The impact of the water crisis is significant, and among the available solutions, the desalination of seawater and brackish water stands out. Herein, a simple, energy-efficient, and scalable, dual-functional method for pretreatment followed by partial desalination of seawater is reported. A hybrid filtration setup was employed, consisting of naturally available, environmentally friendly adsorbents such as fine sand, carbon, and cellulose filters coated with graphene oxide (GO) and Ti3C2T x MXene. These materials are arranged in layers forming a sandwich structure, allowing seawater to pass through naturally by gravity, without external pressure, making the system highly energy-efficient. The lab-made hybrid filter can process up to ∼2 L of water per hour using a small effective filtration area of ∼63 cm2. The influence of coating concentration was studied using four different concentrations, where 1 mg mL-1 coatings showed better performance for both GO and MXene. After filtration, the water was analysed using various quality parameters, and the filter components were examined via FESEM with EDS to assess morphology and elemental composition. Among GO and MXene, GO-coated filters performed better, achieving a satisfactory pretreatment and a 17.7% reduction in salinity without any external energy input. The salt rejection is mainly attributed to adsorption and electrostatic interactions between the coated materials and dissolved ions in seawater.

From fixed points to optimum regions: AI-NSGA-II framework for high-recovery, low-energy brackish water RO.

Waste corrugated paperboard derived binder-free carbon for improved brackish water desalination performance via capacitive deionization

Corrigendum to “Alkali-activation as a facile way to reinforce porosity and defective aromatic structures of rice husk-based carbonaceous electrodes via C and Si etching governing brackish water desalination performance of flow-electrode capacitive deionization” [Desalination 623 (2026) 119859

Capacitive deionization (CDI) is an enormous potentialversatileplatform for energy-efficient seawater electro-desalination technology.However, traditional carbon materials and charge transfer materialshave problems such as low capacity, serious co-ionic effect, ion leakageof transition metal, and rigorous preparation conditions. Vermiculite,a natural clay with a two-dimensional layered structure, offers advantagessuch as cation exchange capacity, wide availability, environmentalfriendliness, nontoxicity, and a negatively charged surface. Here,2D vermiculite nanosheets (VMs) are exfoliated from bulk vermiculitevia a sustainable ion exchange process that is low cost, green, andnontoxic. Compared with bulk vermiculite, the VMs possess an abundanceof internal negative surface charge, which is beneficial for chargetransfer, local conductivity, and more available active sites forNa+ adsorption/desorption in reversible electrochemicalprocesses. Due to the high-density of exposed adsorption sites andrapid Na+ transport pathways, the obtained 2D VMs electrodeenables a high sodium ion adsorption capacity of 26.56 mg g–1 at 1.2 V voltage in 500 mg L–1 salt solution andno secondary pollution of water bodies, which holds significant potentialfor widespread application in brackish water desalination.

Power distribution in the single-pass multi-stage electrodialysis (SPM-ED) for brackish water desalination

Surface textural and rheological properties of rice husk-derived carbonaceous electrodes pyrolyzed under CO2 atmosphere controlling brackish water desalination performance of flow-electrode capacitive deionization: Effects of pyrolysis temperatures

Renewable energy powered membrane technology: Integration of solar irradiance forecasting for predictive control of photovoltaic-powered brackish water desalination system

De-risking high-recovery brackish water desalination via flow reversal and feed flushing using techno-economic assessment

Faradaic deionization (FDI) using intercalation materials with cation-blocking membranes shows promise for energy-efficient desalination. Recently, we demonstrated for the first time the use of a symmetric FDI cell comprising two nickel hexacyanoferrate electrodes separated by an anion-exchange membrane to desalination feeds with seawater salinity down to near freshwater salinity at low energy consumption (Energy Environ. Sci., 2023, 16, 3025). However, reliance on ion-exchange membranes (IEMs) greatly increases the capital cost of FDI, limiting widespread adoption and commercialization. Herein, we investigate the desalination performance of a symmetric FDI cell that uses nanofiltration membranes as separators. The dynamic salt depletion/enrichment mechanism of the cell renders a salt removal that depends on a characteristic time constant and a Damköhler number, which represents the ratio of the rate of salt depletion caused by cation intercalation to the rate of salt diffusion through the NF membrane. This theory predicts that such an IEM-free symmetric FDI cell can produce freshwater from brackish water, though not from seawater. Experimental validation demonstrates the ability of the cell to desalinate 5 g/L NaCl and 3.2 g/L of Instant OceanÒ containing multiple salts to freshwater (< 1 g/L) and drinkable water (< 0.5 g/L), respectively. The cell exhibits a volumetric specific energy consumption of 1.4 – 2.2 kWh/m3, which is comparable to brackish water reverse osmosis, electrodialysis, or membrane capacitive deionization. Controlled experiments using IEMs reveal that salt diffusion through the NF membrane consumed 35 – 50% of the total charge passed to the cell, decreasing with increasing currents, whereas 25 – 40% of the charge is lost by other processes, which increases with currents. Unexpectedly, water recovery (WR) is shown in IEM-free SFDI to increase with the amount of charge transferred during batch-type experiments, contrasting with the usual decrease of WR that accompanies using IEMs.

In Morocco, water resources are increasingly under threat due to population growth, economic expansion, and climate change. Among the proposed solutions, brackish water desalination using membrane technologies such as nanofiltration (NF) and reverse osmosis (RO) with low‐pressure membranes presents a promising alternative. This study evaluated the impact of salinity on the performance of two nanofiltration membranes (NF270 and NF90) and one reverse osmosis membrane (TM710) using three semisynthetic brackish water samples with salinities of 2, 4, and 6 g L−1. Ion transfer mechanisms, particularly for sodium (Na+) and chloride (Cl−), were analyzed using the Spiegler–Kedem (SK) and Kedem–Katchalsky (KK) mathematical models. Additionally, the effects of salinity on diffusion flux (Jdiff), convection‐induced concentration (Cconv), reflection coefficient (σ), and solute permeability (Ps) were examined. Results indicate that the NF270 membrane exhibits the highest permeate flux, while NF90 and TM710 perform similarly. For all three membranes, permeate flux decreases almost linearly as feed water salinity increases. Regarding total dissolved solids (TDS) rejection, the TM710 membrane achieves the highest removal efficiency, followed by NF90 and then NF270. The NF270 membrane shows greater convective transport than NF90, with both diffusive and convective fluxes increasing with salinity. In contrast, the TM710 membrane operates primarily through diffusion, with TDS having little effect on its diffusion flux. NF90 and TM710 exhibit similar σ and Ps values for sodium and chloride ions, independent of TDS, highlighting the NF90's similarity to a reverse osmosis membrane. In contrast, for NF270, the sodium reflection coefficient (σ) increases with TDS, while solute permeability (Ps) rises for both ions due to a decline in retention efficiency.

Evaluation of performance and practicality of small- to medium-scale photovoltaic solar-powered reverse osmosis systems for brackish water desalination: A review

Synthesis of polyacrylonitrile-based terpolymer cation exchange membrane for efficient brackish water desalination via electrodialysis with neural network prediction

Seawater and brackish water desalination using membranes is anticipated to offer a simple and effective solution to the global water shortage, and polysilsesquioxane (PSQ) is expected to be the base material for robust reverse osmosis (RO) membranes for water desalination. Hydroxyethylurea-containing PSQ-based RO membranes for water desalination have recently been developed via a sol–gel process. Although these membranes showed high performance, achieving a water permeability of 1.86 × 10−12 m3 m−2s−1Pa−1 and an NaCl rejection of 95.9%, the membranes showed limited chlorine resistance and processibility and moderate heat resistance. In this study, three new urea-containing monomers were designed and prepared for RO membrane preparation. The copolymerization of these urea-containing monomer with bis(triethoxysilylpropyl)amine resulted in performance comparable to that of hydroxyethylurea-containing PSQ membranes. The present urea-containing PSQ membranes exhibited enhanced chlorine resistance, with only 1–3% decreases in NaCl rejection, even after 10,000 ppm h exposure to chlorine, together with 3–19% increases in water permeability. Additionally, the presently prepared urea-containing PSQ membranes exhibited improved processability. This study provides a new molecular design for robust and high-performance RO membranes that can be prepared through a simple sol–gel process.

Prussian blue analogue compounds are widely recognized as the most promising cathode materials for large-scale capacitive desalination of brackish water in the future owing to their open three-dimensional framework structure and abundant active sites for metal ions. However, practical applications face challenges such as limited desalination capacity and short cycle life due to phase transitions induced by the insertion and extraction of sodium ions. In this study, theoretical calculations revealed that cubic phase aluminum iron hexacyanoferrate (AlFeHCF) does not undergo significant phase transitions during the sodium ion intercalation/extraction process. The coordination environment of aluminum is found to play a crucial role, providing valuable insights for the experimental direction. Building on these findings, we developed a preparation method for AlFeHCF aimed at removing sodium ions during the capacitive deionization (CDI) process. In this approach, aluminum partially substitutes for high-spin iron as a bimetallic component within iron hexacyanoferrate. Experimental validation demonstrates that this material exhibits exceptional performance when utilized in CDI cells, achieving a desalination capacity of up to 27.1 mg g-1 and exhibiting an extended cycle life with a capacity retention rate of 91.8% after 50 cycles. This innovative material shows great potential for advancing the development of CDI devices.

Faradic charged modified wrinkled layered graphene oxide as a capacitive deionization electrode for brackish water desalination

Novel ECOMF system: In situ ferrate generation for contaminant removal and fouling mitigation in brackish water desalination.

Designing of PVDF-Based Cation Exchange Membranes with Improved Electrochemical Properties for Energy-Efficient Brackish Water Desalination

A two-level model-based control system for energy-optimal operation of a two-stage reverse osmosis (RO) membrane desalination system was developed and field demonstrated. The control scheme was based on the specific energy consumption (SEC) framework accounting for pump efficiencies, physical system constraints, and temporal variability of feed salinity. The SEC framework consisted of a higher-level (supervisory) control system that guided a lower-level controller for real-time SEC optimization. The supervisory controller combined real-time plant data and the SEC model to determine the energy-optimal first-stage water recovery and the overall permeate water recovery (unless specified), and membrane permeability for a target permeate production. The derived operating state was then applied to control the RO plant operation through the lower-level control system, consisting of three separate feedback loops regulating the RO feed flow rate, first-stage RO pressure, and the second-stage RO pressure via control of the first-stage and second-stage RO feed pumps, and the RO concentrate valve. The two-level control system was demonstrated for a mobile brackish water desalination plant capable of permeate productivity up to 98 m3/day. Field testing demonstrated robust simultaneous control of the dynamically coupled control variables and effective energy-optimal operation.

Targeting fabrication of a TFC NF membrane for the desalination of sulfate-type brackish water