WO2023141682A1

WO2023141682A1 - A filtration assembly and method of use thereof

Info

Publication number: WO2023141682A1
Application number: PCT/AU2023/050055
Authority: WO
Inventors: Craig John Mair; Shane Law
Original assignee: Blue Quest Group Pty Ltd
Priority date: 2022-01-31
Filing date: 2023-01-31
Publication date: 2023-08-03

Abstract

A filtration assembly and method of use thereof are provided for causing a flowable filter medium composition to form a stable filter membrane. In one form, there is provided a filtration assembly including: a vessel; a main conduit extending into the vessel for receiving a flow of filtrate and conducting the flow of filtrate to an outlet; one or more branch conduits extending out from, and in fluid communication with, the main conduit, each of said branch conduits having at least a porous portion defining a filter medium mount; and a flowable filter medium composition including a hydrate gel configured to be applied to at least the filter medium mount on each branch conduit and form a stable filter membrane when at least one of the vessel has a positive internal pressure, the filter medium mount on each of the one or more branch conduits is maintained under a positive pressure and a positive transmembrane pressure is applied from a filtrate side of the filter membrane.

Description

A FILTRATION ASSEMBLY AND METHOD OF USE THEREOF

TECHNICAL FIELD

[0001 ] The present invention relates to a filtration assembly and method of use thereof.

BACKGROUND

[0002] The separation of solids, such as, particulate material, from water or aqueous solutions, is required in many different industries. In this regard, a number of different techniques have been developed for separating such solids from a liquid, including filtration, sedimentation, settling, clarification, thickening, cyclonic separation and the like.

[0003] Media Filtration typically involves passing an unfiltered liquid, such as, e.g., a contaminated aqueous solution, through a filter medium, and collecting and retaining the filtered liquid, also known as the “filtrate”. The filter medium usually includes a bed or cake of fine material, such as, e.g., sand or diatomaceous earth. Particles in the liquid that are larger than interstitial spaces between the particles of the filter medium become trapped within the filter medium and are removed from the liquid. However, particles in the liquid that are finer than the interstitial spaces are able to pass through the filter medium and are thus not removed.

[0004] Membrane filtration involves passing an unfiltered liquid, e.g., untreated surface water or sewerage, through a membrane made of polymer, ceramic or metal. Each type of membrane has a specific “pore” size, e.g., microfiltration membranes typically have a 0.2 micron effective pore size useful for rejecting certain bacteria and other pathogens, ultrafiltration membranes typically have a 0.01 micron effective pore size, nanofiltration membranes typically have a 0.2-2nm effective pore size, and reverse osmosis membranes have a pore size of approximately 0.0001 microns.

[0005] A problem in general with media filtration is that traditional filters are usually insufficient to filter very fine particles and microorganisms from a liquid. In addition, media filters are known to “shed” trapped particle from time to time, and therefore do not represent an “absolute barrier” to filtration. As such, additional steps may be required to further treat a resulting filtrate. For example, drinking water is normally subjected to chlorination to kill any microorganisms in the water.

[0006] Over the last few decades, the water treatment industry has increasingly moved away from media filtration towards membrane filtration, as a result of increasingly tight regulatory requirements and improved (reduced) costs of membrane systems. [0007] In general, a problem with membrane filtration is the fouling of the membranes. Fouling occurs when contaminants collect on the surface or in the interstitial spaces of the filter membrane thereby clogging the filter membrane and reducing filtration efficiency, limiting the amount filtrate that is available and even possibly damaging the filter membrane requiring costly membrane replacement. Current best practice is to intermittently clean fouled filter membranes with air scouring and gas backwashes and, less frequently, to apply chemical cleaning. However, even when all of the above remedies are routinely applied, it is not uncommon to replace filter membranes at 18-month intervals due to irreversible fouling. Also, it is not uncommon for membranes to require complete replacement because of operational “excursions” where unexpected irreversible membrane fouling or membrane degradation occurs due to changes in feed water quality or other operational conditions. Polypropylene membranes, for example, can be completely degraded by exposure to chlorine in the feed water.

[0008] Water treatment plants are usually compared on the basis of their cost of ownership (COO). For membrane systems, the intermittent replacement of the costly membranes can substantially increase the COO. Therefore, it would be advantageous to develop a membrane system where irreversible membrane fouling or membrane degradation is not an issue.

[0009] Pre-coat filtration is a relatively old filter technology in where the filter medium (e.g., sand perlite, or diatomaceous earth) is used as a separation layer on a substrate. At intervals, the filter medium, when spent (i.e., full and unable to retain further contaminants from the feed water), is physically removed with a mechanical scraper, and then replaced with fresh filter medium material. This technology has found a useful niche inside the water treatment industry, but due to operational costs and treatment specifications (i.e., the treated water is of relatively low quality and not up to modern standards) is not widely used.

[0010] In the academic literature there has, for many years, been active research in the field of dynamic membranes. In this application space, temporary membranes are formed on top of a supporting substrate, and then used to filter liquids. These are called “membranes” because in principle these materials have an absolute pore size, i.e., a particle above a certain size should not be able get through the membrane material. In practice this results in “log reduction values” such as 4-9 (that is, 99.99-99.999999% of certain sized particle are rejected by the dynamic membrane layer). Although there has been a long study of these materials in academia, there has been no successful transition of dynamic membrane systems to industry, primarily because the water treatment industry at all times has been satisfied with the cost and performance of the technology at hand.

[0011 ] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

[0012] Embodiments of the present invention provide a filtration assembly, a filter medium support and methods of use thereof, which may at least partially address one or more of the problems or deficiencies mentioned above or which may provide the public with a useful or commercial choice.

[0013] According to a first aspect of the present invention, there is provided a filtration assembly including: a vessel having an inlet and an outlet; a main conduit extending into the vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet; one or more branch conduits extending out from, and in fluid communication with, the main conduit, each of said one or more branch conduits having at least a porous portion defining a filter medium mount; and a flowable filter medium composition including a hydrate gel, said medium composition configured to be applied to at least the filter medium mount on each of the one or more branch conduits and form a stable filter membrane when at least one of the vessel has a positive internal pressure, the filter medium mount on each of the one or more branch conduits is maintained under a positive pressure and a positive transmembrane pressure is applied from a filtrate side of the filter membrane.

[0014] According to a second aspect of the present invention, there is provided a filtration assembly including: a pressure vessel having an inlet and an outlet; a main conduit extending into the pressure vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet; one or more branch conduits extending out from, and in fluid communication with, the main conduit, each of said one or more branch conduits having at least a porous portion defining a filter medium mount; and a flowable filter medium composition including a hydrate gel, said medium composition configured to be applied to at least the filter medium mount on each of the one or more branch conduits and form a stable filter medium when the pressure vessel has a positive internal pressure or positive transmembrane pressure.

[0015] According to a third aspect of the present invention, there is provided a filtration assembly including: a tank having an inlet and an outlet; a main conduit extending into the tank from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet; one or more branch conduits extending out from, and in fluid communication with, the main conduit, each of said one or more branch conduits having at least a porous portion defining a filter medium mount; and a flowable filter medium composition including a hydrate gel, said medium composition configured to be applied to at least the filter medium mount on each of the one or more branch conduits and form a stable filter membrane when at least one of the filter medium mount on each of the one or more branch conduits is maintained under a positive pressure and a positive transmembrane pressure is applied from a filtrate side of the filter membrane.

[0016] According to a fourth aspect of the present invention, there is provided a filter medium support for use in a vessel having an inlet and an outlet, said support including: a main conduit extending into the vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet; and one or more branch conduits extending out from, and in fluid communication with, the main conduit, each of said one or more branch conduits having at least a porous portion defining a filter medium mount and configured to have a flowable filter medium composition including a hydrate gel applied to at least the filter medium mount, wherein said flowable filter medium composition forms a stable filter membrane when at least one of the vessel has a positive internal pressure, the filter medium mount on each of the one or more branch conduits is maintained under a positive pressure and a positive transmembrane pressure is applied from a filtrate side of the filter membrane.

[0017] Advantageously, the filtration assembly of the present invention provides a filter medium support for supporting the flowable filter medium composition and an environment for causing the flowable filter medium composition to form a stable filter membrane. Accordingly, the present invention provides a means for the industrial application of metal hydroxide hydrates as filter membranes without the metal hydroxide hydrate flowing out of position. Additionally, the present invention provides a filter medium that can be readily removed and/or regenerated as needed without the costs and labour associated with intermittent air scouring, gas backwashes, deep chemical cleaning and replacement air filters of contemporary filtration systems.

[0018] As indicated, the assembly and support of the present invention is for filtration. The present invention is at least in part predicated on the discovery that a hydrate gel, such as, e.g., a metal hydroxide hydrate in particular, forms a stable filter medium when maintained under pressure, preferably of at least 20 kPa.

[0019] As used herein, the term “hydrate gel” may include any gel having flowable properties at room temperature and capable of separating one or more components selected from particulate material, hydrophobic material, non-polar material, microorganisms, or viruses from a mixture of water and the one or more components, or from a mixture of a polar liquid and the one or more components.

[0020] In some embodiments, the hydrate gel may include a metal hydroxide hydrate as disclosed in WO 2015/081384, the contents of which is herein incorporated by reference in its entirety.

[0021 ] The metal hydroxide hydrate may be selected from one or more of aluminium hydroxide hydrate, magnesium hydroxide hydrate, zinc hydroxide hydrate, manganese hydroxide hydrate, cobalt hydroxide hydrate and nickel hydroxide hydrate, or a mixture thereof.

[0022] As indicated, the filtration assembly may include a vessel having an inlet and an outlet for respectively receiving an inflow of an unfiltered liquid and an outflow of the filtrate.

[0023] In some embodiments, such as, e.g., according to the second aspect, the vessel may be a pressure vessel.

[0024] The pressure vessel may be of any suitable size, shape and construction and may be formed from any suitable material or materials capable of holding a positive pressure, typically of at least 20 kPa.

[0025] Generally, the pressure vessel may be formed from metal and/or plastic material or materials, preferably metal, more preferably stainless steel.

[0026] In some embodiments, the pressure vessel may include a pair of opposed ends and at least one sidewall extending therebetween, preferably longitudinally. The opposed ends may include a first end and an opposed second end. A central axis may extend between the opposed ends.

[0027] The opposed ends may each have a substantially circular profile shape, although non circular profile shapes, such as, e.g., triangular, square or rectangle, are also envisaged.

[0028] In some such embodiments, the at least one sidewall may extend linearly between the opposed ends. [0029] In other such embodiments, the at least one sidewall may have a convex curvature. For example, the at least one sidewall may flare away from the central axis between the opposed ends to a widest part located about mid-way between the ends.

[0030] The inlet and the outlet may each be located in any suitable location on the pressure vessel. For example, the inlet and/or the outlet may be located at the first end, the second end or the sidewall.

[0031 ] In some such embodiments, the inlet and the outlet may be located at the same end. In other such embodiments, the inlet and the outlet may be located opposite one another, such as, e.g., at opposite ends.

[0032] In other embodiments, the pressure vessel may include a base, an opening located opposite the base and at least one sidewall extending therebetween. A central axis may be defined between the base and the opening.

[0033] The at least one sidewall may have a convex curvature. Specifically, the at least one sidewall may flare away from the central axis between the base and the opening to a widest part located about mid-way between the base and the opening.

[0034] The inlet and the outlet may be provided at the opening. For example, the pressure vessel may include a cap attachable to the opening and defining the inlet and the outlet therein.

[0035] In other embodiments, such as, e.g., according to the third aspect, the vessel may include a tank. Such embodiments may be primarily directed to the filtration of high volumes of unfiltered fluid.

[0036] The tank may be of any suitable size, shape and construction and may be formed from any suitable material or materials capable of supporting a filter medium support therein, holding a volume of unfiltered fluid and at least initially maintaining the flowable filter medium applied to at least the filter medium mount on each of the one or more branch conduits under pressure, typically of at least 20kPa.

[0037] Generally, the tank may be formed from metal, cementitious, earthen or plastic material or materials. If cementitious or earthen, the tank may preferably include a substantially fluid impermeable liner or coating applied to an inner surface of the tank.

[0038] In some embodiments, the tank may include a base, a rim and at least one wall extending from the base to the rim. The rim may extend from an upper portion of the at least one wall and may extend along an edge of the at least one wall. [0039] In other embodiments, the tank may include a base, a lid and at least one wall extending between the base and the lid.

[0040] The base may be of any suitable shape.

[0041 ] For example, in some such embodiments, the base may be circular or oval-shaped.

[0042] In other such embodiments, the base may be in the shape of a triangle, rectangle, pentagon, hexagon or octagon, for example.

[0043] In preferred such embodiments, the tank may include a rectangular-shaped base with four walls extending from the base to the rim or from the base to the lid. The four walls may include a pair of opposed end walls and a pair of opposed sidewalls.

[0044] The inlet and the outlet may be located in any suitable location on the tank. For example, the inlet and/or the outlet may be located on any one of the base, the at least one wall and/or the lid, if present.

[0045] In some embodiments, the inlet and the outlet may be located adjacent each other, such as, e.g., side by side on the base, a same wall and/or the lid, if present.

[0046] In other preferred embodiments, the inlet and the outlet may be located substantially opposite each other, typically on opposed end walls or opposed sidewalls, preferably opposed end walls.

[0047] As indicated, the filtration assembly includes a main conduit extending into the vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet.

[0048] The main conduit may be of any suitable size and shape for receiving and conducting the flow of filtrate. Likewise, the main conduit may be formed from any suitable material or materials.

[0049] Generally, the main conduit may include a tubular section. The conduit may include a pair of opposed ends and at least one sidewall extending longitudinally therebetween, preferably in a linear direction.

[0050] The pair of opposed ends may include an outlet end coupled to, and in fluid communication with the outlet defined in the vessel, and an opposed distal end. The distal end may preferably be closed.

[0051 ] The at least one sidewall may preferably be curved such that the conduit has a substantially circular profile shape, although non-circular conduits are also envisaged.

[0052] Generally, the main conduit may be formed from ceramic, concrete, fibreglass, plastic and/or metal material or materials, typically steel, polyvinyl chloride (PVC) or ceramic, preferably stainless steel, unplasticized PVC (uPVC) or chlorinated PVC (cPVC).

[0053] The main conduit may be of any suitable length to extend at least partially along a length of an internal volume of the vessel. For example, the main conduit may extend at least 75%, at least 80%, at least 85%, at least 90% or at least 95% of an internal length of the vessel.

[0054] In embodiments in which the vessel is a pressure vessel, the main conduit may preferably extend at least partially along a central axis of the pressure vessel, typically in a generally vertical orientation although a horizontal orientation is also envisaged.

[0055] In embodiments in which the vessel is a tank, the main conduit may extend at least partially along a midline of the tank, preferably along or substantially adjacent the base, more preferably along a longitudinal axis of the tank and substantially adjacent the base.

[0056] In other embodiments in which the vessel is a tank, the main conduit may extend transversely across the tank (perpendicular to a longitudinal axis of the tank), preferably along or substantially adjacent the base.

[0057] As indicated, the one or more branch conduit may extend out from, and be in fluid communication with, the main conduit within the internal volume of the vessel.

[0058] In some embodiments, the one or more branch conduits may each include a tubular section. Each branch conduit may include a pair of opposed ends and at least one sidewall extending longitudinally therebetween.

[0059] In some such embodiments, each branch conduit may extend linearly between the opposed ends.

[0060] In other such embodiments, each branch conduit may include one or more bends or curves as it extends between the opposed ends.

[0061 ] The pair of opposed ends may include a coupling end coupled to, and in fluid communication with, the main conduit, and an opposed distal end. The distal end may extend way from the main conduit into the internal volume of the vessel. The distal end may preferably be closed.

[0062] Again, the at least one sidewall may preferably be curved such that the conduit has a substantially circular profile shape, although non-circular conduits are encompassed.

[0063] The one or more branch conduits may be provided in differing diameters and combinations of branch conduits having differing diameters may extend from the main conduit.

[0064] In other embodiments, each branch conduit may include a plate in fluid communication with the main conduit. In such embodiments, a plurality of branch conduits each in the form of a plate may be arranged in a sandwich arrangement. Each plate may include a pair of opposed surfaces defining the filter medium mounts interconnected by opposing edges.

[0065] In some such embodiments, the assembly may further include a frame for holding the plurality of branch conduits in the sandwich arrangement.

[0066] In preferred such embodiments, the branch conduits may be arranged in a plate- and-frame module as is known in the art.

[0067] In other embodiments, the branch conduits may be arranged in hollow fibres or spiral wound flat sheet systems as are known in the art.

[0068] A person skilled in the art will appreciate that there are many factors that can be customised to provide desired filtration characteristics for a desired application. These include, by way of example only and not by way of limitation, the number of differently sized branch conduits, the patterned arrangement of differently sized branch conduits about the main conduit and the density of branch conduits arranged about the main conduit.

[0069] As indicated, each branch conduit may include at least a porous portion defining a filter medium mount upon which the flowable filter medium composition may be applied and through which a flow of filtrate may pass on its way to the outlet.

[0070] In some embodiments, the porous portion may include one or more discrete portions defined on the sidewall of each branch conduit.

[0071] In some embodiments, the porous portion may extend along and around the entire sidewall and, optionally, the distal end as well.

[0072] In embodiments in which each branch conduit comprises a plate, the porous portions may be defined on at least one or more portions of the opposed surfaces of the plate.

[0073] Each porous portion may define a plurality of pores in the branch conduit for the passage of filtrate emerging from the stable filter membrane. The plurality of pores may range in size between less than about 2pm to about 10pm or more, preferably between about 2pm to about 10pm.

[0074] Each of the one or more branch conduits may typically be formed from any suitable material or materials capable of having the flowable filter medium composition externally mounted thereon and form the stabile filter membrane and convey the filtrate filtered by the stable filter membrane.

[0075] Generally, the one or more branch conduits may be formed from ceramic, plastic and/or metal material or materials, typically steel, steel, polyvinyl chloride (PVC) or ceramic, preferably stainless steel, unplasticized PVC (uPVC) or chlorinated PVC (cPVC).

[0076] In some embodiments, the porous portion may include a mesh portion.

[0077] In other embodiments, the porous portion may be formed by a sintering process. For example, the one or more branch conduits may be formed from a sintered metal, such as, e.g., sintered steel.

[0078] In some embodiments, the one or more branch conduits may each be formed from sintered 306 stainless steel with welded 316 steel caps on the distal end.

[0079] As indicated, in some embodiments, the one or more branch conduits may extend out from the main conduit, typically in a transverse orientation relative to a longitudinal axis of the main conduit. The branch conduits may extend out at any suitable angle relative to the main conduit, preferably orthogonally.

[0080] Any suitable number of branch conduits may extend out from the main conduit. A person skilled in the art will again appreciate that the number of branch conduits may be dependent on the material being filtered, the filtration rate and the type and size of the vessel.

[0081 ] The one or more branch conduits may include one conduit, two conduits, three conduits, four conduits, five conduits, six conduits, seven conduits, eight conduits, nine conduits, 10 conduits, 11 conduits, 12 conduits, 13 conduits, 14 conduits 15 conduits, 16 conduits, 17 conduits, 18 conduits, 19 conduits 20 conduits, 21 conduits, 22 conduits, 23 conduits, 24 conduits, 25 conduits, 26 conduits, 27 conduits, 28 conduits, 29 conduits, or even 30 conduits or more. In preferred embodiments, the assembly may include a plurality of branch conduits.

[0082] The branch conduits may extend out from the main conduit in a spaced arrangement around a periphery of the main conduit and extend at least partially along a length of the main conduit. [0083] In some embodiments, the branch conduits may be arranged in diametrically opposed pairs around a periphery of the main conduit and extending at least partially along a length of the main conduit.

[0084] In other embodiments, the branch conduits may be arranged in a spaced arrangement around the periphery of the main conduit and extending at least partially along a length of the main conduit, preferably an evenly spaced arrangement around the periphery of the main conduit.

[0085] In some embodiments, the branch conduits may extend out from the main conduit in a spaced arrangement from the distal end at least partially towards the outlet.

[0086] For example, in embodiments in which the vessel is a pressure vessel, the main conduit may extend in a generally vertical orientation and the branch conduits may extend out from the main conduit in a spaced arrangement from a lower distal end to an operating depth of the pressure vessel.

[0087] Conversely, in embodiments in which the vessel is a tank, the main conduit may extend in a generally horizontal orientation along a mid-line and/or longitudinal axis of the tank and the branch conduits may extend out from the main conduit in a spaced arrangement from the distal end at least partially towards the outlet, preferably an entire length of the main conduit.

[0088] Alternatively, in embodiments in which the vessel is a tank, the main conduit may extend in a generally horizontal orientation transversely across the tank (perpendicular to a longitudinal axis of the tank) and the branch conduits may extend out from the main conduit in a spaced arrangement from side to side, preferably along an entire length of the main conduit.

[0089] The main conduit and each of the branch conduits may be connected together in any suitable way, preferably a fluid-tight connection.

[0090] For example, in some embodiments, the plurality of branch conduits may be integrally formed with the main conduit.

[0091 ] In other embodiments the branch conduits and the main conduit may be connected together by a connecting mechanism or parts thereof. The connecting mechanism or parts thereof may or may not be of integral formation with each of the coupling end of the branch conduits and the sidewall of the main conduit.

[0092] In some such embodiments, the connecting mechanism may include a first part associated with the coupling end of each branch conduit and a second part connectable to the first part and associated with the sidewall of the main conduit.

[0093] The connecting mechanism may include mateable male and female portions that couple together, such as, e.g., by a threaded connection, an interference (snap-fit) connection, a bayonet-type connection or a friction fit connection.

[0094] In some such embodiments, the first part of the connecting mechanism associated with the branch conduit may include a male formation configured to be inserted into, or coupled with, a female formation of the second part of the connecting mechanism associated with the sidewall of the main conduit.

[0095] Conversely, in other such embodiments, the first part of the connecting mechanism may include a female formation configured to at least partially receive, or be coupled with, a male formation of the second part of the connecting mechanism.

[0096] In yet other embodiments, the main conduit may include a plurality of branch conduit mounting points defined on the at least one sidewall. Each mounting point may include a threaded bore in fluid communication with an inner passageway of the main conduit and the coupling end of each branch conduit may include a threaded boss configured to threadingly engage with the threaded bore of a respective mounting point.

[0097] In some embodiments, each coupling or connection between the main conduit and a branch conduit may include one or more sealing members for providing a fluid-tight coupling or connection.

[0098] Any suitable type of sealing member may be used. For example, in some embodiments, the sealing member may be formed from a resiliently deformable material or materials capable of at least partially deforming for forming a fluid-tight seal between the main conduit and a branch conduit. Preferably, the sealing member may be an O-ring.

[0099] Typically, each sealing member may be formed from plastic and/or rubber material or materials, such as, e.g., polyethylene, high density polyethylene, low density polyethylene, polyvinyl chloride, polyurethane, polypropylene, polystyrene, polycarbonate, silicone, or polyester, preferably polyurethane.

[00100] In some embodiments, the main conduit may include a branch conduit coupling portion having a plurality of mounting points defined thereon.

[00101] As indicated, the assembly further includes a flowable filter medium composition including a hydrate gel for forming a stable filter membrane on at least each filter medium mount of the one or more branch conduits.

[00102] As used herein, the term “flowable” means that the composition is substantially liquid with a viscosity enabling the composition to readily flow when at room temperature and atmospheric pressure.

[00103] The composition is preferably an aqueous composition.

[00104] In some embodiments, the composition may be a homogenous composition containing a single type of hydrate gel.

[00105] In other embodiments, the composition may be a heterogenous composition containing two or more types of hydrate gel and/or other components.

[00106] In some embodiments, the composition may further include a visual marker, such as, e.g., a dye, to enable the stable filter membrane to be readily visualised when formed on the filter medium mounts. Any suitable visual marker may be used, such as, e.g., a brightly coloured dye, a UV dye or a fluorescent dye.

[00107] In some embodiments, the composition may further be a carrier for other materials, such as, e.g., absorption material or materials.

[00108] For example, in some such embodiments, the composition may further function as a carrier molecule for one or more lithium extraction absorber in a direct lithium extraction process, such as, e.g., hydrated alumina, a lithium aluminium layered double hydroxide chloride, a layered double hydroxide modified activated alumina, a layered double hydroxide imbibed ion exchange resin or copolymer or molecular sieve or zeolite, layered aluminate polymer blends, a lithium manganese oxide, a titanium oxide, an immobilized crown ether, or any combination thereof.

[00109] Generally, the composition may be introduced into the vessel via the inlet from a source of the composition. The composition may be poured into the vessel until all of the one or more branch conduits are substantially covered by the composition, preferably entirely covered.

[00110] As indicated, to cause the flowable filter medium composition to form the stable filter membrane on at least the respective filter medium mounts of the one or more branch conduits, a positive internal pressure may be applied within the pressure vessel or the filter medium mounts may be maintained under pressure. [0011 1] Any suitable amount of pressure may be applied. Generally, a pressure of at least 20kPa may be applied, typically a pressure of between about 20kPa and about 42kPa, preferably a pressure of between about 20kPa and about 35kPa.

[00112] Advantageously, the present inventors have found that the application of pressure causes the flowable filter medium composition to form the stable filter membrane on at least the respective filter medium mounts when exposed to a positive pressure (including a positive transmembrane pressure from the filtrate side of the filter membrane) for a period of time.

[00113] Specifically, the stable filter membrane includes a stable filtration bed or cake bonded to the filter medium mount, typically having a thickness of at least about 2pm, preferably having a thickness of between about 2pm and 1 mm.

[00114] In some embodiments, the flowable filter medium composition may be applied to at least the filter medium mount on each of the one or more branch conduits under pressure for any suitable period of time so as to form the stable filter membrane.

[00115] For example, the flowable filter medium composition may be applied for about 10sec, about 20sec, about 30sec, about 40sec, about 50sec, about 1 min, about 1 ,5mins, about 2mins, about 2.5mins, about 3mins, about 3.5mins, about 4mins, about 4.5mins, about 5mins, about 6mins, about 7mins, about 8mins, about 9mins, about 10mins, about 15mins, about 20mins, about 30mins, about 40mins, about 50mins or even about 60mins or longer. Typically, the flowable filter medium composition may be applied for between about 1 ,5mins and about 3mins, preferably about 2mins.

[00116] Once the stable filter membrane has formed, any residual (liquid) composition can be removed from the pressure vessel via the outlet, preferably by a pump or suction.

[00117] In embodiments in which the vessel is a pressure vessel, a positive internal pressure within the vessel may be achieved by pumping the flowable filter medium composition into the pressure vessel via the inlet under pressure.

[00118] In some embodiments in which the vessel is a tank, the filter medium mount on each of the one or more branch conduits may be maintained under a positive pressure, by the pressure head of the volume of flowable filter medium composition above the filter medium mount of each of the one or more branch conduits and/or a continuous circulation of the flowable filter medium composition through the tank from the inlet to the outlet and back to the inlet, preferably both.

[00119] Generally, in such embodiments, a suction may be applied to the outlet to draw the flowable filter medium and/or an unfiltered fluid to the outlet via each of the one or more branch conduits and the main conduit. The suction may be generated by one or more pumps operatively associated with the outlet.

[00120] In other embodiments in which the vessel is a tank, a positive transmembrane pressure may be applied on a filtrate side of the filter medium mounts by the application of suction so as to cause the flowable filter medium composition to form the stable filter membrane.

[00121] In some embodiments, the assembly may further include a main conduit mount for mounting a distal end of the main conduit to an adjacent end of the vessel. Preferably the mount may releasably mount the main conduit in place.

[00122] In some embodiments, each of the one or more branch conduits may include one or more bends and curves. For example, each branch conduit may include one or more angled bends between the coupling end and the distal end.

[00123] According to a fifth aspect of the present invention, there is provided a method of forming a filtration assembly, said method including: providing a vessel having an inlet and an outlet; fitting a main conduit into the vessel extending from the outlet and configured to receive a flow of filtrate and conduct the flow of filtrate to the outlet; fitting one or more branch conduits to the main conduit, each of the one or more branch conduits configured to extend out from, and be in fluid communication with, the main conduit, and each of the one or more branch conduits having at least a porous portion defining a filter medium mount; and forming a stable filter membrane on at least each said filter medium mount by applying a flow of a flowable filter medium composition including a hydrate gel into the inlet of the vessel while at least one of maintaining the vessel at a positive internal pressure, maintaining the filter medium mount on each of the one or more branch conduits under a positive pressure and applying a positive transmembrane pressure from a filtrate side of the filter membrane, so as to cause the flowable filter medium composition to form the stable filter membrane on each said filter medium mount.

[00124] The method may include one or more features or characteristics of the filtration assembly and the filter medium support as hereinbefore described.

[00125] The forming may include maintaining a pressure of at least 20kPA for a period of time, typically a pressure of between about 20kPa and about 42kPa for a period of between about 1 ,5mins and about 3mins, preferably a pressure of between about 20kPa and about 35kPa for a period of about 2mins.

[00126] In embodiments in which the vessel is a pressure vessel, a positive internal pressure within the vessel may be achieved by pumping the flowable filter medium composition into the pressure vessel via the inlet under pressure.

[00127] In some embodiments in which the vessel is a tank, the filter medium mount on each of the one or more branch conduits may be maintained under a positive pressure, by a pressure head of a volume of flowable filter medium composition above the filter medium mount of each of the one or more branch conduits and/or a continuous circulation of the flowable filter medium composition through the tank from the inlet to the outlet and back to the inlet, preferably both.

[00128] In other embodiments in which the vessel is a tank, a positive transmembrane pressure may be applied to a filtrate side of each filter membrane so as to cause the flowable filter medium composition on each filter medium mount to form a stable filter membrane. The pressure may be applied by suction.

[00129] The method may further include removing residual flowable filter medium composition from the vessel via the outlet, preferably by a pump.

[00130] The residual flowable filter medium may preferably still be liquid and be readily removed leaving the formed stable filter membrane bonded at least on the filter medium mount of each of the one or more branch conduits.

[00131] According to a sixth aspect of the present invention, there is provided a filtration assembly when assembled according to the method of the fifth aspect.

[00132] According to a seventh aspect of the present invention, there is provided a filtration assembly including: a vessel having an inlet and an outlet; a plurality of conduits extending into the pressure vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet, each said conduit having at least a porous portion defining a filter medium mount; and a flowable filter medium composition including a hydrate gel, said medium composition configured to be applied to at least the filter medium mount on each of the conduits and form a stable filter membrane when at least one of the vessel has a positive internal pressure, the filter medium mount on each of the one or more conduits is maintained under a positive pressure and a positive transmembrane pressure is applied from a filtrate side of the filter membrane. [00133] The assembly may include one or more characteristics or features of the assembly as hereinbefore described.

[00134] The vessel may preferably be a pressure vessel.

[00135] The plurality of conduits may be connected either directly or indirectly to the outlet, preferably indirectly via a manifold or the like.

[00136] The plurality of conduits may extend into the pressure vessel in a substantially parallel arrangement, preferably in a generally vertical orientation.

[00137] The manifold may be of any suitable size, shape and construction for receiving flows of filtrate from the plurality of conduits and conveying the flows to a single outlet.

[00138] According to an eight aspect of the present invention, there is provided a method of regenerating the filtration assembly of any one of the first, second, third, sixth and seventh aspects, said method including: backwashing the filtration assembly so as to separate each said filter membrane from its corresponding said filter medium mount; optionally, cleaning the pressure vessel; and re-forming a stable filter membrane on at least each said filter medium mount by reapplying a flow of a flowable filter medium composition including a hydrate gel into the inlet of the vessel while at least one of maintaining the vessel at a positive internal pressure, maintaining the filter medium mount on each of the one or more branch conduits under a positive pressure, and applying a positive transmembrane pressure from a filtrate side of the filter membrane, so as to cause the flowable filter medium composition to re-form the stable filter membrane on each said filter medium mount.

[00139] Again, the method may include one or more features or characteristics of the filtration assembly, the filter medium support and the method of forming as hereinbefore described.

[00140] As used herein, “backwashing” may refer to pumping water, filtrate, unfiltered fluid or filter medium composition backwards through the outlet, the main conduit, the one or more branch conduits and into the vessel. The backwashing may additionally include intermittent use of compressed air.

[00141] In some embodiments in which the vessel is a pressure vessel, the method may include an initial step of depressurising an internal pressure of the pressure vessel.

[00142] In some embodiments, the cleaning may include removing all separated said filter membrane from the vessel. The separated said filter membrane may preferably be removed by suction, typically from a bottom of the vessel where the separated filter membranes settle.

[00143] According to a ninth aspect of the present invention, there is provided a method removing filter membranes from the filtration assembly of any one of the first, second, third, sixth and seventh aspects, said method including: separating the filter membranes from corresponding filter medium mounts by backwashing the filtration assembly; and optionally removing separated said filter membranes from the vessel by suction.

[00144] Again, the method may include one or more features or characteristics of the filtration assembly, the filter medium support and the methods as hereinbefore described.

[00145] Advantageously, said separating may be achieved with relative ease in a single step with only a relatively small volume of backwash and without air scouring, gas backwash, and deep chemical cleaning.

[00146] Typically, said backwashing may include pumping a small volume of water, filtrate, unfiltered fluid or filter medium composition pumped backwards through the outlet, the main conduit, the one or more branch conduits and into the vessel, preferably filtrate.

[00147] In some embodiments, said backwashing may include pumping a volume of water, filtrate, unfiltered fluid or filter medium composition pumped backwards at a rate of 5,000 to 10,000 LMH for a period of between about 60s to about 120s. Advantageously, a person skilled in the art will appreciate that this backwash volume is at least a fifth of the volume required with a contemporary filtration system, such as, e.g., a pool pump.

[00148] In some embodiments, said backwashing may include a backwash volume of between about 0.4-0.80 a capacity of the vessel, preferably between about 0.5-0.75 a capacity of the vessel, more preferably between about 0.54-0.71 a capacity of the vessel.

[00149] In some embodiments in which the vessel is a pressure vessel, the method may include an initial step of depressurising an internal pressure of the pressure vessel.

[00150] In some embodiments, said method may include an initial step of draining the vessel.

[00151] In some embodiments, said removing may include removing said separated filter membranes by suction, typically from a bottom of the vessel where the separated filter membranes settle. [00152] In other embodiments, said removing may include draining said separated filter membranes by gravity feed from the bottom of the vessel.

[00153] In some embodiments, the method may include an intermediate step of capturing or recovering the separated said filter membranes. In some such embodiments, said separated said filter membranes may be captured from a bottom of the vessel. In other such embodiments, said separated said filter membranes may be drained from the vessel and recovered from the drainage flow.

[00154] In some embodiments, the method may include a final step of discharging removed said separated filter membranes from the tank for disposal, treatment or further use.

[00155] If disposed, said removed said separated filter membranes may be discharged to a water treatment facility, such as, e.g., a sewer.

[00156] If treated, the removed said separated filter membranes may be discharged for treatment, typically as a sludge.

[00157] If for further use, the removed said separated filter membrane may be re-used as a coagulant in an associated feed system.

[00158] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[00159] The reference to any prior art in this specification is not and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[00160] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[00161] Figure 1 is a sectional view of a filtration assembly according to an embodiment of the present invention;

[00162] Figure 2 is an upper perspective view of the filtration assembly as shown in Figure 1 with the main and branch conduits removed; [00163] Figures 3A to 3C are photographs respectively showing time lapse formation of a stable filter membrane on a filter medium mount of a similar filtration assembly as shown in Figures 1 and 2;

[00164] Figure 4 is a sectional view of a filtration assembly according to another embodiment of the present invention;

[00165] Figure 5 is an upper perspective view of the filtration assembly as shown in Figure 4 with the main and branch conduits removed;

[00166] Figure 6 shows a sectional side view of a filtration assembly according to another embodiment of the present invention;

[00167] Figures 7A and 7B respectively show an upper perspective view and a sectional side view of a filtration assembly according to another embodiment of the present invention;

[00168] Figure 8 is a flowchart showing steps in a method of forming a filtration assembly according to an embodiment of the present invention;

[00169] Figure 9 is a flowchart showing steps in a method of regenerating a filtration assembly according to an embodiment of the present invention; and

[00170] Figure 10 is a flowchart showing steps in a method of removing filter membranes from a filtration assembly according to an embodiment of the present invention.

DETAILED DESCRIPTION

[00171] Figures 1 to 5, 6, 7A and 7B show embodiments of a filtration assembly (100) and parts thereof according to embodiments of the present invention.

[00172] Figures 1 and 2 show a first embodiment of the filtration assembly (100).

[00173] Referring to Figure 1 , the filtration assembly (100) includes: a pressure vessel (1 10) having an inlet (112) and an outlet (114); a main conduit (120) extending into the pressure vessel (1 10) from the outlet (1 14) for receiving a flow of filtrate and conducting the flow of filtrate to the outlet (114); a plurality of branch conduits (130) extending out from, and in fluid communication with, the main conduit (120), each branch conduit (130) having a porous portion defining a filter medium mount (140); and a flowable filter medium composition (150) including a metal hydroxide hydrate and configured to be applied to at least the filter medium mount (140) on each branch conduit (130) and form a stable filter membrane (160) when the pressure vessel (1 10) has a positive internal pressure of at least 20 kPa. [00174] Referring briefly to Figure 2, the pressure vessel (1 10) is formed of stainless steel. The pressure vessel (110) includes a base (1 11 ), an opening (113) located opposite the base (1 11 ) and a curved sidewall (1 15) extending therebetween. A central axis is defined between the base (1 11 ) and the opening (113).

[00175] The curved sidewall (1 15) has a convex curvature. The sidewall (1 15) flares away from the central axis between the base (1 11 ) and the opening (113) to a widest part located midway between the base (111 ) and the opening (113).

[00176] The inlet (112) and the outlet (1 14) are provided at the opening (1 13). Generally, the pressure vessel (1 10) includes a cap (not shown) attachable to the opening (1 13) and defining the inlet (1 12) and the outlet (114) therein.

[00177] Referring back to Figure 1 , the main conduit (120) is a tubular section including a pair of opposed ends and a curved sidewall (122) extending therebetween in a linear direction.

[00178] The opposed ends include an outlet end (124) coupled to, and in fluid communication with the outlet (114) defined in the pressure vessel (110), and an opposed distal end (126). The distal end (126) is closed.

[00179] The curved sidewall (122) is curved such that the conduit (120) has a substantially circular profile shape.

[00180] The main conduit (120) is formed from stainless steel.

[00181] The main conduit (120) extends from the outlet (1 14) at least partially along the central axis of the pressure vessel (1 10) at least 80% an internal length of the pressure vessel (1 10) as defined by the distance between the base (1 11 ) and the opening (113).

[00182] Referring again to Figure 2, a plurality of branch conduits (130) extend out from and are in fluid communication with the main conduit (120) within the internal volume of the pressure vessel (1 10).

[00183] Like the main conduit (120), each branch conduit (130) is of a tubular construction including a pair of opposed ends and curved sidewall (132) extending longitudinally therebetween in a linear direction.

[00184] The opposed ends include a coupling end (134) coupled to, and in fluid communication with, the main conduit (120), and an opposed distal end (136). As shown in Figure 1 , the distal end (136) extends way from the main conduit (120) into the internal volume of the pressure vessel (110).

[00185] Referring back to Figure 2, the distal end (136) is closed.

[00186] Like the main conduit (120), the sidewall (132) is curved such that each branch conduit (130) has a circular profile shape.

[00187] As shown, the branch conduits (130) are provided in two sizes having differing diameters.

[00188] A person skilled in the art will appreciate that there are many factors that can be customised to provide desired filtration characteristics for a desired application. These include, by way of example only and not by way of limitation, the number of differently sized branch conduits (130) and the patterned arrangement of differently sized branch conduits (130) about the main conduit (120).

[00189] Each branch conduit (130) has sidewalls (132) formed from sintered 306 stainless steel with welded 316 steel caps on the distal end (136). The sidewall (132) thus provide a porous portion having a pore size of between about 2pm to about 10pm and define the filter medium mount (140).

[00190] As shown, the branch conduits (130) extend out from the main conduit (120) at an orthogonal orientation relative to a longitudinal axis of the main conduit (120).

[00191] The branch conduits (130) are arranged around a periphery of the main conduit (120) in diametrically opposed pairs and extend at least partially along a length of the main conduit (120) from the distal end (126) to an operating depth of the pressure vessel (110).

[00192] The main conduit (120) and each of the branch conduits (130) are connected together by way of a fluid-tight threaded connection.

[00193] Specifically, the main conduit (120) includes a plurality of branch conduit mounting points (129) defined on the sidewall (122) in a desired arrangement and including a threaded bore in fluid communication with an inner passageway of the main conduit (120). Likewise, each branch conduit (130) includes a threaded boss (139) defined on the coupling end (134) and configured to threadingly engage with the threaded bore of a respective mounting point (129).

[00194] Referring to Figure 1 , and as indicated, the assembly (100) further includes the flowable filter medium composition (150) including a metal hydroxide hydrate for forming the stable filter membrane (160) on each filter medium mount (140). [00195] The composition (100) is substantially liquid with a viscosity enabling the composition (100) to readily flow at room temperature and at atmospheric pressure.

[00196] The composition (100) is an aqueous composition, and the metal hydroxide hydrate is selected from one or more of aluminium hydroxide hydrate, magnesium hydroxide hydrate, zinc hydroxide hydrate, manganese hydroxide hydrate, cobalt hydroxide hydrate and nickel hydroxide hydrate.

[00197] The composition (150) is introduced into the pressure vessel (110) via the inlet (112) from a source of the composition (150) until all of the branch conduits (130) are substantially covered by the composition (150), as shown.

[00198] A positive internal pressure of between about 20kPa and about 35kPa is then applied to the pressure vessel (110) for a period of at least 2mins so as to cause the composition (150) to form the stable filter membrane (160) on each filter medium mount (140).

[00199] Referring to Figures 3A-3C, these figures show a transition of the composition (150; shown only in Figures 3B and 3C) on the branch conduits (130) to the stable filter membrane (160; shown only in Figures 3B and 3C).

[00200] Figure 3A shows an internal view of the pressure vessel (110) prior to introduction of the composition (150; shown in Figures 3B and 3C).

[00201] Figure 3B shows an intermediate stage in the transition of the composition (150) to stable filter membrane (160). The stable filter membrane (160) can be seen accumulating on the filter membrane mount (140).

[00202] Figure 3C shows the resulting filter membrane (160) built up on each filter membrane mount (140). In this figure, residual (liquid) composition (150) is shown partially drained from the pressure vessel (110).

[00203] The stable filter membrane (160) is in the form of a stable filtration bed or cake bonded to the filter medium mount (140) having a thickness of between about 2pm and 1 mm.

[00204] The remaining (liquid) composition (150) is then pumped out of the pressure vessel (110) via the outlet (114; not visible).

[00205] Figures 4 and 5 show a second embodiment of the filtration assembly (100). For convenience, features that are similar or correspond to features of the first embodiment will be referenced with the same reference numerals. [00206] The filtration assembly (100) again includes: a pressure vessel (110) having an inlet (1 12) and an outlet (114); a main conduit (120) extending into the pressure vessel (110) from the outlet (1 14) for receiving a flow of filtrate and conducting the flow of filtrate to the outlet (114); branch conduits (130) extending out from, and in fluid communication with, the main conduit (120), each branch conduit (130) having a porous portion defining a filter medium mount (140); and a flowable filter medium composition (150; not visible) including a metal hydroxide hydrate and configured to be applied to at least the filter medium mount (140) on each branch conduit (130) and form a stable filter membrane (160) when the pressure vessel (1 10) has a positive internal pressure of at least 20 kPa.

[00207] However, in contrast to the first embodiment, in this embodiment the assembly (100) includes four branch conduits (130) arranged in a single layer in diametrically opposed pair around the periphery of the main conduit (120) about mid-way along a length of the main conduit (120).

[00208] Figure 6 shows a third embodiment of the filtration assembly (100). For convenience, features that are similar or correspond to features of the first or second embodiments will be referenced with the same reference numerals.

[00209] In this embodiment the filtration assembly (100) includes a pressure vessel (1 10) having an inlet (112) and an outlet (114); a main conduit (120) extending into the pressure vessel (1 10) from the outlet (1 14) for receiving a flow of filtrate and conducting the flow of filtrate to the outlet (114); branch conduits (130) extending from, and in fluid communication with, the main conduit (120) via a manifold (170), each branch conduit (130) having a porous portion defining a filter medium mount (140); and a flowable filter medium composition (150) including a metal hydroxide hydrate and configured to be applied to at least the filter medium mount (140) on each branch conduit (130) and form a stable filter membrane (160) when the pressure vessel (1 10) has a positive internal pressure of at least 20 kPa.

[00210] However, in contrast to the first and second embodiments and similar to the third embodiment, in this embodiment the branch conduits (130) extend from the manifold (170) in a substantially parallel arrangement relative to the main conduit (120). The branch conduits (130) are arranged about the main conduit (120) in a spaced arrangement and extend from the manifold (170) at least partially towards the outlet (114).

[0021 1] Figures 7A and 7B show a fourth embodiment of the filtration assembly (100). For convenience, features that are similar or correspond to features of the first or second embodiments will be referenced with the same reference numerals. [00212] Referring to Figure 7A, the filtration assembly (100) includes: tank (710) having an inlet (1 12) and an outlet (1 14); a main conduit (120) extending into the tank (710) from the outlet (1 14) along a midline and longitudinal axis of the tank (710) for receiving a flow of filtrate and conducting the flow of filtrate to the outlet (114); a plurality of branch conduits (130) extending out from, and in fluid communication with, the main conduit (120), each branch conduit (130) having a porous portion defining a filter medium mount (140); and a flowable filter medium composition (150; shown in Figure 7B) including a metal hydroxide hydrate and configured to be applied to at least the filter medium mount (140) on each branch conduit (130) and form a stable filter membrane (160; not visible) when the filter medium mount (140) on each of the one or more branch conduits (130) is maintained under a positive pressure or a positive transmembrane pressure is applied from the filtrate side of the filter membrane (160; not visible).

[00213] The tank (710) is formed from metal and includes a base (712), a rim (714) and a pair of opposed end walls (716) and pair of opposed sidewalls (718) extending from the base (712) to the rim (714). The rim (714) extends from an upper portion of, and continuously along an edge of the opposed end walls (716) and opposed sidewalls (718).

[00214] Referring to Figure 7B, the inlet (112) and the outlet (1 14) are located in opposite end walls (816).

[00215] As shown, the main conduit (120) extends centrally in a generally horizontal orientation along a longitudinal axis of the tank (710) and the branch conduits (130) extend out from the main conduit (120) in an opposed and spaced horizontal arrangement from the distal end (126) at least partially towards the outlet (114). The main conduit (120) extends along a lower half of the tank (710) near the base (712) of the tank (710).

[00216] As indicated, in contrast to the earlier embodiments, in this embodiment the flowable filter medium composition (150) is caused to form the filter membrane (160; not visible) on the filter medium mounts (140) of each of the one or more branch conduits (130) through the application and maintenance of pressure on the filter medium mounts (140).

[00217] In some embodiments, a positive pressure is maintained by a pressure head of the volume of flowable filter medium composition (150) above the filter medium mounts (140) and a continuous circulation of the flowable filter medium composition (150) through the tank (710) from the inlet (112) to the outlet (114) and back to the inlet (1 12) until the membrane filters (160) are formed.

[00218] In other embodiments, a positive transmembrane pressure is applied on a filtrate side of the filter medium mounts (140) by the application of suction so as to cause the flowable filter medium composition (150) to form the membrane filters (160).

[00219] Further, and again in contrast to the earlier embodiments, a suction is applied to the outlet (114) to draw the flowable filter medium composition (150) and/or an unfiltered fluid to the outlet (114) via each of the one or more branch conduits (130) and the main conduit (120). The suction is generated by one or more pumps operatively associated with the outlet (1 14).

[00220] Moreover, the filtration assembly (100) further includes an air diffuser (720) running along the base (712) underneath the main conduit (120). When cleaning the tank (710), air may be pumped into the tank (710) via the diffuser (720) to unsettle any debris that may settle on the base (712) of the tank (710) and then drained from the tank (710) via drain (730).

[00221] A method (800) of assembling the filtration assembly (100) as shown in Figure 1 is now described in detail with reference to Figure 8.

[00222] At step 810, a pressure vessel (1 10) is provided having a base (11 1 ), an opening (1 13) located opposite the base (11 1 ) and a curved sidewall (115) extending therebetween. The inlet (1 12) and the outlet (114) are provided at the opening (1 13).

[00223] At step 820, a main conduit (120) is fitted into the pressure vessel (1 10) such that it extends from the outlet (114) and is configured to receive a flow of filtrate and convey the flow of filtrate to the outlet (114).

[00224] At step 830, a plurality of branch conduits (130) are fitted to the main conduit (120). Typically, each branch conduit (130) is threadingly mounted to a respective branch conduit mounting points (129) defined on the sidewall (122) of the main conduit (120).

[00225] The branch conduits (120) are arranged in diametrically opposed pairs around a periphery of the main conduit (120) and at least partially along a length of the main conduit (120) from the distal end (126) to an operating depth of the pressure vessel (110).

[00226] At step 840 the flowable filter medium composition (150) is applied to the pressure vessel (1 10) via the inlet (1 12) to fill the pressure vessel (1 10) until the plurality of branch conduits (130) are substantially covered.

[00227] A positive internal pressure of between about 20kPa and about 35kPa is then applied to the pressure vessel (110) so as to cause the composition (150) to form the stable filter membrane (160) on each filter medium mount (140).

[00228] Residual (liquid) composition (150) is then pumped from the pressure vessel (110) via the outlet (1 14).

[00229] A method (900) of re-generating a filtration assembly (100) as shown in Figure 1 is now described in detail with reference to Figure 9.

[00230] At step 910, the filtration assembly (100) is backwashed so as to separate each said filter membrane (170) from its corresponding filter medium mount (140).

[00231] At step 920, the pressure vessel (110) is optionally flushed clean thereby removing all separated filter membrane (170) and any other contaminants.

[00232] At step 930, the stable filter membrane is re-formed on at least each filter medium mount (140) by re-applying a flow of filter medium composition (150) into the pressure vessel (1 10) via the inlet (1 12) to fill the pressure vessel (1 10) until the plurality of branch conduits (130) are substantially covered.

[00233] A positive internal pressure of between about 20kPa and about 35kPa is then reapplied to the pressure vessel (1 10) so as to cause the composition (150) to re-form the stable filter membrane (160) on each filter medium mount (140).

[00234] A method (1 ,000) of removing filter membranes (170) from a filtration assembly (100) as shown in Figures 1 , 2, 4, 5, 6, 7A and 7B is now described in detail with reference to Figure 10.

[00235] At step 1 ,010, the filtration assembly (100) is backwashed so as to separate each said filter membrane (170) from its corresponding filter medium mount (140).

[00236] The backwashing may be carried out with a relatively small volume of water, filtrate, unfiltered fluid or filter medium composition (150) pumped backwards through the outlet (114), the main conduit (120), the one or more branch conduits (130) and into the vessel (1 10).

[00237] At step 1 ,020, the method (1 ,000) includes the optional step of removing separated filter membranes (170) from the vessel (110) by the application of suction, typically from a bottom of the vessel (110) where the separated filter membranes (170) settle.

[00238] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[00239] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[00240] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

[00241] EXAMPLES

[00242] Example 1 : Filter Membrane Removal

[00243] Exploratory testing was undertaken to determine a minimal backwash volume required to efficiently remove a filter membrane from a filtration assembly according to an embodiment of the present invention.

[00244] Filtration System Set-Up

[00245] In the filtration system tested, the vessel is a closed vessel having an inlet and an outlet and internal volume of 1401.

[00246] The filtration system includes a main conduit extending into the vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet and a plurality of branch conduits extending out from, and in fluid communication with, the main conduit within the internal volume.

[00247] The plurality of branch conduits each define a filter medium mount for having a flowable filter medium composition, including a hydrate gel, set thereon and form filter membranes.

[00248] Backwash Process

[00249] The process involved draining the vessel of unfiltered fluid and reversing a flow so as to pump filtrate backwards through the outlet, the main conduit, the plurality of branch conduits and into the vessel. [00250] Results

[00251] Our testing revealed that between 75-100L of backwash was required to completely remove the filter membranes from the corresponding filter medium mounts. The separated filter membranes were collected in a bottom of the vessel together with a volume of the backwash for drainage.

Claims

1 . A filtration assembly including: a vessel having an inlet and an outlet; a main conduit extending into the vessel from the outlet for receiving a flow of filtrate and conducting the flow of filtrate to the outlet; one or more branch conduits extending out from, and in fluid communication with, the main conduit, each of said one or more branch conduits having at least a porous portion defining a filter medium mount; and a flowable filter medium composition including a hydrate gel, said medium composition configured to be applied to at least the filter medium mount on each of the one or more branch conduits and form a stable filter membrane when at least one of the vessel has a positive internal pressure, the filter medium mount on each of the one or more branch conduits is maintained under a positive pressure and a positive transmembrane pressure is applied from a filtrate side of the filter membrane.

2. The assembly of claim 1 , wherein the hydrate gel is a metal hydrate gel selected from one or more of aluminium hydroxide hydrate, magnesium hydroxide hydrate, zinc hydroxide hydrate, manganese hydroxide hydrate, cobalt hydroxide hydrate and nickel hydroxide hydrate or a mixture thereof.

3. The assembly of claim 1 or claim 2, wherein the vessel is a pressure vessel and the flowable filter medium composition is caused to form a stable filter medium through the application of a positive trans membrane pressure.

4. The assembly of claim 3, wherein the main conduit extends at least partially along a central axis of the pressure vessel in a vertical orientation.

5. The assembly of claim 1 or claim 2, wherein the vessel is a tank having a base, a rim and at least one wall extending from the base to the rim.

6. The assembly of claim 5, wherein the inlet and the outlet are located adjacent each other.

7. The assembly of claim 5, wherein the inlet and the outlet are located substantially opposite each other on opposed end walls or side walls.

8. The assembly of any one of claims 5 to 7, wherein the main conduit extends at least partially along a midline of the tank.

9. The assembly of any one of claims 5 to 7, wherein the main conduit extends transversely across the tank.

10. The assembly of any one of claims 1 to 9, wherein the one or more branch conduits extend out from the main conduit in a transverse orientation relative to a longitudinal axis of the main conduit.

11 . The assembly of claim 10, wherein the assembly includes a plurality of branch conduits.

12. The assembly of claim 10 or claim 1 1 , wherein the branch conduits are arranged in diametrically opposed pairs about a periphery of the main conduit.

13. The assembly of claim 10 or claim 1 1 , wherein the branch conduits are arranged in an evenly spaced arrangement about a periphery of the main conduit.

14. The assembly of claim 11 , wherein each branch conduit includes a plate having a pair of opposed surfaces having one or more porous portions defined thereon defining the filter medium mounts.

15. The assembly of claim 14, wherein the plurality of branch conduits in the form of plates are arranged in a sandwich arrangement.

16. The assembly of any one of claims 1 to 15, wherein the porous portions include a plurality of pores ranging in size between about 2pm and about 10pm.

17. The assembly of any one of claims 1 to 16, wherein stable filter membrane includes a filtration bed bonded to the filter medium mount having a thickness of between about 2pm and about 1 mm.

18. The assembly of any one of claims 5 to 9, wherein the filter medium mount on each of the one or more branch conduits is maintained under a positive pressure so as to cause the flowable filter medium composition to form a stable filter medium by a pressure head of a volume of the flowable filter medium composition above the filter medium mount on each of the one or more branch conduits and/or a continuous circulation of the flowable filter medium composition through the tank from the inlet to the outlet and back to the inlet.

19. The assembly of any one of claims 5 to 9, wherein the filter medium mount on each of the one or more branch conduits is maintained under pressure so as to cause the flowable filter medium composition to form a stable filter medium through application of a positive transmembrane pressure on a filtrate side of the filter medium mounts.

20. The assembly of any one of claims 1 to 19, wherein the flowable filter medium composition is applied to the filter medium mounts under pressure to form the stable filter membranes for a period of between about 1 ,5mins and 3mins.

21. The assembly of any one of claims 1 to 20, wherein the flowable filter medium composition is applied to the filter medium mounts to form the stable filter membranes at a pressure of between about 20kPa and about 35kPa.

22. A method of forming a filtration assembly, said method including: providing a vessel having an inlet and an outlet; fitting a main conduit into the vessel extending from the outlet and configured to receive a flow of filtrate and conduct the flow of filtrate to the outlet; fitting one or more branch conduits to the main conduit, each of the one or more branch conduits configured to extend out from, and be in fluid communication with, the main conduit, and each of the one or more branch conduits having at least a porous portion defining a filter medium mount; and forming a stable filter membrane on at least each said filter medium mount by applying a flow of a flowable filter medium composition including a hydrate gel into the inlet of the vessel while at least one of maintaining the vessel at a positive internal pressure, maintaining the filter medium mount on each of the one or more branch conduits under a positive pressure and applying a positive transmembrane pressure from a filtrate side of the filter membrane, so as to cause the flowable filter medium composition to form the stable filter membrane on each said filter medium mount.

23. A method of regenerating the filtration assembly of any one of claims 1 to 21 , said method including: backwashing the filtration assembly so as to separate each said filter membrane from its corresponding said filter medium mount; optionally, cleaning the pressure vessel; and re-forming a stable filter membrane on at least each said filter medium mount by reapplying a flow of a flowable filter medium composition including a hydrate gel into the inlet of the vessel while at least one of maintaining the vessel at a positive internal pressure, maintaining the filter medium mount on each of the one or more branch conduits under a positive pressure, and applying a positive transmembrane pressure from a filtrate side of the filter membrane, so as to cause the flowable filter medium composition to re-form the stable filter membrane on each said filter medium mount.

24. A method of removing the filter membranes from the filtration assembly of any one of claims 1 to 21 , said method including: separating the filter membranes from corresponding filter medium mounts by backwashing the filtration assembly; and optionally, removing separated said filter membranes from the vessel by suction.