New Technology Can Help Remove Microplastics in Sewage Sludge

Plastic, by design, is durable and non-biodegradable. It is these specific characteristics that make plastic waste products a danger to the environment, especially microplastics, as they will not easily disappear over time.

It is a persistent condition that is being addressed by recycling and the use of plastic alternatives today.

However, aside from recyclable single-use plastic products such as water bottles, plastic bags, and packaging, plastic poses the greatest danger as microplastics. Microplastics are tiny plastic particles often very difficult to see, if not invisible, with the naked eye. They are infused in cosmetics as microscopic balls to act as skin exfoliants, in our clothes as polyester fibers, in laundry and dishwashing agents – forms not commonly associated with plastic.

They can also come from existing plastic waste that breaks down over time – they do not break down chemically, but simply fragment and become increasingly smaller.

Too small to be separated by current water treatment facilities, microplastics find their way back to the oceans and rivers, polluting the marine environment.

Researchers from the Monterey Bay Aquarium Research Institute (MBARI) found microplastics up to depths of 1,000 meters below the surface, where they are consumed by plankton and other marine life and end up in fish caught for human consumption. Surveys in Indonesia, the United States and Australia have reported that, on average, one in three fish dissected revealed the presence of microplastic traces with their digestive systems.

In the journal Matter, researchers reported that they have developed tiny carbon-based nanospring magnets that are designed to purge microplastics from water without harming aquatic life.

“Microplastics adsorb organic and metal contaminants as they travel through water and release these hazardous substances into aquatic organisms when eaten, causing them to accumulate all the way up the food chain” says senior author Shaobin Wang, a professor of chemical engineering at the University of Adelaide (Australia). “Carbon nanosprings are strong and stable enough to break these microplastics down into compounds that do not pose such a threat to the marine ecosystem.”

The article also noted that the previous solution was to generate chemicals called reactive oxygen species to break down microplastics into water soluble components. However, it required the use of heavy metals, such as iron or cobalt, that are pollutants themselves and was eventually rejected by the team as an ecologically sound long-term solution.

The greener alternative were carbon nanotubes laced with nitrogen to help boost generation of reactive oxygen species. Shaped like springs, the carbon nanotube catalysts removed a significant fraction of microplastics in just eight hours while remaining stable themselves in the harsh oxidative conditions needed for microplastics breakdown.

But because plastic waste varies in type and composition, the next step is to rigorously test the nanosprings against different types of plastics to ensure their efficacy, as well as ensuring that no toxic byproducts are produced.

This innovation presents a possible solution to effectively remove microplastics from sewage sludge effluent. If this technology is adopted to a grand scale worldwide, it would significantly lower microplastic levels in our bodies of water and help protect the health of aquatic animals and the marine environment.

If you are a municipality in Ontario and in need of a biosolids management solution, please feel free to contact us at 1 (877) 479-1388.

Sources:
https://www.sciencedaily.com
https://www.earth.com/news/

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