摘要:
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.
摘要:
Hollow fiber membranes are potted by injection molding a thermoplastic material into a cavity containing the fibers. The cavity is formed in part by the interaction of a mold and a layer of an adhesive pre-applied to a bundle of the membranes.
摘要:
In a header (17), or potting head, of a membrane module, each of a plurality of hollow fiber membranes (10) has at least one open end (12) collected together into a group wherein the membranes are surrounded by a solidified adhesive (100) near the ends of the membranes, the open ends of the membranes extend beyond a first side of the solidified adhesive, and a bond between the solidified adhesive and the membranes is less strong than all of the materials in the membrane and any and all bonds between materials in the membranes. A solidified fixing liquid (14) around the membranes extends from the solidified adhesive (100) to a point at or near the ends (12) of the membranes. The solidified fixing liquid (14) : surrounds each membrane (10) for at least a portion of its length in the solidified fixing liquid between the solidified adhesive (100) and the end (12) of each membrane; sealingly connects to the outside of each membrane; does not block the open ends (12) of the membranes; and does not contact the membranes on a second side of the solidified adhesive. A header pan (18) is secured to the solidified fixing liquid (14) in a position where the open ends (12) of the membranes (10) are in fluid communication with a permeate channel in the header pan. The solidified fixing liquid (14) extends to and is secured directly in the header pan (18) and separates the solidified adhesive (100) from the header pan (18).
摘要:
An apparatus to transfer gas to or from a liquid has a flexible and oxygen permeable but liquid water impermeable membrane, a flexible and gas permeable spacer, an inlet conduit, an outlet conduit and a non-rigid restraint system. When used for treating wastewater, an aerobic biofilm is cultured adjacent the planar elements, an anoxic biofilm is cultivated adjacent the aerobic biofilm and the wastewater is maintained in an anaerobic state. A first reactor for treating wastewater has an anaerobic section, a plurality of gas transfer membrane modules, and an aerobic section. A biofilm is cultivated on the surface of the gas transfer membranes in fluid communication with the anaerobic section. Biological reduction of COD, BOD, nitrogen and phosphorous are achieved. In a second reactor, phosphorous is also removed chemically in a precipitation branch.
摘要:
A system for withdrawing permeate from a multicomponent liquid substrate includes a reservoir for containing substrate at substantially ambient pressure and one or more membrane assemblies, or skeins, each having, a first header and a second header disposed in vertically spaced-apart relationship with opposed proximal faces at a selected distance and a multiplicity of hollow fiber filtration membranes, or fibers, having end portions sealingly secured to the headers. All open ends of the fibers open to a permeate-discharging face of at least one header, the fibers being disposed essentially vertically, each of the fibers having a length between the opposed proximal faces of the headers, the exterior of the fibers along their lengths in fluid communication with the substrate. Permeate collection means, sealingly connected to any permeate-discharging face of the headers are in fluid communication with open ends of the fibers. A source of suction in fluid communication with the permeate collection means is operable to apply sufficient suction to withdraw permeate through the fibers. The length of the fibers is less than 5% greater than the selected distance and permits restricted displacement of an intermediate portion of each fiber. An embodiment includes gas distribution outlets for discharging bubbles, disposed between the fibers. In another embodiment, the headers of the skeins are elongated, having a short and a long dimension perpendicular to the fibers, and contain no more than 30 fibers across the short dimension, the gas distribution outlets being disposed in a row parallel to the long dimension of the headers.
摘要:
A filtering element has ultrafiltration or microfiltration hollow fiber membranes extending horizontally between a pair of opposed horizontally spaced, vertically extending headers. Side plates extending between the pair of vertically extending headers define a vertical flow channel through the element. Modules are created by placing the elements in place without obstructing the vertical flow channels. Each element may be released from the frame, however, and removed by sliding it in a direction substantially normal to its headers without disassembling the remainder of the module. The elements have associated releasable water tight fittings between the elements and a permeate collector, the releasable water tight fittings being releasable by removing an element from the frame. An aerator below the module has a plurality of air holes located to provide a line of air holes below each element or below a side plate between each pair of elements. In a preferred process, permeate flux is less than 50 L/m /h and preferably less than 35 L/m /h, aeration to scrub the membranes is provided during periods of time when permeation is periodically stopped and accumulated solids are removed by periodically emptying and refilling a tank containing the elements. A bubble point test is applied to each row of the module in turn, the presence of bubbles in a particular flow channel indicating which, if any, elements of a row are suitable.
摘要:
A system of purifying water to remove at least one of natural organic matter, color, turbidity, bacteria, cysts and oocysts, viruses, arsenic compounds and insoluble impurities. The system comprises the steps of providing a body of water to be purified; controlling the pH of the body in a range of 5 to 8; and adding (12) a coagulant to the body to provide a floc. The floc is maintained in the body in a concentration in the range of 1 to 6, for purposes of adsorbing at least one of the natural organic matter, color, turbidity and bacteria to provide treated water. Thereafter, a first portion of the treated water and floc is removed (8) from the body of water. A submerged semi-permeable membrane (6) is provided in the body of water for removing (4) a second portion of the treated water. The membrane has a pore size in the range of 0.02 to 1 νm to provide a permeate comprised of purified water and to provide a retentate containing the floc. The body of water is treated with a mixing means (16) to minimize membrane fouling and to provide thorough mixing of the floc in the body of water.
摘要:
A method for cleaning a filtration apparatus comprising a plurality of membranes immersed in at least one tank containing the effluent to be treated. According to the method, the effluent is at least partially removed from the tank to expose the membranes to the air, and at least one cleaning solution is fed through said membranes in the opposite direction to the effluent filtration flow by delivering said cleaning solution to the permeate side of said membranes.
摘要:
During normal operation of a hollow fiber membrane in contact with dirty water, a fouling film is produced on the surface of the membrane. Despite the fouling film, the membrane affords a desirable initial stable transmembrane flux which decreases as a function of time by at least 20 %. A method is disclosed for cleaning the outer surface of a microfiltration (MF) or ultrafiltration (UF) semipermeable hollow fiber membrane after its initial stable transmembrane flux has been decreased to an unacceptably low level. The method is specifically applicable to any fiber used to withdraw purified water from dirty water, particularly water containing organic matter including beneficial bacteria and/or undesirable inorganic salts, where the viability of the bacteria population is to be maintained. The membrane is cleaned by flowing a cleaning fluid, preferably a biocidal oxidative electrolyte having an oxidizing anion and an associated cation through the clean, permeate-side of the membrane, at low pressure no more than the bubble pressure breakthrough, usually