The seeds have natural coagulants that clump particles enough to be mechanically filtered / settled.

I wonder what happens to the resulting sludge with concentrated plastics? That’s an issue with bioremediation for lead in soils. The plant materials needs to be removed from the site order to make any difference. If we’re currently using alum in the same way, there must be a strategy for cleaning it or disposing of it safely.

Sounds like this might not be a scalable solution, but great for diy setups and rural communities without access to industrial options.