Edinburgh chemists develop solar technology for water purification in India

Researchers at The University of Edinburgh are developing solar panels that will be able to purify sewage water across India. Solar energy is a low-cost, simple and highly-accessible method of energy. The Indian Government has structures in place for decontaminating stream and river water, however water access would improve drastically by purifying sewage water. The Student spoke to Professor Neil Robertson from Edinburgh’s chemistry department, one of the lead researchers on the project, about the water treatment process. Robertson explained that the team uses photocatalysis, a process whereby a photocatalytic material will absorb light and use that light’s energy to make chemical bonds and destroy molecules. “So, any organic material—which will be pollutants or any bacteria in the water—will be destroyed,” Robertson remarked.

With 77 million people in India lacking access to safe drinking water, Indians have the lowest levels of access to sanitary drinking water in the world. With this being the obvious reason for choice of fieldsite for implementation of the new technology, Robertson explained that he has also had research connections in India for around five years, as part of a UK-India Consortium in solar photovoltaics. “There are of course other ways to do the same thing but it comes down to opportunity and access. In rural parts of India, where people are not wealthy, water purification must be done in a very low cost manner, in a very simple manner, or what would be easier is if it doesn’t require complex equipment that might not be available locally,” Robertson stated.

The research team just completed a five-month pilot project under the Global Challenges Research fund. “That has enabled us to do two things mainly,” said Robertson. “One is to further develop materials and do lab testing to ensure that the materials will indeed destroy organic pollutants and kill bacteria. “The other outcome from that pilot project is that we have further developed our links in India, so going beyond academic connections to connect with a social enterprise, Samuchit Enviro Tech. They work with a lot of local villages to introduce appropriate technology. They are able to  guide us and help us in understanding exactly what the needs are and how best to address them.” Robertson explained that the next stage of the project is to move beyond research in Edinburgh’s chemical lab, on to living lab experiments in India. Living lab experiments would provide the opportunity to test the technology in people’s living environments, so that the team can track how effectively the material works in applied situations.

“I’m hoping to send a student there—this will be a student funded through the Criticat Centre for Doctoral Training—to spend a couple of months doing some preliminary work, to scale up the materials and try them in the real-world situation. That would be in the next few months. We’re just trying to make arrangements for that now.” Beyond India, Robertson remarked that: “The needs and the opportunities in many parts of the developing world are very similar. In many parts of Africa there is the same need for clean water and there’s the same abundant solar energy available, to provide energy to clean the water. “We are working in India because we have good connections there and have been able to introduce our technology to villages and try out the technology in living lab experiments. Once we can work out how best to apply that technology, then it can steadily be applied across India and other parts of the Indian subcontinent, Africa and other sunny parts of the world that need clean water.”

According to UN-Water, approximately 783 million people in the world today don’t have access to purified water. Robertson mentioned that the situation is expected to get worse with climate change and increasing demand on sources of water, affecting not only people in developing countries, but also in economically more developed countries (EMDCs). This has become evident in places like the Southern United States, in California for example. Robertson remarked: “It’s going to be one of the big challenges of this century.”