Abstract: A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for use with a commercial membrane module can comprise a plurality of smaller units.

Abstract: A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for use with a commercial membrane module can comprise a plurality of smaller units.

Abstract: A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for use with a commercial membrane module can comprise a plurality of smaller units.

Abstract: A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for use with a commercial membrane module can comprise a plurality of smaller units.

Abstract: A gas sparger for a filtering membrane system produces an intermittent flow of bubbles even if provided with a relatively continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for can comprise a plurality of smaller units or areas. The supply of gas to the sparger may vary in flow rate over larger periods of time in response to changes in conditions in the membrane system to change the time between consecutive bursts of bubbles. A gas supply pipe may have two or more outlets at different elevations in communication with each of two or more units or areas.

Abstract: A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for use with a commercial membrane module can comprise a plurality of smaller units.

Abstract: A membrane filtration device has a multiplicity of hollow fiber membranes, or fibers, unconfined in a shell of a module; a first header and a second header disposed in vertically spaced-apart relationship; said first header and said second header having opposed ends of each fiber sealingly secured therein, all open ends of said fibers open to a permeate-discharging face of at least one header; permeate collection means to collect said permeate, sealingly connected in open fluid communication with a permeate-discharging face of at least one of said headers; means to withdraw said permeate; said fibers, said headers and said permeate collection means together forming an integrated combination wherein said fibers are essentially vertically disposed and ends of individual fibers are potted in closely spaced-apart relationship in cured resin; with opposed faces at a fixed distance; each of said fibers having a length from 0.1% to less than 5% greater.

Abstract: A gas sparger for a filtering membrane system produces an intermittent flow of bubbles even if provided with a relatively continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for can comprise a plurality of smaller units or areas. The supply of gas to the sparger may vary in flow rate over larger periods of time in response to changes in conditions in the membrane system to change the time between consecutive bursts of bubbles. A gas supply pipe may have two or more outlets at different elevations in communication with each of two or more units or areas. The discharge of gas between two or more units or areas may be synchronized. One or more of a set of units or area may receive a supplied gas at a higher flow rate.

Abstract: A gas sparger produces an intermittent flow of bubbles even if provided with a continuous gas flow. The sparger has a housing to collect a pocket of gas and a conduit to release some of the gas from the pocket when the pocket reaches a sufficient size. Optionally, a cover over an outlet from the conduit may break up or distribute the released gas. A large sparger for use with a commercial membrane module can comprise a plurality of smaller units.

Abstract: A membrane filtration device has a multiplicity of hollow fiber membranes, or fibers, unconfined in a shell of a module; a first header and a second header disposed in vertically spaced-apart relationship; said first header and said second header having opposed ends of each fiber sealingly secured therein, all open ends of said fibers open to a permeate-discharging face of at least one header; permeate collection means to collect said permeate, sealingly connected in open fluid communication with a permeate-discharging face of at least one of said headers; means to withdraw said permeate; said fibers, said headers and said permeate collection means together forming an integrated combination wherein said fibers are essentially vertically disposed and ends of individual fibers are potted in closely spaced-apart relationship in cured resin; with opposed faces at a fixed distance; each of said fibers having a length from 0.1% to less than 5% greater.

Abstract: A hollow gas transfer fiber is arranged in tows and potted into a module. The module may be used to treat wastewater by supplying hydrogen containing gas via the interior of the fibers to a biofilm present on an exterior surface of the fibers.

Abstract: A membrane supported biofilm reactor uses modules having fine, hollow fibers, for example, made from melt spun thermoplastic polymers treated after spinning to increase their permeability to oxygen, used, for example, in tows or formed into a fabric. In one module, one or more sheets of the fabric are potted into a module to enable oxygen containing gas to be supplied to the lumens of the hollow fibers. Various reactors and processes, for example to treat wastewater, using such modules are described. In one process, oxygen travels through fibers, optionally through an attached biofilm, to oxygenate surrounding water. Mechanical, chemical and biological methods, for example endogenous respiration, are used to control the thickness of the biofilm.

Abstract: A process is described for withdrawing filtered permeate from a non-pressurized substrate in a reservoir through an assembly. The assembly has a plurality of hollow fiber filtering membranes disposed generally vertically between two solid bodies, an enclosure sealed to the upper solid body to define a cavity, a permeate port in communication with the cavity and the lumen of each membrane in fluid communication with the port via the cavity. A suction is applied to lumens of the membranes via the permeate port to withdraw permeate. A gas is directed to provide bubbles which contact the membranes. Feed water is added so that the membranes are immersed while applying the suction.

Abstract: A membrane filtration device has a multiplicity of hollow fiber membranes, or fibers, unconfined in a shell of a module; a first header and a second header disposed in vertically spaced-apart relationship; said first header and said second header having opposed ends of each fiber sealingly secured therein, all open ends of said fibers open to a permeate-discharging face of at least one header; permeate collection means to collect said permeate, sealingly connected in open fluid communication with a permeate-discharging face of at least one of said headers; means to withdraw said permeate; said fibers, said headers and said permeate collection means together forming an integrated combination wherein said fibers are essentially vertically disposed and ends of individual fibers are potted in closely spaced-apart relationship in cured resin; with opposed faces at a fixed distance; each of said fibers having a length from 0.1% to less than 5% greater.

Abstract: A process is described for withdrawing filtered permeate from a non-pressurized substrate in a reservoir through an assembly. The assembly has a plurality of hollow fiber filtering membranes disposed generally vertically between two solid bodies, an enclosure sealed to the upper solid body to define a cavity, a permeate port in communication with the cavity and the lumen of each membrane in fluid communication with the port via the cavity. A suction is applied to lumens of the membranes via the permeate port to withdraw permeate. A gas is directed to provide bubbles which contact the membranes. Feed water is added so that the membranes are immersed while applying the suction.

Abstract: A hollow gas transfer fibre is arranged in tows and potted into a module. The module may be used to treat wastewater by supplying hydrogen containing gas via the interior of the fibers to a biofilm present on an exterior surface of the fibers.

Abstract: A continuous flow reactor or method promotes aerobic granule formation. The reactor may comprise three or four zones that may comprise one or more of an aerobic zone, an alternately aerobic and anoxic zone or discrete aerobic and anoxic zones, and a settling zone. The reactor may have a single sludge removal flow. An anaerobic zone may be located at the bottom of a mass of settled granules. Feed may be introduced through the settled granules generally in a plug flow. An aerobic/anoxic zone may be structured or operated partially like a continuously stirred tank reactor (CSTR) but with aeration varying in space or time. Sludge granules may move intermittently from an aerobic zone to an aerobic/anoxic zone, for example by an air lift pump. A settling zone may have an upflow of >4 m/hr or >5 m/hr and wash off flocculated biomass.

Abstract: A membrane supported biofilm reactor uses modules having fine, hollow fibres, for example, made from melt spun thermoplastic polymers treated after spinning to increase their permeability to oxygen, used, for example, in tows or formed into a fabric. In one module, one or more sheets of the fabric are potted into a module to enable oxygen containing gas to be supplied to the lumens of the hollow fibres. Various reactors and processes, for example to treat wastewater, using such modules are described. In one process, oxygen travels through fibers, optionally through an attached biofilm, to oxygenate surrounding water. Mechanical, chemical and biological methods, for example endogenous respiration, are used to control the thickness of the biofilm.

Abstract: A membrane filtration device has a multiplicity of hollow fiber membranes, or fibers, unconfined in a shell of a module; a first header and a second header disposed in vertically spaced-apart relationship; said first header and said second header having opposed ends of each fiber sealingly secured therein, all open ends of said fibers open to a permeate-discharging face of at least one header; permeate collection means to collect said permeate, sealingly connected in open fluid communication with a permeate-discharging face of at least one of said headers; means to withdraw said permeate; said fibers, said headers and said permeate collection means together forming an integrated combination wherein said fibers are essentially vertically disposed and ends of individual fibers are potted in closely spaced-apart relationship in cured resin; with opposed faces at a fixed distance; each of said fibers having a length from 0.1% to less than 5% greater.

Abstract: A gas-scrubbed vertical cylindrical skein of “fibers” has their opposed terminal portions held in headers unconfined in a modular shell, and aerated with a cleansing gas supplied by a gas-distribution means which produces a mass of bubbles serving the function of a scrub-brush for the outer surfaces of the fibers. The skein is surprisingly effective with relatively little cleansing gas, the specific flux through the membranes reaching an essentially constant relatively high value because the vertical deployment of fibers allows bubbles to rise upwards along the outer surfaces of the fibers. The effectiveness is critically dependent upon the length of each fiber in the skein. That length is in the range from at least 0.1% more than the fixed distance between opposed faces of the skein's headers, but less than 5% greater than the fixed distance.