In September, a group of more than 40 health and environmental experts released one of the most comprehensive reports to date on how dirty air affects human health — and the findings are grim. The researchers linked air pollution to 6.5 million premature deaths in 2015, totaling 11.5 percent of all deaths worldwide that year. Air pollutants can also enter the food supply and contribute to climate change, so scientists around the world are seeking ways to thwart this ongoing problem.
One such solution, publicized last year by a pair of Belgian universities, has the potential to destroy pollutants before they enter the environment, with an added bonus: clean energy production.
The prototype device, designed by the University of Antwerp and KU Leuven, is only a few centimeters in size, but with further development, it could one day fight some of the most dangerous man-made pollutants on an industrial scale while producing energy.
AlterNet caught up with Sammy Verbruggen, researcher and professor at the University of Antwerp and KU Leuven, to find out more about this process and how his team has continued to develop it since their research hit the newswires back in May.
How it works
The Belgian research teams created a small device with two rooms separated by a membrane. Air is purified on one side, and the degradation of pollutants produces hydrogen gas, which is stored on the other side.
The technology is based on the use of specific nanomaterials in a process called photocatalysis, Verbruggen told AlterNet by phone. “[The process] uses a semiconductor that is irradiated by light energy to generate free charge carriers. These charge carriers, in turn, produce reactive oxygen species that can attack fouling components.” Specifically, the device can eliminate any organic compound — which includes pesticides like DDT, as well as industrial pollutants such as dioxins and polychlorinated biphenyls (PCBs). Many of these organic pollutants are particularly concerning because they “bio-magnify throughout the food chain and bio-accumulate in organisms,” according to the World Health Organization.
As pollutants are broken down, “protons are extracted from the molecules and migrate to another compartment of the device, where they are reduced to hydrogen gas,” Verbruggen explained. Cell devices like this are most commonly used to extract hydrogen from water, but it turns out the process is even more efficient with polluted air — which is a huge revelation. “It’s actually easier to perform these reactions with fouled components rather than pure water.”
Large-scale potential creates keen interest
The team’s research generated fast buzz. “We received quite a lot of interest from all regions of the world, especially regions centered around India and China,” Verbruggen told us.
Air pollution caused more than 4 million premature deaths in 2015 in India and China alone, and both countries continue to struggle with dangerously high pollution levels. Although China has seen marginal improvements in the three years since it “declared war” on air pollution, inhalable pollutant levels remain over four times higher than WHO’s recommended limit, and cities like Beijing still experience “airpocalypses.” In November, the air grew so toxic in India’s capital, New Delhi, that officials made the unprecedented decision to close 4,000 schools for almost a week.
This process can indeed help industrializing countries curb pollution, but maybe not in the way they’d expect.
“They’re really interested to incorporate this in cities, but in my personal point of view, that would become quite difficult,” Verbruggen said. “Then you have to turn it into an active system rather than a passive system, and you have to invest energy to suck pollution out of the air.”
“The beneficial energy recovery should be a net gain,” Verbruggen explained, “and as soon as you start investing energy to direct polluted air toward the device, the net balance will become negative again.”
The next step
After the warm reception of their first prototype, Verbruggen and his team are working to perfect their process. “We have to take it step by step,” Verbruggen told us. “We are now working on several prototypes that are more easily manufactured with cheaper materials, and we’re also investigating some alternative materials that can interact better with sunlight. As soon as we have a suitable combination of both, then we can start thinking about the next step, which is upscaling to larger dimensions.”
The device only needs light to function, but it will need to absorb light energy far more efficiently to be viable on a larger scale. “The catalysts we’re using now basically only absorb UV light, which is a very minor part of the solar spectrum,” he explained. “Now we’re trying to modify these materials so they can also efficiently interact with visible light in order to expand the activity window of our device.”
It may be a while before we see manufacturers using devices like this to prevent pollution, but Verbruggen told AlterNet and other outlets that he is optimistic about the concept. "There's still a lot of work to do to make this applicable to daily life,” he told Mic. “It's not like we discovered the holy grail yet, but this is a new field of opportunities."
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