New approach to recycling plastic could change the way we reuse waste

Aerial shot top view Garbage trucks unload garbage to a recycle in the vicinity of the city of Bangkok, Thailand
Trucks deal with a mountain of rubbish in Bangkok - but could a new recycling method offer hope? (Getty)

Every person will discard two metric tonnes of plastic in their lifetime.

But a study has suggested a new way to deal with plastic waste.

The Swiss research suggests a proof-of-concept idea of a new approach to plastic recycling – inspired by the way nature 'recycles' the components of organic polymers present in our environment.

Proteins inside organic polymers are constantly broken down into parts and reassembled into different proteins.

Researchers at the Swiss Federal Institute of Technology Lausanne (EPFL) believe that this approach could work with plastics too.

Researcher Simone Gavieri wrote: "A protein is like a string of pearls, where each pearl is an amino acid. Each pearl has a different colour, and the colour-sequence determines the string structure and consequently its properties.

"In nature, protein chains break up into the constituent amino acids and cells put such amino acids back together to form new proteins, that is they create new strings of pearls with a different colour sequence."

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Professor Francesco Stellacci, of EPFL, said: "We selected proteins and divided them up into amino acids. We then put the amino acids into a cell-free biological system that assembled the amino acids back into new proteins with entirely different structures and applications."

Giaveri and Stellacci successfully transformed silk into a protein used in biomedical technology.

Stellacci said: "Importantly, when you break down and assemble proteins in this way, the quality of the proteins produced is exactly the same of that of a newly-synthesised protein. Indeed, you are building something new."

Stellacci said it would take time to develop a working method to recycle plastic in this way.

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He added: "It will require a radically different mindset. Polymers are strings of pearls, but synthetic polymers are made mostly of pearls all of the same colour and when the colour is different the sequence of colour rarely matters.

"Furthermore, we have no efficient way to assemble synthetic polymers from different colour pearls in a way that controls their sequence."

Research this year found that thousands of rivers, including smaller ones, are responsible for most of the plastic pollution worldwide.

Previously, scientists believed that 10 large rivers – such as the Yangtze in China – were responsible for the bulk of plastic pollution.

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In fact, 1,000 rivers – just 1% of all rivers worldwide – carry most of the plastic to the sea.

The research means that areas like tropical islands are likely to be among the worst polluters, the researchers said.

The study by non-profit organisation The Ocean Cleanup used measurements and modelling to work out that 1,000 rivers worldwide are behind 80% of plastic emissions.

Watch: How microplastics are polluting the environment