Ben Schiller writes in a Mar. 1, 2013 article for Fast Company about a not-for-profit organization, PureMadi, a joint venture between the University of Virginia (US) and the University of Venda (South Africa) and its water purification technology,
PuriMadi has already built a factory in the Limpopo province of South Africa and hopes to expand further. “Eventually that factory will be capable of producing about 500 to 1,000 filters per month, and our 10-year plan is to build 10 to 12 factories in South Africa and other countries,” Smith says. “We plan to eventually serve at least 500,000 people per year with new filters.”
The University of Virginia Feb. 5, 2013 news release by Fariss Samarrai describes both a disc and a flowerpot version of the water purification technology (Note: Some links have been removed),
PureMadi, a nonprofit University of Virginia organization, will introduce a new invention – a simple ceramic water purification tablet – during its one-year celebration event Friday [Feb. 8, 2013] from 7 to 11 p.m. at Alumni Hall.
Called MadiDrop, the tablet – developed and extensively tested at U.Va. – is a small ceramic disk impregnated with silver or copper nanoparticles. It can repeatedly disinfect water for up to six months simply by resting in a vessel where water is poured. It is being developed for use in communities in South Africa that have little or no access to clean water.
“Madi” is the Tshivenda South African word for water. PureMadi brings together U.Va. professors and students to improve water quality, human health, local enterprise and quality of life in the developing world. The organization includes students and faculty members from engineering, architecture, medicine, nursing, business, commerce, economics, anthropology and foreign affairs.
During the past year, PureMadi has established a water filter factory in Limpopo province, South Africa, employing local workers. The factory produced several hundred flowerpot-like water filters, according to James Smith, a U.Va. civil and environmental engineer who co-leads the project with Dr. Rebecca Dillingham, director of U.Va.’s Center for Global Health.
Here’s the flowerpot filter,
A worker molds a filter from local clay, sawdust and water. (Photo: Rachel Schmidt)
Here are the discs or, as they are known, the MadiDrops,
The new MadiDrops can be produced in the same factories as the filters. (Photo: Rachel Schmidt)
The factory is more than just a producer of water purification technologies, from the University of Virgina news release,
“Eventually that factory will be capable of producing about 500 to 1,000 filters per month, and our 10-year plan is to build 10 to 12 factories in South Africa and other countries,” Smith said. “Each filter can serve a family of five or six for two to five years, so we plan to eventually serve at least 500,000 people per year with new filters.”
The idea is to create sustainable businesses that serve their communities and employ local workers. A small percentage of the profits go back to PureMadi and will be used to help establish more factories.
The PureMadi website’s About page offers more information about the partners, the technology, and the economic impact,
PureMadi has been created by an interdisciplinary collaboration of students and faculty at the University of Virginia. In partnership with the University of Venda in Thohoyandou, South Africa, and developing-world communities in Limpopo Province, South Africa, PureMadi is working to provide sustainable solutions to global water problems.
Our first project is the development of a sustainable, ceramic water filter factory in South Africa. Ceramic filters are a point-of-use (e.g. household-level) water treatment technology. Ceramic filters can be produced with local materials (clay, sawdust, and water) and local labor. The materials are mixed in appropriate proportions, pressed into the shape of a filter pot, and fired in a kiln at 900 ˚C. Upon firing, the clay forms a ceramic and the sawdust combusts, leaving a porous ceramic matrix for filtration. In addition, the filters are treated with a dilute solution of silver nanoparticles. The nanoparticles lodge in the pore space of the ceramic matrix and act as a highly effective disinfectant for waterborne pathogens like Vibrio cholerae and pathogenic strains of Escherichia coli. Untreated water can then be passed through the filter and collected in a lower reservoir with a spigot to obtain purified water.
In the field and in the laboratory, we have demonstrated that this technology is highly effective at purifying water and the filters are socially acceptable to developing-world communities. In some of our most recent work, we have shown that the filters significantly improve the health outcomes of human populations using the filters relative to groups who only drink untreated water.
A filter factory can become a sustainable business venture that provides economic stimulus to the local community. Our goal is to create a blueprint for a successful factory, including its architecture, efficiency of water and energy use, technological performance of the filter itself, and an effective and sustainable business model.
While the flowerpot filter has been well received the MadiDrop fills another need, from the University of Virginia news release,
MadiDrop is an alternative to the flowerpot filter, but ideally would be used in conjunction with it. The plan is to mass-produce the product at the same factories where the PureMadi filters are produced.
“MadiDrop is cheaper, easier to use, and is easier to transport than the PureMadi filter, but because it is placed into the water, rather than having the water filter through it, the MadiDrop is not effective for removing sediment in water that causes discoloration or flavor impairment,” Smith said. “But its ease of use, cost-effectiveness and simple manufacturing process should allow us to make it readily available to a substantial population of users, more so than the more expensive PureMadi filter.”
Testing shows that the filters are safe to use and release only trace amounts of silver or copper particles, well within the safe water standards of the developed world. The filters also would be useful in rural areas of developed countries such as the United States where people rely on untreated well water.
Smith noted that U.Va. Architecture School professor Anselmo Canfora and his students have worked closely with PureMadi to design sustainable filter factories for developing countries that would optimize use of local labor and materials.
The National Science Foundation, the National Institutes of Health, U.Va.’s Jefferson Public Citizen Program and the Vice Provost for Global Affairs provide support to PureMadi. Partners include the University of Venda in South Africa; Potters for Peace, a nonprofit organization committed to providing safe drinking water in the developing world; and local communities in Limpopo province in South Africa.
Taken in conjunction with my Feb. 28, 2013 posting titled, Silver nanoparticles, water, the environment, and toxicity, where I juxtaposed two articles about toxicity and silver nanoparticles (they’re ok/they’re not ok) to illustrate the complexity surrounding the question of risk, this article which features silver (and copper) nanoparticles in use for water purification adds another dimension to the question. What are the risks?, to add, are they worth taking?