed temperature, concentration, and distillate temperature of MD and (2) the recovery ratio of FD on system operating curves and energy consumptions have been systematically investigated with the aid of mathematical modelling. In addition, the potential of using green energies to power this hybrid system has been explored. For a lab-scale hybrid ZLDD system operating at optimized conditions with a daily seawater processing capacity of 72 kg, 50% of its heating energy can be supported by a 50.5 m2 solar panel and its cooling energy can be 100% provided by re-gasification of 207-kg liquefied natural gas (LNG). This work may provide useful guidance in designing a low-cost FD-MD-C hybrid system for ZLDD. Graphical abstract Unlabelled Image Highlights • The first FD-MD-C hybrid system for zero liquid discharge desalination (ZLDD) • A mathematical model based on theories and verified by experimental results • Investigations of key parameters on system performance and total energy consumption • A pilot with a daily salt production of 2.52 kg and a water production of 69.48 kg • Heating and cooling supported by solar panels and regasification of LNG [ABSTRACT FROM AUTHOR]

Abstract This article uses logistic growth curves to analyze and compare the historical dynamics in technology deployment and unit upscaling experimented by the three main desalination technologies: multi-effect distillation (MED), multi-flash distillation (MSF) and reverse osmosis (RO). It also explores whether these dynamics follow a number of patterns identified in another well studied technology family with increasing strategic importance for desalination, i.e. energy technologies. The analysis suggests that thermal technologies (MED and MSF) are in an advanced growth phase and approaching saturation, with deployment levels likely to peak before 2050. The logistic fit for RO lacks enough significance to derive meaningful future capacity projections. RO also shows a remarkably high average-to-maximum unit capacity ratio mirroring a modular and more granular nature. Meanwhile, the three technologies are found to meet a series of common patterns in the temporal and spatial sequence of deployment identified in energy technologies. Based on such patterns and technology natures, PV-RO hybrid systems may hold the highest potential to overcome the cost and energy footprint challenges of desalination in the future. This analysis can guide the integration of desalination into modelling frameworks intended to assess future technological scenarios to address water scarcity and sustainable development goals related challenges. Highlights • The historical growth dynamics of desalination technologies are analyzed and compared against energy technologies • MED and MSF are in an advanced growth phase and likely to approach saturation before 2050 • RO has a remarkably high average-to-maximum unit capacity ratio mirroring modularity and granularity • The three technologies meet a series of common temporal and spatial deployment patterns detected in energy technologies [ABSTRACT FROM AUTHOR]