Water purification research focuses on making water safer by removing contaminants such as salts, heavy metals, organic pollutants, pathogens and microplastics, while reducing cost, energy use and environmental impact.

Membrane technologies are central. Reverse osmosis and nanofiltration use thin selective barriers to separate salts and pollutants from water. Recent work improves membrane materials to increase flux, reduce fouling and enhance selectivity, for example through nanoporous structures, tailored surface chemistry and composite layers. Researchers also explore forward osmosis and pressure retarded osmosis, which exploit natural osmotic gradients to reduce energy demand.

Advanced oxidation processes use reactive species such as hydroxyl radicals to break down organic contaminants and pharmaceuticals into less harmful compounds. Methods include photocatalysis with semiconductor materials, ozonation and electrochemical oxidation. Current studies seek photocatalysts that work efficiently under visible light and can be recovered and reused.

Adsorption remains important for removing trace metals and organics. Activated carbon is being refined, and new sorbents such as functionalized polymers, metal organic frameworks and bio based materials are being developed to target specific pollutants with higher capacity and easier regeneration.

Disinfection research improves control of bacteria, viruses and protozoa using ultraviolet light, advanced filtration and electrochemical methods, while minimizing harmful byproducts associated with chlorination.

There is also growing interest in integrated systems that combine membranes, adsorption, oxidation and disinfection in compact treatment trains, and in decentralized solutions suited to low resource settings. Across these efforts, researchers evaluate not only contaminant removal, but also energy footprints, life cycle impacts and resilience to emerging pollutants such as PFAS and microplastics.