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Doctoral students from the Department of Environmental Sciences and Engineering recently won a $75,000 research grant from the U.S. Environmental Protection Agency (EPA) to continue testing the effectiveness of low-cost water-purification methods that people in developing countries can use to clean drinking water.
Competing against 64 other teams, the School of Public Health group was one of only seven teams to win one of the EPA's first ever People, Prosperity and the Planet (P3) Awards. The students will use the grant to do field tests of biosand filters, ceramic filters and Proctor and Gamble's PUR water disinfection system for their usefulness as low-cost water treatment technologies.
For most people in the United States, water filters simply make the stuff taste better. More than 1 billion people worldwide, however, do not have access to safe water, according to the World Health Organization. For those people, using an effective water purifier before drinking can mean the difference between life and death. Worldwide, almost 2.5 million people each year die in developing countries from diarrheal illnesses, many of which are caused by unsafe water.
In the doctoral students' pilot study, lab tests showed that all three treatment technologies removed viruses and bacteria from the water, but to differing degrees. The biosand filter was the least effective, but also the least expensive. It involves only the one-time cost of purchasing it, since the filter contains no consumable parts and is made of concrete. It can probably be used for decades, said Mark Elliott, one of the doctoral students on the research team. The ceramic filter can also be effective for years after the initial purchase. The PUR system involves a continuous cost of about 1 cent for every liter of water treated because the system uses a sachet of chemicals that must be replaced.
The pilot study also tested a modification of the porous ceramic filter that Brown developed, called the F2 ceramic filter, which uses an iron coating to create a positively charged surface designed to adsorb viruses, which are negatively charged. In a pilot study, the enhanced filter removed a greater number of viruses than traditional ceramic filters.
Scientists have extensively studied the effectiveness of the PUR system at preventing illness, but not the other two types of filters. So the team will conduct field tests of the biosand filter in the Dominican Republic and of ceramic filters in Cambodia. Team members Christine Stauber and Joe Brown will lead these studies.
"We are trying to determine how much each of the filters reduces waterborne disease," Elliott said.
Doctoral student Lisa Casanova is the remaining member of the research team, and her studies focused on the ability of the PUR system to reduce waterborne pathogens such as hepatitis A virus, a major cause of infectious hepatitis. Mark Sobsey, professor of environmental sciences and engineering leads the team.
Dale Whittington and Francis DiGiano, also professors of environmental sciences and engineering, will work with the team on the second phase of the project. The team is seeking additional financial support for their work, with the goal of developing a special program in global water sanitation and health that will provide research and training opportunities for future graduate and undergraduate students at UNC.
Provided by Research and Economic Development.
Editor: Neil Caudle
Writer: Angela Spivey