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A breakthrough research in water purification

Monday March 4 2019

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Last week, a friend in Silicon Valley sent me an article on the latest scientific breakthrough from China that could bring cheap, clean drinking water to people around the world.

She rightfully thought I would need the article since water is a big issue in developing countries.

Thomas Weiss, in Disabled World, observes that:

In developing countries, four-fifths of all illnesses are caused by water-borne diseases, with diarrhoea being the leading cause of death among children. The global picture of health and water has a strong local dimension for approximately 1.1 billion people who still lack access to improved drinking water sources. Around 2.4 billion people on Earth have inadequate sanitation. There is strong evidence that sanitation, water and hygiene-related diseases account for around 2,223,000 deaths each year, as well as an annual loss of 82,196,000 Disability Adjusted Life Years (DALY's).

Water is a major issue that should concern us all. The article she shared is by McKinley Corbley, titled ''Cheap 2D Material Can Cleanse 99.9999 percent of Bacteria From Water in 30 Minutes Simply by Using the Sun'', and published by the Good News Network.

There is promise in the article that virtually everybody, especially in rural areas, would one day access clean water and thus reduce the disease burden.


In the early part of February, scientists from Yangzhou University, announced that they had developed a water system that uses sunlight and 2D materials to purify water of 99.9999 percent of bacteria – including E. coli. Tests show that this eco-friendly system is capable of purifying enough daily drinking water for four people in just under 30 minutes.

The cost-friendly system, Corbley says, works by using sheets of graphitic carbon nitride as a photo-catalyst inside of a water container. When the sheets are exposed to direct sunlight, they release electrons that bond with the oxygen in the water and create compounds that purge the water of bacteria.

Further, the article says there are modern purification systems that use similar chemical processes for destroying bacteria, but they use photo-catalysts that leave behind harmful chemical pollutants as a by-product. These systems usually also take over an hour to purify the same ten-litre bag of water as the system from Yangzhou University.

The Chinese published their findings in the Journal Chem. The researchers are now working to implement their system into portable drinking containers so they can start being deployed to at-risk areas around the world.

The research is one thing, but we now must figure out how this new knowledge can be cascaded into the villages, urban informal settlements and even the people in the middle and high class that are under the illusion that bottled water is bacteria free.

With non-existent or failed food regulation, we are all at risk of contaminated water. The more widely we start using cheap and effective solutions, the easier it becomes to replicate the process into all areas of society.

In the past, there have been such cheap solutions although they have not been as effective. Getting them to household level has been a problem. Yet World Health Organization (WHO) studies show that water interventions can lead to a benefit of up to $60 for every $1 invested. If this is done, the results will be that the cost of healthcare in developing countries will be lowered.

Storage is an essential element in sustainably developing a culture of water treatment. In countries where these interventions have been made, WHO has established that simple ceramic pot filters moulded by local artisans can be used to filter water in the home for approximately $3 per year, making them sustainable and economical.


Widespread water treatment for the poor will depend on how much we learn from past experiences. A research, ''Combating Waterborne Disease at Household Level'', conducted by WHO in 2015 established that:

… important considerations in home treatment are taste and other aesthetic properties of the water, convenience of use, price and cultural attitudes. Furthermore, positive attitudes and ideas were better predictors of whether people were likely to consistently treat water than were negative attitudes. Experience suggests that educational and promotional messages should target positive ideas, such as clarity, taste, good health, affordability, and ease of use. Researchers are finding that many householders would be willing to pay for home treatment at an acceptable price (e.g. less than $10 for water filters in Southern Africa). Payment by installments may be one method of enabling the poor to deal with the relatively high up-front costs of certain technologies.

Far too many people are dying from waterborne diseases that could eliminated from the face of the world with simple and cheap technologies. Our role is to encourage positive cultural practices, leverage technology and promote positive messaging for improved healthcare and save resources for other interventions like in education.

I feel that all the problems we face on earth are like a puzzle whose solution lies in the wait somewhere, but we must always search for it.

The problem of ensuring cheap and clean drinking water has been solved. We can surely solve the problem of taking it to every human being that needs it.

The writer is an associate professor at University of Nairobi’s School of Business.@bantigito