Global Challenges/Chemistry Solutions

Supplying Safe Drinking Water: Solar-powered nanofilters pump in antibiotics to clean contaminated water

July 15,2013

Bacteria filter
Bacteria filter
American Chemical Society

Summary

Using the same devious mechanism that enables some bacteria to shrug off powerful antibiotics, scientists have developed solar-powered nanofilters that remove antibiotics from the water in lakes and rivers twice as efficiently as the best existing technology. Their report appears in ACS’ journal NanoLetters.

Today’s solution is a solar-powered nanofilter. It removes antibiotics from the water in lakes and rivers twice as efficiently as the best existing technology. The filters use the same devious mechanism that enables some bacteria to shrug off powerful antibiotics — but they run the process backwards.

The report on the nanofilters appears in ACS’ journal NanoLetters.

David Wendell, Ph.D., and Vikram Kapoor explain that antibiotics from toilets and other sources eventually find their way into lakes and rivers. Traces of these medicines appear in 80 percent of waterways. Those antibiotics foster emergence of new antibiotic-resistant bacteria. They also harm beneficial microbes in ways that can degrade aquatic environments and food chains.

Currently, filters containing activated carbon can remove antibiotics from effluent at municipal sewage treatment plants, before its release into waterways. But activated carbon is far from perfect. So the scientists looked for a better technology.

Here’s Wendell, who is at the University of Cincinnati, and is the lead author of the paper…

“In the report, we describe the development and successful laboratory testing of capsule-like ‘vesicles’ containing the very mechanism that enables bacteria to survive doses of antibiotics. Normally, this system pumps antibiotics out of bacterial cells before any damage can occur.”

Wendell and Kapoor turned it around, however, so that the system pumps antibiotics into the vesicles. That way, they can be collected and recycled or shipped for disposal. In addition to the pump, the vesicles contain a propulsion system driven by sunlight.

“The pump system also could be adapted to clean hormones, heavy metals and other undesirable compounds from water.”

Smart Chemists/Innovative Thinking

Smart chemists. Innovative thinking. That’s the key to solving global challenges of the 21st century. Please check out more of our full-length podcasts on wide-ranging issues facing chemistry and science, such as promoting public health, developing new fuels and confronting climate change, at www.acs.org/GlobalChallenges. Today’s podcast was written by Katie Cottingham—that’s me—and I’m at the American Chemical Society in Washington.

David Wendell, Ph.D.
David Wendell, Ph.D., University of Cincinnati