The Risk of Microplastic Pollution From Plastic Recycling Facilities

Wednesday - May 10 2023, 04:10 UTC - 1 year ago

A recent study conducted in Scotland points out that the process of breaking down the plastic for recycling may be responsible for increasing microplastic concentration in the washing water, which is often later released into the city water systems or the environment. The filtration that gets used tries to remove the larger microplastics, but it is not effective for plastic particles smaller than 10µm. This emphasizes the need to improve filtration systems and reduce release of contaminants in plastic recycling facilities to prevent irreparable damage to the environment.

Microplastics may be tiny, but they pose a huge risk to health and the environment. We can’t see them, but they are present everywhere. In our meat, milk, and according to some studies, even in our bloodstream and brain. Ranging from 1µm to 5mm, microplastics can adsorb, transport, and release contaminants that are detrimental to our environment and ecosystem.

It has been estimated that only 9% of the plastic produced worldwide is recycled. In order to recycle plastics, facilities separate the plastic by type and then break down and granulate them. The end result is then pelletized for re-processing.

A new study conducted by researchers in Scotland has pointed out that this process of breaking down the plastic may be responsible for increasing the microplastic concentration in the washing water, which is often later released into the city water systems or the environment. "It seems a bit backward, almost, that we do plastic recycling in order to protect the environment, and then end up increasing a different and potentially more harmful problem," said Erina Brown, lead researcher of the study, in an interview with Wired.

The team visited a state-of-the-art plastic recycling facility in the U.K., which the researchers chose not to name to maintain anonymity. They sampled the wash water, a mixed homogeneous discharge, from four different flow paths at four different points along the production line in the facility. Wash water is used throughout the process and is discharged at each of the four sample sites. The filtration measures undertaken by the facility involve 50µm particle filters, which are mesh sieves forming part of a liquid/solid separator at three of the four outlet locations.

The results were perplexing. They found that the filtration process is effective for larger microplastics but allowed smaller (<10µm) to be discharged into the receiving waterway.

The team concluded that the current process of recycling is a potential source of plastic pollution to the environment that it is designed to help prevent. The researchers calculated that without the filtration process, the facility would be emitting up to 6.5 million pounds of microplastic per year, which currently stands at 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." .

Overall, this study points out the urgent need for advancements in microplastic pollution mitigation technology, with regards to plastic recycling facilities, in order to reduce the release of contaminants and prevent irreparable damage to our environment.