How companies are cleaning the world’s most polluted rivers
Millions of tons of plastic waste enter the oceans every year, most of which comes from about 1,000 highly polluted rivers. And with total waste generation expected to increase by more than 75 percent by 2050, the problem will only get worse.
Companies around the world are turning their attention to the problem of river litter, building various barriers, fences and wheels that help contain and remove litter downstream.
These approaches range from solar-powered trash-collecting boats to stainless steel fences, and different rivers require different methods.
Here’s how three companies, Clearwater Mills, The Ocean Cleanup, and AlphaMERS, are tackling the problem.
Clearwater Mills Garbage Wheel
First introduced in 2014, Baltimore’s Googly-Eyed Garbage Wheels are an early effort to address river litter. Built by Clearwater Mills, founder John Collett was inspired to design the wheels after years of seeing the trash that washed into Baltimore Harbor after major hurricanes.
“We have Mr. Garbage Wheel, Captain Garbage Wheel, Professor Tarshville and Gwynda the Good West Wheel in Baltimore,” Collett said, referring to the names of the anthropomorphic wheels that have become social media celebrities in the city.
Baltimore’s Mr. Garbage Wheel swallows trash and debris after a big storm.
Baltimore Coastal Partnership
Here’s how they work: V-shaped containment booms are installed across the river, with rubber skirts that extend about two feet below the surface of the water. It catches floating debris at the bottom of the river and carries it to the “spout” of a rotating water wheel, which is powered by flowing solar panels connected to the river. The rotation of the wheel powers a conveyor belt that pulls trash and debris out of the river and into a landfill. Attached cameras allow the team to monitor how full the bins are.
“And once the bin is full, we have another floating barge that we bring in with an empty bin. Take out a full bin, slide the empty bin in and keep picking up the trash,” Kellett said.
The four-wheelers have collected a total of about 2,000 tons of trash and debris. Sticks and leaves make up the bulk of this weight, as plastic is so light, but overall the shipment includes about 1.5 million plastic bottles, 1.4 million Styrofoam containers and 12.6 million cigarette butts. Everything is then incinerated in waste-to-energy facilities.
Additional waste wheels are planned for Texas, California and even Panama, where a local nonprofit organization, Marea Verde, has partnered with Clearwater Mills to build a fifth wheel for the family, named Wanda Díaz. The project is funded by the Benioff Ocean Initiative and the Coca-Cola Foundation, which together support a series of river cleanup projects around the world.
Clean up the ocean
Ocean Cleanup is probably best known for its efforts to clean up the Great Pacific Garbage Patch, an effort the company’s young founder Boyan Slott began in 2013 after publishing a TED talk on the subject. The company now pursues a dual focus as it has also developed a series of river cleaning technologies.
“Our goal is to clean the oceans of plastic, and the reason we’re looking at rivers is because we believe it’s the fastest and most cost-effective way to prevent more plastic from entering the ocean,” Slott said.
The company’s first river cleaner, the Interceptor Original, was released in 2019. It’s an all-solar barge that works much like the Baltimore Garbage Wheels, only on a larger scale. At the mouth of a river, it funnels the waste onto a conveyor belt and automatically distributes the waste into six giant bins.
Ocean Cleanup’s Interceptor Original working on the Rio Ozama in the Dominican Republic in summer 2020.
Clean up the ocean
But since this giant interceptor wouldn’t fit in smaller rivers, the team created another solution, a self-contained floating barrier to collect the debris and a small, mobile conveyor belt that collects the debris and transports it to a landfill on land. The system is currently based in Port Kingston, Jamaica, where Slott says the rivers are too narrow for the Interceptor Original.
And for those seriously choked rivers, there’s Trashfence. The concept is simple. A 26-foot steel fence is anchored to the riverbed, stopping the flow of debris during a major storm. When the water level drops, the excavator removes the debris. But the influx of trash in one of the world’s most polluted rivers in Guatemala was too much for 1.0.
“The bin force was so overwhelming that unfortunately the litter fence failed,” Slott said. So we are now working on version two which will hopefully be ready for the next rainy season.
Eight Ocean Cleanup interceptors are currently deployed in Indonesia, Malaysia, Vietnam, the Dominican Republic and Jamaica. Slat expects to have about 20 installed by next year, including one in Los Angeles.
India-based AlphaMERS builds another version of the simple river dam and has 34 installations in eight different cities across the country. It’s much smaller than Ocean Cleanup’s Trashfence and isn’t designed for the same heavy trash flow, but it’s still pretty heavy duty. The AlphaMERS fence, made of stainless steel mesh, floats several feet above the water and sinks about 16 inches below.
“Hydrodynamics and hydrostatics. It’s very simple, but it’s perfect for this,” said Alphamers founder DC Sekhar. “And it’s built very rugged and very heavy, with steel chains holding it up on both sides. So it can withstand the monsoon currents immediately after the rain.”
Sekhar says his floating fence is excellent at stopping debris in rivers with fast currents, while designs that rely on a boom and skirt can fail when currents rise because the water instead runs over the barrier and He brings the garbage with him.
The AlphaMERS floating barrier collects debris as it flows downstream
Eight floating barriers were deployed at various points along the river Kum in Chennai in 2017. Sekhar says they seized about 2,400 tons of plastic in their first year of operation.
These barriers are angled to direct waste toward the river bank, where dredges traditionally remove waste from rivers. AlphaMERS has used a conveyor belt instead, just like Clearwater Mills and The Ocean Cleanup.
Sekhar said about the conveyor belts: “One end is floating, one end is on the ground.” And now it runs on electricity and with portable generators. But soon we will launch it with river water flow.
The future of garbage
These organizations share the same goal of removing as much waste from our lives as possible, but they all know that river cleaning systems are not the ultimate solution.
“One of the things we look forward to is when we no longer need waste wheels. When we take care of the problem upstream to the point where no trash gets into our waterways, we don’t need to have it. Garbage wheel.
Getting there will be difficult and will depend on a combination of better waste infrastructure, more sustainable packaging, less consumption and public awareness of proper disposal.
Middle-income countries such as the Philippines, India, and Malaysia contribute the most to the generation of ocean debris. People have enough money to buy a lot of packaged goods, but the waste collection infrastructure lags behind.
Sandy Wattemberg, executive director of the non-profit organization Marea Verde, is excited that her organization brought Wanda Díaz’s trash wheel to Panama and is optimistic about its future performance.
“So we very much hope that this will be a great success for our country.
“Having these technologies and these types of projects is not the solution. We need to change our habits. We need to look for long-term solutions that allow us to have a cleaner and healthier environment, because these types of projects They help us create awareness and awareness. Help us reduce the decline in the short and medium term. But ultimately, this is not sustainable. We cannot run thousands of projects like this forever.