Abstract: A two-stage filter enclosed within a single vessel is provided. The two-stage filter is provided in the form of the vessel having a first filtration stage configured to capture particles of a first size, and a second filtration stage downstream of the first filtration stage and in fluid communication with the first filtration stage configured to capture particles of a second size, wherein the first size is larger than the second size. The first filtration stage may comprise a porous media. The second filtration stage may comprise one or more membrane filters.

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.