BACKWASHABLE FILTRATION ELEMENT

A planar filtration element includes a planar support structure (11) and at least one filtration layer (12, 13) made of a membrane material. The planar support structure has first and second opposite outer surfaces (111, 112) spaced apart and secured by spacing members (113) to define a drainage compartment (114) between the first and second outer surfaces. At least one of the first and second outer surfaces includes through-openings (115) for fluid connection with the drainage compartment (114), and wherein the outer surfaces (111, 112), when one disregards the through-openings, are formed of a material extending continuously throughout the outer surfaces. The filtration layer (12, 13) coats the outer surface such that the membrane material penetrates the through-openings (115) to anchor the filtration layer (12, 13) to the support structure (11).