Solar Purification Could Provide Clean Water in Rural India
A purification system that harnesses the sun's energy to kill toxic bacteria could soon allow India's countryside to easily access clean water.
Rural India could soon have accessible, clean drinking water for the first time ever thanks to a new solar technology.
Researchers at the University of Edinburgh have designed a water purification system that harnesses the sun's energy to decontaminate polluted water.
According to India-Situation-and-Prospects">UNICEF, millions of people in India die every year from diseases like diarrhea and pneumonia related to contaminated water, including 600,000 children.
Sewage often pollutes the water supply in India's countryside, where 70 percent of the population resides. The Indian government has focused primarily on treating the water in rivers and streams, but Neil Robertson, professor of chemistry, and his team at the University of Edinburgh took a different approach.
"The use of solar photocatalysis to destroy pollutants has been worked on before," Robertson told Seeker. "In our work however, we have made improvements to the material most-typically used by improving the amount of visible light absorbed and improving the efficiency of the photocatalytic process."
Robertson's solar-powered system takes high-energy particles from the sun and induces them within a photolytic material, creating a chemical reaction. Oxygen molecules are activated to break down bacteria and other organic matter in the water.
The materials don't need a power source, so the technology is easy to set up off the grid. It only needs to be hooked up to containers of contaminated water and pointed toward the sun.
"Our aim is for a very simple technology with very low cost, applicable to the domestic environment," Robertson said. "It could be rolled out across the same rural domestic context across India."
Although this technology is an innovative advancement in the field, it's not yet a catch-all solution to India's overall water contamination problem.
"While interesting and promising, I'm not convinced that this approach deals with the full chain of water quality issues that are relevant for large swaths of rural India," Pavani Ram, associate professor of epidemiology and environmental health at SUNY Buffalo, told Seeker.
"This approach might lead to water disinfection but doesn't seem like it would prevent recontamination of the water," Ram continued. "[This] can happen if water is stored in wide-mouthed containers or otherwise comes into contact with unwashed hands or other sources of contamination."
Ram points out that water in some parts of India, particularly the northeast, can also be contaminated with particles other than microbes, for example: "arsenic, [dangerous levels of] fluoride, and other chemical contaminants, which can be very damaging to human health," she said. "We can no longer afford to look only at the microbial quality of water."
Robertson and his team recently partnered with the Indian Institute of Science Education and Research. They're working towards scaling up this technology and hope it will be useful in some of the many other countries where accessing clean water is still a daily struggle.
"The technology will be appropriate in other similar countries with a rural population needing better water purification and good sunlight," Robertson said.
Ram urges that global solutions to clean water must consider the uniqueness of each location, climate and population, sometimes within the same country.
"Particularly when it comes to water, there is no magical one-size-fits-all solution," Ram said. "But more importantly, it's a huge range of geographies that mandate a broad set of solutions. We can't rest our hopes on any one."
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