Abstract: A device for the separation and transport of material from polluted medium, for example waste water, comprises a grate (5) mounted in a support structure (1). The grate is composed of a series of stable rods (3) and adjustable rods (4), where the stable and adjustable rods are respectively joined and form a unit. Said unit is disposed in the grate (5). The grate (5) is provided with or without three wave-shaped shelves (6, 7, 8). One shelf (6) is disposed at the bottom of the device just below the surface of the medium, and the other two shelves (7, 8) are disposed at the top of the device, with the shelf (7) being mounted at about the surface of the medium. The edges of the rods (3, 4) having the shelves are turned against the direction of flow of the medium. The adjustable rod unit (4) is disposed so as to be driven up and down by a piston (8'). The piston (8') is suspended on a rail (10) mounted in the support structure (1). The movement proper is being performed by a wheel (15).