Scientist wants everyone in Africa to have clean water

She has spent countless days and nights in the lab, carefully analysing molecules and nanoparticles that can degrade different impurities and filter water. Her face brightens when she talks about water purification and decontamination in Africa.

Jane Catherine Ngila (61), a respected university professor and the acting executive director of the African Academy of Sciences (AAS), has devoted her life to advancing scientific research to improve water quality and its resource management on the continent.

Over the years, she has developed technologies that can filter out water pollutants such as lead, zinc and inorganic substances, using electrospun cellulose materials or nanofibres.

She has received a number of prizes for this. But the most prestigious came earlier in 2022, when the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the L’Oréal Foundation (Foundation L’Oréal) recognised Ngila’s role in advancing global scientific research and presented her with an award in the category Women in Science in Africa and the Arab States.

Along with the award, came a €100,000 (US$100,066) grant for her to further improve the quality of drinking water in Africa.

Focusing on rural communities

Professor Ngila is passionate about improving water quality in Africa, not so much in the cities, but rather in the rural villages, says Professor Philiswa Nosizo Nomngongo, who is heading research in Nanotechnology for Water at the University of Johannesburg in South Africa and is familiar with Ngila’s work. “She wants to develop technologies that can help people in rural communities who are still drinking contaminated water,” she explained.

When the UNESCO and L’Oréal Foundation gave Ngila the award, they said her nanotechnology-based analytical methods can monitor and remove industrial water pollutants, including lead, iron, and others.

Away from this, her methods can also create a major positive impact and enable millions of people on the continent, including individual households, to access clean drinking water.

But Ngila isn’t done yet. “Our current methods can filter water to levels that are safe for domestic use, or by up to 80%, but we want to refine them to filter [out] about 100% of water contaminants in one filtration cycle,” she says.

“I want us [Africans] to have access to safe drinking water, just as is the case in developed countries such as USA and in Europe,” said Ngila in an interview with University World News. “It is my dream to have an Africa where water is not only abundant but also clean and safe.”

Wondering about water quality

Ngila was perhaps about seven years old when she started to learn about water quality challenges in Africa.

While growing up in Kitui County, south-eastern Kenya, her life revolved around school, fetching water, cultivating land for crops and tending grazing cattle in her extended family. But the water well was in a mess and yet it was the main source of water for domestic consumption.

“We drew water from a river about two miles [about 3km] away. The river where kids went to swim and women laundered their dirty clothes, was the same river we drew water from to fill our calabashes and plastic jerrycans,” she says.

However, she understood the full extent of water quality challenges on the continent after she enrolled for her Bachelor of Education in science and later Master of Science in chemistry at Kenyatta University and started actual research work on the topic, graduating in 1986 and 1992 respectively.

“We are hoodwinked by some few towns that have piped water,” says Ngila. “But, actually, much of Africa is water stressed. And the few water sources that are available are contaminated with metals and organics and other impurities. So, many of our people are drinking dirty water if [it is] not treated.”

A focus on nanotechnology

Figures indicate that almost one in three people still do not have access to clean drinking water in Africa which, according to the World Health Organization, has caused several killer diseases on the continent such as diarrhoea and dysentery.

After obtaining her PhD from the University of New South Wales in Australia in 1996, Ngila decided she would use her knowledge of chemistry to develop smarter technologies that could monitor water quality and purify it to improve its access on the continent.

So, when she joined the University of Botswana as a lecturer in 1998, she enlisted her students and, together, they started lab work on technologies that could filter water. But she made her breakthrough in preparing water filters after transferring to the University of KwaZulu-Natal and, later, the University of Johannesburg in South Africa, in 2011.

The government Department of Science and Innovation in South Africa (formerly the Department of Science and Technology) encouraged higher education institutions in the country to constitute a nanotechnology innovation centre, with membership from universities and research institutions, that it could fund.

Several universities and research institutions in that country came together to develop different nanotechnology projects to solve different challenges.

Ngila coordinated the nanotechnology centres at the University of Johannesburg where her research focused on nanotechnologies that could improve water quality.

Developing her technology

So, she and her students prepared polymers such as cellulose (the same cellulose extracted from trees) and stimulated it into a solution which they dispensed into a pump during the electrospinning process.

“The pump moves the solution in such a way as to produce drops (of the cellulose solution) at intervals, which is the electrostatic production of nanofibres,” says Ngila. “The cellulose solution drops move from points A to B, controlled by electrical voltage.

“When you control the voltage and the distance the drops are moving, you can manipulate the process so that, as the drops move from discharge point A to collecting surface B, the organic solvent evaporates, leaving only the cellulose materials or nanofibres,” she says.

Ngila and her research students collected enough of these nanofibres, packed them into a cartridge and filtered water samples using the nanofilters. “The electrospun materials (in a cartridge) act as a membrane or sieve that helps to degrade or trap water contaminants,” explains Ngila.

This process, as mentioned, can filter water up to 80%. But Ngila is working to refine it to remove all water contaminants in one filtration cycle.

“We are exploring how we can functionalise these nano materials to trap metals, such as aluminium and lead, and to degrade pesticides and other organic materials that can be found in water,” says Ngila.

“One way we can achieve this is to add molecules to the nano materials to trap these impurities. Each one of these molecules will be having different functionalities, meaning they can remove different metals, pesticides and other organics and microbes,” she says.

“For instance, we can add nano metal oxide particles such as silver oxide or titanium oxides that are more effective against bacteria if we want to degrade it.”

After they have functionalised the nano materials (with different molecules) they can then pack them in cartridges and repeat the process to water filtration. Ngila hopes to conclude this technology (that can remove pollutants in one filtration cycle) when she resumes full-time research after her current contract at the AAS.

Vital role for Africa

Ngila says nanotechnologies can play a vital role in water purification processes in Africa, and she is calling for more government funding and donor investment in research in the water sector.

“A number of commercial nanofilters (those that can filter water up to 80%) are already on the market for domestic water filtration. These nanofilters can also be used at the tail end of waste water treatment processes to filter tertiary treated water, enabling millions to access clean and safe drinking water. But few individual households can access these filters because they are still pricey,” she says.

“When our governments start to invest in these technologies and we have more researchers in the field of water purification, then these tools will become more affordable.”

“The beauty about nanotechnologies – or nanofibres – is that they have large surface areas and small pores. So, they can remove large as well as minute and very tiny water contaminants.”

“We need these technologies, not just for industrial use, but also for domestic use, for everyday use. So that individual households can mount them in their homes.

“We can also mount them next to boreholes, at the point of use of water pipes just before they are distributed into people’s houses, so our people can drink clean water from the taps. We can use the conventional techniques for treating water such as chlorination and oxidation, but install nanofilters as the ‘last gate keeper’ to degrade any remnant impurities.”

As the CEO of the AAS, Ngila is also rallying more women in science and technology to take a lead in water research, in part because “traditionally, the lack of clean water has affected women the most”.

“My dream is to produce a commercially viable water nanofilter that removes contaminants in one filtration cycle, enabling rural African families to install affordable water filters in their homes. It is to have a continent where everyone can access safe and clean drinking water,” says Ngila.

And she’s working on it.