New tech cleans up water disinfection

Safe drinking water is essential for public health, but methods of disinfection can cause environmental problems; chlorine is cheap and easy to use in centralised water systems, but at the expense of harmful chemical by-products.

Now, researchers at Georgia Institute of Technology have presented a way to use small pulses of electricity to disinfect water, reducing energy consumption, cost and environmental impact. The technology could be integrated into the electric grid or even powered by batteries, they said.

“This is a pretty new disinfection technology, and we want to demonstrate in the small scale first, and then improve its real-world applications for point-of-use or off-grid water purification,” said Xing Xie, the Carlton S. Wilder assistant professor in the School of Civil and Environmental Engineering.

Xie and his postdoctoral researcher Ting Wang detailed their work in a paper published in Nature Water in January, 2023.

Although conventional electric field treatment (CEFT) is applied for food pastuerisation, it hasn’t been widely used for drinking water disinfection due to its cost. When water and bacteria are exposed to electricity, the bacteria cell membrane acts like a capacitor in a circuit. Typically in CEFT, water’s low conductivity means nanosecond pulses won’t charge the membrane fast enough to kill bacteria.