[carterehsmith]

So, I wonder about these cardboard/paper containers that e.g. juice, milk, etc are being sold in. Are they biodegradable?

[nikanj]

Nope, they have a plastic lining on the inside to make them waterproof.

[nitemice]

Same is true of coffee cups, although there are a number of organizations (in Aus, at least) now that have processes for separating the plastic from the paper so it can be recycled.

E.g. https://www.simplycups.com.au/how-it-works