Is Photocatalysis Our Greatest Weapon in the Fight Against Microplastics?

With the help of a semiconductor and the power of the sun, microplastics can be broken down into harmless substances.

Researchers in Stockholm have developed a process that successfully breaks down harmful microplastics using the power of the sun.

Author Laura Wagener:

Translation Laura Wagener, 11.24.17

A more just society, a better recycling system, lower unemployment – Sweden is often upheld and much envied as a paragon of social and environmental stability. And now it looks as if they might have come up with a solution for the growing problem of microplastics too.

Microplastics, tiny plastic pieces and particles, are increasingly finding their way into our oceans and our drinking water – whether it’s through toothpaste, cosmetics or plastic particles that are shed from clothes made from artificial fibres when we do laundry. And because the pieces are so small, they can easily pass through water filtration systems and end up in our oceans and lakes, where they’re eaten by fish and end up in our food chain.

As part of the program “Cleaning Litter by Developing and Applying Innovative Methods in European Seas” (CLAIM), researchers from the Royal Institute of Technology (KTH) have now found a way of breaking plastic pieces down into CO2 and water using a process called photocatalysis.

The Nanotechnology Nailing Microplastic

How does the process work exactly? Well, it’s all based around the fact that plastics degrade when exposed to the sun – in a process called “photocatalytic oxidation”. When it happens naturally it takes a long, long time – and even longer when the plastics are under water, which sunlight has difficulty penetrating.

That’s why this team of sientists is testing system of filters coated in a material madeup of nano-sized semiconductors that initiate and speed up this natural process. The microplastic – which is first filtered out of the waste water – then comes into contact with the semiconductor and under the influence of ultraviolet light and oxygen, is broken down into harmless CO2 and water via photocatalysis.

The researchers hope that their findings will be able stop more microplastic ending up in our waterways.

These plastics will start accumulating in the food chain, transferring from species to species, with direct adverse consequences to human population,” said Joydeep Dutta from the KTH. “Tackling plastic pollution at its source is the most effective way to reduce marine litter.”

After the trials have been completed, the microplastic filters are set to be installed in the outlets of sewage treatment plants.

Micro or Macro: No Plastic Should Be in Our Waterways

The longterm goal of the CLAIM program is however a much larger move to tackle all kinds of plastic particles in our waters. We’re set to see more anti-plastic devices in the future – alongside this new filter system – including floating booms at the mouths of European rivers to collect larger plastic pieces.

The programme is coordinated by the Hellenic Centre for Marine Research (HCMR) in Greece and is financed with a Horizon 2020 Innovative Action grant from the EU Commission. The project started in November 2017 and will be running until the year 2021.

This is a translation by Marisa Pettit of the original article which first appeared on RESET’s German-language site.
Ecoalf: Transforming Fishing Nets, Coffee Grounds and Plastic Bottles Into Sustainable Fashion

A Spanish fashion company is using discarded plastic bottles, fishing nets, tyres and even coffee to produce a range of upmarket upcycled clothing.

How Cora Ball Could Make Your Laundry More Eco-Friendly

Every time we do laundry, fibres shed off our clothes - microscopic synthetic pieces that end up in our waterways and eventually on our plates. Now, thanks to a successful crowdfunding campaign, the Cora Ball is here to help.

Australia’s 3D WASH Transforms Plastic Waste Into Water Pipes

Engineers at Australia's Deakin University have come up with a way to combine 3D printing and solar power that turns plastic waste pollution into practical water pipes for crisis hit regions.

Litterbase: The Ultimate Map of Ocean Waste and the Damage It Causes to Marine Life

A group of scientists from Germany’s Alfred Wegener Institute have compiled the world’s first ever comprehensive database containing information on the location and environmental effects of litter in our oceans. Their findings are published on Litterbase, available in both German and English, and complete with easily comprehensible maps, charts and infographics. 

A Laundry Wash Bag Against Microplastics

Pollution cycle: every time you wash your laundry, synthetic fabrics shed tiny particles of plastic which end up in waterways. The recyclable laundry bag “Guppy Friend” could prevent this from ever happening again.