a separation tank adapted for use in washing and separating recycled polymeric material from contaminants , the separation tank comprising a centrally disposed baffle and being adapted to receive and circulate an aqueous medium around the baffle ; transversely mounted , rotatable members adapted to submerge floating material within the aqueous medium ; transversely mounted , rotatable members adapted to aggressively agitate the surface of the aqueous medium ; and longitudinally spaced sumps disposed in the floor of the tank on the side of the baffle opposite the agitation members to collect contaminants settling out of the aqueous medium ; and members adapted to divide the aqueous medium into surface and subsurface portions for the respective recovery of the polymeric material and recirculation of the aqueous medium .