The challenge of providing clean water
Tuesday, December 17, 2019
Some countries struggle to provide clean water and sanitation, and scientists in India and the UK are trying to change that. Professor Darren Reynolds and Dr Gillian Clayton at the University of the West of England (UWE), Bristol recently talked to BBC’s Susannah Streeter about a cutting-edge technology pilot under development to turn contaminated water sources into safe drinking water.
There’s a problem that affects almost 2.3 billion people, or around one in three, worldwide. It’s one of the world’s biggest obstacles to public health and economic progress – the lack of access to clean water and decent toilets. It costs the world’s poorest countries $260 billion every year and has been the focus of a recent UN campaign. The Sustainable Development Goals aim to provide safe water and sanitation for all by 2030.
Virginia Newton-Lewis is the senior policy adviser for the charity WaterAid and during the interview addresses just how huge the challenge is. “It’s a significant problem as we have 785 million people, that’s one in 10, who still don’t have access to clean water close to home and if you make the standard a little more stringent and talk about safe water, than we’re up to two billion people so this is a huge problem,” she explains.
“And it has ramifications for public health, so for example diarrhea caused by dirty water and poor toilets kills a child under five every two minutes. It has implications for education, particularly for girls because they often bear the burden of going to collect water. So, it’s a really serious problem.”
The purification of water
But scientists are hard at work trying to find solutions, and a ground breaking project led by research teams in England and India is in progress. It aims to not only map the water quality of the river Ganges but also to purify hundreds of thousands of litres of water in decentralised portable treatment plants.
Professor Darren Reynolds and his team of research scientists at UWE, Bristol have been testing the treatment water in a murky campus pond with new technology that’s designed to improve water quality and produce safe drinking water.
Professor Reynolds explains: “We set out with a simple but overwhelming challenge of how to turn dirty water into clean drinking water. We’ve spent three to five years developing our ideas, testing the equipment and working together with our industrial collaborators to try and come up with the solution that we could engineer into a viable product and deploy overseas to solve these problems.
“In the pond there’s lots of suspended material, not so different from many of the rivers we experience in India. We take water out of the pond and move it into a filtration system with very small membranes that are very good at taking stuff out which is really small, maybe less than one micron. However, not all of the bacteria will be removed, maybe about 99%.
To UK drinking quality levels
“While 99% sounds really great, if you have a billion bacteria in your water that’s still leaving a lot of bacteria and viruses behind. And, in the UK and most European countries, we wouldn’t accept that, so it shouldn’t be acceptable in other parts of the world.”
That means there’s another technology that’s needed to eliminate the remaining one per cent.
Professor Reynolds continues: “That technology is through the generation of our own disinfectant and we’re able to do that onsite as part of the system. We generate the disinfectant from a simple salt solution using a clever device called an electrochemical cell. This operates a little like a battery and electrolyses or reacts with stuff that’s in the salt (sodium and chlorine) and water, and you end up with lots of compounds that are able to disinfect the water and kill the rest of the bacteria and viruses.
“That disinfectant does two things. One, it kills that one per cent and so disinfects the water, and secondly, it maintains membrane health of the filtration system and that helps the membranes to operate continuously.”
This is the same technology that’s being used to clean workplaces by the Toucan Eco bio-cleaning system, which also uses water, salt and an electrochemical reaction. This results in an eco-friendly, effective and safe disinfectant cleaner that kills 99.999% of bacteria while replacing cleaning chemicals and the single use plastics bottles they’re supplied in.
It’s a unique example of how developments in science can be applied to practical day to day activities, such as cleaning surfaces, can work alongside fluorescence-based water quality sensors and solar powered technologies. Implementing such technologies is only possible by closely working with water charities (such as Frank Water), to potentially help save hundreds of thousands of lives across the world in third world countries and areas of natural disaster.
At the time of the interview Dr Robin Thorn and postdoctoral researcher Dr Bethany Fox were in India assessing water quality. “We get crowds of people around watching what we’re doing and talking to us,” explains Dr Fox. “So today, for example, we got a young boy who helped us find access down to the river as they obviously know these areas much better than we do.
“We’ve had a lot of positive comments and people thanking us for making the effort to come and understand their water quality better. It’s really great to talk to people from local communities about what we’re doing and why as well.”Back on campus at UWE, Professor Reynold continued: ”The technology has been developed into a very high-tech mobile system that is now fully automated with the exception of one thing - the salt that’s needed to produce the disinfectant. We have to top that up, but everything else here is totally self-reliant. So, it’s sucking water from that pond, putting it through the system and producing safe drinking water.”
Called the Ninja and measuring just 1.5m2, the unit safely produces drinking water for decentralised communities by using ultrafiltration membranes combined with electrochemically activated technology that disinfectants raw water, removes biological contaminants including bacteria and viruses, and reduces agricultural and industrial contaminants such as nitrates, ammonia and metals.
At UWE, they have produced 300,000 litres of drinking water in just three weeks, that’s enough to fill 900,000 small bottles. In early 2020, the team is planning to deploy and test the technology even further in India with the view to then provide drinking water for local communities and those affected by humanitarian disasters. The potential to provide a solution for millions of people around the globe faced with unsafe drinking water is huge.
The project is in partnership with the Bose Institute in Kolkata, along with private companies Portsmouth Aviation Ltd for water purification system, Centrego Ltd for water disinfection system (manufacturer of Toucan Eco), Chelsea
Technologies Group for sensor technology and Frank Water, a water charity on the ground in India. The scientists behind the project are Professor Darren Reynolds, Dr Robin Thorn and Dr Bethany Fox of UWE, and Professor Tapan Dutta and Rinitia Dhar of the Bose Institute in Indiase Institute.The associations are the Department of Science & Technology, NERC (Science for the Environment), EPSRC (Engineering and Physical Sciences Research Council), and the Newton-Bhabha Fund.
Click here to listen to the BBC podcast.
For more information:
- About this project please contact firstname.lastname@example.org, on Twitter @Reynolds_UWE or follow the project on Facebook @wqTEST.
- Learn how to clean chemically free.
- How Michellin-star Alchemilla restaurant strengthened it's sustainability credentials with Toucan Eco.
- How UWC Atlantic College adopted sustainable cleaning regime with Toucan Eco.
- Watch Professor Darren Reynolds talk about the science behind Toucan Eco.