Global Challenges/Chemistry Solutions

Supplying Safe Drinking Water: Leveraging bacteria in drinking water to benefit consumers

October 22, 2012

Drinking water
Leveraging bacteria in drinking water
to benefit consumers.

Credit: Comstock/Thinkstock

Summary

Contrary to popular belief, purified drinking water
from home faucets still contains bacteria. And
scientists are reporting discovery of a plausible
way to manipulate those populations of mostly
beneficial microbes to potentially benefit
consumers. Their study appears in ACS’ journal
Environmental Science & Technology
.

Today’s report concludes that contrary to popular belief, purified drinking water from home faucets still contains bacteria. And scientists are reporting discovery of a plausible way to manipulate those populations of mostly beneficial microbes to potentially benefit consumers. Their study appears in ACS’ journal Environmental Science & Technology.

Lutgarde Raskin, Ph.D., who is with the University of Michigan and is lead author of the paper, explains that municipal water treatment plants typically try to minimize the growth of microbes in the huge filters that remove small particles and substances that can serve as nutrients for bacterial growth. Here’s Raskin…

“Municipal drinking water treatment plants also add chlorine or other disinfectants to kill bacteria and prevent them from thriving in water distribution pipes. Even with disinfection, it’s not possible to totally eliminate bacteria, which makes it important to determine how the filter and other water treatment steps impact the types and amounts of bacteria that remain. That’s why we set out to do this in a study at a drinking water treatment plant in Ann Arbor, Michigan.”

Their research provides suggestions on how to change which bacteria wind up in the drinking water.

“We found that certain types of bacteria attach to the filters where they form biofilms from which small clumps can break off and make it into the drinking water supply. What was surprising in our results is that the majority of the bacteria that ended up in the finished water originated from the filter and not from the river and well waters that were used as the source waters. This finding provides us the opportunity to select for beneficial bacteria in drinking water.”

Measures as simple as varying the water pH or changing how the filters are cleaned, for example, could help water treatment plant workers shift the balance toward bacteria that are beneficial for humans by not allowing the harmful bacteria to compete.

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. I’m Adam Dylewski at the American Chemical Society in Washington.

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Lutgarde Raskin, Ph.D.,
University of Michigan