Clean-up fever in the ocean

By Andrea Neumeyer

“The Ocean Cleanup” intends to scoop some 90 percent of the plastic waste that’s close to the surface from the world’s oceans by 2040. The non-profit organization was founded by a then teenager whose greatest fans include the UK pop band Coldplay.

#Materials #Recycling #Resources #Sustainability

5
Gigantic garbage patches are floating in the world’s oceans. Two each in the Pacific and the Atlantic, and one in the Indian Ocean.
1.6 MN
square kilometers (620,000 square miles): That’s the size of the largest garbage patch aka the Great Pacific Garbage Patch between Hawaii and California. That equates to three times the size of France. Once it has ended up there, garbage can hardly escape the gyre again because the Oyashio Current in the north and the Equatorial Current in the south keep spitting it back into the vortex.
1.8 quintillion
Plastic parts, estimates “The Ocean Cleanup,” are floating in the Great Pacific Garbage Patch – equating to some 250 pieces per person on Earth. The oldest parts date back to the 1960s.
40 %
of the garbage in the Great Pacific Garbage Patch are residues of fishing nets.

Aiming to rid the oceans of plastic waste

The non-profit organization The Ocean Cleanup has been fighting against the pollution of the world’s oceans for ten years. Its founder and still the driving force is Dutchman Boyan Slat, who while diving in Greece in 2011 at the age of 16 saw more garbage than fish in the water. Two years later, the aerospace engineering student founded “The Ocean Cleanup” with a crowd funding initiative and presented his first ocean filter. Today, the organization that’s based in Rotterdam employs more than 130 people from more than 30 nations. CEO Boyan Slat himself continues to contribute his ideas to the research and development of ocean cleaning systems.

Boyan Slat came up with the idea for the gigantic garbage collection project at the age of 16 © The Ocean Cleanup
Today, more than 130 employees are engaged in the pursuit of his vision © The Ocean Cleanup

Following initial tests with prototypes in 2019 and 2021, “System 03,” which has since tripled in size, has been deployed. The 2.2-kilometer (1.4-mile) long U-shaped barrier is pulled slowly by two ships. The plastic waste is collected in a bag-like net extending four meters (13 feet) below the water surface and subsequently stored on board for later onshore recycling. System 03 is supposed to scoop small plastic fragments the size of a few millimeters as well as large fishing nets weighing tons and, in the process, clean up an area equating to a soccer field within five seconds.

“While we still have a long way to go, our recent successes fill us with renewed confidence that the oceans can be cleaned.”
Boyan Slat, initiator of the Ocean Cleanup project

With cleanup vessels like these … © The Ocean Cleanup
… and mammoth nets, “The Ocean Cleanup” collects plastics from the Pacific © The Ocean Cleanup
Among the places where “The Ocean Cleanup” has been active is the San Francisco Bay from where the crew headed for the world’s largest garbage patch between the U.S. mainland coast and Hawaii © The Ocean Cleanup
The garbage trapper is a net construction with a length of 2.2 kilometers (1.4 miles) slowly being pulled through the water on a U-shaped path by two tugboats © The Ocean Cleanup
The collected garbage is loaded onto ships for onshore recycling © The Ocean Cleanup

Music on recycled plastics

Prominent supporters of “The Ocean Cleanup” include the UK pop band Coldplay with lead singer Chris Martin. When the musicians, who are strong advocates of environmental protection and sustainability on their tours as well, release their new album “Moon Music” on October 4, the release will include a limited edition, 70 percent of which has been produced from recycled plastics that “The Ocean Cleanup” captured from the river Rio Las Vacas in Guatemala. The other 30 percent of the material was recovered from former plastic bottles. In addition, Coldplay is involved in the mission of the “Interceptor 05” boat on Klang River in Malaysia.

Coldplay has always attached great importance to sustainability © Warner Brothers
A pop LP made of recycled plastics © The Ocean Cleanup
“The Ocean Cleanup” scoops garbage from the river Las Vacas in Guatemala © The Ocean Cleanup

Curbing waste streams

Scooping garbage out of rivers has moved into “The Ocean Cleanup’s” focus for good reason because the organization says that 1,000 rivers – which is only one percent of all rivers worldwide – are responsible for 80 percent of the plastic garbage in the world’s oceans. “The Ocean Cleanup” is planning to use tailored solutions positioning interceptors in the mouths of the biggest rivers. 15 of such vessels are initially planned.

This new approach has put “The Ocean Cleanup” on the same page as its critics because many scientists consider the mere removal of plastic waste floating on the surface of the sea to be a drop in the bucket even if the effort succeeded at a rate of 90 percent in line with Boyan Slat’s target for 2040. The reason is that this relatively easy to capture waste accounts for only about one percent of the plastics having migrated into the world’s oceans. Like in the case of icebergs, a much larger part is located underneath the surface. The statistics speak a similar language. Boyan Slat and his fellow campaigners say that they’ve extracted 18,000 metric tons (20,000 short tons) of plastics so far – of 100 million metric tons (110 short tons) moving around in deeper ocean waters or having deposited on the ocean floor or on coastal strips.

Consequently, capturing plastics in rivers – “The Ocean Cleanup” and other scientists agree – is clearly more effective than chasing it in the vastness of the oceans. Another point about which there’s agreement is that curbing the flood of plastics much earlier along the supply chains and/or switching to biodegradable materials is an even more environmentally sensible course of action.

When the plastic parts get into the vortex of the garbage patch, they’ll circulate there for decades in some cases before solar irradiation and saltwater cause them to decompose into smaller and smaller plastic pieces © The Ocean Cleanup
The problem: The smaller the plastic pieces become the more difficult it is to extract them from the water. Ultimately, marine life causes the nano plastics to enter the food chain © The Ocean Cleanup

Alternative methods

Boyan Slat and his team are not alone in their fight against marine pollution: Worldwide initiatives against plastic garbage range from the Surfrider Foundation and Children for the Oceans, which enhance public awareness of the need to avoid waste and organize cleanup campaigns, to a variety of technical solutions.

The solar-powered garbage collection vessel “Circular Explorer” of the One Earth – One Ocean environmental organization scoops 4,000 kilograms (8,800 lbs.) of plastic waste from the ocean per day. To do so, the ship uses conveyor belt technology, an on-board crew sorts the finds and throws marine animals and organic waste back into the sea. One Earth – One Ocean is active in eleven countries with 14 cleanup cells.

Clean-up fever in the ocean — Solar-powered garbage collection ship© Holcim

Marcella Hansch, an architect from Aachen, Germany, launched Everwave. As early as in her master’s thesis she designed a floating platform that, due to its special layout, is supposed to filter even the smallest plastic particles from the water. By now the organization focuses on cleanup campaigns for rivers. The flat-bottomed cleanup boats can remove plastic waste from the banks or the water. Like Ocean Cleanup, Everwave uses floating barriers as needed to intercept and batch up garbage.

The Sea Cleaners organization is planning to collect 5,000 to 10,000 metric tons (5,500 to 11,000 short tons) per year with the solar-powered boat “Manta” starting in 2025. Whereas glass and metal will be hauled to shore for recycling, the plastic materials will be melted and the resulting gas used as an energy source for the on-board systems.

Scientists at Friedrich-Alexander-University Erlangen-Nuremberg (FAU), a cooperation partner of Schaeffler’s, have developed a method for extracting plastic particles of various types (polyethylene, polystyrene, polyvinylchloride, Teflon, etc.) and sizes – including nano-sizes – from the water. The principle: Non-toxic, specially coated iron oxide nanoparticles called SPIONs (superparamagnetic iron oxide nanoparticles), agglutinate – like a type of glue – with the plastics to form larger agglomerates that can subsequently be magnetically collected due to their iron oxide content. The system has not been deployed yet.