Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
  • C02F1/442—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by nanofiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/58—Multistep processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
  • B01D61/025—Reverse osmosis; Hyperfiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
  • B01D61/027—Nanofiltration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
  • B01D61/12—Controlling or regulating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/02—Hollow fibre modules
  • B01D63/031—Two or more types of hollow fibres within one bundle or within one potting or tube-sheet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/10—Spiral-wound membrane modules
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
  • C02F1/441—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by reverse osmosis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2311/00—Details relating to membrane separation process operations and control
  • B01D2311/06—Specific process operations in the permeate stream
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2311/00—Details relating to membrane separation process operations and control
  • B01D2311/24—Quality control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2311/00—Details relating to membrane separation process operations and control
  • B01D2311/24—Quality control
  • B01D2311/246—Concentration control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2317/00—Membrane module arrangements within a plant or an apparatus
  • B01D2317/02—Elements in series
  • B01D2317/025—Permeate series
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2317/00—Membrane module arrangements within a plant or an apparatus
  • B01D2317/06—Use of membrane modules of the same kind
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2317/00—Membrane module arrangements within a plant or an apparatus
  • B01D2317/08—Use of membrane modules of different kinds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/08—Seawater, e.g. for desalination
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
  • Y02A20/124—Water desalination
  • Y02A20/131—Reverse-osmosis

Definitions

• the field of the invention is that of the design and production of installations used to filter liquids under pressure using filtration membranes with a view to removing pollutants, in particular micropollutants, and of reduce the hardness to produce drinking water.
• Such liquids can in particular be sea water, borehole water or surface water.
• Membrane filtration processes are widely used in the production of drinking water.
• the membranes they use have a porous structure which allows them to retain pollutants, in particular micropollutants such as herbicides, pesticides or drug residues and to limit the transfer of one or more solutes with respect to the 'water.
• microfiltration membranes have pores of 0.1 ⁇ m to 1 ⁇ m
• those for ultrafiltration have pores from 5 nm to 0.1 ⁇ m
• those for nanofiltration (NF) have pores of a few nanometers.
• reverse osmosis membranes have an even more dense structure.
• OIBP low pressure reverse osmosis membranes
• Ol seawater desalination
• reverse osmosis, low pressure reverse osmosis and nanofiltration membrane filtration modules are generally spiral membrane modules or hollow fiber membrane modules. These modules are arranged in series within pressure tubes which commonly have a size allowing them to accommodate up to eight modules positioned in series.
• the water to be filtered is introduced at one end of the pressure tube and passes through the filtration membranes.
• the filtered liquid (permeate) is collected by a perforated recovery tube arranged along the longitudinal axis at the center of modules.
• Inter-connector devices make it possible to connect the permeate recovery tubes of the various membrane filtration modules arranged in series inside the pressure tube.
• the permeate is recovered at the end of the pressure tubes using permeate collectors, each connected to permeate discharge means.
• the concentrate consisting of water concentrated in solutes, is collected at the opposite end of the pressure tube from the inlet water.
• these pressure tubes are associated in blocks (also designated by the English term “skids”) in which they are mounted in parallel. Collectors are placed at the outlet of the pressure tubes to collect the permeate and the concentrate. These different collectors are each connected to a common collector.
• the installations can be organized into several filtration stages: the concentrate leaving the first stage feeds and is treated by the membranes of a second stage, the concentrate coming from the second stage feeds and is treated by the membranes of a third stage.
• the permeates of each stage are brought together.
• reverse osmosis membranes can be used in the same pressure tube, the salt passages of which are of the same order of magnitude but with different permeabilities, in order to distribute the membrane production flows in the pressure tubes.
• the patent application DOW (WO200582497A1) relates to a method and an apparatus for treating water of high osmotic pressure, especially sea water, by passing the water through pressure tubes containing at least three elements of pressure.
• Spiral nanofiltration or reverse osmosis membranes having different permeabilities, the most permeable membrane being placed at the tail (concentrate side).
• This invention consists in better distributing the flows between the spiral membranes of the same pressure tube and in reducing the operating pressure.
• Membrane installations for the production of drinking water including the membranes of filtration are only reverse osmosis or low pressure reverse osmosis membranes have the drawback of producing completely demineralized water.
• all of the dissolved salts, in particular the dissolved calcium, in the liquids to be filtered are retained by the reverse osmosis membranes or the low pressure reverse osmosis membranes. It follows that these waters must be remineralized to be made drinkable.
• the post-mineralization step involves the use of chemicals which can lead to an increase in the turbidity of the water produced. This is the case, for example, with lime remineralization. This step therefore requires the inclusion of additional equipment in the installations. This post-mineralization step therefore significantly increases the overall cost of the drinking water operation and the risks of contamination of the water produced.
• An objective of the present invention is to provide a membrane filtration technique for the production of drinking water which makes it possible to dispense with any post-mineralization stage of the water produced by the membranes, whether by addition of reagent or by supply of water. hard water, while allowing the effective reduction of the micropollutants contained in the liquids to be treated.
• An objective of the invention is also to provide such a technique which makes it possible to obtain filtered water having a given target hardness even when the temperature of the liquids to be treated or their calcium concentration varies.
• Another objective of the present invention is to provide a method implementing such an installation making it possible to operate the membranes with higher hydraulic yields than those obtainable with the methods of the prior art.
• each UPM comprising:
• each pressure tube accommodating at least two membrane filtration modules with spiral membranes or hollow fibers mounted in series,
• said membranes of said filtration modules of said installation are at least of two different types chosen from the group consisting of reverse osmosis membranes and low pressure reverse osmosis membranes on the one hand, and nanofiltration membranes on the other hand, and in that said at least one UPM comprises means for modifying the order of supply of said blocks of pressure tubes which it groups together.
• the installation comprises two types of membranes, nanofiltration membranes on the one hand and reverse osmosis membranes and / or low pressure reverse osmosis membranes on the other hand.
• said membranes of at least two different types are provided in different pressure tubes.
• said membranes of at least two different types are provided in the same pressure tubes.
• said nanofiltration membranes used allow a rejection rate of less than or equal to 70% of the calcium during a standard CaC test.
• This standard test is performed on synthetic water consisting of demineralized water containing 500 mg / l of CaCh, the modulus being subjected to a pressure of 75 psi (0.52 MPa) and producing an efficiency of 15% (efficiency defined as flow rate of permeate produced during the test divided by the flow rate of feed water to the membrane module).
• the rejection of calcium during the standard test is measured at a temperature of 25 ° C and with a flow of 31 L / h / m 2 / bar. This test is called the “standard CaCh test”.
• the rejection rate is defined as the rate of solute removal (released into the concentrate), expressed as: concentration in the permeate / concentration in the feed.
• said reverse osmosis membranes and / or said low pressure reverse osmosis membranes allow a rejection rate greater than 90% of the calcium during a standard CaC test.
• the installation has a ratio of the number of nanofiltration membranes to the total number of membranes of between 5% and 95%.
• said nanofiltration membranes have a standard specific flux, or permeability, greater than 3 L / h / m 2 / bar and allow a rejection rate of monovalent salts of less than 82%, said rejection being that observed during a test standard on synthetic water consisting of demineralized water containing 2 g / l of NaCl, the modulus being subjected to a pressure of 70 psi (4.8 bars) and producing a yield of 15%.
• the sodium rejection during the standard test is measured at a temperature of 25 ° C. This test is called the “standard NaCl test”.
• said reverse osmosis or low pressure reverse osmosis membranes have a standard specific flow greater than 3 L / h / m 2 / bar and allow a rejection rate of monovalent salts greater than or equal to 82%, said rejection being that observed during a standard test with NaCl.
• the invention also relates to any liquid filtration process for the production of drinking water using such an installation, characterized in that it comprises the steps of supplying the filtration units with at least one UPM according to a first order.
• each UPM is organized in filtration stages connected in series, each filtration stage comprising, according to the possible configurations thanks to the use of said means making it possible to modify the order of supply of said blocks of pressure tubes, that is to say a single filtration unit, i.e. 2 to 6 filtration units mounted in parallel.
• one or more blocks of pressure tubes operating in parallel in the first configuration can operate in series in the second configuration and one or more blocks of pressure tubes operating in parallel series in the first configuration can operate in parallel in the second configuration. the second configuration.
• the invention relates in particular to such a method implemented with an installation comprising a plurality N of UPMs, with N> 1 integer, characterized in that it comprises a step consisting in supplying the blocks of x / N UPM, with x integer varying from 0 to N, according to said first order, and the blocks of the remaining UPMs according to said second order, and to vary x so that the filtered water obtained at the outlet of the installation meets a predetermined quality factor .
• said parameter is chosen from the group consisting of the temperature of the water to be treated.
• said quality factor is the hardness of said filtered water obtained at the outlet of the installation.
• FIG 1 schematically shows a first embodiment of an installation according to the present invention, the direction of the liquids passing through it being indicated by arrows corresponds to a first operating configuration called “high temperature configuration”.
• FIG 2 schematically represents the same installation operating according to a second configuration called “low temperature water configuration”.
• FIG 3 schematically shows a second embodiment of an installation according to the present invention, the direction of the liquids passing through it being indicated by arrows corresponds to a first operating configuration called “high temperature configuration”.
• FIG 4 schematically represents the same installation as that shown in Figure 3 operating according to a second configuration called "low temperature water configuration”.
• UPMs are shown in Figures 1 and 2. It comprises, in addition to supply means 20 for liquid to be filtered and discharge means 30 for rejected liquid or concentrate, six filtration units 1 to 6.
• Each block filter contains thirty pressure tubes.
• Each pressure tube contains six membrane filtration modules mounted in series. This UPM therefore contains 1080 membrane filtration modules. So the plant, which contains six UPMs, each with 1080 membranes, has a total of 6480 membranes.
• the NF membranes are spiral membranes marketed under the trade reference DOW FILMTEC NF270-400 and the OIBP membranes are spiral membranes marketed under the trade reference DOW FILMTEC ECO-400.
• the NF membranes used exhibit a flow rate of 55.6 m 3 / day under the standard CaC test and a calcium rejection rate of 40 to 60% under the standard CaC test.
• the OIBP membranes used have a flow rate of 44 m 3 / day under the standard NaCl test and make it possible to reject 99.7% of the monovalent ions.
• FIGS. 1 and 2 we therefore distinguish blocks 1, 2 and 3 with NC modules and blocks 4, 5 and 6 with OIBP modules.
• each UM P of the installation is provided with means making it possible to modify the order of supply of the blocks of pressure tubes which it groups together.
• These means consist of valves, or any other isolation device, 21 to 26.
• the order of supplying the modules of each UMP can vary as a function of a parameter.
• valves or isolation device 21, 23 and 26 are open while the valves or isolation devices 22, 24 and 25 are closed.
• a first filtration stage made up of NF blocks 1, 2 and 3 fed in parallel
• a second filtration stage made up of OIBP 4,5 blocks fed in parallel
• a third filtration stage made up of the OIBP module block 6.
• the OIBP takes place at the tail of the UPM on two stages, which allows a good rejection of the micropollutants and of the calcium without degrading the operating pressure.
• the supply order of the blocks 1 to 6 can be modified by closing the valves or isolation devices 21, 23 and 26 and by opening the valves or isolation devices 22, 24 and 25.
• the first filtration stage consists of the blocks of OIBP 4, 5, 6 modules mounted in parallel
• the second filtration stage consists of the blocks of modules of NF 2 and 3
• the third filtration stage consists of the NC module block 1.
• the nanofiltration takes place at the tail of the UPM on two stages, thus promoting a drop in pressure while offering good rejection of the micropollutants.
• block 1 operating in parallel in the first configuration operates in series in the second configuration and block 6 operating in series in the first configuration operates in parallel in the second configuration.
• Simulations have been carried out to show that, thanks to the invention, it is possible to maintain the hardness of the water produced by the installation within a fixed range, for example between 8 and 9 ° F, while maintaining good rejection of the micropollutants, even if the temperature or the quality of the water to be filtered varies.
• Bicarbonate content 230 mg / l
• nitrates 20 mg / l
• Chloride content 30 mg / l
• the flow rate of treated water produced is 100,000 m 3 / d -
• the objective for the water produced is set at a minimum of 30 mg / l of calcium (corresponds to a hardness of 8 ° F) whatever the temperature of the water to be filtered.
• the maximum desired concentration is 35 mg / L of calcium (corresponds to a hardness of 9 ° F).
• the proportion (x / 6) of UPM of the installation operating in the first configuration and of UPM operating in the second configuration was varied as a function of the temperature of the water to be filtered. .
• Table 1 below indicates for each temperature interval, and for each proportion (0/6; 1/6; 2/6; 3/6; 4/6; 5/6; 6/6), the concentration of calcium (Ca, major component of the hardness) of the permeate, the nitrate (NO3) concentration of the permeate as well as the supply pressure (P) of the UPMs.
• the installation in double stream contains a proportion of 25% of NF modules and 75% of OIPB modules.
• Bicarbonate content 230 mg / l
• nitrates 20 mg / l
• Chloride content 30 mg / l
• the flow of treated water produced is 100,000 m3 / d.
• the objective for produced water is set at a minimum of 30 mg / l of calcium regardless of the calcium concentration of the inlet water to be filtered.
• the maximum desired concentration is 35 mg / l of calcium.
• Table 4 indicates for each calcium content in the inlet water to be filtered, and for each proportion (0/6; 1/6; 2/6; 3/6; 4/6; 5/6 ; 6/6), the calcium concentration (major component of the hardness) of the permeate, the nitrate concentration of the permeate and the supply pressure. [TABLE 4]
• the double-channel installation contains a proportion of 30% of NF modules and 70% of OIPB modules.
• This double channel was used to filter the same water with the same variations in calcium concentrations.
• Table 5 indicates, for each calcium content in the inlet water, the concentrations of calcium (the major component of hardness) and of nitrates in the permeate and the supply pressure.
• a second embodiment of an installation according to the present invention comprises six UPMs such as that shown in Figures 3 and 4 similar to that shown with reference to Figures 1 and 2 except in that it has valves or other device for 'additional insulation (21a, 22a, 22b, 22c, 23a, 23b) and in that it includes four filter blocks instead of six.
• one of these blocks contains thirty pressure tubes, each pressure tube containing six NF modules, another block (block 2a) contains sixty pressure tubes, each pressure tube containing six NF modules, another block (block 4) contains thirty pressure tubes, each pressure tube containing six OIBP modules and another block (block 6a) contains sixty pressure tubes, each pressure tube containing six OIBP modules.
• the capacity of the UPM shown in these Figures 3 and 4 is therefore the same as that shown in Figures 1 and 2.
• valves or isolation device 21, 21a, 23, 23a, 23b and 26 are open while the valves or isolation devices 22, 22a, 22b, 22c, 24 and 25 are closed.
• a first filtration stage made up of two NF blocks 1 and 2a supplied in parallel, a second filtration stage made up of OIBP block 6a, and a third filtration stage made up of OIBP block 4 are thus defined.
• the OIBP takes place at the tail of the UPM on two stages, which allows good rejection of micropollutants and calcium without degrading the operating pressure.
• the order of supply of the blocks can be modified by closing the valves or isolation devices 21, 21 a, 23, 23a, 23b and 26 and by opening the valves or isolation devices 22, 22a , 22b, 22c, 24 and 25.
• the first filtration stage consists of blocks of OIBP 4 and 6a modules mounted in parallel
• the second filtration stage consists of the NF 2a block
• the third filtration stage consists of the NF 1 module block.
• the nanofiltration takes place at the tail of the UPM on two stages, thus promoting a drop in pressure while offering good rejection of the micropollutants.
• the block 1 operating in parallel in the first configuration operates in series in the second configuration and the blocks 6a operating in series in the first configuration operate in parallel in the second configuration.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Water Supply & Treatment (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Nanotechnology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Organic Chemistry (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

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• 2019
  • 2019-05-24 FR FR1905469A patent/FR3096279B1/fr active Active
• 2020
  • 2020-05-25 AU AU2020281687A patent/AU2020281687A1/en active Pending
  • 2020-05-25 WO PCT/EP2020/064463 patent/WO2020239707A1/fr unknown
  • 2020-05-25 CN CN202080038447.1A patent/CN113874103B/zh active Active
  • 2020-05-25 EP EP20726498.7A patent/EP3976235A1/de active Pending

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