Access to clean drinking water in rural or underdeveloped areas can be improved with a simple, portable filtration system. The device offers advantages in cost, effectiveness and sustainability compared to existing commercial options, giving users the ability to easily decontaminate water from nearby streams and rivers to make it drinkable.

The new system collects dirty water with a syringe and injects it into a hydrogel filter that removes microplastics and other types of suspended solids. While available filter paper- or microporous membrane-based portable filtration technologies remove about 40% to 80% of particles larger than 10 nanometers, respectively, the new hydrogel filter-based system captures close to 100% of these particles.

A microporous membrane supports the hydrogel film composed of cellulose nanofibers. The hydrogel films are biodegradable and can be used up to 30 times before they need to be replaced.

Syringes with capacities of 1.5 l (1.6 quarts), about 40% of an individual’s daily drinking water needs, have been tested and demonstrated to yield purified water from muddy water, river water and water contaminated with microplastics. The scalable system described in Nature Sustainability was designed by researchers from Northeast Forestry University (China), Tsinghua University (China), ShanghaiTech University (China), Central South University of Forestry and Technology (China) and University of Texas at Austin.