In the study, scientists put the three plastic compounds into ‘hard water’ — a common type of U.S. freshwater that contains high levels of calcium carbonate and magnesium
When the plastic-containing water was boiled, these calcium carbonates formed tiny clumps around most of the microscopic plastics, trapping them within and rendering them harmless.
The report comes with significant caveats, however.
Scientists only looked at three of the most common — and in the case of polyethylene and polypropylenes, the safest — plastic polymers. They didn’t look at vinyl chloride, for example, a compound of serious concern last month’s study found in bottled water.
Boiling also didn’t manage to remove all of the polymers.
It isn’t really a solution, it just encases them in calcium. The plastic is still in there.
The effectiveness may also depend on the type of water and its mineral content.
It is no longer in solution, it precipitated out. This could very well be used to reduce microplastics in water.
https://pubs.acs.org/doi/10.1021/acs.estlett.4c00081
Seems like boiling hard water followed by filtration would do the trick. Decanting after letting the water sit for a while, to allow precipitates to fall to the bottom, could work also.