METHOD OF FILTRATION AND BACKWASHING USING HOLLOW FIBRE MEMBRANE ELEMENTS

摘要

A method of operating a filtration unit comprising a filtration vessel containing at least one dead-end filtration element, the or each filtration element comprised of a plurality of hollow fibre microfiltration or ultrafiltration membranes wherein: during filtration, feed water containing suspended particulate material is fed simultaneously to the inside of the hollow fibres through both ends thereof and filtrate is removed from the outside of the hollow fibres through an outlet of the filtration element(s); and during back-washing, back-wash water is fed to outside of the hollow fibres through the outlet of the filtration element(s) and, in a first back-wash cycle, back-wash water containing entrained particulate material is discharged from the inside of the hollow fibres from one end thereof; and, in a second back-wash cycle, back-wash water containing entrained particulate material is discharged from the inside of the hollow fibres from the other end thereof; and wherein the first and second back-wash cycles may be performed in either order.