China pollution

Chinese, US scientists invent air filter that blocks 99.94pc of PM2.5 pollutants – and it’s made of soya beans

Researchers say environmentally-friendly filter removes most fine pollutants that are dangerous to health – something existing air filters have failed to achieve

PUBLISHED : Monday, 16 January, 2017, 5:26pm
UPDATED : Monday, 16 January, 2017, 11:07pm

A team of Chinese and American scientists have jointly produced an affordable air filter out of soya bean protein that can remove almost all the harmful fine polluting particles that existing air filters were unable to achieve.

The environmentally-friendly air filter removed more than 99.94 per cent of PM2.5 pollutants – fine particles in smog that are smaller than 2.5 microns in diameter and most harmful to health, a study showed.

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The air filter was developed by researchers at the University of Science and Technology Beijing and the Washington State University.

Their study will be officially published on Wednesday in this week’s issue of the Composites Science and Technology journal.

Zhong Weihong, a materials engineering professor at the US university who is part of the joint team, said the filter could remove most toxic chemical pollutants in the air – including carbon monoxide and sulphur dioxide – which existing air filters had failed to achieve.

Fine PM2.5 pollutants, which are produced by all types of combustion, can pass through human lungs and enter a person’s blood supply.

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The new air filter’s filtering material used natural purified soya bean protein as well as bacterial cellulose, an organic compound produced by bacteria, the report said.

Soya contains many functional chemical groups, which could capture polluting particles at a molecular level, it added.

Materials used to make the filter could be cheaply obtained as soy protein and bacterial cellulose were widely used in a variety of household items, including adhesives, plastic products and wound dressings, the study said.

These materials were also biodegradable because they were made from soya beans, which were among the most abundant plants in the world.

The filter material could also be used in existing air filter machines, Zhong said.

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Zhong said she had first-hand experience of the pollution problems facing China when she visited her home country and found Beijing shrouded in smog.

“Air pollution is a very serious health issue,” she said. “If we can improve indoor air quality, it would help a lot of people.”