Abstract: A method for treating ship ballast water with a membrane, which can easily separate and reliably remove a fouling substance attached to a membrane and maintain the membrane flux for long periods. the method including a membrane separation step of taking in seawater in a port area in which a ship is anchored and separating a microorganism with a size equal to or greater than a predetermined size therefrom with a membrane filtration apparatus installed in or on a hull of the ship and having a filtration membrane module, a backwash step of separating a fouling substance attached to a membrane surface of the membrane filtration apparatus from the membrane surface by backwashing is provided.

Abstract: A separation apparatus using a membrane for diafiltration, which provides precise fractionation of a target substance by monitoring and regulating permeability of the target substance based on measurement values and analytical values indicating separation status, such as physical values and concentration of a permeate liquid, a circulating liquid and an internal circulating liquid in a membrane device. A diafiltration process including adding a cleaning liquid to an treating liquid which contains multiple target substances and extracting a target substance into the permeate liquid supplied from a membrane separation apparatus to fractionate the target substance from other target substances remaining in a residual liquid.

Abstract: A method of treating water for municipal use comprises treating the feedwater stream on the feed side of a reverse osmosis membrane with a non-oxidizing, bromine-containing biocide in the substantial absence of a reducing agent, such that biofouling of the membrane is reduced or prevented, and measuring the produced water stream on the permeate side for the presence of bromine-containing compounds. Advantages may include preservation of the membrane, production of water that meets applicable regulations for safe drinking, and simplified processing without additional steps to remove the biocide or its degradation products from the produced water.

Abstract: A method of operating a membrane separator, in which a membrane module comprising a large number of exposed hollow fiber membranes is installed in an untreated water chamber, for making possible stable membrane filtering operation while maintaining a high yield by minimizing loads of the filter membranes and performing effective washing is to be provided, the method including a filtering step at which untreated water is filtered by giving a differential pressure between the primary side (untreated water side) and the secondary side (treated water side) of the hollow fiber membranes, a physical washing step of gas washing by ejecting a gaseous washing medium onto the primary side of the membrane module and of back-pressured water washing by feeding a backwashing medium from the secondary side of the hollow fiber membranes and letting it pass to the untreated water side of the hollow fiber membranes, and a drain step of discharging drain in the chamber out of the system after repeating twice or more the filteri

Abstract: A membrane cleaning apparatus comprising two electrode plates and a filtration unit is provided, wherein the filtration unit is disposed between the electrode plates. The filtration unit comprises a supporting plate and a membrane, and the membrane is disposed on the support plate. This invention can effectively clean the fouling on the membrane by applying an electric field in the membrane region and performing a back flushing process on the membrane. Moreover, a membrane cleaning method is also provided.

Abstract: At the time of loading a ship, ballast water is sent to a ceramic filter membrane having a mesh of 9 to 12 ?m by a filtration pump, and at the time of unloading, ballast seawater is sent to the membrane by the filtration pump to be filtrated under pressure. Thus, marine organisms larger in size than this mesh are removed. The permeated water containing marine organisms smaller in size than the mesh is sterilized with a chemical agent made of chlorine or ozone in a facility for sterilizing with chemical agent, and then discharged into the sea or poured into the ballast tank. With this, it is possible to purify a large amount of ballast water, in a short time, into a level at which the water quality standard according to the guideline can be cleared without requiring any large-sized facility or any high-concentration chemical agent.

Abstract: A method of cleaning a fouled and/or scaled UF or MF membrane with a solution containing one or more thermo-responsive polymers is disclosed. More specifically, the method comprises: (a) treating the membrane in a membrane separation system with a solution containing one or more TRP, wherein said TRP is soluble in said solution and at least an effective amount of said TRP diffuses into a foulant layer that is present on the surface and/or in pores of said membrane; (b) making insoluble said TRP diffused into said foulant layer; (c) optionally rinsing the membrane; (d) optionally backwashing the membrane with air and/or liquid between the steps (b) and (c); and (e) optionally backwashing the membrane with air and/or liquid after the membrane is rinsed in step (c).

Abstract: An apparatus and a method for backwashing filter membrane modules arranged in parallel in the form of a plurality of module rows within a module rack and supplyable with raw water through supply/drain ports at each end face via respectively associated supply/drain lines, and each including a drain port on a wall side for the filtrate, to which a filtrate collection line is connected for draining the filtrate, wherein valve means are provided to control at least one filtration and backwashing mode, wherein, in the backwashing mode, a supply-side control valve of the first supply/drain lines carrying raw water of a module row is closed, but an associated drain-side control valve of the other supply/drain line of one module row serving to drain backwashing water is open, whereas the remaining supply-side control valves in the supply line carrying raw water of the remaining module rows are open, to ensure backwashing of the one module row of the module rack by the filtrate simultaneously produced by the other mod

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

Abstract: The present invention generally relates to a filtration system having one or more apparatuses for filtering gases, liquids, or fluids (e.g., water) to remove particulate matter, and methods of making and using the apparatus. More particularly, embodiments relate to apparatuses and methods for applying centrifugal force(s) to push a fluid or gas to be filtered through a porous membrane or filter within the apparatus to separate particulate matter therefrom. The present invention takes advantage of the Coriolis effect within a cylindrical filter radiating out from a rotating central body. The filtration apparatus provides an energy efficient system for microfiltration (or other filtration process) to remove contaminants from gases and fluids, such as waste water.

Abstract: A method of cleaning a fouled or a scaled RO or NF membrane surface with a solution containing one or more thermo-responsive polymers is disclosed. More specifically, the method comprises: treating the membrane surface in a membrane separation system with a solution containing one or more TRP, wherein said TRP is soluble in said solution and at least an effective amount of said TRP diffuses into a foulant layer on said membrane surface; making insoluble said TRP diffused into said foulant layer; optionally, rinsing the membrane.

Abstract: Direct-osmosis (DO) method for cleaning a semi-permeable membrane in a RO separation module, the membrane having a feed side with foulant located thereon, and an opposite permeate side. A normal RO separation process in the same module includes: feeding, under gauge pressure PGr, raw saline solution having osmotic pressure POr to the membrane feed side; collecting permeate (solvent) having osmotic pressure POp from the permeate side, under gauge pressure PGp; and removing residual brine from the membrane feed side. The method comprises feeding to the feed side of the membrane, for a predetermined injection time, super saline solution having osmotic pressure POs>POr, such that backward flow of permeate towards the feed side of the membrane is provided so as to lift the foulant from the feed side.

Abstract: An aeration system for a submerged membrane module has a set of aerators connected to an air blower, valves and a controller adapted to alternately provide a higher rate or air flow and a lower rate of air flow in repeated cycles. In an embodiment, the air blower, valves and controller, simultaneously provide the alternating air flow to two or more sets of aerators such that the total air flow is constant, allowing the blower to be operated at a constant speed. In another embodiment, the repeated cycles are of short duration. Transient flow conditions result in the tank water which helps avoid dead spaces and assists in agitating the membranes.

Abstract: A method for cleaning and maintaining reverse osmosis membrane filters by injecting sulfurous acid into water to form sulfurous acid (H2SO3), and then sequentially filtering the acidified water through membrane filters to reduce alkalinity and mineral scaling, add sufficient SO2 as a biocide to attack bacteria and other micro organisms to prevent membrane fouling, reduce iron to prevent iron deposit build-up, scavenge and remove dissolved oxygen prior to filtration to prevent membrane oxidation, and prevent concentrated salts within the retentate from precipitating out of solution during transport for land application.

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

Abstract: The present invention is in relation to an apparatus for purification of blood and a method for assembling such apparatus. Also, the invention provides solution to the problem of kidney damage, wherein the damaged kidney can be replaced with the apparatus of instant invention to help in the purification of blood and thus helps the patients at large having kidney related disorders.

Abstract: A method of cleaning a membrane (6) in a membrane filtration system by flowing gas bubbles past the surfaces of the membrane (6) to scour accumulated solids therefrom. The method includes flowing a liquid past a supply of gas; creating a reduced pressure within the liquid flow to cause a flow of gas from the supply of gas (9) into the liquid flow and form gas bubbles therein and then flowing the liquid containing the gas bubbles past the surfaces of the membrane (6) to scour the surfaces thereof. Apparatus for performing the method is also disclosed.

Abstract: A method of improving the water permeability and/or cleaning a porous polymeric membrane (such as a microfiltration or ultrafiltration membrane comprising the step of contacting said a porous polymeric membrane with a source of monopersulfate and a halide ion, such as chloride and optionally a base. The source of monopersulfate may be potassium monopersulfate in conjunction with potassium hydrogen sulfate and potassium sulfate, ie a triple salt of formula 2KHSO5.KHSO4.K2SO4.

Abstract: A membrane module for an immersed operation has a fiber bundle of hollow fiber membranes which are cast into a headpiece and in immersed operation are surrounded by a liquid to be filtered. The module has a permeate collection chamber connected to the headpiece with an outlet for permeate draining from the interior of the hollow fiber membranes, and a gas supply having a pipe guided by the headpiece. The pipe terminates in the interior of the fiber bundle and has a gas outlet for a gaseous medium, which after the transfer from the pipe to the liquid to be filtered rises as bubbles between the hollow fiber membranes. The fiber bundle is divided into sections and free spaces remain between the sections which extend from the pipe to the outer circumference of the headpiece and promote an inflow of the liquid into a foot area adjoining the headpiece.

Abstract: The invention refers to a method for membrane filtration of a product in a membrane plant (1), containing the phases A) filtering the product with a first membrane system (2) of the membrane plant (1), B) cleaning the first membrane system (2) by a multi-step cleaning procedure including at least one rinsing-step with water and at least one cleaning step with a cleaning solution, resulting in at least one contaminated cleaning solution, C) filtering the at least one contaminated cleaning solution with a second membrane system (9), resulting in a recovered cleaning solution and D) using the recovered cleaning solution in a cleaning step of phase B).

Abstract: A cross-flow filtration apparatus is provided. The cross-flow filter is a spiral wound filter that includes a semi-permeable membrane wrapped around a perforated central tube. The semi-permeable membrane includes a feed spacer and a membrane. The feed spacer is a biocidal feed spacer with a biocidal agent impregnated within the feed spacer to prevent biofouling of the feed spacer and the membrane.

Abstract: An aeration system for a submerged membrane module has a set of aerators connected to an air blower, valves and a controller adapted to alternately provide a higher rate or air flow and a lower rate of air flow in repeated cycles. In an embodiment, the air blower, valves and controller, simultaneously provide the alternating air flow to two or more sets of aerators such that the total air flow is constant, allowing the blower to be operated at a constant speed. In another embodiment, the repeated cycles are of short duration. Transient flow conditions result in the tank water which helps avoid dead spaces and assists in agitating the membranes.

Abstract: Provided herein is an innovative hemoperfusion system and method including a thermal-fused broad-spectrum biocidal iodinated interactive polymer for the treatment of biological contaminants in body fluids. In one exemplary embodiment, the system and method utilizes a Triosyn® thermal fused broad-spectrum iodinated interactive polymer, included in a hemoperfusion column, for devitalizing high levels of cell-free microorganisms in whole blood and biological fluids in relation with the characterization of blood cells viability and function post-treatment.

Abstract: In cleaning the dialysis device, first, the concentrate passage is disconnected from the dialysis solution concentrate container and is connected to the branched passage, and a pre-cleaning process is performed in which the fluid circuit is replace with the purified water, and determining means (4a) of a control device (4) determines that the fluid circulating in the fluid circuit is not the dialysis solution by using a conductivity meter (29), and also determines that gas is not contained in the fluid circuit by using a downward movement detecting sensor 34b in a deaeration tank, and then a main cleaning process is performed by using a cleaning solution. Incomplete cleaning due to incomplete connection can be prevented.

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

Abstract: A method for operating a reverse osmosis membrane filtration plant having a raw water intake unit, a pre-treatment unit, and a reverse osmosis membrane filtration unit having a reverse osmosis membrane module in this order, the method including: disposing a biofilm formation base material under conditions that reverse osmosis membrane supply water and/or reverse osmosis membrane non-permeated water in the reverse osmosis membrane filtration unit are/is flowed at a linear speed equal to a non-permeated water linear speed in the reverse osmosis membrane module of the reverse osmosis membrane filtration unit; evaluating a biofilm amount on the biofilm formation base material at a frequency of from once a day to once in six months; and controlling the method for operating a reverse osmosis membrane filtration plant based on results of the evaluation.

Abstract: The invention relates to a device (1) for separating blood into individual components and/or groups of components, in the form of a sterilisable system comprising a filter arrangement (2), which forms an inlet chamber (4) and an outlet chamber (5) by means of filter elements (3) which are arranged therein, a receptacle (6) for cellular blood components and a receptacle (7) for blood plasma. The inlet chamber (4) of the filter arrangement (2) can be connected to the blood source (10) via a line on the inlet side to conduct the blood and is connected, on the outlet side, to the receptacle (6) for cellular components of the blood. The outlet chamber (5) is connected to the receptacle (7) for blood plasma via a line on the outlet side. The aim of the invention is to use thermal sterilisation, in particular vapour sterilisation, in order to sterilise said device.

Abstract: An aerating device for a water treatment system includes an upper and lower chamber separated by a partition. The upper chamber includes a plurality of immersed membranes for removing contaminants from the water. The lower chamber includes a gas inlet and a water inlet for directing gas and water to be treated respectively into the lower chamber. The water inlet is disposed at a lower depth in the lower chamber than the gas inlet. A plurality of air dispersers extend through the partition from the lower chamber to the upper chamber for directing gas from the lower chamber to the upper chamber to aerate the immersed membranes. Finally, the device includes at least one passageway extending through the partition from the lower chamber to the upper chamber for directing water to be treated from the lower chamber to the upper chamber.

Abstract: A method of backwashing a membrane filtration system comprising at least one permeable hollow membrane, the method comprising the step of applying a low-pressure gas to the permeate remaining present in the system when the filtration process is stopped or suspended to provide liquid for backwashing the pores of the membrane during a backwashing process.

Abstract: Desalination system includes a submersible module defining a water-receiving interior and including openings leading from the interior to an exterior, reverse osmosis (RO) membranes arranged in each opening such that the RO membrane is exposed to seawater when the module is submersed, a pump arranged in connection with the interior of module, and a movement system for adjusting the vertical depth at which the module is submersed. The movement system can move the module in vertical and horizontal directions, in any predetermined pattern, or in vertical—horizontal planes defined by the movement system from one location to another location to prevent an elevated salt concentration in an area adjacent the RO membranes and to thereby maintain the osmotic pressure of the seawater in the area adjacent the RO membranes low.

Abstract: Systems and methods for filtering and softening water in combination are disclosed. The systems may include a water filtering system, having a water filter and a water softening system connected to the water filtering system. In addition, a controller may be connected to the water filtering system and the water softening system via wired or wireless connections. The methods may include filtering incoming water, monitoring the hardness of the incoming water, and softening the incoming water when the water hardness is above a maximum level. Furthermore, the performance of the water filtering system may be altered in response to the performance of the water softening system. In addition, the performance of the water softening system may be altered in response to the performance of the water filtering system.

Abstract: A membrane filtration module having a plurality of permeable, hollow membranes is disclosed. In use, a pressure differential is applied across the walls of the permeable, hollow membranes when immersed in a liquid suspension containing suspended solids. Some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate, and at least some of the solids are retained on or in the permeable, hollow membranes or otherwise as suspended solids within the liquid suspension. The module has a shell or similar structure that at least partially surrounds the membrane module and substantially effects retaining at least portion of fluid flowed into the membrane module.

Abstract: A method of cleaning a membrane filtration module (6), the module (6) including at least one membrane (8) located in a feed-containing vessel (7), the membrane (8) having a permeable wall which is subjected to a filtration operation wherein feed containing contaminant matter is applied to one side of the membrane wall and filtrate is withdrawn from the other side of the membrane wall. The method comprising the steps of: suspending the filtration operation; performing a cleaning process on the membrane wall to dislodge contaminant matter therefrom into liquid surrounding the membrane (8); performing a high velocity sweep of the feed-containing vessel (7) to remove the liquid containing the dislodged contaminant matter; and recommencing the filtration operation. An improved gas scouring method is also disclosed.

Abstract: A method for treating a hardly-decomposable-substance-containing water which including: (B) adding an adsorbent to water containing a hardly decomposable substance to cause the hardly decomposable substance to be adsorbed on the adsorbent (adsorption treatment step); (C) separating a permeated liquid through a filter membrane to concentrate the adsorbent which has adsorbed the hardly decomposable substance (membrane filtering treatment step); (D) decomposing the hardly decomposable substance which has been adsorbed on the concentrated adsorbent (hardly decomposable substance decomposition step); and (E) returning the adsorbent after the decomposition of the hardly decomposable substance to the adsorption treatment step (B) (adsorbent returning step); and an apparatus for the treatment.

Abstract: Methods of concentrating an analyte that is in liquid and method of detecting an analyte in a liquid are disclosed. Methods of screening a liquid for the presence of an analyte are also disclosed. Processes comprising continuously collecting a sample of fluid throughout the process and analyzing the sample are disclosed as are processes comprising treating ultrafilter membranes. Devices and systems for concentrating an analyte that is in liquid and for screening a liquid for an analyte are disclosed as well as devices and systems for concentrating an analyte from a continuous sample are disclosed.

Abstract: A method of removing silicon dioxide from a waste liquid is described. A solution containing fluoride ions is added into the waste liquid to form a reaction product. A method of cleaning a membrane tube for processing waste water is also described, wherein the membrane tube contains residues of waste water that include a first residue and a second residue containing silicon dioxide. A first cleaning step is conducted to reduce the concentration of the first residue in the membrane tube to a first concentration. A solution containing fluoride ions is added into the tube to react with the second residue to form a reaction product. A second cleaning step is then conducted to reduce the concentration of the residual fluorine ions in the membrane tube to a second concentration.

Abstract: The invention concerns a water clarifying device comprising a flotation zone (c), a membrane-based filtering zone (e) and extracting means (d), the flotation zone (c) and the membrane-based filtering zone (e) having a common partition wall (P), the common partition wall (P) including in its lower part an opening (o) directly allowing through flotated water towards the filtering zone (e), thereby feeding the membranes with flotated water from down upwards both in filtering phase and in backwashing phase.

Abstract: A method for operating a tapered flow pressure driven arrangement containing a plurality of membrane modules, which comprises positioning said membrane modules in at least two successively arranged flow stages, such that the number of membrane modules operating in parallel in a given flow stage is greater than their number in the consecutive flow stage, passing a feed stream through a flow stage to generate a permeate and a concentrate, directing said concentrate to the consecutive flow stage and passing said concentrate therethrough, while periodically replacing one or more of the membrane modules belonging to said consecutive flow stage with one or more membrane modules belonging to the previous flow stage, wherein the periodicity of said replacement is such that the surface of membranes disposed in said consecutive flow stage is exposed to super-saturation conditions associated with the passage of said concentrate for a period of time that is shorter than the time required for said concentrate to precipita

Abstract: A membrane separating method and a membrane separating device capable of preventing sludge from being accumulated on the surface of hollow fiber membranes in a membrane cartridge and having filtration performance stably sustained for a long period. The membrane cartridge formed by sticking and fixing both ends of two or more hollow fiber membranes arranged in the vertical direction is formed in such a structure that the collected state of the hollow fiber membranes on an upper side adhesive boundary surface is divided into a plurality of hollow fiber membrane bundles.

Abstract: A hollow-fiber porous membrane, comprising a hollow fiber-form porous membrane in a network texture of vinylidene fluoride resin showing a pore size distribution in a direction of its membrane thickness including an outer surface-average pore size P1 as measured by a scanning electron microscope and a membrane layer-average pore size P2 as measured by half-dry method giving a ratio P1/P2 of at least 2.5. The hollow-fiber porous membrane is excellent in long-term water filtration performance including efficiency of regeneration by air scrubbing. The hollow-fiber porous membrane is produced through a process, wherein a mixture of vinylidene fluoride resin, a plasticizer and a good solvent for vinylidene fluoride resin, is melt-extruded in a hollow-fiber film and cooled and formed into a solidified film within a cooling medium containing at least a certain proportion of a good solvent for vinylidene fluoride resin.

Abstract: A method for cleaning a reclaimed water reuse device, the reclaimed water reuse device comprising a clean water supply device, a first aeration device, a backwash device and a membrane module, the method comprising detecting an operating signal of the clean water supply device; enabling the first aeration device or the backwash device according to the operating signal, so as to perform backwash of the membrane module; and completing washing back and restoring to a normal operating state.

Abstract: An HPLC column holding apparatus used to mount an HPLC column in one of a plurality of positions is disclosed herein. The apparatus comprises a clip-device interface that secures the apparatus to a platform and a clip-column interface that secures the HPLC column to the apparatus.

Abstract: The present invention provides methods for cleaning surfaces that are sensitive to high temperatures and/or that have pH limitations. Exemplary surfaces to be cleaned using the methods of the present invention include membranes. The methods of the present invention include applying an active oxygen use solution including an active oxygen source to the surface. An activator complex and an alkaline override use solution are applied to the surface, either in combination, or in a stepwise manner, before, after or simultaneously with the active oxygen use solution.

Abstract: Compositions, methods and devices for the removal of organic contaminants from fluids using hydrophobic micro-porous adsorbents, which are regenerated by advanced oxidation.

Abstract: Embodiments of the invention provide a reverse osmosis system including a feed water inlet, a reverse osmosis module coupled to the feed water inlet, and at least one blend valve. The blend valve can be coupled to a permeate outlet and the feed water inlet and can be capable of blending the feed water and the permeate water to produce mixed water. The blend valve can be adjusted to achieve a desired TDS level in the mixed water.

Abstract: Intermittent gas flow and membrane separation apparatus and methods of use including an internal gas chamber including an upper wall; at least one inlet for supplying gas to the internal gas chamber; a column pipe that extends above the upper wall of the internal gas chamber, the column pipe including a lower end portion including a lower end portion opening in the internal gas chamber, the column pipe linking the internal gas chamber to an area external to the internal gas chamber for fluid flow between the internal gas chamber and the external area; an auxiliary pipe including one end portion connected to the column pipe for fluid flow between the auxiliary pipe and the column pipe, and another end portion branched off from the column pipe, the another end portion including an opening located in the internal gas chamber at a position higher than the lower end portion opening of the column pipe by a predetermined height; and an auxiliary pipe external tubular member including a closed end, the auxiliary pipe

Abstract: A method of controlling fouling of a reverse osmosis membrane disposed in an aqueous medium by an inorganic foulant involves providing a fouling control agent comprising an acidic polysaccharide such as alginic acid fouling control agent dissolved in the aqueous medium in an amount effective to reduce, reverse, or prevent fouling by an inorganic foulant.

Abstract: A microfiltration apparatus and method for separating cells, such as circulating tumor cells, from a sample using a microfiltration device having a top porous membrane and a bottom porous membrane. The porous membranes are formed from parylene and assembled using microfabrication techniques. The porous membranes are arranged so that the pores in the top membrane are offset from the pores in the bottom membrane.

Abstract: The use of dihalogeno-hydroxydiphenyl ethers as antimicrobial agents in water treatment processes, such as in purification and decontamination of drinking or waste water, is claimed. Preferably the water treatment is performed in a membrane filtration system. The antimicrobial agents protect the membrane system against bacterial and/or algal decay and assist in maintaining a high efficiency of the membrane filtration process. Methods of maintaining membrane filtration efficiency using dihalogeno-hydroxydiphenylethers as well as aqueous antimicrobial rinsing liquors comprising dihalogeno-hydroxydiphenylethers are also claimed.

Abstract: A method of cleaning a fouled RO membrane in a module for RO separation, the membrane having feed side and permeate side, the foulant accumulating at the feed side. The cleaning method comprises: feeding concentrated saline solution to the feed side of the RO membrane under the high gauge pressure of the normal RO separation process; feeding dilute saline solution to the permeate side of the RO membrane under higher pressure than the permeate pressure of the normal RO process, so that a net driving differential ?PN is directed to the feed side, whereby the solvent is being sucked from the permeate side to the feed side, penetrates into the interface between the membrane and the accumulated foulant, and separates the foulant from the membrane surface; and withdrawing the concentrated saline solution together with the separated foulant and the penetrated solvent from the feed side of the RO membrane.