First of all, thanks for the great idea and for getting the implementation started.
Perhaps the following ideas would be fairly easy to implement and could be included in a future update.
To start with, I think it might be worth considering having the recyclables and regular waste come out in a compacted form.
I took a look at the statistics for waste processing in Germany and think the breakdown could perhaps look like this:
15% Plastic
15% Biomass
30% Remains as regular waste
35% Recyclables
5% Sludge (possibly toxic)
That way, your mod would be even more meaningful and realistic.