October 26, 2012
Adding Microbes To Water To Benefit Consumers
Brett Smith for redOrbit.com - Your Universe Online
The award-winning Global Challenges/Chemistry Solutions podcast produced by the American Chemical Society (ACS) has consistently been putting forth groundbreaking, research-based solutions to problems facing people around the world.The latest episode, based on a paper recently published in the ACS journal Environmental Science & Technology, explains how water filtration systems might be used to encourage the growth of beneficial microbes in "purified" drinking water that would benefit consumers and outcompete harmful bacteria.
“Municipal drinking water treatment plants also add chlorine or other disinfectants to kill bacteria and prevent them from thriving in water distribution pipes,” Lutgarde Raskin, a co-author of the journal report and professor of environmental engineering at the University of Michigan explained in the podcast.
“Even with disinfection, it´s not possible to totally eliminate bacteria, which makes it important to determine how (filtration) and other water treatment steps impact the types and amounts of bacteria that remain,” Raskin said. “That´s why we set out to do this in a study at a drinking water treatment plant in Ann Arbor, Michigan.”
In their study, Raskin and her team produced some surprising results they said could be used to improve how drinking water is filtered.
“We found that certain types of bacteria attach to the filters when they form bio-films, from which small clumps can break off and make it into the drinking water supply,” Raskin said. “But what´s 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 the well waters that were used as source waters.”
“This finding provides us with the opportunity to select for beneficial bacteria in drinking water,” she added.
The podcast, which incidentally coincides with the 40th anniversary of the Clean Water Act, went on to assert that pH modulation could play a role in selecting bacteria that end up in filtered water as it was the strongest factor to affect the bacterial populations.
The results of the study could have massive ramifications not only for American water plant facilities, but also for those in developing nations where access to clean water still remains a problem.
Jacques Morisset, an economist with the World Bank, wrote in a recent blog post that this problem is particularly pronounced in certain parts of Tanzania, even though it has “three times more renewable water resources than Kenya.”
“Few households have access to clean drinking water from a piped source,” he wrote. “Only a small fraction of rural households can access water to irrigate their farms. “
The World Health Organization (WHO) is also sounding the alarm with regard to clean water access. According to the organization, 80 percent of all illnesses in developing countries are the result of unsafe drinking water.
"At any given time, one-half of all people in the developing world are suffering from one, or more of the six main diseases (diarrhea, ascaris, dracunculiasis, hookworm, chistosomiasis, trachoma),” according to a recent statement from the WHO.