Abstract: An apparatus for the recovery of liquid from a liquid medium containing solids includes a rotatable outer drum having a liquid-permeable drum wall and containing liquid-absorbing material, a rotatable inner wall having a liquid impervious drum wall and being mounted for rotation within and eccentrically relative to the outer drum, the drums being rotatable in the same direction into the liquid medium so as to transport the material through a compression zone in which the material is compressed so as to remove absorbed liquid therefrom and subsequently through a pressure-relief zone in which the liquid-absorbing material is allowed to expand and to absorb liquid from the liquid medium, a device or devices contacting the exterior surface of the outer drum to remove solids deposited thereon, such devices being located between the zones, and a device for collecting liquid removed from the liquid-absorbing material in the compression zone.