Abstract: The present invention provides: a porous fiber that exhibits both improved adsorption capacity, and suppressed exposure and detachment of particulates; an adsorption column filled with said porous fiber; and a blood purification system in which an adsorption column is connected to a water removal column. The porous fiber according to the present invention has a three-dimensional pore structure formed by a solid fiber, and satisfies all of the following conditions. (1) The porous fiber has particulates having a diameter of not more than 200 ?m, and the percentage of area occupied by said particulates having a diameter of not more than 200 ?m in a horizontal cross section of the three-dimensional pore structure is at least 3.0%. (2) The porous fiber does not contain said particulates having a diameter of not more than 200 ?m in the region within 1.0 ?m in the depth direction from the outermost surface.

Abstract: The present invention provides: a porous fiber that exhibits both improved adsorption capacity, and suppressed exposure and detachment of particulates; an adsorption column filled with said porous fiber; and a blood purification system in which an adsorption column is connected to a water removal column. The porous fiber according to the present invention has a three-dimensional pore structure formed by a solid fiber, and satisfies all of the following conditions. (1) The porous fiber has particulates having a diameter of not more than 200 ?m, and the percentage of area occupied by said particulates having a diameter of not more than 200 ?m in a horizontal cross section of the three-dimensional pore structure is at least 3.0%. (2) The porous fiber does not contain said particulates having a diameter of not more than 200 ?m in the region within 1.0 ?m in the depth direction from the outermost surface.

Abstract: A phosphorus adsorbent, which is used for adsorbing phosphorus in extracorporeal circulation, is a powder comprising a carbonate of a rare earth metal or an oxide of a Group 4 element and having a solubility in 100 g of water at 20° C. of 10 mg or less. The porous fiber, which comprises the phosphorus adsorbent carried therein, shows a change in pH value of from ?1.0 to +1.0 inclusive before and after stirring in physiological saline for 4 hours. The phosphorus adsorption columns respectively comprise the phosphorus adsorbent and the porous fiber each disposed therein.