Desalination Methods Research Articles

Microfluidic Electrochemical Desalination Systems: A Review

Microfluidic techniques have emerged as promising, efficient, cost-effective, and environmentally friendly desalination solutions. By utilizing fluid dynamics at the microscale, these techniques offer precise control over chemical, biological, and physical processes, presenting advantages such as reduced energy consumption, miniaturization, portability, and enhanced process control. A significant challenge in scaling microfluidic desalination for macro applications is the disparity in flow rates. Current devices operate at microliters per minute, while practical applications require liters daily. Solutions involve integrating multiple units on a single chip and developing stackable chip designs. Innovative designs, such as 3D microfluidic chips, have shown promise in enhancing scalability. Fouling, particularly in seawater environments, presents another major challenge. Addressing fouling through advanced materials, including graphene and nanomaterials, is critical to improving the efficiency and longevity of devices. Advances in microfluidic device fabrication, such as photo-patterned hydrogel membranes and 3D printing, have increased device complexity and affordability. Hybrid fabrication approaches could further enhance membrane quality and efficiency. Energy consumption remains a concern, necessitating research into more energy-efficient designs and integration with renewable energy sources. This paper explores various electrochemical-based microfluidic desalination methods, including dialysis/electrodialysis, capacitive deionization (CDI)/electrochemical capacitive deionization (ECDI), ion concentration polarization (ICP), and electrochemical desalination (ECD).

Zinc-based metal-organic frameworks for sustainable water desalination and anti-scaling solutions.

Water scarcity and pollution pose significant challenges worldwide, necessitating innovative solutions for sustainable water supply. Traditional desalination methods have limitations in terms of energy consumption, fouling, and environmental impact. This study focuses on the synthesis and characterization of zinc-based metal-organic frameworks (Zn-MOFs) as advanced fillers for desalination techniques. Zn-MOFs were synthesized using a simple precipitation technique and characterized using techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The performance of Zn-MOFs was evaluated in terms of scale deformation experiments. The findings revealed that Zn-MOFs not only significantly reduce the concentration of Ca2⁺ ions responsible for scale (e.g., calcium carbonate scale) formation but also exhibit superior fouling resistance and high salt rejection capabilities. At a dosage of 3000mg/L and pH 7.5, a remarkable 99% removal efficiency was achieved for half-scale concentration (synthetic water was prepared by the following scale concentrations: 3665mg/L CaCl2, 685mg/L NaHCO3, and 12,000mg/L NaCl), while a 91.6% efficiency was obtained at normal scale concentrations (synthetic water was prepared by the following scale concentrations: 7330mg/L CaCl2, 1370mg/L NaHCO3, and 24,000mg/L NaCl). These results highlight the Zn-MOFs' advantages over conventional fillers and traditional techniques by offering improved stability, superior adsorption capacity, and enhanced scale management for desalination applications. This work contributes to advancing water treatment technologies by providing a more sustainable and effective approach for mitigating fouling and enhancing desalination efficiency.

Experimental Analysis of Fresnel Lens-Based Solar Desalination Systems with Copper Receivers for Enhanced Thermal and Electrical Performance

Solar desalination represents a breakthrough technology for creating sustainable freshwater because it meets both the water quality standards and technology efficiency requirements of modern times. The current desalination methods, which depend on fossil fuels, encounter major obstacles regarding their energy requirements and economical performance. The research investigates the improvement of solar desalination performance through coupling Fresnel lens technology with copper-based receivers to maximize thermal characteristics and power generation benefits. This research successfully unites Fresnel lenses of high performance with copper receivers to reach increased steam temperatures alongside power production during the same procedure. The research team performed experimental tests using a system that included four large Fresnel lenses in Sharjah, UAE. Under different operating settings, the system demonstrated its performance by measuring its flow rates together with ambient temperatures and recording the steam output values. The experimental data showed that bigger Fresnel lenses boosted the steam temperature beyond 1000°C as well as pushing pressure levels to 8 bar, which led to remarkable system efficiency benefits. The copper receiver system generated 775 mA DC electric current, which collectively enhanced the system's power efficiency. The tested combination of Fresnel lenses and copper receivers demonstrates an effective way to enhance solar desalination systems, according to observed experimental data. The dual-function technology combines desalination efficiency improvement with electricity production capabilities to establish a sustainable freshwater production method for arid regions. This investigation creates a basis for developing economical renewable desalination systems going forward.

Design and Construction of a Solar-Powered Seawater Desalination System for Remote Areas in India

Solar energy, a renewable energy source with zero emissions, has attracted attention all over the world as a supplier of sustainable energy. The present study, is to develop a sustainable and cost-effective solution for producing fresh water using renewable energy resource and desalination method, addressing minimal electricity generation and water shortage in coastal and arid regions, respectively. Solar stills are simple to build, can be executed by indigenous folks using locally provided accoutrements, uncomplicated in procedure by untrained manpower, no stringent conservation conditions and almost no operating cost, However, they have the drawbacks of being expensive initially, requiring a lot of land for installation, and being reliant on the amount of solar radiation available. The work serves as the initial reference for identifying electricity generation and the quality of fresh water production, which contributes to overall environmental sustainability.

Light-Activated Desalination: A Review on Photoluminescence-Based Water Purification for Sustainable Agriculture and Drinking Water

Abstract: Water scarcity is a growing challenge, necessitating the development of innovative desalination techniques that are energy-efficient and environmentally sustainable. Conventional desalination methods such as reverse osmosis and thermal distillation suffer from high energy demands and operational limitations. This review explores photoluminescence-assisted desalination, an emerging technique that leverages photoluminescent nanomaterials to facilitate salt removal through photothermal heating, ion-selective interactions, and photocatalytic precipitation. Key materials—including lanthanide-doped phosphors (Eu³⁺-Y₂O₃, Tb³⁺-Gd₂O₃), carbon quantum dots (CQDs), graphitic carbon nitride (g-C₃N₄), and semiconductor-based nanostructures (ZnO, TiO₂, CdS)—are examined for their role in desalination. The practical applications of this method in sustainable agriculture and drinking water production are also discussed, highlighting its potential for real-world implementation. The review concludes with insights into current challenges and future directions for scaling up photoluminescence-assisted desalination systems. Keywords: Desalination, photoluminescent materials, lanthanide-doped phosphors, carbon quantum dots, graphitic carbon nitride, quantum engineering, salt removal, water purification

Sodium‐Manganese Oxides in Faradaic Desalination: Achieving Long‐Cycling Stability Through Morphological and Structural Optimization

Water scarcity, driven by climate change and population growth, necessitates innovative desalination technologies. Conventional methods for brackish water desalination are limited by high‐energy demands, especially in the low salinity range, prompting the exploration of electrochemical approaches like faradaic deionization. Sodium‐manganese oxides, traditionally used in sodium‐ion batteries, show promise as faradaic deionization electrode materials due to their abundance, low toxicity, and cost‐effectiveness. However, capacity fading during cycling, often caused by structural changes, volume expansion, or chemical transformations, remains a critical challenge. This study investigates the impact of morphology and crystal structure on the electrochemical performance of commercial and synthesized sodium‐manganese oxides for faradaic deionization applications. Structural and electrochemical characterization in three‐electrode cells with low‐concentration electrolytes provided insights into the charge storage mechanisms. Rocking‐chair full flow cell experiments demonstrated that the mixed‐phase sodium‐manganese oxide exhibited superior desalination performance, achieving a high salt removal capacity of 54.5 mg g−1 and a mean value in the salt removal rate of 1.49 mg g−1 min−1. Notably, mixed‐phase sodium‐manganese oxide maintained 98% capacity retention over 870 cycles, one of the longest reported cycling experiments in this field, effectively mitigating the Jahn‐Teller effect. These findings highlight the crucial role of sodium‐manganese oxide structure and morphology in electrochemical performance, positioning mixed‐phase sodium‐manganese oxide as a strong candidate for sustainable water treatment technologies.

Nitrogen‐Doped Carbon Quantum Dot as Novel Nano Additive to Improve Performance and Fouling Resistance of Forward Osmosis Thin Film Nanocomposite Membranes

ABSTRACTForward osmosis (FO) is considered a strong and energy‐efficient desalination method. The thin film composite (TFC) membranes are widely used in the FO process. In this study, nitrogen‐doped carbon quantum dot (NCQD) was synthesized from citric acid (CA) and m‐phenylene diamine (MPD) as carbon and amine precursors, respectively, by a one‐step hydrothermal method. It was characterized completely by FT‐IR, XRD, UV–visible spectroscopy, DLS, and TEM analysis. Then, NCQD was incorporated in the polyamide (PA) layer to synthesize novel thin film nanocomposite (TFN) membranes. All membranes were analyzed by FT‐IR, WCA, AFM, and FE‐SEM. The TFN‐NCQD membrane, optimized with a concentration of 2000 ppm NCQD, exhibited outstanding FO performance, achieving a 70% increase in water flux compared to the pristine TFC. This membrane attained a peak water flux of 20.4 LMH, a reverse salt flux of 2.1 gMH, and showcased the best selectivity, with values as low as 0.10 g/L among the others. The strong interaction between amine functional groups of NCQD with both MPD and TMC during interfacial polymerization resulted in excellent adhesion and compatibility between the nanofiller and PA, increasing the lifespan of TFN membranes. Moreover, the novel TFN‐NCQD2 membrane showed better fouling behavior than pristine TFC, a 22% improvement when sodium alginate solution (600 ppm) was used as a foulant model.

Optimal Day‐Ahead Coordinated Scheduling for Efficient and Sustainable Energy Hubs Incorporating Electric Vehicles and Hydrogen Systems

ABSTRACTGlobally, energy and fresh water are essential for well‐being, but industrial growth and population increases pose significant challenges in meeting current and future demands. To address the freshwater crisis, desalination methods like reverse osmosis are widely adopted. Simultaneously, the push for carbon neutrality has boosted interest in clean energy alternatives, such as electric vehicles and hydrogen, to decarbonize energy systems. In this regard, this study proposes a day‐ahead optimization model aimed at reducing operational and environmental costs while meeting the demands for pure water and hydrogen. The proposed model is comprehensive, incorporating key energy hub (EH) components, specifically wind turbines, photovoltaic cells, and combined cooling, heating, and power systems. Additionally, energy storage systems—such as ice storage conditioners, thermal energy storage systems, water storage tanks, and solar‐powered compressed air energy storage—are integrated, along with seawater desalination using reverse osmosis technology to address freshwater needs. A hydrogen system, including an electrolyzer, fuel cell, and hydrogen tank, is also included. The model accounts for uncertainties in intermittent generation and seasonal load variations. Simulation results show a 5.96% reduction in total costs (operational and emissions) compared to existing methods, with a 6.17% decrease in operational costs and a 1.12% reduction in emissions costs, highlighting the advantages of the comprehensive approach. Seasonal cost reductions are observed at 9.28% in winter, 6.62% in spring, 2.94% in summer, and 3.37% in fall compared to existing methods. Therefore, the optimal and coordinated scheduling of EH units enables efficient operation, maximizes benefits, and contributes to sustainable energy management.

Enhanced organic matter removal and fouling mitigation in seawater desalination using electrocoagulation pretreatment using ZnO coated Fe electrodes

This study introduces a novel application of electrocoagulation (EC) as a pretreatment method for seawater desalination, uniquely focusing on reducing organic and biological fouling in reverse osmosis membranes. The EC process was investigated as an alternative to conventional approaches such as chemical coagulation, chlorination, and fouling inhibitors. EC was conducted in a batch cell using iron electrodes. The effectiveness of the EC process in removing organic matter from water was monitored by measuring absorbance UV254 and dissolved organic carbon (DOC), as well as total hardness. Various operational parameters, including mixing speed, current density, initial pH, and electrode spacing, were examined. Results demonstrated that increasing current density and decreasing pH enhanced the removal of organic matter from seawater via EC. The process achieved a 62% reduction in DOC and a 59.7% reduction in absorbance, indicating that higher current density is more favorable for these reactions. However, the reduction in total hardness was relatively low at approximately 11.2%, suggesting that EC is not suitable for reducing water hardness. Overall, the experimental findings highlight the high potential of electrocoagulation as a pretreatment method for mitigating organic and biological fouling of reverse osmosis membranes due to its effectiveness in removing dissolved organic matter and microorganisms from seawater.

Characterization and mitigation strategies for inorganic scaling in reverse osmosis system treating brackish groundwater

Characterization and mitigation strategies for inorganic scaling in reverse osmosis system treating brackish groundwater

The Synergy of Renewable Energy and Desalination: An Overview of Current Practices and Future Directions

Water is one of the most valuable and essential resources for human life, yet its scarcity has become a pressing global issue exacerbated by climate change and population growth. To address the increasing demand for water driven by urbanization, industrial expansion, tourism, and agricultural needs, many countries are turning to desalination as a viable solution. This study investigates the integration of renewable energy sources (RES) with desalination technologies to enhance both sustainability and efficiency. A comprehensive review of major desalination methods has been conducted, with a particular focus on the application of solar and wind energy. Additionally, the challenges associated with renewable energy-powered desalination, including the need for effective energy storage systems and the inherent volatility of power supply, were explored. Our findings indicate that coupling renewable energy with desalination not only significantly reduces carbon emissions but also enhances the sustainability of water supply systems. The study also emphasizes the importance of emerging technologies, such as hybrid energy storage systems (HESS) and machine learning (ML), in optimizing RES powered desalination processes. Ultimately, this study aims to guide future research and development initiatives, promoting the global adoption of desalination systems powered by renewable energy.

Strategies for leaching and agricultural use of saline lands under conditions of water shortage

An analysis of the authors' experimental data on land leaching from salinization was carried out. The regularity of specific water consumption for salt leaching is assessed depending on the degree of soil salinization and negative environmental factors when leaching the soil with a layer of water. It is shown that leaching at high rates reduces soil fertility indices (NPK). The results of studies of alternative innovative methods of soil desalination and agricultural use of lands subject to salinization are presented. Soil desalination technologies that ensure enhanced salt leaching and water savings are considered: leaching against the background of deep soil loosening and the use of a local preparation containing an organic acid. The data of experiments with microbiological preparations produced in Uzbekistan, adapted to soil salinization and ensuring crop yields, are presented.

Dynamic Simulation of a Hybrid Energy System for Powering a Water Treatment Facility in McCallum, Newfoundland and Labrador

Clean water, a basic human need, is in short supply in McCallum, Newfoundland and Labrador, primarily due to lead contamination, forcing residents to rely on collected rainwater. Reverse Osmosis (RO) has been identified as the most suitable desalination method because of its lower energy requirements and high effectiveness in treating lead-contaminated water. Powering the RO system with renewable energy sources (RES) offers a promising solution for this remote, off-grid area, currently powered by a diesel generator. The proposed hybrid energy system (HES) provides not only the most economically optimal configuration but also greater reliability. The system consists of a 3.6 kW solar array, a 2-kW wind turbine, a 3-kW DC diesel generator, and a 680 Ah 48 V battery bank to supply the single-phase water treatment system, which includes a 0.3 kW resistive load, lighting, and two asynchronous machines rated at 0.5 hp and 0.75 hp, respectively. A dynamic simulation of the proposed system, based on calculation done in Kafrashi and Iqbal [1], is presented in this paper. All system components are modeled in MATLAB/Simulink. Simulation results show expected dynamics in the system. Results indicate proper system operation with reasonable within-range system voltage and current during normal operation.

Optimization of Tubular Solar Distillation Performance With Nano-PCM and Parabolic Trough Collector

Solar distillation is a desalination method that utilizes solar energy to convert saline water into freshwater. However, the efficiency of this process is often limited by temperature fluctuations and low heat storage capacity. Phase Change Material (PCM) has been used as a thermal storage medium in solar distillation systems, but the low thermal conductivity of pure PCM remains a major challenge. To address this limitation, this study incorporates graphene carbon nanoparticles into beeswax-based PCM to enhance its thermal properties. This research examines the effect of adding 0.3% graphene to beeswax PCM on the performance of a tubular solar distillation system equipped with a Parabolic Trough Collector (PTC). The experiment compares the performance of pure PCM and nano-PCM, each weighing 90 grams and enclosed in an aluminum foil bag. The experimental results indicate that the addition of graphene to beeswax PCM improves solar distillation performance based on three key parameters, namely temperature, productivity, and efficiency. Nano-PCM achieved a maximum temperature of 76 °C, representing a 2.7% increase compared to pure PCM. In terms of productivity, the distilled water yield of nano-PCM was recorded at 0.834 L/m² on October 15, 2024, and 0.819 L/m² on October 17, 2024, marking an increase of 3.22% and 6.64%, respectively, compared to pure PCM. Furthermore, the system’s efficiency also improved with an increase of 3.03% on October 15, 2024, and 6.7% on October 17, 2024. Overall, this study demonstrates that the use of nano-PCM enhances the performance of solar distillation, particularly in terms of operating temperature, water productivity, and system efficiency. These findings highlight the significant potential of nano-PCM applications in large-scale solar distillation systems to improve freshwater production efficiency.

Mathematical and experimental study of the direct contact membrane distillation method for desalination using a hydrophobic electrospun nanofibers membrane

This paper examines the performance of a Direct Contact Membrane Distillation (DCMD) system experimentally and theoretically. The system uses a super hydrophobic electrospun nanofiber membrane to desalinate water. Investigations were carried out into how the feed concentration, feed flow rate, and feed temperature affected permeate flux. as system operating parameters to aid in comprehending the factors impacting the DCMD process. The application of DOE and Taguchi methods achieved statistical optimization of the DCMD process's performance. In addition, the study of mass and heat transport in DCMD was described by a theoretical model. While the feed concentration (0- 210 g/L) significantly affected flux, the feed's temperature (35-55 °C) and flow rate (0.2-0.6 L/min) mostly dominated the impact on system performance. The created model numerically solved the DCMD process using MATLAB software, describing it as a system of nonlinear equations. Various operating conditions were used to investigate the efficiency of the superhydrophobic electrospun nanofiber membrane in treating 210 g/L NaCl salt water. Changing the feed temperature and concentration affected the hypothetically suggested path across the membrane, according to the simulation results presented in this paper. Excellent agreement was observed between the experiment results and the constructed model's predicted results. Every instance maintained a high salt rejection rate (over 99.9%). The DCMD produced a gain output ratio (GOR) of 0.87 and a temperature polarization coefficient of 0.78 to 0.91. The system achieved a maximum thermal efficiency of 73.5%. The optimal parameters, which are 70 g/L, 0.6 L/min, and 55°C.

Considering Micro/nanostructures at the Surface of Photothermal Materials: A Game Changer in Correct Estimation of Evaporation Rate and Energy Conversion Efficiency in Interfacial Solar Vapor Generation Systems.

Interfacial solar evaporator generation (ISVG) is a new, cost-effective, and eco-friendly emerging method for water desalination. Two main criteria for evaluating ISVG performance are evaporation rate (ṁ) and solar-to-vapor conversion efficiency (η). The main challenge of the previously presented models for the estimation of ṁ and η in 2D systems is that in most cases the calculated values are beyond the theoretical limits, ṁ > 1.47 kg m-2 h-1 and η > 100%, both of which are not acceptable from the thermodynamics viewpoint. Also, the recently presented strategy of reduced vaporization enthalpy for obtaining η < 100% is unacceptable from the thermodynamics approach for ISVG as a two-step continuous process. Therefore, this work aims to present a model and consequently new equations for the correct estimation of evaporation rate and energy conversion efficiency in two-dimensional (2D)-ISVG systems, which are consistent with their corresponding theoretical limits. The basis of the present model is discrimination between the projection area and evaporation area by considering the micro/nanostructures on the surface of interfacial support (photothermal material). This leads to the presentation of new equations for ṁ and η having consistency with thermodynamics laws. The presence of micro/nanostructures on the surface of photothermal material provides a higher evaporation area which is not considered in the previous models and led to theoretically inconsistent results. The results of the present study provide a theoretical basis for the correct estimation of the evaporation rate and energy conversion efficiency in 2D-ISVG systems in future works.

Fast Seawater Desalination Integrated with Electrochemical CO2 Reduction.

Coupling desalination with electrocatalytic reactions is an emerging approach to simultaneously addressing freshwater scarcity and greenhouse gas emissions. However, the salt removal rate in such processes is slow, and the applicable water sources are often limited to those with high salt concentrations. Herein, we show high-performance electrocatalytic desalination by coupling with electrochemical CO2 reduction using a carbon catalyst. A ZIF-8-derived carbon catalyst embedded with Cu nanoparticles delivers a high Faradaic efficiency of 94.3 % for CO production at 288 μmol cm-2 h-1. The efficient CO2 electroreduction generates high current densities, which drive fast salt ion transfer across ion exchange membranes. The integrated device enables one of the highest salt removal rates of 1043.49 μg cm-2 min-1 among various desalination methods. Drinking water can be obtained with an ion removal rate of 99 % when natural seawater is used as the water source.

Fast Seawater Desalination Integrated with Electrochemical CO2 Reduction

AbstractCoupling desalination with electrocatalytic reactions is an emerging approach to simultaneously addressing freshwater scarcity and greenhouse gas emissions. However, the salt removal rate in such processes is slow, and the applicable water sources are often limited to those with high salt concentrations. Herein, we show high‐performance electrocatalytic desalination by coupling with electrochemical CO2 reduction using a carbon catalyst. A ZIF‐8‐derived carbon catalyst embedded with Cu nanoparticles delivers a high Faradaic efficiency of 94.3 % for CO production at 288 μmol cm−2 h−1. The efficient CO2 electroreduction generates high current densities, which drive fast salt ion transfer across ion exchange membranes. The integrated device enables one of the highest salt removal rates of 1043.49 μg cm−2 min−1 among various desalination methods. Drinking water can be obtained with an ion removal rate of 99 % when natural seawater is used as the water source.

Experimental Study of a Brackish Water Desalination Plant

Water desalination is crucial for addressing global water scarcity affecting over 2 billion people. By 2050, water demand could rise by 20-30% due to population growth and urbanization. Currently, over 40% of the global population lacks access to clean water due to overexploitation of conventional sources like rivers and groundwater. This report focuses on experimental analysis of brackish water desalination, primarily using reverse osmosis (RO). Desalination plays a vital role in converting seawater or brackish water into drinkable water, especially in coastal areas. The study explores various desalination methods such as ion exchange, membrane distillation, and vapor compression distillation. Technological advancements, particularly in RO distillation process has enhanced efficiency and sustainability. In this report, pre-treatment processes, including filtration, chemical dosing, antiscalant injection, water softening, are also employed to remove contaminants before desalination. The performance of RO is evaluated based on factors like pressure drop, feed flow rate, and recovery ratio, analyzing water flux, salt rejection rate, energy consumption, and system efficiency. The results provide insights into optimizing brackish water desalination and the discussions are carried out for improvement of the ways such as post treatment, membrane cleaning and advancement in membrane materials for sustainable freshwater production.

Efficient Light-Driven Ion Pumping for Deep Desalination via the Vertical Gradient Protonation of Covalent Organic Framework Membranes.

Traditional desalination methods face criticism due to high energy requirements and inadequate trace ion removal, whereas natural light-driven ion pumps offer superior efficiency. Current synthetic systems are constrained by short exciton lifetimes, which limit their ability to generate sufficient electric fields for effective ion pumping. We introduce an innovative approach utilizing covalent-organic framework membranes that enhance light absorption and reduce charge recombination through vertical gradient protonation of imine linkages during acid-catalyzed liquid-liquid interfacial polymerization. This technique creates intralayer and interlayer heterojunctions, facilitating interlayer hybridization and establishing a robust built-in electric field under illumination. These improvements enable the membranes to achieve remarkable ion transport across extreme concentration gradients (2000:1), with a transport rate of approximately 3.2 × 1012 ions per second per square centimeter and reduce ion concentrations to parts per billion. This performance significantly surpasses that of conventional reverse osmosis systems, representing a major advancement in solar-powered desalination technology by substantially reducing energy consumption and secondary waste.