Solvents such as paint thinner / mineral spirits, turpentine actually should be reused and not disposed.
Place the used solvent in a tightly sealed closed glass container for a period of time until the particulates settle to the bottom of the jar.
Carefully pour the clean solvent off the top and into a clean container with a tightly sealing top.
Add absorbent material such as cat litter or sawdust into the container of residual dirty solvent.
Let the residual dirty solvent dry into the absorbent and then dispose in the trash.
