Summary

Membrane systems provide a physical barrier to various contaminants in water and therefore are attractive for different applications. Depending on the type of the membrane and its pore size, membranes might remove microbial contaminants, organic chemicals, or salts. The membrane-based systems for drinking water purification exist at different scales. The costs have decreased considerably since the 1990s, increasing the attractiveness for various needs and affordability levels. Household tabletop filters and filters installed under a sink can be used when public water supply quality is unreliable or in emergencies with locally available buckets or jerry cans. Gravity or solar-driven systems exist for off-grid applications in schools, health care facilities, or small communities. Skid-mounted and container-based desalination units are deployed in emergencies when brackish or saline water sources are the only option. Large-scale membrane-based drinking water treatment plants operate worldwide for municipal drinking water treatment. The modular design and flexibility around the capacity, target contaminants, and available energy sources offer opportunities for membrane-based drinking water treatment in various contexts. Further research and development should focus on mitigating membrane fouling, and reducing energy consumption, costs, and the overall technical complexity of the systems.