[mchannon]

It's not sulfur so much as sulfate.

It doesn't always come from mining. A huge problem with acid rock drainage (ARD) showed up when they built a freeway in Pennsylvania by merely exposing the rock.

The concept of making batteries out of drainage because both contain sulfur is like making socks out of cow manure because both contain carbon. There's so much of the latter that you could never use it all, but also the ingredient is dirt cheap in pure form.

I have a side project that could convert ARD into industrial strength sulfuric acid, which is unbelievably difficult to buy and transport, despite it being the most common industrial chemical in the world after water.

[mapt]

Acid rock drainage is currently devastating Arctic streams with the melting of pockets of permafrost, which are in effect strip mines.

https://youtu.be/Lxfpgqn6NOo?feature=shared

One of the larger sinks for waste sulfur might be stratospheric injection for geoengineering, which is looking increasingly likely.

[pfdietz]

It's sulfides like pyrite that, when exposed to air, are oxidized by bacteria to sulfate.

There's an enormous belt of pyrite in Spain that has caused a river, the Rio Tinto, to be one of the most acid rivers on the planet.

https://en.wikipedia.org/wiki/Rio_Tinto_(river)

[cyanydeez]

Yes, and it's not just "random" sulfur, it's integral to the geologic complexes that miners look for to get the minerals they want.

Think of it like the husk of a corn cob, or the cob of your corn. It's a byproduct of the very things we're looking for in mining.

The only other activity that could get hose minerals is indistinguishable from magic.

[mapt]

I'm not sure the belt of pyrite is best labelled as the cause here.

It might have something to do with the inferred activities of Rio Tinto, a transnational corporation that is one of the largest mining firms in the world.

[duskwuff]

The river was polluted millennia before the Rio Tinto company came into existence. There's been mining operations along the Rio Tinto since ca. 3000 BC.

[mapt]

Yes. Sure.

But before the mining operations? Probably not very polluted. It's the mining doing the polluting, not the belt of pyrite simply existing.

[pfdietz]

> But before the mining operations? Probably not very polluted.

From the wikipedia page:

"The discovery of multiple oxide terraces mediated by microorganisms at up to 60 metres above the current water level, and as far away as 20 kilometres from the current river's path, may suggest that the unusual ecosystem is a natural phenomenon since before human mining activities started in this region.[9]"