According to certain estimates, one-third of the world’s population does not have access to clean drinking water and half of the population could end up living in water-stressed conditions by 2025.
A hydrogel tablet developed by engineers at The University of Texas at Austin can purify a liter of river water in an hour or less. Image Credit: The University of Texas at Austin.
Addressing this issue could improve the lives of millions of people, hence making it a high priority among the scientific and engineering community across the globe.
Scientists and engineers at the University of Texas in Austin have developed a hydrogel tablet capable of rapidly converting contaminated water into purified water. One tablet can disinfest a liter of river water within an hour and make it suitable for drinking.
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.
Guihua Yu, Associate Professor, Walker Department of Mechanical Engineering and Texas Materials Institute, Cockrell School of Engineering
The study was published in the journal Advanced Materials by Yu ad his team.
Presently, an important method to purify water is to boil or pasteurize. However, it consumes more energy and takes necessitates more time and effort. This method is not possible for people living in regions across the world where the resources for these processes are not available.
The special hydrogel produces hydrogen peroxide to neutralize bacteria at an efficient rate of more than 99.999%. The hydrogen peroxide interacts with activated carbon particles to attack necessary cell components of bacteria and distracts their metabolism.
No energy input is required for this process and it produces no harmful byproducts. It is simple to remove the hydrogel as it does not leave behind any residue.
Further to the purification of water on its own, the hydrogel could also enhance solar distillation, a process that is practiced for thousands of years. Solar distillation is the process in which sunlight is used to separate water from harmful contaminants through vaporization.
Biofouling is a challenge in solar distillation, a phenomenon in which microorganisms get accumulated on the equipment causing it to malfunction. The bacteria-killing hydrogel can prevent this from happening.
A highly vigilant graduate student, Youhong Guo, discovered these hydrogels unexpectedly while doing something else, that is purification of water with sunlight.
Keith Johnston, Project Co-Lead and Professor, McKetta Department of Chemical Engineering, University of Texas-Austin
The researchers are working to enhance the hydrogels by enhancing the different kinds of pathogens and viruses in water so that they can be neutralized. The team is also looking forward to commercializing several prototypes.
Increasing the manufacturing quantity would be straightforward, according to the researchers. As the materials for manufacturing are inexpensive and the synthesis processes are easy and remain the same, it is simple to scale up the manufacturing. It is also possible to change the shape and size of the hydrogels, turning them flexible for various types of uses.
Youhong Guo, a graduate student in Yu’s lab, is the first author of the paper. Graduate students Christopher Dundas from chemical engineering and Xingyi Zhou from mechanical engineering were also part of the team. The research was supported by grants from the Energy Institute at UT Austin and the Dreyfus Foundation.
Journal Reference:
Guo, Y., et al. (2021) Molecular Engineering of Hydrogels for Rapid Water Disinfection and Sustainable Solar Vapor Generation. Advanced Materials. doi.org/10.1002/adma.202102994.