Using bubbles to remove plastic from rivers

‘Bubble curtains’ remove 86 per cent of river plastic before it reaches the sea

Spotted: Our seas are choking on plastic. According to the United Nations Environment Programme, there is currently 75 to 199 million tonnes of plastic in the ocean. How does it get there?

A large proportion comes from the world’s rivers, with 1.8 billion kilogrammes of plastic swept from rivers to the sea each year. And this flow of pollution is expected to triple by 2040.  

For this reason, Netherlands-based startup The Great Bubble Barrier is focusing on removing plastic before it ever reaches the ocean. Its solution is to create a ‘bubble curtain’ by pumping air through a tube that runs along the riverbed. The upward current pushes plastic to the surface, and the flow of the river, combined with the diagonal placement of the curtains, funnels the plastic waste into a catchment area where it can be recovered. The plastic is then collected, processed, and re-used.

The bubble curtain is created using electric compressors, and the company aims to power these with renewable energy wherever possible. The system runs 24 hours a day without an operator and can be monitored remotely.

Rivers come in a range of shapes and sizes – from canals to tideways – and are used by humans in a variety of different ways. Each bubble barrier system is therefore tailored to the local conditions of the river where it is deployed.

Springwise has spotted other systems for intercepting river plastic, including two that use floating booms. Methods for removing micro-plastics include the use of water-filtering mussels.

Written By: Matthew Hempstead