Abstract: A method of filtering a feed liquid in a membrane filtration assembly is provided comprising introducing feed liquid to be treated into a filtration chamber of a membrane filtration system including a membrane module having one or more permeable hollow membranes, the module being located in the filtration chamber, and the filtration chamber having an open upper end located above an upper header of the membrane module and a closed lower end, and feed tank surrounding the filtration chamber. The feed tank may be configured to provide the feed liquid through the open upper end of the filtration chamber, and the feed liquid may be applied to the surface of the membranes within the membrane module and withdrawn from the lumens of the membranes as filtrate.

Abstract: A method of filtering a feed liquid in a membrane filtration assembly is provided comprising introducing feed liquid to be treated into a filtration chamber of a membrane filtration system including a membrane module having one or more permeable hollow membranes, the module being located in the filtration chamber, and the filtration chamber having an open upper end located above an upper header of the membrane module and a closed lower end, and feed tank surrounding the filtration chamber. The feed tank may be configured to provide the feed liquid through the open upper end of the filtration chamber, and the feed liquid may be applied to the surface of the membranes within the membrane module and withdrawn from the lumens of the membranes as filtrate.

Abstract: A membrane filtration assembly (10) including having a filtrate carrier (9) for minimizing backwash. The membrane filtration assembly includes a membrane module (5) having one or more permeable hollow membranes (6) supported therein by an upper header (7) and a lower header (8). The filtrate carrier (9) extends between the upper (7) and lower (8) headers to allow filtrate to be collected from either or both ends of membranes (6). A filtrate collection chamber (18) is associated with the upper (7) and lower headers (9) and in fluid communication with lumens of the membranes (6) for collecting filtrate withdrawn through said membrane lumens. A filtration chamber (11) is provided for receiving feed liquid to be applied to the surface of membranes (6) within the module (5). The filtration chamber (11) includes an open end for receiving the feed liquid. The open end is located beyond the height of the module (5) to enable gravity feed.

Abstract: An aeration/backwash device (16) for use with a porous membrane filtration module (5) including one or more membranes (6) extending longitudinally between vertically spaced upper (7) and lower headers (8) into which the ends of the membranes are potted. The membranes (6) having a permeable wall which, in use, is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. The aeration/backwash device (16) adapted to at least partially surround a portion of said membrane module (5) and including a communication chamber (17) having spaced through-openings (18, 19) in fluid communication with the chamber (17) and the membrane module (5).

Abstract: A method of cleaning permeable, hollow membranes in an arrangement of the type wherein a pressure differential is applied across the walls of the permeable, hollow membranes immersed in a liquid suspension, the liquid suspension being applied to the outer surface of the porous hollow membrane to induce and sustain filtration through the membrane walls. The method of cleaning comprises the steps of applying a cleaning solution to one side of the membrane wall; applying a pressure differential across the membrane wall to cause flow of the cleaning solution through the wall from the one side of the membrane wall to the other side of the membrane wall and applying a reverse pressure differential across the membrane wall to cause flow of the cleaning solution through the wall from the other side of the membrane wall back to the one side of the membrane wall.

Abstract: A method of operating a membrane filtration module, the module including one or more membranes extending longitudinally between vertically spaced upper and lower headers into which the ends of the membranes are potted. The membranes have a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. At least one of the upper and/or lower headers has one or more openings therein and the method including flowing the feed, at least in part, through the one or more openings for application to the membrane wall. Apparatus for performing the method is also disclosed.

Abstract: A method of operating a membrane filtration module (5), the module (5) including one or more membranes (7) extending longitudinally between vertically spaced upper and lower headers (8, 9) into which the ends of the membranes (7) are potted. The membranes (7) have a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. At least one of the upper and/or lower headers (8, 9) has one or more openings (10) therein and the method including flowing the feed, at least in part, through the one or more openings (10) for application to the membrane wall. Apparatus for performing the method is also disclosed.

Abstract: A method of cleaning permeable, hollow membranes is disclosed. In one embodiment, the membranes are immersed in a liquid suspension. A pressure differential is applied across the walls of the membranes. During filtration, liquid suspension passes through the walls of the membranes to be drawn off as permeate, and at least some solids are retained on or in the membranes. The steps of cleaning include: applying a cleaning solution to one side of the membrane walls; applying a pressure differential across the membrane walls to cause flow of the cleaning solution through the walls from the one side of the membrane walls to the other side of the membrane walls; and, applying a reverse pressure differential across the membrane walls to cause flow of the cleaning solution through the wall from the other side of the membrane walls back to the one side of the membrane walls.

Abstract: A method of controlling fouling in a membrane filtration system (5) of the type where gas is used to clean or scour the membranes (6) wherein the method includes supplying the gas to the system with a continuously variable flow rate. A continuously variable valve arrangement (17) is also disclosed.

Abstract: A method of backwashing a membrane filtration module (4), said module (4) including one or more membranes (5) located in a feed-containing vessel (3), the membranes (5) having a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall, the method including: removing liquid from the feed-containing vessel (3) until the level of liquid in the feed-containing vessel (3) falls to a first level (L2) below an upper level of the membranes; suspending the filtration operation; performing a liquid backwash of the membrane wall until liquid level within the feed-containing vessel (3) rises to a second predetermined level (L1) above said first level; aerating the membrane surface with gas bubbles to dislodge fouling materials therefrom; performing a sweep or drain down of the feed-containing vessel (3) to remove the liquid containing the dislodged contaminant matter

Abstract: A method and apparatus for reducing the effect of integrity loss in a hollow fiber membrane module, said module including a plurality of hollow fiber membranes (5), at least one end of the fiber membranes (5) being supported in a pot (6), the method including the step of increasing flow resistance of the liquid through the lumen (8) of the fiber membrane (5) in the region of the pot (6).

Abstract: A filtration arrangement including one or more membrane modules (5) positioned vertically within a feed tank (6), each membrane module (5) having one or more membranes positioned therein. An aeration hood (10) having an upper wall (11) and one or more downwardly extending side walls (12, 13) is configured to at least partially shroud the membrane modules (5) within the tank (6). The aeration hood (10) includes a number of open-ended tubes (14), each extending downwardly from the upper wall (11) and forming a respective opening (15) therein. Each tube (14) is adapted to have at least one of the modules (5) mounted therein and extending through the respective openings (15) in the upper wall (11) so as to at least partially surround an outer periphery of an associated module or modules (5). One or more aeration openings (17) are provided in each tube (14) at a location spaced from a proximal end of the tube (16).

Abstract: A membrane module (3) comprising a plurality of porous hollow membranes (8). The membranes (8) extend between and are fixed at each end in a header (5, 6). One header (6) has one or more of openings (12) formed therein. The openings (12) are in fluid communication with a source of gas and/or liquid (13, 14, 15). The other of the headers (5) is sealingly connected to and in fluid communication with a head-piece (9). The head-piece (9) is adapted to couple to an associated head-piece of a further module to form a rack of modules (17). A potting head (6) for use in mounting porous hollow membranes (8) is also disclosed comprising a preformed potting element (29). The potting element (29) includes one or more cavities (30) for receiving curate potting material which, in use, supports said membranes (8).

Abstract: Described herein are methods and systems for combination membrane/biolytic filtration. In one embodiment a filtration system is operated under suction. The arrangement includes a feed tan (5) having a smaller filtrate vessel (6) positioned therein. The region within, the feed tank (5) not occupied by the filtrate vessel (6) is partially filled with layers of decomposing and decomposed solid organic waste material to form an aerobic filter bed (7) of the type used in biolytic filtration as described above. A further module vessel (8) is mounted within the filtrate vessel (6) to form a membrane chamber (9) containing a membrane filtration module (10).

Abstract: A filtration system for removing fine solids from a liquid suspension comprising a vessel for containing the liquid suspension, one or more permeable, membranes (9) within the vessel, means for providing a pressure differential across walls of the membranes (9) such that some of the liquid suspension passes through the walls of the membranes (9) to be drawn off as permeate and means for withdrawing the permeate from the membranes. A screen (8) is positioned in a flow path of the liquid suspension through to the membrane walls.

Abstract: A method of concentrating the solids of a liquid suspension by providing pressure differential across the walls of permable hollow membranes (6) immersed in the liquid suspension (9). The liquid suspension (9) is applied to the outer surface of the porous hollow membranes (6) to induce and sustain filtration through the membrane walls (12) wherein some of the liquid suspension passes through the walls (12) of the membranes (6) to be drawn off as clarified liquid or permeate from the hollow membranes lumens (11), and at least some of the solids are retained on or in the hollow membranes (6) or otherwise as suspended solids within the liquid (9) surrounding the membranes (6).

Abstract: A membrane filtration system (5) including: a feed containing vessel (7); a membrane module (6) including one or more hollow permeable membranes (8) for filtering feed liquid, located in the feed containing vessel (7); means for applying a pressure differential across walls of the membranes (8) to induce filtration therethrough; a feed liquid reservoir (9) in fluid communication with the membrane module (6) to supply feed liquid thereto; a source of feed liquid (12); a source of gas (10) and means (11) for selectively producing a flow of gas from the gas source (10) and feed liquid from the feed liquid source (12) through the membrane module (6) and into the feed liquid reservoir (9). The flow of gas producing gas bubbles within the feed liquid to clean the membranes (8).

Abstract: An aeration/backwash device (16) for use with a porous membrane filtration module (5) including one or more membranes (6) extending longitudinally between vertically spaced upper (7) and lower headers (8) into which the ends of the membranes are potted. The membranes (6) having a permeable wall which, in use, is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. The aeration/backwash device (16) adapted to at least partially surround a portion of said membrane module (5) and including a communication chamber (17) having spaced through-openings (18, 19) in fluid communication with the chamber (17) and the membrane module (5).

Abstract: Described herein are methods and systems for combination membrane/biolytic filtration. In one embodiment a filtration system is operated under suction. The arrangement includes a feed tan (5) having a smaller filtrate vessel (6) positioned therein. The region within, the feed tank (5) not occupied by the filtrate vessel (6) is partially filled with layers of decomposing and decomposed solid organic waste material to form an aerobic filter bed (7) of the type used in biolytic filtration as described above. A further module vessel (8) is mounted within the filtrate vessel (6) to form a membrane chamber (9) containing a membrane filtration module (10).

Abstract: A method of backwashing a membrane filtration module, where the module includes one or more membranes located in a feed-containing vessel. The membranes having a permeable wall which is subjected to a filtration operation wherein feed liquid containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. The method includes the steps of suspending the filtration operation; aerating the membrane surface with gas bubbles to dislodge fouling materials therefrom; recommencing the filtration operation while suspending the flow of feed liquid to the feed-containing vessel for a predetermined period; again suspending the filtration operation; performing a liquid backwash of the membrane wall to dislodge fouling materials therefrom; removing at least some of the liquid containing the dislodged contaminant matter from the feed-containing vessel; and then recommencing the filtration operation.