Abstract: An apparatus and method for filtering a fluid is provided. The apparatus includes a filtration unit having an inlet and hollow fiber membranes. The hollow fiber membranes are each formed from an elongated tube having an exterior surface and an interior surface. The hollow fiber membranes are configured to separate the filtration unit into a permeate side that allows permeate to exit the filtration unit through a permeate outlet and a retentate side that allows retentate to exit the filtration unit through a retentate outlet. The hollow fiber membranes include a coating linked to the exterior surface or interior surface of the hollow fiber membranes. The coating includes a poly electrolyte electrostatically coupled to the charged exterior surface or the charged interior surface.

Abstract: A tubular membrane comprises a support tube made out of one or more flexible tapes of porous support material which have been helically wound into a tube shape with overlapping tape edges which have been sealed to each other, and a semi-permeable membrane layer made of membrane forming material on an inner wall of the support tube. At least one inwardly projecting helical ridge is provided on said inner wall of the support tube, which helical ridge is covered with or forms part of the membrane layer.

Abstract: A tubular membrane comprises a support tube made out of one or more flexible tapes of porous support material which have been helically wound into a tube shape with overlapping tape edges which have been sealed to each other, and a semi-permeable membrane layer made of membrane forming material on an inner wall of the support tube. At least one inwardly projecting helical ridge is provided on said inner wall of the support tube, which helical ridge is covered with or forms part of the membrane layer.

Abstract: A tubular membrane includes a support tube made out of one or more flexible tapes of porous support material which have been helically wound into a tube shape with overlapping tape edges which have been sealed to each other, and a semi-permeable membrane layer made of membrane forming material on an inner wall of the support tube. At least one inwardly projecting helical ridge is provided on the inner wall of the support tube, which helical ridge is covered with or forms part of the membrane layer.

Abstract: A tubular membrane includes a support tube made out of one or more flexible tapes of porous support material which have been helically wound into a tube shape with overlapping tape edges which have been sealed to each other, and a semi-permeable membrane layer made of membrane forming material on an inner wall of the support tube. At least one inwardly projecting helical ridge is provided on the inner wall of the support tube, which helical ridge is covered with or forms part of the membrane layer.