Real world details
If they are self propelled then good luck in magnetically retrieving them from the sea or a lake. If you can get access to them for retrieval then why not just stir the contaminated water or pump it over a sheet of GOx?
Thousands of miniature microbots could be used to clean up toxic heavy metals in contaminated water in tests purging some 95 percent of lead in an hour. The findings promise to reduce the impact of industrial spill clean up efforts by avoiding the introduction of additional contaminants, and salvaging lead for recycling. It …
"I don't know of too many Uranium-contaminated water sources,"
There are a few near mines.
More importantly, there's a shitload of uranium-contaminated sites in the middle east, thanks to the USA freely hosing targets down with DU rounds in various wars (the uranium catches fire, spreading uranium oxide everywhere, not just inside the tank that were the usual targets (the fire was what killed the crew) On top of that, with kids being kids a bombed out tank is a great playground)
Depleted uranium is effectively non-radioactive, but it's an extremely toxic environmental heavy metal so having it in the environment is a bad thing if you want civilians to lead ordinary lives.
or just plain worried - where does this H2O2 come from? It's not normally abundant in the wild, owing to its tendency to disassociate when faced with most any catalyst or just plain sunlight. Is the lead pollution to be fixed by stirring in vast quantities of a potent oxidiser? That would be shades of the "old lady who swallowed a fly"
To the person who mentioned cleaning up of oil spills, there are already various microbes being investigated by the Woods Hole Institute to do this. Crude is a natural mineral of course, and nature has a way of evolving something to take advantage of any local abundance. As an example, have a look at the sea water just off Baku (disgusting) and then start to wonder why the rest of the Caspian basin hasn't filled up with crude over years - the pollution remains very local to its source. Ok, there are no currents or tides to speak of, but the pollution spread does remain baffingly small in comparison to the output.
In relation to this article, who can tell me if the future of these microbots possibly include marine mining for precious metals, not just used for cleaning up local pools of pollution? Dump a 'bag of bots' (equivalent to the SI unit of excess, i.e. a firkin lot of the buggers) into a well-known current in the middle of the Atlantic and wait for ingots of gold to be carried ashore at your bot-base, volcano lair optional.
"In relation to this article, who can tell me if the future of these microbots possibly include marine mining for precious metals, not just used for cleaning up local pools of pollution? Dump a 'bag of bots' (equivalent to the SI unit of excess, i.e. a firkin lot of the buggers) into a well-known current in the middle of the Atlantic and wait for ingots of gold to be carried ashore at your bot-base, volcano lair optional."
Glad I'm not the only one who thought this :-)