“In water, they removed about 94% of test polystyrene particles and 89% of PET (polyethylene terephthalate) in around an hour.”
Magnetic MXene particles spun through liquid by an external field, dragging plastic out with them. The soil numbers drop to 81 and 72 percent, and everything here happened in a lab with clean test particles. The researchers list the real problems themselves: metal ions leaching, and getting every robot back out of the dirt afterwards. Worth watching, and nowhere near a river yet.