scavenge

To collect (useful items) by searching through refuse.

To search through (a place or container) for useful items.

To feed on (dead or decaying matter). Used especially of animals.

To expel (exhaust gases) from a cylinder of an internal-combustion engine.

To expel exhaust gases from (such a cylinder).

To clean (molten metal) by chemically removing impurities.

To remove or inactivate (harmful chemicals or impurities) in a mixture.