Membrane Technologies for Water Treatment and Purification

Membrane‐based processes have become central to addressing global water scarcity by enabling energy‐efficient separation of contaminants from water. Pressure‐driven methods such as microfiltration, ultrafiltration, nanofiltration and reverse osmosis dominate large‐scale desalination and wastewater reuse, whereas emerging approaches including forward osmosis, electrodialysis and membrane distillation offer new pathways to treat challenging feed streams. Advances in material science have yielded polymeric membranes with tailored pore structures, ceramic and carbon‐based membranes for enhanced chemical and thermal stability, and two‐dimensional frameworks and mixed‐matrix composites that combine high flux with precise solute selectivity. Key challenges remain in reducing energy consumption, mitigating fouling through surface engineering and dynamic cleaning strategies, and extending membrane lifetime under variable operating conditions. Integration of membrane units with renewable energy sources and process intensification schemes is accelerating the adoption of circular‐economy approaches for resource recovery, such as nutrient reclamation and brine mining. Ongoing innovation at the nanoscale, informed by multiscale modelling and real-time monitoring, is driving the development of next‐generation membranes that balance sustainability, cost-effectiveness and performance in diverse water treatment applications.

Research from Nature Portfolio

Hybrid modelling approaches have been developed to compare membrane separations with evaporation, extraction and hybrid processes, combining data-driven and mechanistic models to predict solute rejection and energy consumption. This methodology identifies solute-specific thresholds that can deliver up to 40 % reductions in energy use and carbon dioxide emissions for industrial separations, and maps global opportunities for low-carbon water treatment. Innovations in surfactant-assembly regulated interfacial polymerisation have enabled the fabrication of polyamide membranes with highly uniform sub-nanometre pores, achieving step-wise size-dependent sieving of solutes and near-perfect rejection across half-ångström scales. Nanoparticle-templated thin-film composite nanofiltration membranes have demonstrated ultrahigh permeance with maintained salt rejection by using sacrificial metal-organic framework particles to create crumpled active layers, yielding permeance above 50 L m⁻² h⁻¹ bar⁻¹ for efficient desalination.

Membrane Technologies for Water Treatment and Purification publication trend

The graph below shows the total number of articles in membrane technologies for water treatment and purification across all publications each year (not limited to Nature Index journals).

Technical terms

Reverse osmosis (RO): A pressure‐driven membrane process that removes dissolved salts and small organics by forcing water through a dense polymer film.

Nanofiltration (NF): A membrane separation technique with pore sizes between ultrafiltration and RO, enabling selective removal of multivalent ions and small organic molecules.

Membrane fouling: The accumulation of particles, organic matter, biofilms or scale on membrane surfaces, leading to reduced flux and performance.

Permeance: A measure of the volumetric flux of water per unit membrane area, pressure differential and time, indicating intrinsic membrane permeability.

Selective separation: The capacity of a membrane to distinguish between species based on size, charge or chemical affinity, often quantified by rejection or selectivity ratios.

References

1. A hybrid modelling approach to compare chemical separation technologies in terms of energy consumption and carbon dioxide emissions. Nature Energy (2024).
2. Polyamide nanofiltration membrane with highly uniform sub-nanometre pores for sub-1 Å precision separation. Nature Communications (2020).
3. Nanoparticle-templated nanofiltration membranes for ultrahigh performance desalination. Nature Communications (2018).
4. Mechanisms and models for water transport in reverse osmosis membranes: history, critical assessment, and recent developments. Chemical Society Reviews (2023).
5. Engineer Nanoscale Defects into Selective Channels: MOF-Enhanced Li+ Separation by Porous Layered Double Hydroxide Membrane. Nano-Micro Letters (2023).
6. Membrane Technologies in Wastewater Treatment: A Review. Membranes (2020).