Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New UD technology removes viruses from drinking water

01.03.2007
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

The idea for the UD research sprang up when Jin and Chiu were discussing their respective projects over lunch one day.

Since joining UD in 1995, Jin's primary research area has been investigating the survival, attachment and transport behavior of viruses in soil and groundwater aquifers. One of the projects, which was sponsored by the American Water Works Association Research Foundation, involved testing virus transport potential in soils collected from different regions across the United States. Jin's group found that the soils high in iron and aluminum oxides removed viruses much more efficiently than those that didn't contain metal oxides.

“We knew that iron had been used to treat a variety of pollutants in groundwater, but no one had tested iron against biological agents,” Chiu said. So the two researchers decided to pursue some experiments.

With partial support from the U.S. Department of Agriculture and the Delaware Water Resources Center, through its graduate fellowship program, the scientists and their students began evaluating the effectiveness of iron granules in removing viruses from water under continuous flow conditions and over extended periods. Two bacteriophages--viruses that infect bacteria--were used in the initial lab studies.

Kali Kniel, a virologist at UD, has provided critical expertise in documenting the UD technology's effectiveness in removing pathogens such as rotavirus, shown in the magnified view at right. Rotavirus is the number-one cause of diarrhea in children.

Since then, Kniel has been documenting the technology's effectiveness against human pathogens including E. coli 0157:H7, hepatitis A, norovirus and rotavirus. Rotavirus is the number-one cause of diarrhea in children, according to Kniel.

“In 20 minutes, we found 99.99 percent removal of the viruses,” Chiu said. “And we found that removal of the viruses got even better than that with time, to more than 99.999 percent.”

The elemental iron also removed organic material, such as humic acid, that naturally occurs in groundwater and other sources of drinking water. During the disinfection process, this natural organic material can react with chlorine to produce a variety of toxic chemicals called disinfection byproducts.

“Our iron-based technology can help ensure drinking-water safety by reducing microbial pathogens and disinfection byproducts simultaneously,” Chiu noted.

Applications in agriculture and food safety

Besides helping to safeguard drinking water, the UD technology may have applications in agriculture.

Integrated into the wash-water system at a produce-packing house, it could help clean and safeguard fresh and “ready to eat” vegetables, particularly leafy greens like lettuce and spinach, as well as fruit, according to Kniel.

“Sometimes on farms, wash-water is recirculated, so this technology could help prevent plant pathogens from spreading to other plants,” she said.

This UD research underscores the importance of interdisciplinary study in solving problems.

“There are lots of exciting things you can discover working together,” Jin said, smiling. “In this project, we all need each other. Pei is the engineer and knows where we should put this step and how to scale it up. I study how viruses and other types of colloidal particles are transported in water, and Kali knows all about waterborne pathogens.

“Our hope is that the technology we've developed will help people in our country and around the world, especially in developing countries,” Jin noted.

Currently, the Centre for Affordable Water and Sanitation Technology in Calgary, Canada, is exploring use of the UD technology in a portable water treatment unit. Since 2001, the registered Canadian charity has provided technical training in water and sanitation to more than 300 organizations in 43 countries of the developing world, impacting nearly a million people.

The University of Delaware is pursuing commercialization opportunities for the research. Patents have been filed in the United States, Canada, France, Germany and Switzerland. For more information, contact Bruce Morrissey, UD director of technology development, Office of the Vice Provost for Research and Graduate Studies, at [brucem@udel.edu] or (302) 831-4230.

Tracey Bryant | EurekAlert!
Further information:
http://www.udel.edu

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>