Technological watch

Taking aim at​ ocean plastics

Detroit — Public service spots in the early 1970s showed Iron Eyes Cody clad in a Native American costume shedding a tear about trash fouling the land. Keep America Beautiful.

But nearly five decades later, litter has fallen off society's radar screen — litter on land, that is, according to a civil engineer speaking at Antec 2019. But litter in the oceans? That's a different story.

"We have forgotten this litter awareness over a period of time. I've just seen it evaporate in my lifetime to the point where there's such a thing as 'litter blindness,' and it's worldwide," said Thomas Sprehe, senior vice president at KCI Technologies Inc. in Sparks, Md., just north of Baltimore. "I've been in the nicest neighborhoods in Rio de Janeiro. Million-dollar houses. And the streets are just covered with litter, outside. It's just an incredible ability to be blind to something that is so obnoxious and gross. But for some reason, [litter blindness] is a little less prominent when it gets to marine litter. You see litter in the water; it's incredibly powerful, sort of an eye-catching thing."

Sprehe was one of the speakers at a session on ocean plastics at the Society of Plastics Engineers' Antec conference in Detroit. The diverse range of speakers covered a technical look at how ocean plastics break down, biodegradability and Sprehe's topic: how to set up trash barriers where a river empties into the sea.

Litter starts on land, then if it's not properly disposed of, it can end up in the river then into a larger body of water. Rivers end up being good trash collectors, he said. Once it gets into the ocean, plastic waste is hard to remove.

"You can take a large area — 60 or 70 square miles of land — and compress that litter into the mouth of the river. And you've got a chance to get it before things go completely crazy, in terms of cost and difficulty," Sprehe said. He is also KCI's director of ​ innovation and technology.

One problem is that government policies for ocean waste still largely focus on the sewer overflow model: When it rains really hard, stormwater and sewage runoff runs through combined sewer overflows, and the foul stuff gets diluted. But in the case of plastic, Sprehe said, the problem gets worse the more rain you get. Sprehe said regulations are starting to recognize the problem of waterborne plastics.

Sprehe said Europe is far ahead of the United States in dealing with the issue as well as moving to a circular economy.

He put up slides of simple booms strung across the mouth of rivers. The problem is, once the plastic builds up, how do you remove it from the middle of the river?

Steve Russell, vice president of the American Chemistry Council's plastics division, was on a panel discussion at the ocean plastics session. Earlier, he addressed the issue in a keynote speech during Antec.

"Our system has failed to keep up with the pace of growth and access to consumer goods," he said.

Much of the ocean waste comes from developing countries in Asia that do not have adequate trash collection systems, Russell said. Rain washes the plastic away, eventually to the ocean.

To help tackle the global ocean plastics problem, industry companies have created the Alliance to End Plastic Waste, raising $1 billion.

Bill Bregar Andrady Another speaker at the ocean waste session explained how plastics break down into smaller pieces. Anthony Andrady, an adjunct professor of chemical engineering at North Carolina State University, said the beach is where much of the degradation happens.

Citing laboratory research, he said the outer surface of a plastic fragment has a different chemistry from the inner area.

"So if you keep this in the beach, the drying and wetting of this, or even hot-cold changes, would impact the expansion and contraction of the two layers, so that the outer layer would crack and disengage from the bulk very easily," Andrady said.

Some degradation does happen on surface water, through oxidation.

More research needs to be done to see if these microplastics continue to break down into nano-sized particles, Andrady said. These could get into drinking water and food and enter the human body.

"There's no cause for immediate concern, but we don't know what nanoparticles would do to the human system. But there's a lot of caution that is justified," he said.

Bill Bregar Lewis Commitment to captureLeaders of Envision Plastics, a recycler based in Reidsville, N.C., made a commitment to collect and recycle 10 million pounds of ocean-bound plastic over two years through its OceanBound Plastic program. Sandra Lewis, director of business development, said it targets coastal communities that do not have a formal waste system — like Haiti, one of the world's poorest countries.

About 10 years ago, Envision Plastics was approached by Method Products, which wanted to package its liquid soap in bottles from ocean waste in Hawaii.

Lewis told the story: "There's this one particular beach where a lot of plastic washes up and accumulates on this beach. So they were gonna go to Hawaii, pick up all this plastic off the beach, ship them to our plant in California. We were gonna magically recycle it, and they were gonna turn it into a new bottle," she laughed. "If anybody knows about recycling, that is a lot harder than it sounds."

Envision Plastics received the material, which included a few kayaks, a toilet set, a fishing net, and even a bag of dog poop, she said.

The actual plastic pieces were not good after degrading on the beach.

"It's been sitting in the sun, the sand, the salt, and literally crumbled in our hands when we received it. And we're like, this is never going to make a new product," Lewis said.

So Envision watered down the ocean plastic in a solution and added 90 percent of its post-consumer HDPE from its main recycling business.

"That's the ratio we use. And they were able to make a bottle with it," she said.

When the Method bottle came out, the recycling company was flooded with calls. But Lewis had to tell them that Method had collected a few thousand pounds of beach plastic, and there was no more.

Envision then started OceanBound Plastic.

"It's this program to pay people to go pick up plastic. They turn it in. They get paid for it. But the company we picked to work with has gone through this very rigorous auditing process," she said. "Our partner in Haiti today has 9,000 pickers registered for him to collect plastic. So that created 9,000 jobs in the poorest country in the Western Hemisphere. One supersack of plastic, when they redeem it, feeds a family of four for a week."

Today, OceanBound Plastic is working in some regions of Mexico, and officials are looking expanding to Honduras, Lewis said.

The plastic gets shipped to Envision for reprocessing.

"The reason we did this was because we wanted to give companies and brands confidence that there is a lot of this material. We can collect it and recycle it. And we will have it available to you," she said.

Envision is nearing the mark of 10 million pounds. Unfortunately, Lewis said, she has sold maybe 10 percent of it.

Jennifer Ronk of Dow Chemical Co. said companies need to design products upfront for a circular economy and collaborate more widely with other parties. Some are calling for bans of plastics.

"We can lead and give them different solutions for how we can work to solve this problem together," Ronk said.

True biodegradabilityRamani Narayan, a Michigan State University professor, called for true biodegradability to be part of the answer — but he insisted it must be done in a municipal composting center.

Companies can't call a product "compostable" unless it goes into a composting environment where microorganisms break the plastic down and complete biodegradation happens, he said. The term biodegradable "has been abused and misused," said Narayan, a professor at MSU's Department of Chemical Engineering and Materials Science.

He said whether something is "compostable" has to be quantified and certified by a third-party lab. Narayan drew laughter when he quipped, "You can call anything biodegradable. You are biodegradable; everything is biodegradable. Given time and environment, everything will disappear. So we should have no problems. But we have a lot of problems."

Narayan also addressed confusion about "bio-based" plastics, saying that they are not necessarily biodegradable. "I want to leave you with the fact that, just because you have a bio-based product, you still need to address end of life. And this is where we are not fulfilling the role," he said.

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Publication date: 16/04/2019

Plastics News

This project has been co-funded with the support of the LIFE financial instrument of the European Union [LIFE17 ENV/ES/000438] Life programme

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Last update: 2022-01-31