Purifying hydrogel tablet makes river water drinkable within an hour

 

Access to clean water is a major unmet need in many parts of the world. Researchers at the University of Texas at Austin have developed a new hydrogel tablet that could help, with a prototype able to disinfect a liter of river water in one hour.

The most common way to disinfect water is usually to boil it, but that can take a lot of time and energy that may not be readily available in developing regions. Scientists are tackling the problem with devices like solar stills, graphene filters and automatic chlorine dispensers, but often these can be inefficient or still require energy.

For the new study, the researchers developed a method that should be relatively easy and require no energy to run. It’s a hydrogel tablet that can simply be dropped into a container of water, where it kills more than 99.999 percent of bacteria within an hour or so. The hydrogel can then be removed, leaving no residue or chemicals behind.

The tablets work by generating hydrogen peroxide, which works with activated carbon particles to kill bacteria by disrupting their metabolism. The team says that no harmful byproducts are created in the process.

These hydrogel purifiers could also find use in improving other techniques, like solar distillation. These systems work by focusing the heat of the Sun to evaporate water and collect it in another container, leaving contaminants behind. This equipment can get clogged up with microbes, but the team says that the new hydrogel could prevent that.

Although only small scale tests have been conducted so far, the new hydrogels should also be fairly easy to scale up, the researchers say. The materials and processes are inexpensive and simple, and the stuff can be molded into all kinds of shapes and sizes to fit specific use cases.

“Our multifunctional hydrogel can make a big difference in mitigating global water scarcity because it is easy to use, highly efficient and potentially scalable up to mass production,” says Guihua Yu, corresponding author of the study.

The team says that the next steps are to find ways to hone the hydrogels to kill a wider variety of bacteria and viruses. Commercialization is already in the works.

The research was published in the journal Advanced Materials.

Source: University of Texas at Austin