This is the 4th post in a blog series to be published in 2023 by the APET Secretariat on behalf of the AU High-Level Panel on Emerging Technologies (APET) and the Calestous Juma Executive Dialogues (CJED)

Access to clean water is a basic human need and right for all African people. Since people cannot survive without water, the African Union Agenda 2063 and the United Nations Sustainable Development Goals (UN-SDGs) have emphasised access to water as a critical component of socio-economic development. Water is a prerequisite for improving the quality of life and ensuring universal access to sanitation. Additionally, clean water is an essential component of food, energy, health, industrial development, liveable cities, biodiversity, and ecosystems.[1]

About 2.1 billion people across the world do not have access to clean and safe drinking water. Additionally, some of the scarce water sources are also hazardous and cause over 3.4 million deaths, annually. Millions of women and children spend three to six hours fetching water from long distances and sometimes, contaminated sources, daily. As such, it takes an average of 3.7 miles to walk for clean water, which is time that could be spent working, taking care of family members, or going to school. Patients with illnesses linked to a lack of access to clean water occupy 50% of all hospital beds worldwide at any given moment.[2] In particular, the African continent has approximately 208 million people engaging in open defecation. Additionally, over 418 million people still lack access to even the most basic level of drinking water service. Most importantly, approximately 779 million people need access to basic sanitation services and 839 million people lack access to basic hygiene services.[3] Notwithstanding efforts and initiatives to extend and sustain water, sanitation, and hygiene (WASH) systems and services, Africa as a whole and Sub-Saharan Africa in particular have experienced a variety of health issues leading to death (see figure 1).[4]

Figure 1: A glimpse of Africa's Drinking Water and Sanitation

The under-performance of the water sector in Africa has resulted in the advent of waterborne diseases such as cholera.  Cholera is an acute diarrhoeal infection caused by the ingestion of food or water contaminated with the bacterium Vibrio cholerae.[5] In many African countries, cholera continues to be a major source of illness and death despite having been mostly eradicated from industrialised countries through efficient wastewater treatment over a century ago. A crucial first step to lessening the cholera burden in Africa is increasing worldwide access to water, sanitation, and hygiene (WASH).[6] Reports are estimating that there are approximately 1.3 million to 4.0 million cases of cholera each year. These cases of cholera are resulting in 21 000 to 143 000 deaths annually, and 54% of these deaths are reported in Africa.[7]

Malawi has recently observed a surge in cholera cases since 2022. Remarkedly, Malawi had almost entirely eradicated cholera and there were only two cases that were reported in 2021. However, in the last 11 months, over 950 Malawians have died and approximately 29,000 cases of cholera were reported during the same period.[8] The surge of cholera in Malawi was attributable to Tropical Storm Ana and Cyclone Gombe. This is because these storms destroyed existing latrines and hand-washing facilities in 2021. There was also the emergence of informal mining settlements that emerged along Lake Malawi. Unfortunately, the informal settlers are utilising the lake for washing and sanitation.

To address these challenges, the Malawi Red Cross Society is implementing and administering Oral Rehydration Therapy at local and community levels lifesaving treatments. Furthermore, volunteers are ensuring that water supplies are safe and that sanitation facilities are working. Volunteers are undertaking door-to-door campaigns and raising awareness to prevent the disease from spreading.[9] Since there is currently a rainy season underway, citizens are encouraged to take the necessary precautions to protect themselves and their families.

In addition, groundwater and shallow wells are commonly utilised in rural regions, and this is a common residential water source in Malawi. However, to make this water safe for drinking, the currently utilised water treatment techniques include boiling, solar disinfection, chlorination, and filtration.[10] Even though these techniques have proven to be inexpensive, easy to use, and cost-effective, they still fail to completely eradicate the contamination. Therefore, after such treatments, the water remains unclean and unsafe to drink. Hence, alternative, and much more effective methodologies and technologies to treat such water should be sought.

The African Union High-Level Panel on Emerging Technology (APET) recognises that adopting and implementing emerging technologies for water treatment and effective sanitation can help eradicate waterborne diseases such as cholera in Africa. APET advises that widespread access to clean water and effective sanitation can eradicate waterborne diseases such as cholera. Therefore, to ensure the use of safe water, basic sanitation, and good hygiene practices in cholera hotspots, WASH solutions should be integrated with emerging technologies to enhance safe drinking water. This is because the identification of new and uncommon contaminants and the adoption of new water quality standards can help African countries manage sanitation challenges; these can largely influence the development and application of water treatment technology.

APET recommends the integration of emerging water treatment technologies such as nanotechnology and membrane technology into existing water treatment methods. For example, the application of membrane filtration technology can promote efficient water purification systems to prevent the spread of microbes that are causing waterborne diseases. Membrane technology can remove microorganisms in a gainful manner. Furthermore, if African governments could invest in the installation and energy operating costs, these technologies can be cost-effective. Notably, the operational costs to provide electricity to operate the membrane systems, are substantial impediments to membrane technology. Therefore, consideration of renewable energy systems to power these treatment systems can reduce the cost significantly.[11] Additionally, membrane technologies can be coupled with nanotechnology to enhance removal and water permeation performances.

Nanotechnology has also proven to substantially reduce membrane fouling that is due to the accumulation of contaminants on the surfaces of the membranes, thereby, making them lose performance capacities. Further to this, nanotechnology can effectively deactivate microorganisms and remove micro-pollutants from water, even at low concentrations. For example, these nanoparticles can be incorporated into existing adsorbents and membrane filters to improve water treatment procedures.[12] This makes the current adsorbents and membranes even more effective to remove pollutants from water bodies.

For example, South Africa has demonstrated the deactivation of laboratory-cultured bacteria by percolation through a thick paper sheet containing silver (Ag) and copper (Cu) nanoparticles (NP). These paper filters containing AgNPs or CuNPs successfully treated contaminated streams in Limpopo, South Africa to remove coliform and E. coli bacteria.[13] Furthermore, the Nanotechnology Innovation Centre under the Department of Science and Innovation (DSI/Mintek), Water Research Commission and the Medical Research Council, in partnership with South African universities such as the University of Johannesburg and the University of South Africa are currently undertaking ongoing research initiatives in the nanotechnology field. As such, Mintek has been progressively developing the critical mass in nanoscience and nanotechnology to enhance water treatment and purification.[14]

APET notes that there are some concerns about releasing nanoparticles and nanomaterials into the environment without a comprehensive understanding of pathways, reactions, and the eventual fate of such nanoparticles. These concerns include the toxicity of bulk material, such as solid silver, but do not help predict the toxicity of such nanoparticles of that same material. There are concerns that the nanoparticles will linger and accumulate in the environment, and effectively bioaccumulating in the food chain and creating unanticipated effects on human health. However, researchers are currently addressing these challenges by ensuring the non-leaching of these nanoparticles, thereby, preventing secondary contamination. 

Conventional water and wastewater treatment employs a variety of physical-chemical and biological processes to generate clean drinking water and decontaminate wastewater. The substances that can be removed from drinking water include monovalent ions such as sodium and chlorine ions using reverse osmosis membranes. They can also remove water hardness such as calcium and magnesium using ion exchange, chemical softening and nanofiltration. Organic contaminants that cause taste and odour challenges are removed by activated carbon and catalytic oxidation such as ozone, ultraviolet irradiation, and chlorination. The colloids causing turbidity can be removed by chemical coagulation and ultrafiltration. The pathogenic viruses, bacteria and protozoa are traditionally removed by disinfection and membrane processes. Even though these processes function on the micro-levels and nano-levels, they are normally not considered nanotechnology since the materials and equipment that are used are produced conventionally.

The current examples of nanotechnology and nanomaterials in water treatment include nanostructured membranes, nano filters such as carbon nanotube filters, electrospun nanofibrous membranes capable of treating microbes from water, and nanoscale photocatalysts that utilise sunlight to degrade pollutants. Furthermore, the nanoscale photocatalysts promote photocatalytic degradation of toxic chemicals that pose severe environmental pollution. Some researchers have demonstrated the utilisation of nanoscale sorbents to target near complete removal of highly toxic compounds such as heavy metal species. On the other hand, nano biocides such as Cu-HT can be utilised as an alternative disinfectant to chlorine in a water purification system. Notably, Cu-HT possesses strong disinfection activities against Escherichia coli, phage Q β, Salmonella, and Staphylococcus aureus.

South Africa and Mozambique are also adopting other kinds of water treatment technologies such as the CabECO technology to treat water in Ressano Garcia, Incomati River in Mozambique, and one in South Africa at Waterval and Klip River.[15] This water treatment technology utilises electrochemical oxidation to generate strong oxidants such as ozone without the addition of any extra chemicals. In such cases, when low voltage is harnessed between the two diamond-coated electrodes, the water molecules are split into ozone and reactive hydroxyl (OH·) radicals. These hydroxyl radicals will speedily and efficiently destroy micro-organisms and organic contaminants. Daily, the two units are generating approximately 10 m3 of water and this can sufficiently supply 300 people. This is demonstrating promise and can be scaled up to provide clean water.

In conclusion, APET advises African Union Member States to scale up and adopt these water treatment technologies, although some of these ideas and technologies are still in the laboratory and pilot stages. Therefore, African governments are encouraged to provide resources to enable these technologies to be adopted and commercialised. African researchers and innovators are also encouraged to create easy-to-operate, agile, and cost-effective water treatment systems that may be deployed by local communities. These can then be utilised in rural areas that are most susceptible to cholera infections to improve the healthcare and social well-being of Africans.

 

Featured Bloggers – APET Secretariat

Justina Dugbazah

Barbara Glover

Bhekani Mbuli

Chifundo Kungade

Nhlawulo Shikwambane

 

[1] https://sustainabledevelopment.un.org/content/documents/17825HLPW_Outcome.pdf.

[2] https://wholives.org/our-mission/mission/.

[3] https://www.unicef.org/senegal/en/press-releases/africa-drastically-accelerate-progress-water-sanitation-and-hygiene-report#:~:text=On%20the%20continent%2C%20however%2C%20418,still%20lack%20basic%20hygiene%20services.

[4] https://www.un.org/waterforlifedecade/africa.shtml

[5] https://www.who.int/news-room/fact-sheets/detail/cholera.

[6]https://www.cdc.gov/cholera/africa/index.html#:~:text=Cholera%2C%20largely%20eliminated%20from%20industrialized,to%20reducing%20Africa's%20cholera%20burden.

[7] https://tropmedhealth.biomedcentral.com/articles/10.1186/s41182-021-00376-2.

[8] https://www.nytimes.com/2023/01/22/world/africa/malawi-cholera-outbreak.html#:~:text=Malawi%2C%20in%20southern%20African%2C%20had,scrambling%20to%20contain%20its%20spread.

[9] https://reliefweb.int/report/malawi/malawi-red-cross-scales-response-worst-cholera-outbreak-two-decades

[10] https://www.ijsrp.org/research-paper-0621/ijsrp-p11472.pdf.

[11] https://www.ijsrp.org/research-paper-0621/ijsrp-p11472.pdf.

[12] https://www.nepad.org/blog/achieving-water-security-africa-role-of-innovation-and-emerging-technologies.

[13] Dankovich, T. A., Levine, J. S., Potgieter, N., Dillingham, R., & Smith, J. A. (2016). Inactivation of bacteria from contaminated streams in Limpopo, South Africa by silver- or copper-nanoparticle paper filters. Environmental science : water research & technology, 1, 85–96. https://doi.org/10.1039/c5ew00188a.

[14] https://www.wrc.org.za/wp-content/uploads/mdocs/KV195-07.pdf. 

[15] https://cordis.europa.eu/article/id/415837-new-technology-provides-clean-water-in-africa