Submarines restock food, some air supplies, and... deal with waste. Food https://youtu.be/bPJUVKizh90 https://youtu.be/bPJUVKizh90 Air https://youtu.be/g3Ud6m

Submarines restock food, some air supplies, and... deal with waste. Food https://youtu.be/bPJUVKizh90 https://youtu.be/bPJUVKizh90 Air https://youtu.be/g3Ud6mHdhlQ https://youtu.be/g3Ud6mHdhlQ (MEA and LIOH for CO2, electrolysis and "candles" for oxygen) Toilet https://youtu.be/SYFuA3xnkUE?t=985 https://youtu.be/SYFuA3xnkUE?t=985 Nothing is "recycled" as such - and certainly not any of the carbon (you're not eating the carbon captured from MEA or LIOH... or your waste).