[MarianaM (OP)]

Paul asks...

Could we have S-bends in every ship funnel so the exhaust can be passed through a chemical wash to clean out the sulphur and nitrogen and other particulates? And at the next port the wash can be offloaded.

What do you think?

[alancalverd]

And then what do you do with the toxic waste? Pour it into the river and poison the shellfish? Bury it underground and poison the drinking water? "The next port" could be your home!

[chiralSPO]

Waste can be remediated, alancalverd... but you're right that it probably won't be. Possibly better to use fuel cells and electric motors.

[chiralSPO]

I have split Hayseed's question off into a new topic, which can be found here: https://www.thenakedscientists.com/forum/index.php?topic=77831.0

[evan_au]

The worst offenders are the low-cost container ships, which use the cheapest fuel available - bunker fuel (which is more like thick tar). It contains a lot of sulphur, so it produces a lot of sulphur dioxide.

Some cities/ports have banned the use of this fuel within a certain radius of the port,so they have to switch to a cleaner (and more expensive) fuel as they approach port.

Modern passenger liners use diesel-electric propulsion, so they can use similar techniques to diesel trucks to reduce particle emissions, largely due to incomplete combustion, leaving carbon dust particles.

See: https://en.wikipedia.org/wiki/Fuel_oil#Bunker_fuel

[Bored chemist]

And then what do you do with the toxic waste? Pour it into the river and poison the shellfish? Bury it underground and poison the drinking water? "The next port" could be your home!

Well, they typically use it to make plasterboard.