Professor Askwar Hilonga has developed a sustainable, low-cost water purification system already providing drinking water to more than 400,000 people in East Africa and solves a regional issue with a high concentration of fluoride in water.
Askwar Hilonga, a nanotechnology specialist at the Nelson Mandela African Institution of Science and Technology in Tanzania, grew up in the poor farming village of Gongali in the north of the country, a few hours away from the city of Arusha, with his nine siblings. The health problems and infant mortality linked to the lack of clean water in these rural areas prompted him to undertake research to directly impact the health of his family and other people in the surrounding areas.
Only 61% of Tanzanian households currently have access to a water supply and 32% to basic sanitation, according to data from the World Bank’s International Development Association. Diseases like diarrhea, cholera, dysentery, typhoid, and polio caused by the lack of access to clean water weigh most heavily on women and children. The 31,000 annual deaths caused by lack of access to clean water account for more than 10% of preventable deaths in Tanzania.
Aware of the problem, Professor Hilonga began research into nanomaterials capable of purifying water shortly after obtaining his doctorate in nanotechnology in South Korea.
A low-cost, low-tech and customizable filter
Professor Hilonga’s Nanofilter is now used in many villages in Tanzania, Zambia, and Kenya, providing drinking water for almost 400,000 people daily. The low-cost system is sold for around 200 dollars for the smallest filter (capable of supplying a school with around 40 children) by Gongali Model, the company that the researcher set up with his wife, Ruth Lukwaro, now acting as CEO.
Installed in a Maasai village near Mount Meru in the Arusha region a few weeks ago, the filter now provides clean water to a community of over 500 people. “We have lost many children to illnesses resulting from a lack of access to drinking water, and many of them have developed malformations,” explains Isaaya Olemtoto, one of the village chiefs, “this filter will change our lives.” The level of fluoride in the local water was 9 milligrams per liter, six times higher than the WHO-recommended level of 1.5 milligram per liter.
When asked about the development of the filter, Professor Hilonga explains: “The hardest part was moving from theory to practice. To do that, we needed money. A grant of almost 9,000 dollars from my university enabled me to launch a prototype.”
The Nanofilter, officially launched in 2015 and approved by the World Health Organization as a “99.999% effective solution” in 2021, works exactly like a sand filter. The principle is to percolate water through a mass of sand. The grains form a layer through which the water flows and, by a simple sieving effect, stops microorganisms such as bacteria and viruses that are larger than the spaces between the grains. In the case of Nanofilter, it is combined with nano-components capable of retaining pesticides and heavy metals such as copper and fluoride.
Using nanotechnology in water purification is pretty common. In 2010, researchers at Stanford University’s Yi Cui Lab developed a synthetic system consisting of two layers of silver that allowed nanoparticles to disinfect water from contaminating bacteria.
So… What’s new? Professor Hilonga’s filter can be easily customized and adapted to the needs of each community. “Since water pollutants vary from one geographic area to another, depending on human activities and the geological formation of soil and rocks, we test the water in-house before installation to adapt the filter type used: If the water contains more fluoride, we can adapt the composition of the filter,” he adds.
A problem with fluoride
Cases of high levels of fluoride in groundwater have been reported throughout most of sub-Saharan Africa, but are more common in East African countries, Sudan, and South Africa, according to a recent study conducted by the Department of Hydrology and Water Resources at the University of Venda in South Africa.
Absorbing too much fluoride is responsible for several diseases, including skeletal fluorosis, a condition that results from the excessive accumulation of fluoride in the bones, leading to changes in bone structure.
The same study reveals that the higher levels in East Africa are the result of volcanic activity in the Rift Valley. Cases of dental fluorosis, an affection of the tooth enamel manifested by the appearance of white or black spots, have been reported in South Africa, Tanzania, Uganda, Ethiopia, Kenya, Sudan, Niger, Nigeria, Benin, Ghana, Senegal, and Malawi.
The ones most affected by the consumption of fluoride-rich water are groups of low socio-economic status living in rural areas. “Defluoridation techniques, such as nano filters, which are inexpensive and durable, remain the best way of treating contaminated water,” concludes the study.
The U.N. World Water Development Report 2023, issued earlier this year, paints a stark picture of the huge gap that needs to be filled to meet U.N. goals to ensure all people have access to clean water and sanitation by 2030. The estimated cost of meeting the goals is between 600 billion and 1 trillion dollars a year, according to Richard Connor, editor-in-chief of the report. “It’s necessary for investors, governments and climate change communities to forge partnerships to see that money is invested to sustain the environment and provide potable water to the 2 billion people who don’t have it,” said Connor.
African Innovation Prize
The Nanofilter has won numerous awards, including the 2015 African Innovation Award from the Royal Academy for Engineering, which described the filter as an innovation that could change the lives of many Africans and people around the world.
When asked about his future, Professor Hilonga explains that he wants to raise more funds to bring the production in-house and reduce costs so that he can provide Nanofilter free of charge to more schools and hospitals. “I also hope to inspire my students by showing them that it is possible to build great things in Africa if you give yourself the means,” concludes the scientist.