Student Spotlight

A “smart” switch for clean water


Rui Guo. Photo by David Stobbe

By Kirk Sibbald

Deep in the recesses of the Thorvaldson Building, chemists are developing materials that could soon be used to improve water quality worldwide.

Alongside her supervisors, Lee Wilson (PhD’98) and Lalita Bharadwaj (BSc’89, MSc’93, PhD’97), PhD student Rui Guo (BSc’07) has developed biopolymer materials with enhanced adsorbent properties. Referred to in scientific circles as smart materials, Wilson said Guo’s synthetically-engineered biopolymers hold enormous potential in various applications, with water remediation being the most notable.

While contaminants such as oil are relatively easy to remove from water, soluble contaminants—such as dyes, nitrates and detergents—are considerably more challenging, said Wilson. The materials engineered by Guo, however, have exhibited remarkable uptake of soluble contaminants in recent experiments.

Guo moved to Saskatoon from China, finishing her undergraduate education at the U of S in 2007. She has been here ever since, and is now in the final stages of writing her thesis.

“Some of my dad’s friends graduated from the University of Saskatchewan, and they said it was a very good academic environment here,” said Guo, explaining her motivation for coming to Saskatoon.

“I’m not going to say it’s because of the nice weather,” she added with a laugh on a particularly frigid afternoon.

With Guo’s laboratory experiments showing considerable promise, large-scale applications are already in the works. Wilson and Guo will soon be working with a professor in Guyana on an international project looking to capture contaminants in surface water bodies.

Closer to home, Wilson said Guo’s smart materials could also be used to remove arsenic from both surface and ground water in Saskatchewan.

“Wherever you find gold or uranium you will also find arsenic. So Saskatchewan has an arsenic problem, and we can potentially use Rui’s materials to address this.”

Smart materials, like the ones developed by Guo, are novel in their ability to essentially turn on and off in response to external stimuli, such as changes in temperature or pH balance. While filtration methods like reverse osmosis require pressure to remove molecules or ions, minimal energy inputs are required for smart materials to function.

For example, Wilson said desalination of ocean water and producing certain biofuels is currently cost prohibitive and requires exorbitant energy inputs. Smart materials could soon streamline such processes, making them both economically and environmentally viable.

“We are running out of fresh water. It’s not a question of if, but when,” he said. “So the ability to, for example, desalinate water using little-to-no energy would be huge. This could address water quality issues around the world.”

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