All it requires is a large enough mass (with directional ability) to travel in the near vicinity of the most dangerous objects, pull them into 'orbit' (or take on board) , then process/dismantle and send downwards to burn up.
Apart from the precious metal retrieval, and hazardous material separation, current technology wont allow for recycling of the majority of materials, but in the future it should be possible to 'print' parts from detritus autonomously, creating useful stuff that has already had the expense of earlier launch costs.
Not forgetting the much earlier series, Salvage 1
Hints of fracking there
(but possibly forgetting Quark, though it did win an award for costumes)