Reclaiming Recycling

Majumder was an expert in heavy-metal contamination before turning her attention to plastics. “It keeps me up at night,” she says of the proliferation of plastics in landfills and the environment more generally. “You have plastic contamination everywhere, but you don’t usually have very high concentrations of plastic in any one place. So it’s very difficult to degrade that, and the microorganisms themselves aren’t acting on a quick enough time scale.”

One of Majumder’s recent projects was to sample the layers of a landfill in Dane County. “We were looking for the microbial communities growing on plastics, and we’ve been trying to figure out what is preventing them from decomposing plastic and what we could do to encourage them to decompose plastics in the landfill,” she says.

Her team found that mixes of different microbes are needed to metabolize with the various soil chemistries produced by plastic materials. “We don’t think there’s a super microbe out there that can eat every single type of plastic,” she says.

Her work now is to bioengineer microbes to enhance their natural capabilities for decomposing plastics. And while those engineered microorganisms can’t go out into the wild, they could eventually help break down plastics in waste plants and other controlled environments.

Equally important to the challenge of decomposing plastics, says Majumder, is to rethink our approach to producing new materials in the first place. “The materials of the future need to be designed with the end of the life of the material in mind,” she says. “We don’t want to just design the material for the function that we’re going to use it for, but also so it could be easily biodegraded or easily recycled or easily reused. We should really be thinking strategically about what the materials are [from the beginning].”

The Plastic Tray

Since the early 1990s, a high volume of U.S. plastic waste has been shipped overseas — specifically to China, Thailand, and Vietnam — to be recycled or dumped. In 2018, China announced it would no longer accept imported plastic waste, sending shockwaves through environmental circles. Some, like Greenpeace, began to (inaccurately) spread the word that plastic recycling wasn’t possible — or worthwhile — in the United States.

Yet for UW plastics researchers, the change in policy is a reason to celebrate rather than panic. “We shouldn’t be shipping waste around,” says Huber. “Every state should figure out what they’re going to do with the waste they generate. Wisconsin should try to develop our own industry, especially because the plastic industry is so important. How can we use our capital costs as efficiently as possible to design technology to better recycle or better use our resources?”

That’s one of the questions that drives Victor Zavala, the Baldovin-DaPra Professor in Chemical and Biological Engineering, who analyzes the life cycle of plastic at a systems level. His lab, which runs massive computer simulations, has found that scaling up plastics recycling can be economically viable — and, more importantly, play a role in social and environmental justice.

“The plastic pollution issue creates not only environmental degradation locally, but also creates informal economies for collecting plastic waste around the world,” Zavala says. He offers an example from his native country of Mexico, where people known as waste pickers collect plastic from landfills under dangerous, exploitative conditions to sell to multinational corporations as stock materials for recycling.

“I’m trying to raise awareness through my work on all these hidden problems that are being created indirectly by the plastics industry and also make a case for how new technologies could actually help us solve these societal problems,” Zavala says. Strengthening the recycling industry in the United States, he says, “is also a way to help formalize the waste-collection problem in Mexico, which could have consequences for quality of life there.”

Why not simply ban plastic entirely, as some cities are now trying to do with plastic grocery bags and single-use plastics in restaurants? Every action matters, but the massive scale of plastic use makes it functionally impossible to ban altogether, Huber says. The United States uses 37 million tons of plastic each year, which roughly equates to 200 pounds of plastic per person. Alternatives work in some instances, but materials like glass, metal, and cardboard can’t replace plastic entirely, especially when it comes to safe food packaging and shipping.

In large part, solving the problem of plastic waste comes down to creating better economic and social incentives for corporations to implement new and existing technologies to improve sustainability, says Zavala.

“The chemical industry sees the urgent need to actually get it done. The societal awareness of plastic waste has increased dramatically, to the point that now people are finally taking these technologies seriously and making them happen,” he says. “It is a combined synergy of technology and policy and economics. It’s not just that the technology will solve the problem. It has to be the whole community.”

Wisconsin Distinguished Professor Emeritus Craig Benson, an expert in geoengineering and waste management systems at CUWP, says the last five years have been transformative in terms of public enthusiasm for plastics recycling. “Seventy percent of the value in your [household] recycle bin right now is the plastic,” he says. “That’s a complete change from five years ago, where that plastic was practically worth nothing, and the metal was the valuable part.”

Whatever You Do, Just Don’t Litter

At the same time that economic incentives for corporations to get involved with plastics recycling are increasing, Benson has noticed a worrying uptick in littering, which is the worst possible choice for dealing with waste.

“Litter is really a major problem in the United States,” he says. “There are many folks who are very self-conscious about their behavior with waste and recycling. But there’s a much broader cross-section of our society that does not give that too much effort or consideration. What incentives can we put in place that will encourage people to think twice when they’re done with a plastic material in daily life?”

One place to start might be to remind people that plastics do, in fact, break down over time in the environment — but that breakdown isn’t a good thing if it happens in the open environment rather than in a controlled setting. A cup-sized piece of plastic is relatively easy to pick up and put in a waste bin. However, if that cup erodes into tiny pieces, those microplastics become functionally impossible to remove from soil and waterways. Eventually, tiny plastic particles can even end up circulating in the air.

“The bigger the piece of plastic, the less of an environmental problem it is because it’s pretty inert, and [for the most part] nothing can swallow it,” says Majumder. “So the remediation method just becomes picking it up. But the smaller the pieces get, the more toxic they become, and the harder they become to remove from the environment.”

As for your lunch packaging? The UW researchers have a clear answer: recycle what you can, because it’s definitely worth doing so from an environmental, economic, and social-justice perspective. And for those plastics that aren’t yet recyclable, be sure to put them in a waste basket.

“They should go in a landfill, and there’s nothing wrong with that,” Benson says of nonrecyclable plastics. “Our modern landfills are very sophisticated environmental containment systems. They have a remarkable record of environmental performance.”

More broadly, though, your lunch packaging is part of a bigger, ongoing societal challenge to rethink our collective relationship with the environment and material consumption.

“If we’re going to solve our sustainability problems, it is super important that we understand that we are all part of the problem, and that we’re also all part of the solution,” says Zavala.

Nelson, the Amcor engineer, says it comes down to individuals throwing away materials so that they don’t leak into the environment. “It’s on all of us to do a little bit, and at some point it’s just making the choice of the recycle bin or the trash bin. Do you care enough to pick the right bin?” •