| 摘要 |
<p>A method for providing dual-skinned membranes (88) useful as one-way or rectifying membranes which reduce back filtration of solute molecules in dialysis and which improve nutrient supply and product recovery in membrane bioreactors. The membranes are dual-skinned polymeric materials preferably in the form of hollow fibers. The membranes have skins (12, 14) of polymer on the opposite sides with differing permeability to solutes and sieving coefficient characteristics. The skin on each side has pores that are invisible at 10,000 times magnification. A microporous structure (16) between the skins contains pores capable of retaining solutes in a molecular weight range of about 5000 to 200,000 in an increased concentration between the interior (14) and the exterior (12) skins. Dialysis devices are formed by using bundles of the hollow fiber membranes as a dialysis member having rectifying properties. By repeatedly cycling solution back and forth across the membrane (88), the solute can be separated and concentrated on one side of the membrane (88).</p> |
