Abstract: System includes a closed housing having a plurality of rectangularly configured beds with perforate sidewalls longitudinally disposed in housing in laterally spaced disposition with each other. Alternate spaces at inlet end are closed and alternate spaces opposite the open ends are closed at exit end whereby contaminated gas is laterally squeezed through the beds filled with particulate adsorbent. The lower portions of the beds funnel into longitudinally extending discharge chutes enclosed within respective wells, the lower edges of the chutes rising at a constant angle above the well floor. An evacuation system coupled to the wells suctions the pile of particulate from the most remote portion of the chutes first.