A child dies every minute from a waterborne disease, and he or she most likely lives in sub-Saharan Africa. Millions of people in the region don’t have access to clean water and thus face the risk of diarrhoea or other deadly water-related diseases.
Each of these endangered persons could be saved by the Nanofilter, a water purifier developed by Tanzanian innovator Askwar Hilonga. It recently won him the £25,000 ($39,000) Africa Prize for Engineering Innovation, awarded by the Royal Academy for Engineering, which described the innovation as one that could change the lives of many Africans, and people all over the world.
The Nanofilter is a sand-based water filter which uses nanotechnology to cleanse contaminated water and make it safe for drinking. While the sand traps debris, the nanomaterials remove heavy metals, fluoride and biological contaminants. Because water pollutants vary in different geographical areas, depending on human activities and the geological formation of soil and rocks, Hilonga says he tailors the properties of nanomaterials according to the water condition. This means that he first tests the water before designing a Nanofilter that will remove the specific contaminants observed.
The Nanofilter guarantees a 99.999% purification of water, because it absorbs all contaminants in the water. It is also harmless. “It acts like a sieve and is therefore not released in drinking water,” Hilonga explains. “It does not need any kind of electrical power, solar power, UV treatment, nor any chemical treatment.”
It is also relatively cheap. The Nanofilter goes for $130 per piece which can produce up to 60 litres of safe drinking water per day. For a product targeted at the rural areas, which make up 80% of those without access to improved water sources, the price seems high for individual households. However, this cost is substantially lowered by the fact that it can be shared by communities, as is already been done in some schools in Tanzania, and that it can cleanse water from any source.
For a continent in need of a sustainable fix to its water crisis and the consequent health challenges, the Nanofilter has the potential to be a breakthrough. Not only does it make water safe for drinking, it helps further the possibility of low-cost water recycling. To put it weirdly, it makes it possible to drink the water one just bathed in.
Hilonga says he is at the moment able to fabricate up to 20 filters a week, although he expects the numbers to climb as he expands his production to meet demand. “We have orders now from various places in Tanzania, Uganda, and Ethiopia. At present the demand for our filter is higher than our ability to supply,” he says.