A hollow fiber membrane module for recovering or therapeutically removing blood components from blood or blood products, comprising (a) a cylindrical filter housing; (b) a bundle of essentially parallel hollow fiber membranes distributed longitudinally within the housing, wherein the open ends are in fluid communication with a distribution space and with a collection space, and wherein the ends are embedded in a sealing compound such that the open ends of the hollow fibers extend through the sealing compound, and wherein the fiber allocation in the cylindrical filter housing is between 15% and 70%, wherein the fiber allocation is calculated from the percentage of the cross section surface allocated by the fibers per utilizable cross section surface in the filter housing; (c) a filtrate space, which is closed off from the distribution space and the collection space and the lumen space of the hollow fiber membranes, the filtrate space having an inlet and outlet means (7a,9) which is closed off; (d) an inlet means for feeding the fluid into the distribution space which is in fluid communication with the lumen side of the hollow fiber membranes; (e) a first outlet means for removing the treated fluid from the housing, said first outlet means being in fluid communication with collection space; characterized in that the filtrate space is homogenously populated with a particulate material having an average diameter in the range of from 10 μm to 500 μm and being capable of interacting with at least one component of the fluid with a filling ratio of between 0.6 and 1.0, wherein the filling ratio is the volume in ml of the maximal amount of particulate material which can be accommodated in the filtrate space of a given hollow fiber membrane module (V PM) and the utilizable volume in ml of the filtrate space of said module (V FS): Filling ratio = V PM ml V FS ml., wherein V PM represents the volume of the particulate material which can be accommodated in the filtrate space of the module, and V FS represents the utilizable filtrate space, and wherein V PM is calculated from V PM ml = m PM g ρ g / ml., wherein m PM represents the amount of particulate material which can be accommodated in the filtrate space of the module and ρ represents the tapping density of the particulate material according to DIN ISO 3953. (a) a cylindrical filter housing; (b) a bundle of essentially parallel hollow fiber membranes distributed longitudinally within the housing, wherein the open ends are in fluid communication with a distribution space and with a collection space, and wherein the ends are embedded in a sealing compound such that the open ends of the hollow fibers extend through the sealing compound, and wherein the fiber allocation in the cylindrical filter housing is between 15% and 70%, wherein the fiber allocation is calculated from the percentage of the cross section surface allocated by the fibers per utilizable cross section surface in the filter housing; (c) a filtrate space, which is closed off from the distribution space and the collection space and the lumen space of the hollow fiber membranes, the filtrate space having an inlet and outlet means (7a,9) which is closed off; (d) an inlet means for feeding the fluid into the distribution space which is in fluid communication with the lumen side of the hollow fiber membranes; (e) a first outlet means for removing the treated fluid from the housing, said first outlet means being in fluid communication with collection space;