The present disclosure relates to a vacuum filter that incorporates a large area pleated filter element having pleated hydrophilic membrane configured along slanting surface in pyramid shape and incorporated with in a filter housing that can be accommodated in neck of a filtrate container. The disclosed configuration reduces overall height of the filtering system improving its stability and reducing space requirement. Further, top portion of the filter housing is configured to receive either a feed cup for direct feeding of feed liquid by pouring in the cup or a fitting with tube that can be used to suck the feed from a feed solution container under action of a vacuum thus allowing universal use. In another embodiment, a single hydrophobic membrane is provided to avoid problems of low flow due to bubbles coming with the feed solution and also to allow restart of filtration without air lock.

A cross-flow membrane filtration channel for filtration of a liquid feed comprising particulate foulants includes an inlet and an outlet, and at least one liquid-permeable membrane configured for filtration of the particulate foulants in the liquid feed based on size of the particulate foulants and for filtered liquid permeate to pass through the at least one liquid-permeable membrane where the channel is defined by the at least one liquid-permeable membrane.

A spiral wound membrane module adapted for hyperfiltration and including at least one membrane envelope and feed spacer sheet wound about a central permeate tube to form an inlet and outlet scroll face and an outer periphery, wherein the feed spacer sheet includes: i) a feed entrance section extending along the permeate collection tube from the inlet scroll face toward the outlet scroll face, ii) a feed exit section extending along the outer periphery from the outlet scroll face toward the inlet scroll face, and iii) a central feed section located between the feed entrance section and the feed exit section; and wherein the feed entrance section has a median resistance to flow in a direction parallel to the permeate collection tube that is less than 25% of the median resistance to flow of the central feed section in a direction perpendicular to the permeate collection tube.