With new sensors and materials, hope for conserving water

Less than 3 percent of the water on Earth is freshwater – a limited resource that is becoming even more scarce through climate change and a growing human population.

It’s a global issue that even affects cities and regions in which water is abundant. Chicago, for example, sits on the vast freshwater resources of Lake Michigan. But the Great Lakes face threats of lower water levels due to climate change and increased water use, and the city of Chicago has more lead service pipes than any other city in the United States, leading to unsafe drinking water for many.

Scientists and engineers within the University of Chicago’s Pritzker School of Molecular Engineering (PME) are up for the challenge. In fact, they are galvanized by it, leading them to help develop technology that can sense and remove contaminants from water, and materials that can harness water from the air.

“We of course cannot live without water, and it’s also the backbone of our economy,” said Junhong Chen, Crown Family Professor of Molecular Engineering. “Not only that – the United States is one of the most advanced nations in the world, and we are still exposing ourselves to lead contamination in water. Eleven years ago, I made the decision to start applying my research to this critical issue.”

As a PME professor and also lead water strategist and senior scientist at Argonne National Laboratory, Chen works with researchers and partners in industry to reduce water stress. One main goal across institutions is to find new ways to recycle and reuse wastewater by developing new technologies that can remove harmful bacteria and heavy metals like lead and mercury from water, while reclaiming useful nutrients like phosphates and nitrates to reuse in fertilizer.

“We need new materials, sensors, controls, and mechanisms for this kind of separation, so even a few decades from now, we will be able to reuse 100 percent of our water,” he said.

Argonne recently launched a ten-year strategy to address water security called Water Science and Engineering empowered by Artificial Intelligence. One goal of the program is to develop a smart system for monitoring and recycling water, and sensors developed by Chen are one piece of that puzzle.

Chen’s sensors – developed from the 2-D material graphene – can detect a wide range of contaminants in water. His company, NanoAffix, has commercialized these real-time sensors, and the company recently launched a handheld device that allows homeowners to test their tap water for lead.

“We are driven by these grand challenges to society, which require interdisciplinary solutions,” he said. “The Pritzker School of Molecular Engineering is designed just for this. It offers an array of toolkits to help solve these problems, and we are equipping our students and postdocs with interdisciplinary training that will help them continue throughout their careers with this mentality.”