This hydrogel tablet can purify a liter of river water in an hour

According to some estimates, up to a third of the world’s population does not have access to safe drinking water, and half of the population could live in areas of water stress by 2025. Finding a solution to this problem could saving and improving the lives of millions of people, and it is a high priority among scientists and engineers around the world.

Scientists and engineers at the University of Texas at Austin have created a hydrogel tablet that can quickly purify contaminated water. One tablet can disinfect a liter of river water and make it drinkable in an hour or less.

“Our multifunctional hydrogel can make a big difference in alleviating the global water scarcity because it is easy to use, highly efficient and potentially scalable to mass production,” said Guihua Yu, associate professor in the department. in Mechanical Engineering from the Cockrell School of Engineering. and Texas Materials Institute.

Yu and his team recently published their findings in the journal Advanced materials.

Today, the main way to purify water is by boiling or pasteurizing it. But it takes energy, a lot of time and a lot of work. It is impractical for people in some parts of the world without the resources for these processes.

Special hydrogels generate hydrogen peroxide to neutralize bacteria at an efficiency rate of over 99.999%. Hydrogen peroxide works with activated carbon particles to attack essential cell components of bacteria and disrupt their metabolism.

The process does not require any energy input and does not create harmful by-products. Hydrogels come off easily and leave no residue.

In addition to purifying water on their own, hydrogels could also improve a process that has been around for thousands of years: solar distillation, the use of sunlight to separate water from harmful contaminants via the vaporization.

Solar distillation systems often run into problems with biofouling, the buildup of microorganisms on the equipment that causes it to malfunction. Bacteria-killing hydrogels can prevent this from happening.

“A very vigilant graduate student, Youhong Guo, discovered these hydrogels unexpectedly while doing something else, namely purifying water with sunlight,” said Keith Johnston, professor in the McKetta Department of Chemical Engineering who co-led the project.

The team is working to improve hydrogels by increasing the different types of pathogens and viruses in the water that they can neutralize. And the team is also in the process of marketing several prototypes.

Scaling the hydrogels would be straightforward, the researchers said. The materials for making them are inexpensive, and the synthetic methods are simple and remain so on a large scale. And they can easily control the shape and size of hydrogels, making them flexible for different kinds of uses.