A method of reducing the sorbate concentration of a process fluid stream using a sorption bed system includes the following steps. A mass of a sorbent material is rotated so that, in a cycle of operation, a given volume of the sorbent mass sequentially passes through first, second, third, fourth, fifth, and sixth zones, before returning to the first zone. A process fluid stream is passed through the sorbent mass in the first zone, and a regeneration fluid stream is passed through the sorbent mass in the fourth zone. A first isolation fluid stream is recycled in a closed loop, independent of the process fluid stream and the regeneration fluid stream, between the sorbent mass in the second zone and in the sixth zone. A second isolation fluid stream, meanwhile, is recycled in a closed loop, independent of the process fluid stream, the regeneration fluid stream, and the first isolation fluid stream, between the sorbent mass in the third zone and in the fifth zone.