Drinking Water :: New technology removes viruses from drinking water

University of Delaware researchers have developed an inexpensive, nonchlorine-based technology that can remove harmful microorganisms, including viruses, from drinking water.

UD’s patented technology, developed jointly by researchers in the College of Agriculture and Natural Resources and the College of Engineering, incorporates highly reactive iron in the filtering process to deliver a chemical ?knock-out punch? to a host of notorious pathogens, from E. coli to rotavirus.

The new technology could dramatically improve the safety of drinking water around the globe, particularly in developing countries. According to the World Health Organization (WHO), over a billion people–one-sixth of the world’s population–lack access to safe water supplies.

Four billion cases of diarrheal disease occur worldwide every year, resulting in 1.8 million deaths, primarily infants and children in developing countries. Eighty-eight percent of this disease is attributed to unsafe water supplies, inadequate sanitation and hygiene.

In the United States, viruses are the target pathogenic microorganisms in the new Ground Water Rule under the Environmental Protection Agency’s Safe Drinking Water Act, which took effect on Jan. 8.

?What is unique about our technology is its ability to remove viruses–the smallest of the pathogens–from water supplies,? Pei Chiu, an associate professor in UD’s Department of Civil and Environmental Engineering, said.

Chiu collaborated with Yan Jin, a professor of environmental soil physics in UD’s plant and soil sciences department, to develop the technology. They then sought the expertise of virologist Kali Kniel, an assistant professor in the animal and food sciences department, who has provided critical assistance with the testing phase.

?A serious challenge facing the water treatment industry is how to simultaneously control microbial pathogens, disinfectants such as chlorine, and toxic disinfection byproducts in our drinking water, and at an acceptable cost,? Chiu noted.

Viruses are difficult to eliminate in drinking water using current methods because they are far smaller than bacteria, highly mobile, and resistant to chlorination, which is the dominant disinfection method used in the United States, according to the researchers.

Of all the inhabitants of the microbial world, viruses are the smallest–as tiny as 10 nanometers. According to the American Society for Microbiology, if a virus could be enlarged to the size of a baseball, the average bacterium would be the size of the pitcher’s mound, and a single cell in your body would be the size of a ballpark.

?By using elemental iron in the filtration process, we were able to remove viral agents from drinking water at very high efficiencies. Of a quarter of a million particles going in, only a few were going out,? Chiu noted.

The elemental or ?zero-valent? iron (Fe) used in the technology is widely available as a byproduct of iron and steel production, and it is inexpensive, currently costing less than 40 cents a pound (~$750/ton). Viruses are either chemically inactivated by or irreversibly adsorbed to the iron, according to the scientists.

Technology removes 99.999 percent of viruses.


Leave a Comment