My 'cold' interpretation in a strict sense is that recovery would be from additions and removal from existing levels. However, I'm a native English speaker and many are not, so in practice they may be equivalents.

In the context of wastewater nutrients, removal and recovery refer to the same thing. "Recovery" just indicates that the obtained struvite is precious enough not to be disposed of. Instead it can be used as a fertilizer.

You recover nutrients for reuse and you remove for disposal.

Recuperarea nutrienţilor se face pentru a putea fi utilizaţi ulterior în diferite domenii.

Eliminarea nutrienţilor se face pentru a-i îndepărta definitiv din probă.