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an alarming new study has found that even when plastic makes it to a recycling center, it can still end up splintering into smaller bits that contaminate the air and water. This pilot study focused on a single new facility where plastics are sorted, shredded, and melted down into pellets. Along the way, the plastic is washed several times, sloughing off microplastic particles—fragments smaller than 5 millimeters—into the plant’s wastewater.
Because there were multiple washes, the researchers could sample the water at four separate points along the production line. (They are not disclosing the identity of the facility’s operator, who cooperated with their project.) This plant was actually in the process of installing filters that could snag particles larger than 50 microns (a micron is a millionth of a meter), so the team was able to calculate the microplastic concentrations in raw versus filtered discharge water—basically a before-and-after snapshot of how effective filtration is.
Their microplastics tally was astronomical. Even with filtering, they calculate that the total discharge from the different washes could produce up to 75 billion particles per cubic meter of wastewater. Depending on the recycling facility, that liquid would ultimately get flushed into city water systems or the environment. In other words, recyclers trying to solve the plastics crisis may in fact be accidentally exacerbating the microplastics crisis, which is coating every corner of the environment with synthetic particles.
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The good news here is that filtration makes a difference: Without it, the researchers calculated that this single recycling facility could emit up to 6.5 million pounds of microplastic per year. Filtration got it down to an estimated 3 million pounds. “So it definitely was making a big impact when they installed the filtration,” says Brown. “We found particularly high removal efficiency of particles over 40 microns.”
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Depending on the recycling facility, that wastewater might next flow to a sewer system and eventually to a treatment plant that is not equipped to filter out such small particles before pumping the water into the environment. But, says Enck, “some of these facilities might be discharging directly into groundwater. They’re not always connected to the public sewer system.” That means the plastics could end up in the water people use for drinking or irrigating crops.
The full extent of the problem isn’t yet clear, as this pilot study observed just one facility. But because it was brand-new, it was probably a best-case scenario, says Steve Allen, a microplastics researcher at the Ocean Frontiers Institute and coauthor of the new paper. “It is a state-of-the-art plant, so it doesn’t get any better,” he says. “If this is this bad, what are the others like?”
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Still, researchers like Brown don’t think that we should abandon recycling. This new research shows that while filters can’t stop all the microplastics from leaving a recycling facility, they at least help substantially. “I really don’t want it to suggest to people that we shouldn’t recycle, and to give it a completely negative reputation,” she says. “What it really highlights is that we just really need to consider the impacts of the solutions.”
Scientists and anti-pollution groups agree that the ultimate solution isn’t relying on recycling or trying to pull trash out of the ocean, but massively cutting plastic production. “I just think this illustrates that plastics recycling in its traditional form has some pretty serious problems,” says Enck. “This is yet another reason to do everything humanly possible to avoid purchasing plastics.”
Source: Yet another problem with recycling: It spews microplastics | Ars Technica
Robin Edgar
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