A screw-centrifugal pump (1) comprises a pump housing (3) having an inlet opening (3c) and also an impeller (2) arranged within the pump housing (3) and rotatable about an axis of rotation (2d) in a direction of rotation (4a). The impeller (2) has a spirally extending blade entry edge (2a) and a guide vane (5) projects into the interior space of the impeller (2) and is disposed in the region of the inlet opening (3c). A method of conveying a liquid permeated with solid additions using such a pump is also described and claimed.