Access to clean water is an ever-present struggle for over 780 million people on the planet -- so no wonder affordable and effective water purification tools are considered life-savers in such cases. Based out of the University of Virginia, the non-profit organization PureMadi has come up with an easy-to-use water purification system that combines ceramics with copper and silver nanoparticles to clean up to 99.9% of the potentially deadly pathogens found in water.
The filters are made of local clay, sawdust and water. Those materials are mixed and pressed into a mold. The result is a flowerpot-shaped filter, which is then fired in a kiln. The firing burns off the sawdust, leaving a ceramic with very fine pores. The filter is then painted with a thin solution of silver or copper nanoparticles that serve as a highly effective disinfectant for waterborne pathogens, the type of which can cause severe diarrhea, vomiting and dehydration.
The design allows a user to pour water from an untreated source, such as a river or well, into the pot and allow it to filter through into a five-gallon bucket underneath. The pot has a flow rate of one to three liters per hour, enough for drinking and cooking. The filtered water is accessed through a spigot in the bucket.
They've also developed MadiDrop, a water purification tablet made out of the same nanoparticles that can work in conjunction with the flowerpot-shaped ceramic filters or alone. It's a cheaper alternative to the more costly filter, and a single tablet can work up to six months in the same vessel, purifying water that is poured in -- though it doesn't eliminate sediment as the filter would.
There are big plans in store for PureMadi, says project leader James Smith, a civil and environmental engineer at U.Va:
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. 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.