Theoritically some filaments are recyclable, and the main one (PLA) is even advertised as biodegradable. However in practice this is not the case, both for mate

Theoritically some filaments are recyclable, and the main one (PLA) is even advertised as biodegradable. However in practice this is not the case, both for material reasons (PLA needs actually to be processed to decompose) and logistic reasons (there is no recycling center for 3d prints and you'll need to print only a single filament type)