Several million tonnes of plastic waste are dumped into the ocean every year, with by far the majority coming out of the mouths of the world’s biggest rivers. So a cleanup of waste on rivers, before it reaches the sea, would make a massive difference. Nobody has done this effectively before – until a Dutch inventor came up with the Interceptor. By Jeremy Torr.
Rotterdam, 25 October 2019. According to some research, more than five million tonnes of plastic enters the ocean every year from coastal populations worldwide. And one estimate says that almost half of that (up to 2.41 million tonnes) currently enters the ocean every year from rivers, with the top 20 polluting rivers, which are mostly in Asia, accounting for a staggering 67% of the global total.
“What we found was that 1000 rivers are responsible for 80% of pollution,” said Boyan Slat, founder and CEO of The Ocean Cleanup, a techno-solutions organisation. “So that means that just one percent of the rivers cause 80% of pollution. This means that it is quite achievable to solve this (problem).”
It’s not just pollution - it’s a costly problem too. A Marine Pollution Bulletin study estimated that yearly economic costs due to marine plastic pollution are estimated to be up to US$2.5 trillion a year, through its impact on tourism, fisheries and aquaculture and through funding cleanups.
So, reasoned Slat, why not try to cut off the plastic outflow from the main culprit rivers – and potentially cut plastic ocean pollution by a massive amount?
The Interceptor is an autonomous solar powered plastic catcher. Courtesy Ocean Cleanup.
A significant percentage of the plastic that enters the oceans from rivers drifts into large systems of circulating ocean currents, also known as gyres. Once trapped in a gyre, the plastic will slowly break down into microplastics and become increasingly easier to mistake for food by fish and other aquatic lifeforms – including ones that we eat.
“Our mission to rid the ocean of plastic garbage is within our sight.” - Boyan Slat.
Slat and his team are working on a system of floating ‘catcher nets’ that are deployed in deep ocean sites where plastic gather through the forces of wind and wave – like the Great pacific Gyre. But its latest introduction, the Interceptor™ is a floating solar-powered harvester system which catches river-borne plastic trash as it heads towards the sea.
It then scoops up the floating rubbish and automatically funnels it into hoppers which can be removed by barge and taken either to recycling or disposal plants before they get into the deep sea areas and get broken up into dangerous microplastic pollutants.
Capable of extracting up to 50,000 kilos of plastic and other floating rubbish a day, each Interceptor system has a storage capacity of 50m3 (several tonnes) but can be emptied as soon as needed by replacing the hoppers with new ones. Using remote sensing, the operators can send out a refill barge when needed so the system never overfills or spills.
As Ocean Cleanup notes, as the system is 100% solar-powered, it extracts plastic autonomously, and can be placed in the majority of the world’s most polluting rivers no matter if there is a source of power there or not.
Interceptors are already working on rivers in Malaysia, Indonesia and Vietnam, with the Dominican Republic and Thailand due to take vessels soon. “And we are signing agreements with more and more governments - and talking to Los Angeles too,” adds Slat.
“We plan on tackling 1000 of the most polluting rivers (with Interceptors) all over the world in the next five years,” says the website. “It is our ultimate goal to reach a 90% reduction of floating ocean plastic by the year 2040.”
Slat, who was born in Delft, Holland, set an early innovation record when he set a Guinness World Record by launching over 200 water rockets simultaneously when he was only 12. From that, he moved on to investigating ocean plastic pollution as a school project, and after a highly acclaimed TED X talk online about pollution, he set up The Ocean Cleanup in 2014.
Ocean Cleanup’’s floating plastic-catching nets are being trialled in the Pacific. Courtesy Ocean Cleanup.
"Technology is the most potent agent of change. It is an amplifier of our human capabilities", Slat wrote in a recent article. “Whereas other change-agents rely on reshuffling the existing building blocks of society, technological innovation creates entirely new ones, expanding our problem-solving toolbox.”
He says that the group's mission to develop advanced technologies to rid the world's oceans of plastic has currently raised US$2.2 million through crowd funding plus the help of 38,000 corporate and government donors from 160 countries.
The initiative is garnering considerable business support. “As coatings partner to The Ocean Cleanup, we’re committed to supporting the fantastic work they’re doing to stop the world drowning in plastic,” says Jean Michel Gauthier, of AkzoNobel’s Marine Coatings business which helped with the design of the equipment.
Ocean Cleanup technical teams are also continuing to work to develop solutions for the group’s ocean cleaning systems, which are still in the prototype phase. They are optimistic that the new systems to harvest already released plastic will be able to remove 50% of the Great Pacific Garbage Patch every five years.
"Now, we have a self-contained system in the great pacific garbage patch that is using the natural forces of the ocean to passively catch and concentrate plastics," said Slat.
“The beginning of our mission to rid the ocean of plastic garbage, which has accumulated for decades, is within our sights.”