Plastic pollution is one of today’s most critical environmental issues. Its particles have already spread to every environment imaginable across the world, from the peak of Mount Everest to the depths of the Mariana Trench. A global UN treaty to limit or eradicate plastic pollution is under way based on the evident impact of plastics on human health and ecosystems.

Global plastic production growth

Plastics cause up to a million deaths annually, owing to the diseases and accidents linked to poorly managed waste. Gradually, plastics are broken down to form microplastics less than five millimetres but greater than a micrometre in size. These tiny particles have been found in the blood and lungs of humans and even in breast milk.

One source is synthetic textiles. Items such as carpets and curtains and the elastane found in T-shirts, socks and clothing release more than 700,000 plastic fibres each time a washing machine is run. The wear and tear of plastic products is another source, say from car tyres and peeling paints. “Microplastics have been linked to fertility changes and cancers, they also disrupt the nervous system. They are genuinely bad news and that’s why I care,” explained Adam Root, CEO and founder of Matter, a UK-based company that has developed filtration technology for consumers and industry.

Laundry’s contribution to the microplastic problem

Estimated number of fibres released when laundering a washing load of 6kg, by fabric type.

Microplastics are shed by synthetic fabrics and discharged with washing machine effluent, although they can be released at any point in the textile value chain from production to use and disposal. Adding filtration systems in washing machines can prevent this. One study shows that filters can reduce up to 80% of shedding. In France and Australia, washing machines with microfibre filters are required by law from 2025 and 2030, respectively.

Armed with a £250 grant from the Prince’s Trust, a UK charity, Mr Root, an engineer who has previously held roles at industrial companies like GE Power and Dyson, took apart a washing machine and created a filter able to capture microplastics. He started Matter as a mission to capture, harvest and recycle microplastics at scale. The business supplies regenerative washing machine filtration systems that can be retrofitted in any washing machine in the UK and Europe, available in miniaturised and scaled-up versions. Matter has partnerships allowing them to retrofit existing product ranges in the EU, the UK, the US and China.

In the longer term, the company wants to find uses for collected microplastics. “We are not fully circular yet, but we have a programme on how to get to circularity, which is the absolute foundational piece about how this company existed and started,” remarked Mr Root.

Other players in the microplastics filtration market include Planet Care in Slovenia, which uses a swap-and-replace system wherein fibres are turned into insulation mats, and Filtrol from Minnesota. For domestic customers without the space or capital to invest in a retrofit filtration system, Guppyfriend sells a bag that tackles microfibre pollution by catching synthetic fibres and preventing them from leaving in the washing machine’s effluent.

Industry coalitions are emerging, such as a microplastics partnership between technology group Wärtsilä and shipping company Grimaldi Group. They reported a new system for trapping microplastic particles from a system that takes in seawater to clean the ship’s exhaust before discharging the waste overboard. The system, known as an open-loop scrubber, automatically draws 450 cubic metres of water from the sea per hour, and cleans a concentration of 76 microparticles per cubic metre of water collected.

Nicky Eshtiaghi, professor of chemical engineering at RMIT University in Australia, has led a team of researchers using magnet technology to remove microplastics from water in just one hour. This is a marked upgrade from existing methods, which can take days.

They developed an adsorbent using nanomaterials containing iron, mixed with water containing microplastics. Their idea came from a desire to recycle olive waste without damaging soil. “We put the olive waste in a high pressure, high temperature environment to bring about what we call hydrothermal carbonisation, where the olive is converted to a carbon-like material. The material has lots of applications and is a good material for adsorbing pollution,” explained Professor Eshtiaghi.

The carbon-like adsorbent attracts the microplastics. Within this adsorbent is iron, which is magnetic, and allows its removal via a magnet. This cost-effective method can also remove dissolved pollutants from water, since pollutants adsorb on to the surface of microplastics, which is one of the concerning dynamics in terms of human health.

Despite the strong anti-capitalist agenda around net zero and calls for degrowth to combat climate change, Mr Root believes start-ups and companies can find business models to facilitate change. “We’re seeing a pivot into this realisation, we need to weaponise the system that we have to develop change. I’m a big believer in partnerships and doing it that way,” he said. “The issue of degrowth is because we designed a system for 2 billion people, but now there are 7.8 billion people using the same system. Designing a more efficient system won’t work, we need to change the way we think about design and this is the fundamental principle that will change the planet,” he explained.

When starting his business, Mr Root had a strong business incentive to succeed. “I had no money, no backing and no safety net, so if things didn’t go well, I would have been homeless,” he recalled. His was a story of success, having raised over US$500,000 in 2022 in a successful seed round with backers including Sky Ocean Ventures. As the business grows, its capital-intensive nature is also being funded through access to loans and grants from sources such as Innovate UK, a national agency. The company has just completed a Series A round and its investors are sources of not just capital but also expertise and networks to help the company secure customers.

Professor Eshtiaghi believes that academic research can derisk innovations, which can, in turn, help industry to adopt novel solutions. “Often, industry wants research that is polished with minimal risk in order to have a commercial advantage. Some industries are not ready to take on products at the early stage of research and development; the way to go is working collaboratively to solve the problem.”

Government funding can also help bridge the gap from early stage academic research, when industry partners are hesitant to take on development risk, to commercialisation. “The Australian government is offering a lot of money to bridge the gap between the lab and the commercial stage, to ensure industry does not shoulder the costs of scale up. This also happens in the UK at the moment,” explained Professor Eshtiaghi.

But eventually, industry expertise becomes an asset. “We as researchers can predict the problem, but industry knows how things work,” she explained. She has partnered with companies with expertise in scale-up technology for chemical engineering and magnetic separators. “There is a lot of interest in industry as people recognise that this is a pressing issue for the environment. Our aim now is to find companies able to commercially produce the adsorbent at a lower price. We are hopeful that we can join different industry partners to implement their specific issues,” she said.

How biology-based innovations are driving a revolution in plastics recycling.

Consumers believe the plastics in their recycling bins will be reused. However, in the US, to name but one, the majority goes to landfills, and only 9% is successfully recycled globally. Most products use virgin or primary plastics and only 6% are from recycled or secondary plastics—down from 9.5% in 2014.

Recycling plastics is hard. This is for myriad reasons, including how toxic the recycling process is to site workers and local communities, the cost of recycling compared with producing new plastic, and the properties of some plastics, which make them harder to recycle than glass and paper.

Hard-to-recycle plastics yield poor quality products after mechanical recycling. This process involves collecting, cleaning, sorting, shredding and melting the plastics to a reusable pellet. The process fails when plastics are not carefully sorted, as even a small amount of the wrong type can lead to poor quality.

Plastics accumulate in landfills and persist indefinitely. Additives used to increase the quality of final plastic products are known to be harmful to humans due to the presence of endocrine-disrupting chemicals. As the plastics fragment, they produce microplastics, which have been shown to cause human cell death.

The most effective way to tackle the plastic waste problem, for some start-ups and researchers, is to give the commodity greater economic value and thereby incentivise circular approaches.

The health risks of plastics are a powerful incentive for researchers and start-ups to find a new approach. “I have four children and it’s important for me to try to do something for the environment. As a scuba diver for about 30 years, I see all the pollution in the ocean—not only plastics but mainly plastics we leave in the oceans, and I was keen to join a company to try to help solve this,” said Emmanuel Ladent, CEO of Carbios, a French biotechnology company that has pioneered the use of enzymes to break down plastics for reuse.

Because recycled plastics using conventional technologies are poorer quality than primary plastics, Carbios, founded in 2011, is applying a novel approach that improves the quality of recycled material. “With our biorecycling technology, 100% of the waste becomes recyclable and the quality will always be like virgin polyethylene terephthalate (PET) even after 10 or 20 cycles of recycling,” explains Mr Ladent. “We optimised one enzyme that has activity on plastics and it plays the role of molecular scissors,” he explains.

Unlike mechanical methods, enzymes break apart plastic and convert PET back to its original components, purified terephthalic acid and monoethylene glycol, allowing the recycled product to be of the same quality as primary plastic. It allows any type of PET waste to be recycled at a temperature of 60-70°C, removing the need for solvents.

Other research groups are harnessing biology-based approaches to plastic recycling. Professor Berl Oakley from the University of Kansas has used fungi to transform plastic waste. “Fungi are used to make a lot of valuable things like enzymes and a number of drugs such as antibiotics and statins, and the market for fungal products is billions of dollars a year, it’s a huge industry,” he explains. “If you’re going to deal with plastics, you probably want something that is economically viable, can operate at scale and put a dent in the problem.”

Using a proof of concept approach of initial chemical breakdown of plastics followed by fungal digestion using a genetically modified Aspergillus fungus, the team produced pharmaceutically active compounds. Their research on fungi has helped turn hard-to-recycle plastics waste from the Pacific Ocean into ingredients like asperbenzaldehyde, which is shown to inhibit tau aggregation in neurodegenerative diseases. They have also created citreoviridin, known for its antiviral, antifungal and antibacterial properties, and mutilin, which has antibacterial properties.

Professor Oakley thinks that products from the fungal breakdown of plastic could be used to produce enzymes, although his research is just the beginning. “If you’re going to try to get rid of plastic, you will need an application that would make a million tonnes of something, not a few grams. We have mainly been expanding our repertoire of fungi that can do various things, rather than trying to start a company to make a million tonnes of proteases annually,” he remarked, referring to the potential ability to create enzymes that can break protein bonds.

Professor Oakley is assured that, despite the scale of plastic pollution, fungi could make a difference. “If you look at the things that fungi make, if we added plastic breakdown products to the fermentation processes that these fungi make, it wouldn’t solve the problem but it will make a dent—that is certainly worth doing.”

Consumers are forcing the packaging, retail and plastics industries to adapt, and Mr Ladent says several industries are interested in recycled plastics from Carbios’ technology, investing in a licence for the technology, including brands such as L’Oréal, Nestlé Waters, PepsiCo, Patagonia, Calvin Klein and Tommy Hilfiger. “We have quite a lot of industries keen to adopt this technology.” Cosmetics and food and beverage industries are attracted by the quality of Carbios’ recycled PET, while textiles brands see an opportunity to achieve circularity.

Despite a tough economic climate, regulatory pressure on brands will drive demand for novel technology. “By 2025, European countries will have to incorporate 25% of recycled materials in their packaging, 30% by 2030 and possibly up to 65% by 2040,” Mr Ladent said. This regulation is being copied by several US states and some countries in South-east Asia, putting pressure on business.

Countries need to do more to collect plastic waste and divert waste from incineration. “We need to have efforts made on collection, so that it is better organised and gives more feedstock to recycling technologies,” warned Mr Ladent. “One of the reasons for pollution is that our waste, which ended up in the oceans, has zero value. If we start to give it a little bit of value, the chance of it going to the oceans is more limited,” he continued.

Technology cannot solve the plastics crisis. A global plastics treaty in the works, and national legislation, will be essential to achieving a truly sustainable plastics sector. But given the scale of the pollution crisis, technology innovations that can capture and repurpose the vast quantities of already-circulating plastics on land and sea will be essential.