Solar Tech could provide clean water in rural india
University of Edinburgh researchers are working on low-cost, low-energy technologies to simply and effectively treat wastewater, which could provide clean drinking water to residents in rural, remote areas of India and also stem the spread of diseases.
The central material is an inexpensive, coated plastic that relies on light to create a chemical reaction. It absorbs sunlight, then activates oxygen in the water, destroying organic compounds, including bacteria. There are no moving parts and no external energy source is required.
This material allows for the inexpensive production of water purifiers, according to the researchers. Neil Robertson, a chemistry professor leading the team, told Fast Company:
It’s just channeling the sunlight towards the destruction of all these pollutants and bacteria. What we’re aiming for is simplicity. […] The 750 million people in the world who have no access to improved water are often living in fairly poverty-stricken conditions and don’t have access to the money to buy complex systems.
The material could even be made into a sheet that, when rolled up inside a plastic bottle full of contaminated water and left in the sun for several hours, could purify the water to the point that it’s safe to drink. It could also be used after filtration, which would be needed for water sources containing larger particles.
Because these materials — both the plastic and the photocatalytic material — are inexpensive, the greater costs would be for a product’s production and distribution, Robertson said. These materials could be made locally.
India’s Water Challenges
India, the second most populous nation in the world, after China, needs solutions to its water challenges. Of its estimated 1.2 billion residents, 77 million have no access to safe water and 769 million lack access to improved sanitation, according to Water.org. More than 500 children under the age of 5 die each day from diarrhea in India alone, making the improvement of sanitation and water supplies critical.
Compounding the problem is that about 70 percent of India’s residents live in rural areas, according to Digital Journal. Most of these areas have no sanitation.
Roughly 60 percent of groundwater is contaminated in the Indo-Gangetic River Plain, which includes both the Indus and the Ganges river deltas. It can’t be used for irrigation or human consumption. The groundwater in the region is not only being over-abstracted, it is also not being replenished by rain, compounding water scarcity throughout the region.
The University of Edinburgh’s material could also be used to treat sewage. Wastewater in developing nations is often untreated and is a common pollutant of water sources. Robertson told Fast Company:
A more attractive, or longer-term solution is to purify water before it runs to ground, but that requires more thought on infrastructure and also the social science of the choices people make. […] From a social science perspective, there’s probably less of an immediate personal benefit to treating water you’re disposing of rather than water you’re about to drink […] it’s a harder challenge.
The technologies, which were developed over a five-month period, are now being scaled up in collaboration with the Indian Institute of Science Education & Research. According to the university, these will soon be tested in villages that lack water treatment.