Silver and similar metals have been known for their bacteria killing properties and in a new research that utilises this particular potential of the metals, researchers have created ‘The Drinkable Book’ wherein each page is impregnated with bacteria-killing metal nanoparticles to purify drinking water.
Theresa Dankovich, Ph.D., while studying material properties of paper as a graduate student, developed a novel way that is not only inexpensive and simple but easily transportable nanotechnology-based method to purify drinking water.
During her doctorate at McGill University, Dankovich found that sheets of thick filter paper embedded with silver nanoparticles could make water bacteria free by eliminating a wide variety of microorganisms, including bacteria and some viruses.
Continuing with her research at the University of Virginia’s Center for Global Health, Dankovich expanded the repertoire of embedded nanoparticles to include ones made of inexpensive copper. Dankovich also began field investigations of water purification applications in Limpopo, South Africa, as well as northern Ghana, Haiti and Kenya.
She found that the thick paper based filter she had developed, a purity of 99.9 percent was achieved bringing bacteria levels comparable to those of U.S. drinking water. Addressing the concerns about leaching metals into water, she said, “Some silver and copper will leach from the nanoparticle-coated paper, but the amount lost into the water is within minimal values and well below Environmental Protection Agency and World Health Organization drinking water limits for metals.”
Dankovich formed a nonprofit company named pAge Drinking Paper last year. Working with nonprofit WATERisLIFE organization and Brian Gartside, a designer formerly with DDB New York and now with Deutsch, her company developed a unique product that is essentially a book comprised of pages embedded with silver nanoparticles. Printed on each page is information on water safety both in English and the language spoken by those living where the filter is to be used. Each page can be removed from the book and slid into a special holding device in which water is poured through and filtered. A page can clean up to 26 gallons (100 liters) of drinking water; a book can filter one person’s water needs for four years.
Now a postdoctoral researcher at Carnegie Mellon University, Dankovich is further developing the technology and conducting more field studies in rural communities. In June, Dankovich teamed up with International Enterprises (iDE)-Bangladesh, an international nonprofit, in a field trial to explore commercialization of the silver nanoparticle paper filter for household water treatment. In several districts in southern Bangladesh, customer-focused surveys provided rich insights into easily accepted and culturally appropriate filter designs, she says, adding that the field tests continued to show significant reductions in coliform bacteria counts.
Dankovich is also connecting her chemistry expertise with industrial designers at the University of Cincinnati and with environmental engineers at Carnegie Mellon. “We have a bunch of designs, and we are trying to trim them down and keep them simple,” she says. “Worldwide, many people use a 5-gallon bucket for many needs, so we are basing our approach on that type of container.
“Along with applications, our biggest current focus is to scale up, going from a lab bench experiment to a manufactured product. We have to go from ‘cool chemistry’ to something everyone can understand and use.”