Modeling a bypass flow pressure vessel to balance flux and energy use in seawater reverse osmosis

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

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

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

Optimal design of energy-saving spacer for reverse osmosis seawater desalination: A swimming crab - shaped spacer

This study focused on the fouling of two seawater reverse osmosis (SWRO) membranes at the Beni Saf Water Company desalination plant in Algeria, which has a daily capacity of 200 000 m3 and a recovery rate of 45% using 17 920 membranes. Approximately 3 234 membranes are replaced annually due to fouling. A detailed study of the fouling agents of the two membranes was conducted using various analytical techniques, such as moisture analysis, loss on ignition (LOI), determination of calcium carbonate (CaCO3) content, x-ray fluorescence (XRF), x-ray diffraction (XRD), and Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). Surface characterization was also performed using scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy (SEM-EDS), FTIR-ATR, and XRD. The LOI analysis indicated that more than 30% of the fouling material was organic in nature. FTIR-ATR identified the presence of –OH groups, phenolic C–O groups, and amide bonds, suggesting the accumulation of organic substances such as proteins, humic substances, and polysaccharides. Additionally, SEM-EDS, XRF, and XRD revealed relatively high concentrations of silica, primarily in the form of quartz, confirming the formation of an organo-inorganic complex on the membrane surface. Based on these findings, a sequential chemical cleaning protocol was developed, incorporating alkaline (NaOH), metal chelator (EDTA), surfactant (SDS), oxidant (H2O2), and sulfuric acid (H2SO4), each followed by rinsing with deionized water (DI). This cleaning regime effectively removed fouling from the membrane surface, resulting in an average weight loss of 15% for one membrane and 14% for the other.

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

Fabricating breakthrough materials capable of desalinating seawater and brine with high selectivity and low energy consumption is crucial for addressing global water and energy challenges. We report here the desalination capability of ultra-thin polymeric films with subnanometer pores synthesized through the polymerization of fluorinated trichlorosilane monomers and diamine-based monomers. The combination of subnanometer pore size, submicron thickness, and superhydrophobicity facilitates efficient liquid-to-vapor phase change in the membrane distillation process, enabling effective desalination performance. The thin-films demonstrate high salt rejection (99.8%), complete boron rejection, and water fluxes of 40 L.m-2.h-1 (1.88 kWh.m-3, WRRsp 0.32%) and 238 L.m-2.h-1 (20.65 kWh.m-3, WRRsp 3.87%) for seawater at 25 °Cand 60 °C, respectively. For the desalination of real seawater reverse osmosis brine at 25 °C, the thin-films maintain 12 L.m-2.h-1 (4.4 kWh.m-3, WRRsp 0.09%) under comparable conditions. Their polymeric nature, chlorine resistance, and low energy requirements, indicate a potential for scalable and sustainable desalination systems.

Conventional reverse osmosis (RO) membranes have poor boron rejection at neutral pH due to the small size and neutrality of boric acid. To overcome this issue, we have developed a nanoconfined transport layer by coassembling cyclodextrin-MOF and exfoliated LDH nanosheets within the polyamide layer. Cyclodextrin-MOF offers adsorption sites and steric hindrance that temporarily retain boron species, while single-layer LDH forms hydrophilic channels for fast water transport, together creating a dual-channel mechanism for efficient boron-water separation. The optimized membrane has a boron rejection of 82.24% and a NaCl rejection of 99.27% using a feed containing 5 ppm of boron and 2,000 ppm of NaCl. In addition, the separation performance remains stable for 96 h without degradation. Its efficacy is further validated by using seawater RO permeate, where the boron concentration is reduced below the threshold of WHO drinking water. Mechanistic analyses highlight the role of hydrogen bonding in impeding boron diffusion. Preliminary in vivo toxicity studies in mice reveal that the nanofillers have no adverse effects on the renal or intestinal tissues. Therefore, this work may provide an effective strategy to design RO membranes for selective boron separation and desalination.

A complete and thorough understanding of the complicated heterogeneous structure of polyamide separation membranes is crucial to improving their performance. Electron tomography has been used to study density variations in dense polymer membranes; however, the nonuniformity of membrane thickness and surface morphology present major challenges to the accuracy of that method. In this article, we show that nanoscale 2D electron energy loss spectroscopy (EELS) maps can be correlated with 3D scanning transmission electron microscopy (STEM) tomography to improve the quantitative mapping of density. We reveal quantitative nanoscale structural differences between commercial seawater and brackish water polyamide thin film composite reverse osmosis membranes and compare them to thin uniform printed membranes. To reduce electron beam damage, we employ a high-speed direct electron detector for low-dose EELS, which allows for membrane thickness and electron scattering measurements to be spatially correlated to improve the measurement of density. We resolve nanoscale differences between three polyamide membranes which have distinctly different separation performances. Our work provides a framework for the use of STEM and EELS to extract heterogeneous density variations in structurally complex membranes.

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

Ocean acidification, rising sea temperatures, and changes in seawater composition are mainstream effects of climate change. Nevertheless, seawater desalination projects, plant designs, simulations, and experimental studies largely ignore these long-term...

The integration of Reverse Osmosis (RO) desalination with Renewable Energy (RE) sources offers a sustainable approach to freshwater production, particularly in remote and off-grid regions. However, the variable and intermittent output of RE power can cause operational instability that affects membrane performance and system reliability. This study experimentally evaluated a flat sheet seawater RO membrane under variable conditions emulating a Photovoltaic (PV)-powered system over three days. Three scenarios were examined: (i) steady full-load operation representing PV with battery storage, (ii) variable operation representing sunny-day PV output, and (iii) highly variable operation representing cloudy-day PV output. A Variable Frequency Drive (VFD) regulated by an Arduino microcontroller adjusted high-pressure pump operation in real time to replicate power fluctuations without energy storage. Each scenario operated for eight hours per day and was tested with and without end-of-day rinsing. Under the highly variable cloudy-day scenario without rinsing, water permeability decreased by 37%, salt rejection decreased by 18%, and membrane resistance increased by 37%, indicating compaction and fouling effects. Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR) confirmed structural changes in membranes exposed to fluctuating conditions. These results highlight the need for improved operational strategies to protect membrane longevity in RE-powered desalination systems.

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

Analysing practical inefficiencies of closed-circuit reverse osmosis (CCRO) seawater desalination via finite-difference time-dependent model

Impact characterization of salinity in seawater reverse osmosis brine and preference rankings of potential treatment technologies

The Gaza Strip faces a dual challenge of severe freshwater scarcity and chronic electricity shortages, constraining the operation of critical infrastructure such as seawater desalination plants. This study investigates the design and feasibility of integrating a solar photovoltaic (PV) system into the Deir El-Balah seawater reverse osmosis (SWRO) desalination plant to enhance sustainability, reduce dependency on external electricity supplies, and minimize environmental impacts. Using the Helioscope simulation tool, both on-grid and off-grid scenarios were evaluated to assess system performance under local solar conditions. The optimized design requires 2,663 Canadian Solar HiKu CS3W-415P modules with Enphase M250 inverters, yielding a total installed capacity of 1.11 MWp and an AC output of 639 kW. Modules were allocated across rooftop structures and ground-mounted plots to maximize land-use efficiency. The system can meet the plant’s daily demand of approximately 1,100 kWh, thereby reducing reliance on fossil fuels and mitigating greenhouse gas emissions. Beyond technical performance, the integration of solar PV offers strategic benefits, including cost savings, improved energy security, and alignment with global sustainability agendas. The findings highlight the potential of renewable-powered desalination to contribute to Sustainable Development Goals (SDGs 6, 7, and 13) while advancing resilience and energy–water security in resource-constrained regions.

Reverse osmosis (RO) technology, as a mainstream method of water treatment, is widely used worldwide for water resource acquisition. However, in the context of the current global effort to achieve carbon neutrality, its carbon footprint has gradually attracted attention. The aim of this study is to systematically assess the carbon footprint of the RO water treatment process during its full life cycle and to explore the carbon reduction potential of the RO water treatment process under different decarbonization scenarios. To analyze RO’s carbon footprint in different applications, this study constructed a life cycle model of the RO water treatment process under the business model, calculating footprints for seawater reverse osmosis (SWRO), brackish water reverse osmosis (BWRO), and reclaimed water reuse. Results showed carbon footprints of 3.258, 2.868, and 3.083 kg CO₂-eq/m³ for the three applications, with operational power as the main carbon source, followed by chemical use, membrane production, and disposal. The carbon footprint of the three applications can be reduced by up to 93.23%, 87.81%, and 51.12% by predicting the grid structure, waste recycling and disposal methods, and energy consumption after process operation optimization. Sensitivity analyses of key process variables showed that the carbon footprint was more sensitive to influent temperature, system energy recovery, and influent salinity than membrane product life. Thus, the study recommends a comprehensive strategy involving renewable energy, energy efficiency improvements, and operational optimization to lower RO’s carbon footprint and support carbon neutrality.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-24518-2.

Seawater desalination has emerged as a crucial solution for addressing global freshwater scarcity. However, it generates significant volumes of concentrated brine waste. This brine is rich in dissolved salts and minerals, primarily, chloride (55%), sodium (30%), sulfate (8%), magnesium (4%), calcium (1%), potassium (1%), bicarbonate (0.4%), and bromide (0.2%), which are often discharged into marine environments, posing ecological challenges. This study presents a comprehensive global review of innovative technologies for recovering these constituents as valuable products, thereby enhancing the sustainability and economic viability of desalination. The paper evaluates a range of proven and emerging recovery methods, including membrane separation, nanofiltration, electrodialysis, thermal crystallization, solar evaporation, chemical precipitation, and electrochemical extraction. Each technique is analyzed for its effectiveness in isolating salts (NaCl, KCl, and CaSO4) and minerals (Mg(OH)2 and Br2), with a discussion of process-specific constraints, recovery efficiencies, and product purities. Furthermore, the study incorporates a detailed techno-economic assessment, highlighting revenue potential, capital and operational expenditures, and breakeven timelines. Simulated case studies of a 100,000 m3/day seawater reverse osmosis (SWRO) facility demonstrates that a sequential brine recovery process and associated energy balances, supported by pilot-scale data from ongoing global initiatives, can achieve over 90% total salt recovery while producing marketable products such as NaCl, Mg(OH)2, and Br2. The estimated revenue from recovered materials ranges between USD 4.5 and 6.8 million per year, offsetting 65–90% of annual desalination operating costs. The analysis indicates a payback period of 3–5 years, depending on recovery efficiency and product pricing, underscoring the economic viability of large-scale brine valorization alongside its environmental benefits. By transforming waste brine into a source of commercial commodities, desalination facilities can move toward circular economy models and achieve greater sustainability. A practical integration framework is proposed for both new and existing SWRO plants, with a focus on aligning with the principles of a circular economy. By transforming waste brine into a resource stream for commercial products, desalination facilities can reduce environmental discharge and generate additional revenue. The study concludes with actionable recommendations and insights to guide policymakers, engineers, and investors in advancing brine mining toward full-scale implementation.

Integrated techno-economic modelling and analysis of a wind-powered seawater reverse osmosis desalination plant with hydrogen storage as a backup system