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.
You’re not supposed to drink the flocculated plastic particles. You still have to decant or filter the boiled water; this just makes it easier to remove the microplastics by increasing the particle size.