Scientists invent air filter that’s cheaper, greener, better – and soy

Air pollution in China (Credit: Nicolò Lazzati / Global Panorama / Flickr)

As air pollution continues to plague China, India and cities around the world, researchers have developed a new air filter that can block 99.94 percent of the most harmful particulates in smog as well as toxic chemicals that existing filters miss, including carbon monoxide, formaldehyde and sulphur dioxide. Even better, it’s inexpensive and eco-friendly, because it’s made of paper towels, bacteria and soybeans.

Using natural, purified soy protein and bacterial cellulose – an organic compound produced by bacteria – a team of researchers from Washington State University and China were able to chemically capture gaseous pollution, not just particles like commercial air filters do. Then, they reinforced the all-natural filter with a paper towel.

“Air pollution is a very serious health issue,” Katie Zhong, a materials engineering professor at Washington State University and member of the research team, said in a press release. “If we can improve indoor air quality, it would help a lot of people.”

According to the World Health Organization (WHO), outdoor air pollution was estimated to cause 3 million premature deaths in 2012. About 88 percent of those deaths occurred in low- and middle-income countries, particularly in Asia. Additionally, more than 4 million people die prematurely each year from diseases linked to indoor pollution from cooking and heating methods.

Zhong, a native of China, and her colleagues from the University of Science and Technology Beijing have first-hand knowledge of the debilitating effects of air pollution. Just last week, northern China finally escaped from under a dense smog that blanketed the region starting mid-December. Media outlets dubbed the episode “airpocalypse,” as the government issued red alerts, cities shut down schools and transportation and tens of thousands of people fled.

A report last week by Greenpeace also failed to find a single city in northern India that met international air quality standards. According to the report, air pollution kills more than 1 million Indians each year and costs the economy about 3 percent of its gross domestic product.

Although existing air filters have been relatively effective at blocking small particles, the researchers found that the 18 types of chemical groups found in soy make it uniquely well-suited to capture a wide array of pollutants at the molecular level.

“We can take advantage from those chemical groups to grab the toxics in the air,” Zhong said in the press release.

Also unlike commercial air filters, which are usually made of glass and petroleum products that lead to secondary pollution, Zhong noted the materials are biodegradable as well as cost-effective. Many household items, including adhesives, plastic products and wound dressings already utilize soy protein and cellulose, and soybeans are one of the most abundant plants the world, Zhong said.

According to Washington State University, the researchers have filed patents on the technology and are now pursuing commercial opportunities. Their findings will be published tomorrow in this week’s issue of the Composites Science and Technology journal.

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Joanne Lu

Joanne Lu is a South Carolina-based writer and editor dedicated to global development, poverty alleviation and social justice. After a year in Rwanda, she now covers the Asia-Pacific and economics. Find her on Twitter @joannelu or email joanne@humanosphere.com.