US20050218073A1 - Method of cleaning membranes - Google Patents

Method of cleaning membranes Download PDF

Info

Publication number
US20050218073A1
US20050218073A1 US11073137 US7313705A US2005218073A1 US 20050218073 A1 US20050218073 A1 US 20050218073A1 US 11073137 US11073137 US 11073137 US 7313705 A US7313705 A US 7313705A US 2005218073 A1 US2005218073 A1 US 2005218073A1
Authority
US
Grant status
Application
Patent type
Prior art keywords
wt
membrane
sodium
agent
sulfite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11073137
Inventor
Paul Gallagher
Tom Rainier
Aaron Balczewski
Daniel Cargnel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Filter Wastewater Group Inc
Original Assignee
US Filter Wastewater Group Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D65/00Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
    • B01D65/02Membrane cleaning or sterilisation ; Membrane regeneration
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D61/00Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis, ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14Ultrafiltration; Microfiltration
    • B01D61/145Ultrafiltration
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D61/00Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis, ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14Ultrafiltration; Microfiltration
    • B01D61/147Microfiltration
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D61/00Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis, ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14Ultrafiltration; Microfiltration
    • B01D61/16Feed pretreatment
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D71/00Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06Organic material
    • B01D71/30Polyalkenyl halides
    • B01D71/32Polyalkenyl halides containing fluorine atoms
    • B01D71/34Polyvinylidene fluoride
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2311/00Details relating to membrane separation process operations and control
    • B01D2311/04Specific process operations in the feed stream; Feed pretreatment
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2321/00Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
    • B01D2321/04Backflushing
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2321/00Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
    • B01D2321/16Use of chemical agents
    • B01D2321/168Use of other chemical agents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/444Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00Water conservation; Efficient water supply; Efficient water use
    • Y02A20/10Relating to general water supply, e.g. municipal or domestic water supply
    • Y02A20/124Water desalination
    • Y02A20/126Water desalination characterized by the method
    • Y02A20/131Reverse-osmosis

Abstract

The present invention relates a method for cleaning polymeric microfiltration membranes and membrane units, and to compositions useful in such methods.

Description

    RELATED APPLICATIONS
  • [0001]
    This application is a continuation of Application Ser. No. 10/298,471, filed Nov. 15, 2002, which claims the benefit of U.S. Provisional Application No. 60/333,828, filed Nov. 16, 2001.
  • FIELD OF THE INVENTION
  • [0002]
    The present invention relates a method for cleaning polymeric microfiltration membranes and membrane units, and to compositions useful in such methods.
  • BACKGROUND OF THE INVENTION
  • [0003]
    Synthetic membranes are used for a variety of applications including desalination, gas separation, filtration, and dialysis. The properties of the membranes vary depending on the morphology of the membrane, i.e. properties such as symmetry, pore shape, and pore size, and the polymeric material used to form the membrane.
  • [0004]
    Different membranes can be used for specific separation processes, including microfiltration (MF), ultrafiltration (UF), and reverse osmosis. MF and UF processes are carried out under differential pressure and are distinguished by the size of the particle or molecule that the membrane is capable of retaining or passing. MF can remove very fine colloidal particles in the micrometer and sub micrometer range. As a general rule, it can filter particles down to 0.1 μm, whereas ultrafiltration can retain particles as small as 0.01 μm and smaller. Reverse osmosis operates on an even smaller scale.
  • [0005]
    As the size of the particles to be separated decreases, the pore size of the membrane decreases and the pressure required to carry out the separation accordingly increases.
  • [0006]
    A large surface area is generally needed when a large filtrate flow is required. One known technique to make a filtration apparatus more compact is to form a membrane in the shape of a hollow porous fiber. Modules of such fibers can be made with an extremely large surface area per unit volume. Microporous synthetic membranes are particularly suitable for use in hollow fibers and are typically produced by phase inversion techniques.
  • [0007]
    Microporous phase inversion membranes are particularly well suited to the application of removal of colloidal suspensions, viruses, and bacteria. Of all types of membranes, the hollow fiber membrane contains the largest membrane area per unit volume.
  • [0008]
    UF and MF membranes are used in separating particles and colloidal matter from liquids. In a typical scenario, water containing solutes and precipitates is passed through a bank of semipermeable tubular membranes housed in a module, often at elevated pressures. The filtered water is drawn off and collected, leaving a residue of solid material in the membrane pores or on the unfiltered side of the membrane.
  • [0009]
    It is preferred that the pores of the membrane be kept relatively free of contaminants. As the amount of pore blockage increases, the filtration efficiency of the module decreases and the amount of pressure required to maintain a viable throughput of liquid increases. As pressure increases, the likelihood of membrane rupture becomes more significant.
  • [0010]
    Under some circumstances, it may be desirable to treat water containing impurities with a flocculating agent prior to filtration. The purpose of flocculating agents is to cause dispersed colloids to coagulate and form ‘flocs’. Flocs have the advantage of entrapping smaller colloidal particles, thereby making filtration more efficient. They may also aid in the removal of dissolved particles. Under the influence of a flocculating agent, dissolved and suspended particles coagulate and precipitate from the water, thereby removing color, and turbidity.
  • [0011]
    Thus, in practice, the filtrate containing the flocculating agents, colloids, bacteria and other particulate matter is passed through the filtration unit under pressure, expelling filtered water and leaving the floc trapped within the unit, and more particularly on the waste side of the membrane and in the pores of the membrane. Flocs are particularly problematical in causing membrane blockage, and membrane performance gradually diminishes with use until it becomes necessary to clean the membranes.
  • [0012]
    One of the most commonly employed flocculating agents in the water purification field is ferric chloride, and the resultant floc is known as Fe floc. Build-up of Fe floc leads to iron fouling and eventually results in membrane performance degradation that diminishes the lifetime of these high cost membrane units. Two of the most widely used membrane compositions, polypropylene (PP) and polyvinylidene fluoride (PVDF), foul irreversibly with Fe floc and can become useless.
  • [0013]
    Residual material accumulating in and on the membrane is often removed by ‘backwashing’, that is, running the current of water counter to its normal direction of flow to dislodge the contaminants from the membrane. Gas backwashing of the membrane is also possible.
  • [0014]
    Backwashing generally involves increasing the pressure on both sides of the hollow fibers within a module a relatively high value before suddenly releasing that pressure on the unfiltered side of the membrane walls to cause a sudden pressure differential across the walls, which causes a backwash action. However, it is difficult to achieve complete removal of particulate matter, especially when flocculants have been used.
  • [0015]
    In addition to backwashing, the membranes may be de-fouled by more conventional cleaning regimes such as solution treatment with one or more of (and usually in a sequential manner) citric acid, oxidizing agents, in particular chlorine, and chelating agents such as EDTA.
  • [0016]
    Citric acid is usually regarded as a satisfactory cleaning agent, however, even it does not provide ideal levels of cleaning, and the membrane performance diminishes even following regular use/cleaning cycles. Moreover, the cleaning process usually involves a number of steps, and one or more of the steps may need to be conducted for long periods of time. Temperature control is also usually required.
  • [0017]
    Inorganic acids and bases are the mainstay of conventional cleaning agents. As well as suffering from the drawbacks mentioned above, these agents present their own problems because they may chemically attack the membranes and/or module components. Combinations of an aqueous inorganic acid, generally nitric acid, and a reducing agent, e.g., ascorbic acid, have also been used. However, none of the above regimes sufficiently de-foul membranes, particularly PVDF membranes, of the floc. Hence, there exists the need to improve the cleaning regime while at the same time avoiding the use of potentially severe cleaning agents.
  • SUMMARY OF THE INVENTION
  • [0018]
    It is desirable to overcome or ameliorate at least one of the disadvantages of the prior art methods of de-fouling membranes, to provide a useful alternative to conventional methods of de-fouling membranes, or to provide suitable compositions for use in cleaning or de-fouling membranes.
  • [0019]
    In a preferred embodiment, there is provided a method of cleaning a membrane contaminated with a contaminant including the step of contacting the contaminant with a composition including at least one soluble sulfite reducing agent and a compatible solvent. The term sulfite as used herein is used in its broadest general sense and includes, without limitation, sulfite, bisulfite, metabisulfite, hydrosulfite, and the like.
  • [0020]
    Preferably the membrane is of a hollow fiber configuration, although alternatively it may be a flat sheet membrane or other membrane configuration. In highly preferred embodiments, the membrane is formed from PVDF (polyvinylidene fluoride) polymer, although the methods of the preferred embodiments are applicable to polysulfone, polyethylene, polypropylene, polyacrylonitrile (PAN), fluorinated membranes, cellulose acetate membranes and the like and mixtures of the above, as well as all commonly used membrane polymers.
  • [0021]
    Preferably, the soluble sulfite reducing agent is sodium metabisulfite, sodium hydrosulfite, sodium sulfite or mixtures thereof. Most preferably, a mixture of sodium metabisulfite and sodium hydrosulfite is used. Those skilled in the art will appreciate that, for instance, besides sodium, other soluble salts such as potassium or other alkali metals or alkaline earth metals may be used. The solvent is preferably water. However any suitable solvent that is compatible with the materials comprising the membrane and is a suitable solvent for the sulfite may also be employed.
  • [0022]
    It is also preferred that the sodium metabisulfite and sodium hydrosulfite are present in an amount of 20 wt. % to 65 wt. % each, when used alone or in combination. This combination may be used neat or further diluted when in use, for example, to around 0.5 wt. %. Dilutions of about 2 wt. % are particularly preferred. However, any suitable dilution may be employed.
  • [0023]
    Preferably, and without wishing to be bound by any particular theory, the contaminant is believed to be removed by solubilization resulting from a reduction to a lower valence state of at least a part of the contaminant.
  • [0024]
    Preferably, the method reduces the cleaning time relative to known cleaning methods and is carried out at low or ambient temperatures.
  • [0025]
    Accordingly, in a first embodiment, a method of cleaning a membrane contaminated with a contaminant is provided, the method including the step of contacting the contaminant with a composition including a sulfite reducing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the membrane.
  • [0026]
    In an aspect of the first embodiment, the contaminant includes a metal oxide or a metal hydroxide.
  • [0027]
    In an aspect of the first embodiment, the contaminant includes ferric floc.
  • [0028]
    In an aspect of the first embodiment, the contaminant includes an organic compound.
  • [0029]
    In an aspect of the first embodiment, the solvent includes water.
  • [0030]
    In an aspect of the first embodiment, the sulfite reducing agent includes sodium metabisulfite, sodium hydrosulfite, sodium sulfite, potassium metabisulfite, potassium hydrosulfite, potassium sulfite, or mixtures thereof.
  • [0031]
    In an aspect of the first embodiment, method further includes the step of reducing a valence state of an atom of the contaminant to a lower valence state, whereby the contaminant is solublized and removed from the membrane.
  • [0032]
    In an aspect of the first embodiment, the composition further includes an enhancing agent.
  • [0033]
    In an aspect of the first embodiment, the enhancing agent includes inorganic acids, organic acids, or mixtures thereof.
  • [0034]
    In an aspect of the first embodiment, the enhancing agent includes citric acid.
  • [0035]
    In an aspect of the first embodiment, the solvent includes water and the sulfite reducing agent includes sodium metabisulfite, sodium hydrosulfite, or mixtures thereof.
  • [0036]
    In an aspect of the first embodiment, the sulfite reducing agent includes from about 0.1 wt. % to about 5 wt. % of a component including sodium metabisulfite, sodium hydrosulfite, or mixtures thereof.
  • [0037]
    In an aspect of the first embodiment, the sulfite reducing agent includes from about 0.5 wt. % to about 2 wt. % of a component including sodium metabisulfite, sodium hydrosulfite, or mixtures thereof.
  • [0038]
    In an aspect of the first embodiment, the composition includes from about 0.5 wt. % to about 1.5 wt. % sodium metabisulfite and from about 0.5 wt. % to about 1.5 wt. % sodium hydrosulfite.
  • [0039]
    In an aspect of the first embodiment, the membrane includes a hollow fiber microfiltration membrane or a hollow fiber ultrafiltration membrane.
  • [0040]
    In an aspect of the first embodiment, the membrane includes a flat microfiltration membrane or a flat ultrafiltration membrane.
  • [0041]
    In an aspect of the first embodiment, the membrane includes a polyvinylidene fluoride polymer.
  • [0042]
    In a second embodiment, a composition for cleaning a membrane contaminated with a contaminant is provided, the composition including a sulfite reducing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the membrane.
  • [0043]
    In an aspect of the second embodiment, the contaminant includes a metal oxide or a metal hydroxide.
  • [0044]
    In an aspect of the second embodiment, the contaminant is ferric floc.
  • [0045]
    In an aspect of the second embodiment, the sulfite reducing agent includes sodium metabisulfite, sodium hydrosulfite, sodium sulfite, potassium metabisulfite, potassium hydrosulfite, potassium sulfite, or mixtures thereof.
  • [0046]
    In an aspect of the second embodiment, the sulfite reducing agent includes sodium metabisulfite and sodium hydrosulfite.
  • [0047]
    In an aspect of the second embodiment, the composition further includes an enhancing agent.
  • [0048]
    In an aspect of the second embodiment, the enhancing agent includes an inorganic acid or an organic acid.
  • [0049]
    In an aspect of the second embodiment, the organic acid includes citric acid.
  • [0050]
    In an aspect of the second embodiment, the sulfite reducing agent includes from about 20 wt. % to about 60 wt. % sodium metabisulfite, wherein the sulfite reducing agent is capable of dilution to a working concentration of about 0.5 wt. % to about 2 wt. % of sulfite reducing agent in a solubilized form.
  • [0051]
    In an aspect of the second embodiment, the sulfite reducing agent includes from about 0.5 wt. % to about 2 wt. % sodium metabisulfite.
  • [0052]
    In an aspect of the second embodiment, the sulfite reducing agent includes from about 20 wt. % to about 65 wt. % sodium hydrosulfite, and wherein the sulfite reducing agent is capable of dilution to a working concentration of about 0.5 wt. % to about 2 wt. % soluble sulfite reducing agent present in solubilized form.
  • [0053]
    In an aspect of the second embodiment, the sulfite reducing agent includes from about 0.5 wt. % to about 2 wt. % sodium hydrosulfite.
  • [0054]
    In an aspect of the second embodiment, the composition includes from about 20 wt. % to about 65 wt. % sodium metabisulfite and from about 20 wt. % to about 65 wt. % sodium hydrosulfite, wherein the sodium metabisulfite and sodium hydrosulfite are capable of dilution to a working concentration of about 0.5 wt. % to about 2 wt. % sulfite reducing agent in solubilized form.
  • [0055]
    In an aspect of the second embodiment, the composition includes from about 0.5 wt. % to about 2 wt. % sodium metabisulfite and sodium hydrosulfite.
  • [0056]
    In a third embodiment, a method for cleaning a membrane is provided, the method including the step of cleaning the membrane using a composition including a sulfite reducing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the membrane.
  • [0057]
    In a fourth embodiment, a membrane is provided wherein the membrane is capable of cleaning by a composition including a sulfite reducing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the membrane.
  • [0058]
    In a fifth embodiment, a membrane is provided, wherein the membrane is contaminated with a contaminant including a metal oxide or a metal hydroxide, and wherein the membrane is capable of cleaning by a composition including a sulfite reducing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the membrane.
  • [0059]
    In an aspect of the fifth embodiment, the membrane includes a hollow fiber or a flat sheet.
  • [0060]
    In an aspect of the fifth embodiment, the membrane includes a polyvinylidene fluoride polymer.
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
  • [0061]
    The following description and examples illustrate a preferred embodiment of the present invention in detail. Those of skill in the art will recognize that there are numerous variations and modifications of this invention that are encompassed by its scope. Accordingly, the description of a preferred embodiment should not be deemed to limit the scope of the present invention.
  • [0062]
    Ferric chloride is the preferred flocculating agent in water clean-up procedures. However, standard cleaning regimes have not been highly effective in cleaning PVDF membranes of the resultant Fe floc, leading to significant commercial costs associated with ultimate irreversible membrane fouling by metal oxides and/or hydroxides.
  • [0063]
    Surprisingly, the present inventors have found that the methods of the preferred embodiments are particularly suited for PVDF membranes. When metabisulfite was used as a cleaning agent on PVDF membranes, there was successful removal of metal oxides and metal hydroxides.
  • [0064]
    More surprisingly, when sodium hydrosulfite and sodium metabisulfite were used in combination as cleaning agents for PVDF membranes, significant antifouling properties were observed.
  • [0065]
    One commercial blend of sodium hydrosulfite (20-65 wt. %) and sodium metabisulfite (20-65 wt. %) was found to be particularly useful. This mixture, marketed as SUPER IRON OUT®, has been commercially available since the 1950's, although it has not been used for cleaning membranes. SUPER IRON OUT® has been marketed to household consumers as an all-purpose rust and stain remover, water softener, a cleaning agent for toilets, sinks tubs, dishwashers, white clothing, and fabrics as well as exterior surfaces, i.e. as a general household reductant.
  • [0066]
    This material may be used neat, although it is possible to use it diluted in an amount such that the dilution is as low as 0.5 wt. %, although dilutions of around 2 wt. % have been found advantageous.
  • [0067]
    Alternatively, standardized solutions may be prepared from the starting materials. While the exact concentration will be selected depending on the time limits set for the membrane cleaning and on cost considerations, it has been found particularly useful to use solutions of around 2 wt. %/volume total sulfite content based on the starting materials, i.e. 2 g sodium metabisulfite per 100 ml of water, or 1 g sodium bisulfite and 1 g of sodium hydrosulfite per 100 ml of water, and the like.
  • [0068]
    The commercial importance of this new application is that it allows ferric floc applications to be run at 20 to 30 % higher water flux than has previously been thought possible. Using such high fluxes is normally to be avoided because of the extreme fouling that takes place under such conditions, and the resultant difficulty in cleaning badly fouled membranes, wherein the floc is forced hard into the pores and cannot be readily physically removed by backwashing, or by chemical cleaners.
  • [0069]
    With the advent of the cleaning method of the preferred embodiments, the ferric floc applications can be run at the higher flux and the fouled membranes can be quickly and efficiently cleaned. The ability to use such high fluxes can translate into a significant commercial advantage.
  • [0070]
    As more liquid is filtered, the amount of residue removed from that liquid increases in the pores and on the outside and needs to be cleaned.
  • [0071]
    The methods of the preferred embodiments can be used in conjunction with backwashing methodology, or as a stand-alone cleaning method suitable for carrying out “cleaning-in-place” (CIP). CIP involves cleaning the membrane module without removal from its normal in situ place of operation.
  • [0072]
    In general terms, one form of CIP cleaning involves isolating the module to be cleaned by means of taps and pipes and the like from fluid communication with the remainder of the system. The water or liquid normally filtered is then replaced with a cleaning fluid. The cleaning fluid is then allowed to run through the membrane module to carry out the cleaning. The cleaning fluid may be recycled through the module, or allowed to pass through the module just once before being run off to waste, depending upon the particular requirements of the system and the amount of contaminants being removed.
  • [0073]
    The CIP procedure can take place at ambient temperatures or at controlled temperatures outside the normal range of filtration temperatures, e.g. at higher temperatures to increase dissolution of solids, or at lower temperatures to allow for a greater concentration of dissolved gaseous agents e.g., especially chlorine gas, in the fluid. The CIP can be carried out for varying lengths of time and at pressures outside the normal range of those used for filtration.
  • [0074]
    Once the cleaning is completed, the filtration agent is flushed to remove traces of the cleaning agent before being returned to service by being reconnected to the normal fluid flow.
  • [0075]
    CIP can be carried out manually or by means of fully automated systems which activate in response to pressure differentials or after predetermined module operating times.
  • [0076]
    A preferred embodiment is described below, by way of example only.
  • [0077]
    The examples given below relate to modules prepared from banks of hollow fiber PVDF membranes. The membrane modules are as described in U.S. Pat. No. 6,159,373, the contents of which are incorporated herein by reference. The module includes a shell within which is positioned a bundle containing from about 2800 to about 30,000 hollow fibers with a diameter of 500 μm to 650 μm and a lumen diameter of 250 μm to 310 μm, with a pore size of 0.2 μm, but these sizes may be varied as required. Moreover, membrane and module configurations different from the one described above may also be employed with the methods of preferred embodiments, as will be appreciated by one skilled in the art.
  • [0078]
    At each end of the fiber bundle, a potting compound holds the ends of the fibers in place without blocking the lumens and closes off each end of the module. The liquid feed is pumped into the module, between the shell and the outside of the hollow fibers. Some of the feed liquid passes into the lumen of the fibers, being filtered as it does so. The clean liquid then concentrates in the inside of the lumen, and flows, or is drawn off and taken outside the module, as a clarified liquid.
  • [0079]
    In the CIP method exemplified, the cleaning agent is introduced in place of the untreated liquid stream. However, those skilled in the art will realize that the flow can be introduced counter to that normally used.
  • EXAMPLES
  • [0000]
    CIP Comparative Method 1—Raw Water Filtration Module
  • [0080]
    Membranes in a raw water filtration module were cleaned using a 2 wt. % solution of citric acid in water at 35° C., which was recirculated for 60 minutes. Three repeats of a 300 second aeration followed by a 300 second soak were conducted. Then, a solution of 300 ppm Cl in water at 20° C. was recirculated for 60 minutes, followed by a 30 minute soak. The total duration of the CIP was 3 hours. Table 1 provides measurements of transmembrane pressure (TMP), resistance (R), and flow (in gallons per minute per module) both before and after the CIP.
    TABLE 1
    BEFORE CIP AFTER CIP
    TMP Flow TMP Flow
    (psi) R (gpm/mod) (psi) R (gpm/mod)
    8.1 4.27 4.4 3.5 2.21 4.9

    CIP Comparative Method 2—Clarified Water Filtration Module
  • [0081]
    Membranes in a clarified water filtration module (containing flocculant) were cleaned 400 ppm solution of Cl in water at 20° C., which was recirculated for 60 minutes, followed by a 30 minute soak. Then the membranes were washed with a 2.7 wt. % citric acid solution in water at 35° C., which was recirculated for 60 minutes. Three repeats of a 300 second aeration followed by a 300 second soak were conducted. Then, an overnight soak was conducted. The total duration of the CIP was 13 hours. Table 2 provides measurements of transmembrane pressure, resistance, and flow both before and after the CIP.
    TABLE 2
    BEFORE CIP AFTER CIP
    TMP Flow TMP Flow
    (psi) R (gpm/mod) (psi) R (gpm/mod)
    11 7.48 4.9 5.9 3.56 4.9

    CIP Comparative Method 3—Clarified Water Filtration Module
  • [0082]
    Membranes in a clarified water filtration module (containing flocculant) were cleaned using a 1000 ppm solution of Cl in water at 20° C., which was recirculated for 60 minutes, followed by a 30 minute soak. Then the membranes were washed with a 4 wt. % citric acid solution in water at 35° C., which was recirculated for 60 minutes. Three repeats of a 300 second aeration followed by a 300 second soak were conducted. Then, an overnight soak in a 1000 ppm Cl solution in water was conducted. The total duration of the CIP was 13 hours. Table 3 provides measurements of transmembrane pressure, resistance, and flow both before and after the CIP.
    TABLE 3
    BEFORE CIP AFTER CIP
    TMP Flow TMP Flow
    (psi) R (gpm/mod) (psi) R (gpm/mod)
    10.9 10.61 3.6 5.4 3.34 3.6

    CIP Comparative Method 4—Raw Water Filtration Module
  • [0083]
    Membranes in a raw water filtration module were cleaned using a solution of 300 ppm Cl in water at 20° C., followed by an overnight soak. Then, the membranes were cleaned with a 2 wt. % citric acid solution in water at 40° C. for two hours. The total duration of the CIP was 13 hours. Table 4 provides measurements of transmembrane pressure (TMP), resistance (R), and flow (in gallons per minute per module) both before and after the CIP.
    TABLE 4
    BEFORE CIP AFTER CIP
    TMP Flow TMP Flow
    (psi) R (gpm/mod) (psi) R (gpm/mod)
    5.58 4.08 3.85 3.5 2.63 3.75

    CIP Method 1—Clarified Water Filtration Module
  • [0084]
    Membranes in a clarified water filtration module (containing flocculant) were cleaned using a 2 wt. % solution of SUPER IRON OUT® in water at 20° C. for 30 minutes. Then the membranes were washed with a solution of 1000 ppm Cl in water at 20° C., which was recirculated for 60 minutes, followed by a 30 minute soak. The total duration of the CIP was 2 hours. Table 5 provides measurements of transmembrane pressure, resistance, and flow both before and after the CIP. The data demonstrate a substantial reduction in transmembrane pressure and resistance, and an increase in flow following the cleaning method.
    TABLE 5
    BEFORE CIP AFTER CIP
    TMP Flow TMP Flow
    (psi) R (gpm/mod) (psi) R (gpm/mod)
    10.6 7.19 4.8 5 2.8 5.7
  • [0085]
    It can be seen from all the above examples that cleaning the membranes, by both conventional methods and by the methods of the preferred embodiments, results in a reduction in transmembrane pressure, a decrease in resistance, and an increase in flow, all indicators that the membrane has been cleaned.
  • [0086]
    The results with SUPER IRON OUT® are significantly better than the comparative conventional methods. It enables the highest restoration of flow and the most significant decrease in resistance on cleaning.
  • [0087]
    It has also achieved these results at ambient temperatures, and with fewer steps, meaning that the amount of external apparatus required to carry out the CIP of the module is considerably reduced.
  • [0088]
    Possibly most significantly, however, it achieved this high level of cleaning in 2 hours for clarified (flocculant-containing) water. To achieve close to this result using the standard methods required overnight CIP times, typically around 13 hours. This dramatic reduction in CIP time translates into a reduction in downtime of modules, as well as allowing higher liquid throughput by permitting effective clean up after running at high flux rates.
  • [0089]
    Sulfite agents such as sodium metabisulfite and SUPER IRON OUT® can also be used in conjunction with other conventional methods, for example, in conjunction with sulfuric acid for cleaning membranes (including polypropylene membranes). In low concentrations, it is believed sodium metabisulfite may act as a sacrificial agent, protecting the membrane from degradation by other cleaning agents.
  • [0090]
    Further investigations were carried out to better standardize the active amount of sulfite agent present (rather than relying on the broader ranges which may be found in proprietary formulations and to investigate the optimal cleaning compositions, as established by the differing criteria to determine membrane de-fouling.
  • [0091]
    Two sets of experiments were carried out to determine the efficiency of sulfite cleaning compositions of precisely defined composition relative to citric acid and chlorine, and measured with reference to different criteria. In both sets of experiments, the membranes were fouled with a mixture of 100 ppm humic acid and 100 ppm FeCl3.6H2O, by filtering this mixture through the membranes.
  • [0092]
    In the transmembrane pressure recovery and refouling experiments, the same equipment was used to filter the cleaning solution through the membranes. The TMP change versus time was recorded while filtering this humic acid/iron solution through the membrane before and after the clean. The results are shown in Table 6.
    TABLE 6
    Fouling
    Final TMP Initial TMP TMP rate
    before clean after clean recovery post-clean
    Clean (kPa) (kPa) (kPa) (kPa/min)
    2 wt. % Citric acid 38 18 20 0.07
    200 ppm NaOCl 46 21 25 0.6
    2 wt. % SHS 60 21 39 0.15
    2 wt. % SMBS 36 20 16 0.08
    1.5 wt. % SMBS + 31 17 14 0.1
    0.5 wt. %SHS
    0.5 wt. % SMBS + 39 20 19 0.1
    1.5 wt. %SHS
    1 wt. % SMBS + 36 20 16 0.3
    1 wt. %SHS

    SMBS = sodium metabisulfite

    SHS = sodium hydrosulfite
  • [0093]
    The results in the experiment show that the TMP recoveries were similar for all the cleaning methodologies used except for 2 wt. % sodium hydrosulfite which gave a significantly higher recovery than the other cleaning agents.
  • [0094]
    The best post-clean fouling rates were also investigated. The poorest post-clean fouling rate was found using the conventional chlorine clean. The best post clean fouling was found using 2 wt. % citric acid and 2 wt. % SMBS, with the 1.5 wt. % SMBS/0.5 wt. % SHS and 0.5 wt. % SMBS/1.5 wt. % SHS mixtures also performing very well.
  • [0095]
    In the second set of experiments, the dirty membranes were placed in jars of the cleaning solution and allowed to soak. The permeability of the fibers was measured before and after the clean. The results are shown in Table 7.
    TABLE 7
    Permeability Permeability Permeability %
    before clean after clean recovery Permeability
    Clean (L/m2 · hour) (L/m2 · hour) (L/m2 · hour) recovery
    2 wt. % 589 795 206 135
    Citric acid
    200 ppm 277 576 299 207
    NaOCl
    2 wt. % SHS 383 795 412 208
    2 wt. % SMBS 454 714 260 157
    1.5 wt. % 350 774 424 221
    SMBS + 0.5
    wt. % SHS
    0.5 wt. % 591 835 244 141
    SMBS + 1.5
    wt. % SHS
    1 wt. % 378 824 446 236
    SMBS + 1
    wt. % SHS

    SMBS = sodium metabisulfite

    SHS = sodium hydrosulfite
  • [0096]
    The citric acid gave the lowest permeability recovery. Three cleans, 1.5% SMBS+0.5 wt. % SHS, 1 wt. % SMBS+1 wt. % SHS, and 2 wt. % SHS gave the best permeability recoveries. The permeability recoveries for the sulfite cleaning agents show that for two specific combinations, 1.5 wt. % SMBS/0.5 wt. % SHS and 1 wt. % SMBS/1 wt. % SHS, the permeability recovery (of 221% and 236%, respectively) was greater than the permeability recovery for either the SMBS or SHS alone, indicating a synergistic relationship between the two. On the basis of the individual mixture components, a 1 wt. %:1 wt. % SMBS/SHS mixture would be expected to restore about 183% (based on 208%/2+157%/2) of the permeability, yet the actual value was 236%.
  • [0097]
    The other cleaning combinations are likewise not simply additive, indicating that in combination, the two sulfite cleaning agents may act co-operatively.
  • [0098]
    Thus, it can be seen that the sulfite cleaning method of the preferred embodiments provided in all cases a good TMP recovery, good permeability recovery and a low rate of post clean fouling. The all round performance was not matched by conventional cleaning methodologies. Further, sulfite cleaning required less time to achieve CIP (cleaning in place) de-fouling of membranes than conventional (chlorine) membrane cleans.
  • [0099]
    The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims. All patents, applications, and other references cited herein are hereby incorporated by reference in their entirety.

Claims (30)

  1. 1. A method of cleaning a porous polymeric membrane contaminated with a contaminant, the method comprising the step of:
    contacting the contaminant with a composition comprising a sulfite reducing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the porous polymeric membrane.
  2. 2. The method according to claim 1, wherein the contaminant comprises a metal oxide or a metal hydroxide.
  3. 3. The method according to claim 1, wherein the contaminant comprises an organic compound.
  4. 4. The method according to claim 1, wherein the solvent comprises water.
  5. 5. The method according to claim 1, wherein the sulfite reducing agent is selected from the group consisting of sodium metabisulfite, sodium hydrosulfite, sodium sulfite, potassium metabisulfite, potassium hydrosulfite, potassium sulfite, and mixtures thereof.
  6. 6. The method according to claim 1, further comprising the step of:
    reducing a valence state of an atom of the contaminant to a lower valence state, whereby the contaminant is solublized and removed from the membrane.
  7. 7. The method according to claim 1, wherein the composition further comprises an enhancing agent.
  8. 8. The method according to claim 7, wherein the enhancing agent is selected from the group consisting of inorganic acids, organic acids, and mixtures thereof.
  9. 9. The method according to claim 7, wherein the enhancing agent comprises citric acid.
  10. 10. The method according to claim 1, wherein the solvent comprises water and the sulfite reducing agent is selected from the group consisting of sodium metabisulfite, sodium hydrosulfite, and mixtures thereof.
  11. 11. The method according to claim 10, wherein the sulfite reducing agent comprises from about 0.1 wt. % to about 5 wt. % of a component selected from the group consisting of sodium metabisulfite, sodium hydrosulfite, and mixtures thereof.
  12. 12. The method according to claim 10, wherein the sulfite reducing agent comprises from about 0.5 wt. % to about 2 wt. % of a component selected from the group consisting of sodium metabisulfite, sodium hydrosulfite, and mixtures thereof.
  13. 13. A method according to claim 10, wherein the composition comprises from about 0.5 wt. % to about 1.5 wt. % sodium metabisulfite and from about 0.5 wt. % to about 1.5 wt. % sodium hydrosulfite.
  14. 14. The method according to claim 1, wherein the membrane comprises a hollow fiber microfiltration membrane or a hollow fiber ultrafiltration membrane.
  15. 15. The method according to claim 1, wherein the membrane comprises a flat microfiltration membrane or a flat ultrafiltration membrane.
  16. 16. The method according to claim 1, wherein the membrane comprises a polyvinylidene fluoride polymer.
  17. 17. A composition for cleaning a porous polymeric membrane contaminated with a contaminant, the composition comprising a sulfite reducing agent, an enhancing agent and a solvent, wherein the sulfite reducing agent is soluble in the solvent, and wherein the solvent is compatible with the membrane.
  18. 18. The composition according to claim 17, wherein the contaminant comprises a metal oxide or a metal hydroxide.
  19. 19. The composition according to claim 17, wherein the contaminant is ferric floc.
  20. 20. The composition according to claim 17, wherein the sulfite reducing agent is selected from the group consisting of sodium metabisulfite, sodium hydrosulfite, sodium sulfite, potassium metabisulfite, potassium hydrosulfite, potassium sulfite, and mixtures thereof.
  21. 21. The composition according to claim 17, wherein the sulfite reducing agent comprises sodium metabisulfite and sodium hydrosulfite.
  22. 22. The composition according to claim 17, further comprising an enhancing agent.
  23. 23. The composition according to claim 22, wherein the enhancing agent comprises an inorganic acid or an organic acid.
  24. 24. The composition according to claim 23, wherein the organic acid comprises citric acid.
  25. 25. The composition according to claim 17, wherein the sulfite reducing agent comprises from about 20 wt. % to about 60 wt. % sodium metabisulfite, wherein the sulfite reducing agent is capable of dilution to a working concentration of from about 0.5 wt. % to about 2 wt. % of sulfite reducing agent in a solubilized form.
  26. 26. The composition according to claim 17, wherein the sulfite reducing agent comprises from about 0.5 wt. % to about 2 wt. % sodium metabisulfite.
  27. 27. The composition according to claim 17, wherein the sulfite reducing agent comprises from about 20 wt. % to about 65 wt. % sodium hydrosulfite, and wherein the sulfite reducing agent is capable of dilution to a working concentration of about 0.5 wt. % to about 2 wt. % soluble sulfite reducing agent present in solubilized form.
  28. 28. The composition according to claim 17, wherein the sulfite reducing agent comprises from about 0.5 wt. % to about 2 wt. % sodium hydrosulfite.
  29. 29. The composition according to claim 17, comprising from about 20 wt. % to about 65 wt. % sodium metabisulfite and from about 20 wt. % to about 65 wt. % sodium hydrosulfite, wherein the sodium metabisulfite and sodium hydrosulfite are capable of dilution to a working concentration of from about 0.5 wt. % to about 2 wt. % sulfite reducing agent in solubilized form.
  30. 30. The composition according to claim 17, comprising from about 0.5 wt. % to about 2 wt. % sodium metabisulfite and sodium hydrosulfite.
US11073137 2001-11-16 2005-03-04 Method of cleaning membranes Abandoned US20050218073A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US33382801 true 2001-11-16 2001-11-16
US10298471 US6955762B2 (en) 2001-11-16 2002-11-15 Method of cleaning membranes
US11073137 US20050218073A1 (en) 2001-11-16 2005-03-04 Method of cleaning membranes

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11073137 US20050218073A1 (en) 2001-11-16 2005-03-04 Method of cleaning membranes
US12130664 US20080237125A1 (en) 2001-11-16 2008-05-30 Method of cleaning membranes

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10298471 Continuation US6955762B2 (en) 2001-11-16 2002-11-15 Method of cleaning membranes

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US10298471 Continuation US6955762B2 (en) 2001-11-16 2002-11-15 Method of cleaning membranes

Publications (1)

Publication Number Publication Date
US20050218073A1 true true US20050218073A1 (en) 2005-10-06

Family

ID=23304416

Family Applications (4)

Application Number Title Priority Date Filing Date
US10298471 Active 2023-06-28 US6955762B2 (en) 2001-11-16 2002-11-15 Method of cleaning membranes
US11073137 Abandoned US20050218073A1 (en) 2001-11-16 2005-03-04 Method of cleaning membranes
US11145773 Abandoned US20050224411A1 (en) 2001-11-16 2005-06-06 Method of cleaning membranes
US12130664 Abandoned US20080237125A1 (en) 2001-11-16 2008-05-30 Method of cleaning membranes

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10298471 Active 2023-06-28 US6955762B2 (en) 2001-11-16 2002-11-15 Method of cleaning membranes

Family Applications After (2)

Application Number Title Priority Date Filing Date
US11145773 Abandoned US20050224411A1 (en) 2001-11-16 2005-06-06 Method of cleaning membranes
US12130664 Abandoned US20080237125A1 (en) 2001-11-16 2008-05-30 Method of cleaning membranes

Country Status (3)

Country Link
US (4) US6955762B2 (en)
EP (1) EP1312408B1 (en)
DE (2) DE60213184T2 (en)

Families Citing this family (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2353254T3 (en) 1996-12-20 2011-02-28 Siemens Water Technologies Corp. Washing procedure.
US20040232076A1 (en) * 1996-12-20 2004-11-25 Fufang Zha Scouring method
ES2326590T3 (en) * 2000-04-10 2009-10-15 Siemens Water Technologies Corp. Retention system hollow fiber.
WO2002038256A1 (en) * 2000-11-13 2002-05-16 Usf Filtration And Separations Group Inc. Modified membranes
DE60217848D1 (en) 2001-04-04 2007-03-15 Us Filter Wastewater Group Inc Potting of hollow fibers
WO2002102500A1 (en) * 2001-06-20 2002-12-27 Us Filter Wastewater Group, Inc. Membrane polymer compositions
JP4975950B2 (en) 2001-08-09 2012-07-11 シーメンス・ウォーター・テクノロジーズ・コーポレーション Membrane module cleaning method
JP2005502467A (en) * 2001-09-18 2005-01-27 ユー・エス・フィルター・ウェイストウォーター・グループ・インコーポレイテッドU.S. Filter Wastewater Group, Inc. High-solids module
DE60213184T2 (en) * 2001-11-16 2007-06-28 U.S. Filter Wastewater Group, Inc. Method for cleaning membranes
US7247238B2 (en) * 2002-02-12 2007-07-24 Siemens Water Technologies Corp. Poly(ethylene chlorotrifluoroethylene) membranes
CN100503018C (en) 2002-06-18 2009-06-24 西门子水技术公司 Methods of minimizing the effect of integrity loss in hollow fibre membrane modules
KR101002466B1 (en) 2002-10-10 2010-12-17 지멘스 워터 테크놀로지스 코포레이션 Backwash method
CN1735452B (en) 2002-12-05 2010-04-28 西门子水技术公 Mixing chamber
CN103285737B (en) 2003-08-29 2016-01-13 伊沃夸水处理技术有限责任公司 Backwash
WO2005046849A1 (en) 2003-11-14 2005-05-26 U.S. Filter Wastewater Group, Inc. Improved module cleaning method
US8758621B2 (en) 2004-03-26 2014-06-24 Evoqua Water Technologies Llc Process and apparatus for purifying impure water using microfiltration or ultrafiltration in combination with reverse osmosis
EP2380854A3 (en) 2004-04-22 2012-07-04 Siemens Industry, Inc. Filtration apparatus comprising a membrane bioreactor and a treatment vessel for digesting organic materials
US7862719B2 (en) 2004-08-20 2011-01-04 Siemens Water Technologies Corp. Square membrane manifold system
EP1807180B1 (en) 2004-09-07 2013-02-13 Siemens Industry, Inc. Reduction of backwash liquid waste
JP4896025B2 (en) 2004-09-14 2012-03-14 シーメンス・ウォーター・テクノロジーズ・コーポレイションSiemens Water Technologies Corp. Method and apparatus for removing solids from the membrane module
WO2006029465A1 (en) 2004-09-15 2006-03-23 Siemens Water Technologies Corp. Continuously variable aeration
US7591950B2 (en) * 2004-11-02 2009-09-22 Siemens Water Technologies Corp. Submerged cross-flow filtration
CN101065177B (en) * 2004-11-02 2011-07-27 西门子水技术公司 Submerged cross-flow filtration
EP1838422A4 (en) 2004-12-24 2009-09-02 Siemens Water Tech Corp Simple gas scouring method and apparatus
CA2591408C (en) 2004-12-24 2015-07-21 Siemens Water Technologies Corp. Cleaning in membrane filtration systems
CN101184548B (en) 2005-04-29 2011-10-05 西门子水技术公司 Chemical clean for membrane filter
US20060273038A1 (en) * 2005-06-02 2006-12-07 Syed Murtuza A Chemical cleaning for membranes
JP2009504399A (en) 2005-08-22 2009-02-05 シーメンス・ウォーター・テクノロジーズ・コーポレーション Assembly for a water filtration minimizing backwashing using a tubular manifold
WO2007044442A3 (en) * 2005-10-05 2009-05-07 Edward J Jordan Method and system for treating wastewater
US20070138090A1 (en) 2005-10-05 2007-06-21 Jordan Edward J Method and apparatus for treating wastewater
US20070092464A1 (en) * 2005-10-25 2007-04-26 Duff Rocky J Betadine neutralizer
US8293098B2 (en) 2006-10-24 2012-10-23 Siemens Industry, Inc. Infiltration/inflow control for membrane bioreactor
WO2008123972A1 (en) 2007-04-02 2008-10-16 Siemens Water Technologies Corp. Improved infiltration/inflow control for membrane bioreactor
US9764288B2 (en) 2007-04-04 2017-09-19 Evoqua Water Technologies Llc Membrane module protection
EP3078411A1 (en) 2007-05-29 2016-10-12 Evoqua Water Technologies LLC Membrane cleaning with pulsed airlift pump
US8236178B2 (en) * 2007-08-20 2012-08-07 Earth Renaissance Technologies, Llc Reverse osmosis water recover method
JP2013500144A (en) 2008-07-24 2013-01-07 シーメンス インダストリー インコーポレイテッドSiemens Industry, Inc. Method and filtration systems for performing a structural support to the filtration membrane module array in the filtration system
CA2734796A1 (en) 2008-08-20 2010-02-25 Siemens Water Technologies Corp. Improved membrane system backwash energy efficiency
DE102008039676A1 (en) * 2008-08-26 2010-03-04 Inge Watertechnologies Ag Apparatus and method for backwashing of filter membrane modules
WO2010142673A1 (en) 2009-06-11 2010-12-16 Siemens Water Technologies Corp. Methods for cleaning a porous polymeric membrane and a kit for cleaning a porous polymeric membrane
WO2011136888A9 (en) 2010-04-30 2011-12-29 Siemens Industry, Inc Fluid flow distribution device
US9022224B2 (en) 2010-09-24 2015-05-05 Evoqua Water Technologies Llc Fluid control manifold for membrane filtration system
EP2763776A4 (en) 2011-09-30 2015-07-01 Evoqua Water Technologies Llc Improved manifold arrangement
CN103958034B (en) 2011-09-30 2017-03-22 伊沃夸水处理技术有限责任公司 Isolation valve
CN102407076B (en) * 2011-10-11 2014-05-07 清远加多宝草本植物科技有限公司 Membrane element cleaning agent in membrane separation industry
WO2014004645A1 (en) 2012-06-28 2014-01-03 Siemens Industry, Inc. A potting method
DE112013004713T5 (en) 2012-09-26 2015-07-23 Evoqua Water Technologies Llc Membrane safety device
US9962865B2 (en) 2012-09-26 2018-05-08 Evoqua Water Technologies Llc Membrane potting methods
US9815027B2 (en) 2012-09-27 2017-11-14 Evoqua Water Technologies Llc Gas scouring apparatus for immersed membranes

Citations (96)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2105700A (en) * 1936-07-13 1938-01-18 William D Ramage Process for purification of beverages
US2926086A (en) * 1957-07-30 1960-02-23 Universal Oil Prod Co Stabilization of non-distilled alcoholic beverages and the resulting product
US3183191A (en) * 1960-04-19 1965-05-11 Hach Chemical Co Stain and rust removing composition
US3228876A (en) * 1960-09-19 1966-01-11 Dow Chemical Co Permeability separatory apparatus, permeability separatory membrane element, method of making the same and process utilizing the same
US3708071A (en) * 1970-08-05 1973-01-02 Abcor Inc Hollow fiber membrane device and method of fabricating same
US3955998A (en) * 1973-06-21 1976-05-11 Phillips Petroleum Company Aqueous gels for plugging fractures in subterranean formation and production of said aqueous gels
US3968192A (en) * 1974-04-19 1976-07-06 The Dow Chemical Company Method of repairing leaky hollow fiber permeability separatory devices
US4082683A (en) * 1975-09-19 1978-04-04 Lever Brothers Company Cleaning of hard surfaces
US4188817A (en) * 1978-10-04 1980-02-19 Standard Oil Company (Indiana) Method for detecting membrane leakage
US4192750A (en) * 1976-08-09 1980-03-11 Massey-Ferguson Inc. Stackable filter head unit
US4193780A (en) * 1978-03-20 1980-03-18 Industrial Air, Inc. Air filter construction
US4248648A (en) * 1979-07-18 1981-02-03 Baxter Travenol Laboratories, Inc. Method of repairing leaks in a hollow capillary fiber diffusion device
US4384474A (en) * 1980-10-30 1983-05-24 Amf Incorporated Method and apparatus for testing and using membrane filters in an on site of use housing
US4385150A (en) * 1980-10-17 1983-05-24 Asahi Glass Company, Ltd. Organic solution of fluorinated copolymer having carboxylic acid groups
US4451369A (en) * 1980-12-18 1984-05-29 Toyo Boseki Kabushiki Kaisha Fluid separation apparatus
US4496470A (en) * 1981-01-12 1985-01-29 The B. F. Goodrich Company Cleaning composition
US4511471A (en) * 1982-06-03 1985-04-16 Drm, Dr. Muller Ag Filter apparatus for continuously thickening suspensions
US4636296A (en) * 1983-08-18 1987-01-13 Gerhard Kunz Process and apparatus for treatment of fluids, particularly desalinization of aqueous solutions
US4642182A (en) * 1985-03-07 1987-02-10 Mordeki Drori Multiple-disc type filter with extensible support
US4647377A (en) * 1984-07-24 1987-03-03 Kabushiki Kaisha Ito Tekkousho Filter apparatus
US4650596A (en) * 1983-05-13 1987-03-17 Henkel Kommanditgesellschaft Auf Aktien Pour point depressants for paraffin solutions
US4656865A (en) * 1985-09-09 1987-04-14 The Dow Chemical Company System for analyzing permeation of a gas or vapor through a film or membrane
US4660411A (en) * 1985-05-31 1987-04-28 Reid Philip L Apparatus for measuring transmission of volatile substances through films
US4670145A (en) * 1986-07-08 1987-06-02 E. I. Du Pont De Nemours And Company Multiple bundle fluid separation apparatus
US4673507A (en) * 1985-05-06 1987-06-16 Eco-Tec Limited Fluid treatment process and apparatus
US4718270A (en) * 1983-05-17 1988-01-12 Coulter Electronics, Ltd. Porosimeter and methods of assessing porosity
US4744240A (en) * 1986-05-27 1988-05-17 Akzo Nv Method for determining the bubble point or the largest pore of membranes or of filter materials
US4749487A (en) * 1984-04-11 1988-06-07 Syrinx Research Pty. Ltd. High flux membrane
US4756875A (en) * 1983-09-29 1988-07-12 Kabushiki Kaisha Toshiba Apparatus for filtering water containing radioactive substances in nuclear power plants
US4797211A (en) * 1985-12-24 1989-01-10 Kernforschungszentrum Karlsruhe Gmbh Cross flow microfilter
US4810384A (en) * 1986-06-20 1989-03-07 Rhone-Poulenc Recherches Hydrophilic PVDF semipermeable membrane
US4812235A (en) * 1982-03-29 1989-03-14 Hr Textron, Inc. Filter element assembly replaceable mesh pack
US4816160A (en) * 1985-03-28 1989-03-28 Memtec Limited Cooling hollow fibre cross-flow separators
US4834998A (en) * 1986-12-22 1989-05-30 Heublein, Inc. Ultrafiltration of red wines
US4846970A (en) * 1987-06-22 1989-07-11 Osmonics, Inc. Cross-flow filtration membrane test unit
US4921610A (en) * 1986-09-04 1990-05-01 Memtec Limited Cleaning of hollow fibre filters
US4931186A (en) * 1985-03-05 1990-06-05 Memtec Limited Concentration of solids in a suspension
US4935143A (en) * 1986-07-11 1990-06-19 Memtec Limited Cleaning of filters
US4988444A (en) * 1989-05-12 1991-01-29 E. I. Du Pont De Nemours And Company Prevention of biofouling of reverse osmosis membranes
US4999038A (en) * 1989-02-07 1991-03-12 Lundberg Bo E H Filter unit
US5005430A (en) * 1989-05-16 1991-04-09 Electric Power Research Institute, Inc. Automated membrane filter sampler
US5024762A (en) * 1985-03-05 1991-06-18 Memtec Limited Concentration of solids in a suspension
US5079272A (en) * 1989-11-30 1992-01-07 Millipore Corporation Porous membrane formed from interpenetrating polymer network having hydrophilic surface
US5094867A (en) * 1990-01-16 1992-03-10 Basf Aktiengesellschaft Removal of heavy metal ions from wine and wine-like beverages
US5094750A (en) * 1986-09-12 1992-03-10 Memtec Limited Hollow fibre filter cartridge and header
US5104546A (en) * 1990-07-03 1992-04-14 Aluminum Company Of America Pyrogens separations by ceramic ultrafiltration
US5104535A (en) * 1990-08-17 1992-04-14 Zenon Environmental, Inc. Frameless array of hollow fiber membranes and module containing a stack of arrays
USH1045H (en) * 1990-11-19 1992-05-05 The United States Of America As Represented By The Secretary Of The Army Air bubble leak detection test device
US5182019A (en) * 1990-08-17 1993-01-26 Zenon Environmental Inc. Cartridge of hybrid frameless arrays of hollow fiber membranes and module containing an assembly of cartridges
US5192478A (en) * 1984-10-22 1993-03-09 The Dow Chemical Company Method of forming tubesheet for hollow fibers
US5192456A (en) * 1991-03-07 1993-03-09 Kubota Corporation Apparatus for treating activated sludge and method of cleaning it
US5194149A (en) * 1989-09-29 1993-03-16 Memtec Limited Filter cartridge manifold
US5198116A (en) * 1992-02-10 1993-03-30 D.W. Walker & Associates Method and apparatus for measuring the fouling potential of membrane system feeds
US5209852A (en) * 1990-08-31 1993-05-11 Japan Organo Co. Ltd. Process for scrubbing porous hollow fiber membranes in hollow fiber membrane module
US5211823A (en) * 1991-06-19 1993-05-18 Millipore Corporation Process for purifying resins utilizing bipolar interface
US5221478A (en) * 1988-02-05 1993-06-22 The Dow Chemical Company Chromatographic separation using ion-exchange resins
US5227063A (en) * 1989-10-03 1993-07-13 Zenon Environmental Inc. Tubular membrane module
US5297420A (en) * 1993-05-19 1994-03-29 Mobil Oil Corporation Apparatus and method for measuring relative permeability and capillary pressure of porous rock
US5320760A (en) * 1992-12-07 1994-06-14 E. I. Du Pont De Nemours And Company Method of determining filter pluggage by measuring pressures
US5389260A (en) * 1993-04-02 1995-02-14 Clack Corporation Brine seal for tubular filter
US5393433A (en) * 1992-03-11 1995-02-28 Aquasource, Societe En Nom Collectif Method using separation membranes to treat a fluid containing matter in suspension and in solution
US5401401A (en) * 1993-01-13 1995-03-28 Aquaria Inc. Hang on tank canister filter
US5403479A (en) * 1993-12-20 1995-04-04 Zenon Environmental Inc. In situ cleaning system for fouled membranes
US5405528A (en) * 1990-04-20 1995-04-11 Memtec Limited Modular microporous filter assemblies
US5417101A (en) * 1991-06-10 1995-05-23 Pall Corporation Method and apparatus for testing the integrity of filter elements
US5419816A (en) * 1993-10-27 1995-05-30 Halox Technologies Corporation Electrolytic process and apparatus for the controlled oxidation of inorganic and organic species in aqueous solutions
US5480553A (en) * 1992-02-12 1996-01-02 Mitsubishi Rayon Co., Ltd. Hollow fiber membrane module
US5531848A (en) * 1992-05-18 1996-07-02 Minntech Corporation Method of manufacturing of hollow fiber cartridge with porous ring
US5531900A (en) * 1994-07-07 1996-07-02 University Of Arizona Modification of polyvinylidene fluoride membrane and method of filtering
US5607593A (en) * 1993-11-30 1997-03-04 Otv Omnium De Trajtements Et De Valorisation S.A. Installation for making water potable with submerged filtering membranes
US5639373A (en) * 1995-08-11 1997-06-17 Zenon Environmental Inc. Vertical skein of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate
US5643455A (en) * 1991-08-07 1997-07-01 Memtel Limited Concentration of solids in a suspension using hollow fibre membranes
US5888401A (en) * 1996-09-16 1999-03-30 Union Camp Corporation Method and apparatus for reducing membrane fouling
US5906742A (en) * 1995-07-05 1999-05-25 Usf Filtration And Separations Group Inc. Microfiltration membranes having high pore density and mixed isotropic and anisotropic structure
US5910250A (en) * 1995-08-11 1999-06-08 Zenon Environmental Inc. Baffle for conversion of fine bubbles to coarse while filtering with a vertical skein of hollow fibers
US5914039A (en) * 1997-07-01 1999-06-22 Zenon Environmental Inc. Filtration membrane with calcined α-alumina particles therein
US5918264A (en) * 1992-11-02 1999-06-29 Usf Filtration And Separations Group Inc. Fiber monitoring system
US6039872A (en) * 1997-10-27 2000-03-21 Pall Corporation Hydrophilic membrane
US6048454A (en) * 1997-03-18 2000-04-11 Jenkins; Dan Oil filter pack and assembly
US6077435A (en) * 1996-03-15 2000-06-20 Usf Filtration And Separations Group Inc. Filtration monitoring and control system
US6193890B1 (en) * 1995-08-11 2001-02-27 Zenon Environmental Inc. System for maintaining a clean skein of hollow fibers while filtering suspended solids
US6202475B1 (en) * 1997-05-30 2001-03-20 Usf Filtration And Separations Group, Inc. Predicting logarithmic reduction values
US6221247B1 (en) * 1999-06-03 2001-04-24 Cms Technology Holdings, Inc. Dioxole coated membrane module for ultrafiltration or microfiltration of aqueous suspensions
US6245239B1 (en) * 1998-10-09 2001-06-12 Zenon Environmental Inc. Cyclic aeration system for submerged membrane modules
US6354444B1 (en) * 1997-07-01 2002-03-12 Zenon Environmental Inc. Hollow fiber membrane and braided tubular support therefor
US6387189B1 (en) * 1997-01-09 2002-05-14 Bayer Aktiengesellschaft Surface-cleaning method
US20020070157A1 (en) * 2000-08-18 2002-06-13 Yosuke Yamada Filter device
US6524481B2 (en) * 1998-09-25 2003-02-25 U.S. Filter Wastewater Group, Inc. Apparatus and method for cleaning membrane filtration modules
US20030057155A1 (en) * 1999-09-29 2003-03-27 Hidayat Husain Ultrafiltration and microfiltration module and system
US6550747B2 (en) * 1998-10-09 2003-04-22 Zenon Environmental Inc. Cyclic aeration system for submerged membrane modules
US20030075504A1 (en) * 1998-09-25 2003-04-24 Fufang Zha Apparatus and method for cleaning membrane filtration modules
US6555005B1 (en) * 1996-12-20 2003-04-29 Usf Filtration & Separations Group Inc. Scouring method
US20030089659A1 (en) * 2000-04-10 2003-05-15 Fufang Zha Hollow fibre restraining system
US20040000520A1 (en) * 2001-11-16 2004-01-01 Gallagher Paul Martin Method of cleaning membranes
US6685832B2 (en) * 1995-08-11 2004-02-03 Zenon Environmental Inc. Method of potting hollow fiber membranes
US20040035782A1 (en) * 2000-11-13 2004-02-26 Heinz-Joachim Muller Modified membranes

Family Cites Families (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US655505A (en) * 1900-02-13 1900-08-07 Lloyd Sherbondy Morrow End-gate fastener for mining-cars.
US3139401A (en) * 1962-01-05 1964-06-30 Hach Chemical Co Method for removing rust from water softeners
US3693406A (en) 1970-01-26 1972-09-26 Air Intake Renu Method for inspecting filters
US3700591A (en) * 1970-09-24 1972-10-24 Us Interior Cleaning of used membrane with oxalic acid
US3992301A (en) 1973-11-19 1976-11-16 Raypak, Inc. Automatic flushing system for membrane separation machines such as reverse osmosis machines
JPS54162684A (en) * 1978-06-14 1979-12-24 Ebara Infilco Co Ltd Preliminary treating method for contaminated membrane
JPS5634133B2 (en) * 1979-03-28 1981-08-08
US4218324A (en) 1979-05-03 1980-08-19 Textron, Inc. Filter element having removable filter media member
JPS5621604A (en) * 1979-07-27 1981-02-28 Toray Ind Inc Separation of liquid by semipermeable composite membrane
JPS56121685A (en) * 1980-02-29 1981-09-24 Ebara Infilco Co Ltd Treatment of liquid containing iron ion and manganese ion
US4540490A (en) 1982-04-23 1985-09-10 Jgc Corporation Apparatus for filtration of a suspension
WO1983003984A1 (en) 1982-05-13 1983-11-24 Gerhard Kunz Method for the treatment of a liquid phase, particularly method for desalting aqueous solutions, as well as device for its implementation
GB2132366B (en) 1982-12-27 1987-04-08 Brunswick Corp Method and device for testing the permeability of membrane filters
CA1221645A (en) 1983-02-28 1987-05-12 Yoshihiro Okano Filtration apparatus using hollow fiber-membrane
EP0126714A3 (en) * 1983-05-20 1986-03-05 Christ AG Method and apparatus for the treatment of solutions by reverse osmosis
US4650586A (en) 1983-09-26 1987-03-17 Kinetico, Inc. Fluid treatment system
EP0160014B1 (en) 1983-09-30 1993-01-07 Memtec Limited Cleaning of filters
US4609465A (en) 1984-05-21 1986-09-02 Pall Corporation Filter cartridge with a connector seal
DE3568946D1 (en) 1984-07-09 1989-04-27 Millipore Corp Improved electrodeionization apparatus and method
DE3428307C2 (en) 1984-08-01 1990-06-07 Filterwerk Mann & Hummel Gmbh, 7140 Ludwigsburg, De
JPS62502452A (en) 1985-04-10 1987-09-24
JPH0472569B2 (en) * 1985-04-27 1992-11-18 Toyo Boseki
US4876006A (en) 1985-10-08 1989-10-24 Ebara Corporation Hollow fiber filter device
US4779448A (en) 1986-01-28 1988-10-25 Donaldson Company, Inc. Photoelectric bubble detector apparatus and method
JPH0742861B2 (en) 1986-03-10 1995-05-15 ヤマハ発動機株式会社 An intake system for an internal combustion engine
JP2607579B2 (en) 1986-09-12 1997-05-07 メムテック・リミテッド Hollow fiber filter cartridge and the head
US4784771A (en) 1987-08-03 1988-11-15 Environmental Water Technology, Inc. Method and apparatus for purifying fluids
DE3904544C2 (en) 1989-02-15 1990-12-06 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung Ev, 8000 Muenchen, De
NL8901090A (en) 1989-04-28 1990-11-16 X Flow Bv Method for the production of a microporous membrane and such a membrane.
US5364527A (en) 1990-06-20 1994-11-15 Heinz Zimmermann Apparatus and process for treating water
US5138870A (en) 1989-07-10 1992-08-18 Lyssy Georges H Apparatus for measuring water vapor permeability through sheet materials
DE3923128A1 (en) 1989-07-13 1991-01-24 Akzo Gmbh Flat or capillary membrane of polyvinylidene fluoride on the basis of a homogeneous mixture and a second, rendered hydrophilic by chemical reaction of the polymeric
US5158721A (en) 1989-11-30 1992-10-27 Millipore Corporation Porous membrane formed from interpenetrating polymer network having hydrophilic surface
US5066375A (en) 1990-03-19 1991-11-19 Ionics, Incorporated Introducing and removing ion-exchange and other particulates from an assembled electrodeionization stack
US5248424A (en) 1990-08-17 1993-09-28 Zenon Environmental Inc. Frameless array of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate
FR2666245B1 (en) 1990-08-31 1992-10-23 Lyonnaise Eaux method for controlling the operating modes of an automatic water filtration device to the tubular membranes.
JP2858913B2 (en) 1990-09-26 1999-02-17 オルガノ株式会社 Filtration methods using a hollow fiber membrane
US5069065A (en) 1991-01-16 1991-12-03 Mobil Oil Corporation Method for measuring wettability of porous rock
US5135663A (en) * 1991-10-18 1992-08-04 Loctite Corporation Method of treating (meth)acrylic monomer-containing wastewater
US5137631A (en) 1991-10-22 1992-08-11 E. I. Du Pont De Nemours And Company Multiple bundle permeator
EP0592066B1 (en) 1992-05-01 1997-09-03 Memtec Japan Limited Apparatus for testing membrane filter integrity
US5361625A (en) 1993-04-29 1994-11-08 Ylvisaker Jon A Method and device for the measurement of barrier properties of films against gases
FR2705734B1 (en) 1993-05-25 1995-06-30 Snecma Method and device for improving the safety of fluid filters.
JPH07313850A (en) * 1994-05-30 1995-12-05 Kubota Corp Method for backward washing immersion-type ceramic membrane separator
US5470469A (en) 1994-09-16 1995-11-28 E. I. Du Pont De Nemours And Company Hollow fiber cartridge
US5944997A (en) * 1995-08-11 1999-08-31 Zenon Environmental Inc. System for maintaining a clean skein of hollow fibers while filtering suspended solids
FR2741280B1 (en) * 1995-11-22 1997-12-19 Omnium Traitement Valorisa Method for cleaning a filtration installation of the type submerged membrane
JP3686918B2 (en) * 1996-10-16 2005-08-24 森村興産株式会社 Wastewater, solid-liquid separation for filtration devices such as wastewater
WO1998025694A1 (en) * 1996-12-10 1998-06-18 Usf Filtration And Separations Group Inc. Improved microporous membrane filtration assembly
US6083393A (en) * 1997-10-27 2000-07-04 Pall Corporation Hydrophilic membrane
US6468430B1 (en) * 1998-07-21 2002-10-22 Toray Industries, Inc. Method for inhibiting growth of bacteria or sterilizing around separating membrane
US6280626B1 (en) * 1998-08-12 2001-08-28 Mitsubishi Rayon Co., Ltd. Membrane separator assembly and method of cleaning the assembly utilizing gas diffuser underneath the assembly
DE69924642D1 (en) * 1998-11-23 2005-05-12 Zenon Environmental Inc Water filtration by means of underwater membranes
JP2000157850A (en) * 1998-11-27 2000-06-13 Nitto Denko Corp Separating membrane preservation liquid and separating membrane module
US6214231B1 (en) * 1999-08-27 2001-04-10 Zenon Environmental Inc. System for operation of multiple membrane filtration assemblies
JP3603692B2 (en) * 1999-09-14 2004-12-22 日立プラント建設株式会社 Membrane separation method and apparatus
CA2290053C (en) * 1999-11-18 2009-10-20 Zenon Environmental Inc. Immersed membrane module and process
US6440303B2 (en) * 2000-03-02 2002-08-27 Chapin Manufacturing, Inc. Fluid filter
DE60217848D1 (en) * 2001-04-04 2007-03-15 Us Filter Wastewater Group Inc Potting of hollow fibers
US7247238B2 (en) * 2002-02-12 2007-07-24 Siemens Water Technologies Corp. Poly(ethylene chlorotrifluoroethylene) membranes

Patent Citations (100)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2105700A (en) * 1936-07-13 1938-01-18 William D Ramage Process for purification of beverages
US2926086A (en) * 1957-07-30 1960-02-23 Universal Oil Prod Co Stabilization of non-distilled alcoholic beverages and the resulting product
US3183191A (en) * 1960-04-19 1965-05-11 Hach Chemical Co Stain and rust removing composition
US3228876A (en) * 1960-09-19 1966-01-11 Dow Chemical Co Permeability separatory apparatus, permeability separatory membrane element, method of making the same and process utilizing the same
US3708071A (en) * 1970-08-05 1973-01-02 Abcor Inc Hollow fiber membrane device and method of fabricating same
US3955998A (en) * 1973-06-21 1976-05-11 Phillips Petroleum Company Aqueous gels for plugging fractures in subterranean formation and production of said aqueous gels
US3968192A (en) * 1974-04-19 1976-07-06 The Dow Chemical Company Method of repairing leaky hollow fiber permeability separatory devices
US4082683A (en) * 1975-09-19 1978-04-04 Lever Brothers Company Cleaning of hard surfaces
US4192750A (en) * 1976-08-09 1980-03-11 Massey-Ferguson Inc. Stackable filter head unit
US4193780A (en) * 1978-03-20 1980-03-18 Industrial Air, Inc. Air filter construction
US4188817A (en) * 1978-10-04 1980-02-19 Standard Oil Company (Indiana) Method for detecting membrane leakage
US4248648A (en) * 1979-07-18 1981-02-03 Baxter Travenol Laboratories, Inc. Method of repairing leaks in a hollow capillary fiber diffusion device
US4385150A (en) * 1980-10-17 1983-05-24 Asahi Glass Company, Ltd. Organic solution of fluorinated copolymer having carboxylic acid groups
US4384474A (en) * 1980-10-30 1983-05-24 Amf Incorporated Method and apparatus for testing and using membrane filters in an on site of use housing
US4451369A (en) * 1980-12-18 1984-05-29 Toyo Boseki Kabushiki Kaisha Fluid separation apparatus
US4496470A (en) * 1981-01-12 1985-01-29 The B. F. Goodrich Company Cleaning composition
US4812235A (en) * 1982-03-29 1989-03-14 Hr Textron, Inc. Filter element assembly replaceable mesh pack
US4511471A (en) * 1982-06-03 1985-04-16 Drm, Dr. Muller Ag Filter apparatus for continuously thickening suspensions
US4650596A (en) * 1983-05-13 1987-03-17 Henkel Kommanditgesellschaft Auf Aktien Pour point depressants for paraffin solutions
US4718270A (en) * 1983-05-17 1988-01-12 Coulter Electronics, Ltd. Porosimeter and methods of assessing porosity
US4636296A (en) * 1983-08-18 1987-01-13 Gerhard Kunz Process and apparatus for treatment of fluids, particularly desalinization of aqueous solutions
US4756875A (en) * 1983-09-29 1988-07-12 Kabushiki Kaisha Toshiba Apparatus for filtering water containing radioactive substances in nuclear power plants
US4749487A (en) * 1984-04-11 1988-06-07 Syrinx Research Pty. Ltd. High flux membrane
US4647377A (en) * 1984-07-24 1987-03-03 Kabushiki Kaisha Ito Tekkousho Filter apparatus
US5192478A (en) * 1984-10-22 1993-03-09 The Dow Chemical Company Method of forming tubesheet for hollow fibers
US4931186A (en) * 1985-03-05 1990-06-05 Memtec Limited Concentration of solids in a suspension
US5024762A (en) * 1985-03-05 1991-06-18 Memtec Limited Concentration of solids in a suspension
US4642182A (en) * 1985-03-07 1987-02-10 Mordeki Drori Multiple-disc type filter with extensible support
US4816160A (en) * 1985-03-28 1989-03-28 Memtec Limited Cooling hollow fibre cross-flow separators
US4673507C1 (en) * 1985-05-06 2001-10-16 Eco Tec Fluid treatment process and apparatus
US4673507A (en) * 1985-05-06 1987-06-16 Eco-Tec Limited Fluid treatment process and apparatus
US4660411A (en) * 1985-05-31 1987-04-28 Reid Philip L Apparatus for measuring transmission of volatile substances through films
US4656865A (en) * 1985-09-09 1987-04-14 The Dow Chemical Company System for analyzing permeation of a gas or vapor through a film or membrane
US4797211A (en) * 1985-12-24 1989-01-10 Kernforschungszentrum Karlsruhe Gmbh Cross flow microfilter
US4744240A (en) * 1986-05-27 1988-05-17 Akzo Nv Method for determining the bubble point or the largest pore of membranes or of filter materials
US4810384A (en) * 1986-06-20 1989-03-07 Rhone-Poulenc Recherches Hydrophilic PVDF semipermeable membrane
US4670145A (en) * 1986-07-08 1987-06-02 E. I. Du Pont De Nemours And Company Multiple bundle fluid separation apparatus
US4935143A (en) * 1986-07-11 1990-06-19 Memtec Limited Cleaning of filters
US4921610A (en) * 1986-09-04 1990-05-01 Memtec Limited Cleaning of hollow fibre filters
US5094750A (en) * 1986-09-12 1992-03-10 Memtec Limited Hollow fibre filter cartridge and header
US4834998A (en) * 1986-12-22 1989-05-30 Heublein, Inc. Ultrafiltration of red wines
US4846970A (en) * 1987-06-22 1989-07-11 Osmonics, Inc. Cross-flow filtration membrane test unit
US5221478A (en) * 1988-02-05 1993-06-22 The Dow Chemical Company Chromatographic separation using ion-exchange resins
US4999038A (en) * 1989-02-07 1991-03-12 Lundberg Bo E H Filter unit
US4988444A (en) * 1989-05-12 1991-01-29 E. I. Du Pont De Nemours And Company Prevention of biofouling of reverse osmosis membranes
US5005430A (en) * 1989-05-16 1991-04-09 Electric Power Research Institute, Inc. Automated membrane filter sampler
US5194149A (en) * 1989-09-29 1993-03-16 Memtec Limited Filter cartridge manifold
US5227063A (en) * 1989-10-03 1993-07-13 Zenon Environmental Inc. Tubular membrane module
US5079272A (en) * 1989-11-30 1992-01-07 Millipore Corporation Porous membrane formed from interpenetrating polymer network having hydrophilic surface
US5094867A (en) * 1990-01-16 1992-03-10 Basf Aktiengesellschaft Removal of heavy metal ions from wine and wine-like beverages
US5405528A (en) * 1990-04-20 1995-04-11 Memtec Limited Modular microporous filter assemblies
US5104546A (en) * 1990-07-03 1992-04-14 Aluminum Company Of America Pyrogens separations by ceramic ultrafiltration
US5104535A (en) * 1990-08-17 1992-04-14 Zenon Environmental, Inc. Frameless array of hollow fiber membranes and module containing a stack of arrays
US5182019A (en) * 1990-08-17 1993-01-26 Zenon Environmental Inc. Cartridge of hybrid frameless arrays of hollow fiber membranes and module containing an assembly of cartridges
US5209852A (en) * 1990-08-31 1993-05-11 Japan Organo Co. Ltd. Process for scrubbing porous hollow fiber membranes in hollow fiber membrane module
USH1045H (en) * 1990-11-19 1992-05-05 The United States Of America As Represented By The Secretary Of The Army Air bubble leak detection test device
US5192456A (en) * 1991-03-07 1993-03-09 Kubota Corporation Apparatus for treating activated sludge and method of cleaning it
US5417101A (en) * 1991-06-10 1995-05-23 Pall Corporation Method and apparatus for testing the integrity of filter elements
US5211823A (en) * 1991-06-19 1993-05-18 Millipore Corporation Process for purifying resins utilizing bipolar interface
US5643455A (en) * 1991-08-07 1997-07-01 Memtel Limited Concentration of solids in a suspension using hollow fibre membranes
US5198116A (en) * 1992-02-10 1993-03-30 D.W. Walker & Associates Method and apparatus for measuring the fouling potential of membrane system feeds
US5480553A (en) * 1992-02-12 1996-01-02 Mitsubishi Rayon Co., Ltd. Hollow fiber membrane module
US5393433A (en) * 1992-03-11 1995-02-28 Aquasource, Societe En Nom Collectif Method using separation membranes to treat a fluid containing matter in suspension and in solution
US5531848A (en) * 1992-05-18 1996-07-02 Minntech Corporation Method of manufacturing of hollow fiber cartridge with porous ring
US5918264A (en) * 1992-11-02 1999-06-29 Usf Filtration And Separations Group Inc. Fiber monitoring system
US5320760A (en) * 1992-12-07 1994-06-14 E. I. Du Pont De Nemours And Company Method of determining filter pluggage by measuring pressures
US5401401A (en) * 1993-01-13 1995-03-28 Aquaria Inc. Hang on tank canister filter
US5389260A (en) * 1993-04-02 1995-02-14 Clack Corporation Brine seal for tubular filter
US5297420A (en) * 1993-05-19 1994-03-29 Mobil Oil Corporation Apparatus and method for measuring relative permeability and capillary pressure of porous rock
US5419816A (en) * 1993-10-27 1995-05-30 Halox Technologies Corporation Electrolytic process and apparatus for the controlled oxidation of inorganic and organic species in aqueous solutions
US5607593A (en) * 1993-11-30 1997-03-04 Otv Omnium De Trajtements Et De Valorisation S.A. Installation for making water potable with submerged filtering membranes
US5403479A (en) * 1993-12-20 1995-04-04 Zenon Environmental Inc. In situ cleaning system for fouled membranes
US5531900A (en) * 1994-07-07 1996-07-02 University Of Arizona Modification of polyvinylidene fluoride membrane and method of filtering
US5906742A (en) * 1995-07-05 1999-05-25 Usf Filtration And Separations Group Inc. Microfiltration membranes having high pore density and mixed isotropic and anisotropic structure
US5910250A (en) * 1995-08-11 1999-06-08 Zenon Environmental Inc. Baffle for conversion of fine bubbles to coarse while filtering with a vertical skein of hollow fibers
US6685832B2 (en) * 1995-08-11 2004-02-03 Zenon Environmental Inc. Method of potting hollow fiber membranes
US6193890B1 (en) * 1995-08-11 2001-02-27 Zenon Environmental Inc. System for maintaining a clean skein of hollow fibers while filtering suspended solids
US5639373A (en) * 1995-08-11 1997-06-17 Zenon Environmental Inc. Vertical skein of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate
US6042677A (en) * 1995-08-11 2000-03-28 Zenon Environmental, Inc. Potted header for hollow fiber membranes and method for making it
USRE37549E1 (en) * 1995-08-11 2002-02-19 Zenon Environmental Inc. Vertical skein of hollow fiber membranes and method of maintaining clean fiber surfaces while filtering a substrate to withdraw a permeate
US6077435A (en) * 1996-03-15 2000-06-20 Usf Filtration And Separations Group Inc. Filtration monitoring and control system
US5888401A (en) * 1996-09-16 1999-03-30 Union Camp Corporation Method and apparatus for reducing membrane fouling
US6555005B1 (en) * 1996-12-20 2003-04-29 Usf Filtration & Separations Group Inc. Scouring method
US6387189B1 (en) * 1997-01-09 2002-05-14 Bayer Aktiengesellschaft Surface-cleaning method
US6048454A (en) * 1997-03-18 2000-04-11 Jenkins; Dan Oil filter pack and assembly
US6202475B1 (en) * 1997-05-30 2001-03-20 Usf Filtration And Separations Group, Inc. Predicting logarithmic reduction values
US5914039A (en) * 1997-07-01 1999-06-22 Zenon Environmental Inc. Filtration membrane with calcined α-alumina particles therein
US6024872A (en) * 1997-07-01 2000-02-15 Zenon Evironmental Inc. Method of making a dope comprising hydrophilized PVDF and α-alumina, and a membrane made therefrom
US6354444B1 (en) * 1997-07-01 2002-03-12 Zenon Environmental Inc. Hollow fiber membrane and braided tubular support therefor
US6039872A (en) * 1997-10-27 2000-03-21 Pall Corporation Hydrophilic membrane
US20030075504A1 (en) * 1998-09-25 2003-04-24 Fufang Zha Apparatus and method for cleaning membrane filtration modules
US6524481B2 (en) * 1998-09-25 2003-02-25 U.S. Filter Wastewater Group, Inc. Apparatus and method for cleaning membrane filtration modules
US6550747B2 (en) * 1998-10-09 2003-04-22 Zenon Environmental Inc. Cyclic aeration system for submerged membrane modules
US6245239B1 (en) * 1998-10-09 2001-06-12 Zenon Environmental Inc. Cyclic aeration system for submerged membrane modules
US6221247B1 (en) * 1999-06-03 2001-04-24 Cms Technology Holdings, Inc. Dioxole coated membrane module for ultrafiltration or microfiltration of aqueous suspensions
US20030057155A1 (en) * 1999-09-29 2003-03-27 Hidayat Husain Ultrafiltration and microfiltration module and system
US20030089659A1 (en) * 2000-04-10 2003-05-15 Fufang Zha Hollow fibre restraining system
US20020070157A1 (en) * 2000-08-18 2002-06-13 Yosuke Yamada Filter device
US20040035782A1 (en) * 2000-11-13 2004-02-26 Heinz-Joachim Muller Modified membranes
US20040000520A1 (en) * 2001-11-16 2004-01-01 Gallagher Paul Martin Method of cleaning membranes

Also Published As

Publication number Publication date Type
EP1312408B1 (en) 2006-07-19 grant
DE60213184T2 (en) 2007-06-28 grant
EP1312408A3 (en) 2003-08-06 application
US6955762B2 (en) 2005-10-18 grant
DE60213184D1 (en) 2006-08-31 grant
US20080237125A1 (en) 2008-10-02 application
EP1312408A2 (en) 2003-05-21 application
US20050224411A1 (en) 2005-10-13 application
US20040000520A1 (en) 2004-01-01 application

Similar Documents

Publication Publication Date Title
Crozes et al. Impact of ultrafiltration operating conditions on membrane irreversible fouling
Jacangelo et al. Mechanism of Cryptosporidium, Giardia, and MS2 virus removal by MF and UF
Schäfer et al. Fouling effects on rejection in the membrane filtration of natural waters
Yan et al. Application of the Al2O3–PVDF nanocomposite tubular ultrafiltration (UF) membrane for oily wastewater treatment and its antifouling research
US6171496B1 (en) Antimicrobial filter cartridge
US5501798A (en) Microfiltration enhanced reverse osmosis for water treatment
US20070278152A1 (en) Method of improving performance of ultrafiltration or microfiltration membrane process in landfill leachate treatment
US20070181496A1 (en) Process and apparatus for purifying impure water using microfiltration or ultrafiltration in combination with reverse osmosis
US20020011443A1 (en) Porous hollow fiber membranes and method of making the same
Schlichter et al. Study of a hybrid process combining ozonation and membrane filtration—filtration of model solutions
US6071413A (en) Process for removing organic and inorganic contaminants from phenolic stripped sour water employing reverse omosis
US5024762A (en) Concentration of solids in a suspension
US4931186A (en) Concentration of solids in a suspension
Jacangelo et al. Low‐pressure membrane filtration for removing Giardia and microbial indicators
US20070278151A1 (en) Method of improving performance of ultrafiltration or microfiltration membrane processes in backwash water treatment
US6027649A (en) Process for purifying water using fine floc and microfiltration in a single tank reactor
US20060273038A1 (en) Chemical cleaning for membranes
JP2005087887A (en) Membrane washing method
US20050173341A1 (en) Blended polymer media for treating aqueous fluids
US20110042320A1 (en) Treatment of contaminated water from gas wells
Li et al. Treatment of oily wastewater by organic–inorganic composite tubular ultrafiltration (UF) membranes
US4986918A (en) Membrane separation system and method of operation
Van Hoof et al. The effect of ultrafiltration as pretreatment to reverse osmosis in wastewater reuse and seawater desalination applications
JPH10286441A (en) Cleaning method of hollow yarn membrane module and filtration device used for the method
JPH1176769A (en) Cleaning method of filter membrane module

Legal Events

Date Code Title Description
AS Assignment

Owner name: U.S. FILTER WASTEWATER GROUP, INC., PENNSYLVANIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GALLAGHER, PAUL MARTIN;RAINIER, TOM;BALCZEWSKI, AARON J.;AND OTHERS;REEL/FRAME:016363/0357;SIGNING DATES FROM 20030423 TO 20030425