METHOD FOR IDENTIFYING THE TYPE OF CLOGGING IN A MEMBRANE FILTRATION APPARATUS

Abstract

The present invention relates to a method for processing a membrane filtration apparatus having at least one fluid inlet and at least one fluid outlet, said method comprising a first step a) of supplying and flowing a first enzyme solution comprising at least one protease through said membrane filtration apparatus for a first predetermined time period, said first step a) being followed by a first measurement, performed at said at least one fluid inlet and/or said at least one fluid outlet of said membrane filtration apparatus, of at least one first parameter value making it possible to characterize the fluid flowing within said membrane filtration apparatus, said at least one first measured parameter value being compared to a value of the same parameter measured before step a).

Claims

1. Method for treating a membrane filtration apparatus having at least one fluid inlet and at least one fluid outlet, said method comprising a first step a) of supplying and flowing, through said membrane filtration apparatus for a first predetermined period of time, a first enzyme solution comprising at least one protease, said first step a) being followed by a first measurement, carried out at said at least one fluid inlet and/or at said at least one fluid outlet of said membrane filtration apparatus, of at least one first value of a parameter for characterising the fluid flowing in said membrane filtration apparatus, this at least one first measured value of a parameter being compared with a measured value of this same parameter prior to step a), said method being characterised in that it comprises, for identifying the nature of the clogging present in said membrane filtration apparatus, a second step b) of supplying and flowing in said membrane filtration apparatus, for a second predetermined period of time, a second enzyme solution comprising at least one enzyme other than a protease, said second step b) being followed by a second measurement, carried out at said at least one fluid inlet and/or at said at least one fluid outlet of said membrane filtration apparatus, of at least one second value of a parameter for characterising the fluid flowing in said membrane filtration apparatus, this at least one second measured value of a parameter being compared with a measured value of this same parameter prior to step b), said steps a) and b) being implemented in any order.

2. Method for treating a membrane filtration apparatus according to claim 1, characterised in that said second step b) of supplying and flowing a second enzyme solution comprising at least one enzyme other than a protease is based on a supply and a flow of at least one enzyme chosen from the group consisting of -polysaccharidases (lactase, amylase, alpha-glucosidase, etc.), -polysaccharidases (-N-acetylglucosaminidase, cellulase, hemicellulase, -glucanase, arabanase, pectinase, chitinase, xylanase, dextranase, lysozyme, pullulanase, -glucisidase, mannanase, etc.), oxidoreductases (laccase, etc.), lyases (pectate lyase, etc.), transferases, lipases and esterases (lysophospholipase, phospholipase, etc.) and mixtures thereof.

3. Method for treating a membrane filtration apparatus according to claim 1, characterised in that it also comprises at least one additional step c) of supplying and flowing in said membrane filtration apparatus for a third predetermined period of time a third enzyme solution comprising at least one enzyme chosen from the group consisting of -polysaccharidases (lactase, amylase, alpha-glucosidase, etc.), -polysaccharidases (-N-acetylglucosaminidase, cellulase, hemicellulase, -glucanase, arabanase, pectinase, chitinase, xylanase, dextranase, lysozyme, pullulanase, -glucisidase, mannanase, etc.), oxidoreductases (laccase, etc.), lyases (pectate lyase, etc.), transferases, proteases and peptidases (metallo-protease, serine-proteases, exo-peptidase, endo-protease, cystine-protease, etc.), and lipases and esterases (lysophospholipase, phospholipase, etc.) and mixtures thereof, an additional measurement of at least one value of a parameter, making it possible to characterise the fluid flowing in said membrane filtration apparatus, then being able to be carried out at said at least one fluid inlet and/or said at least one fluid outlet of said membrane filtration apparatus following this additional step c), this at least one measured value of a parameter being compared with a measured value of this same parameter prior to this additional step c).

4. Method for treating a membrane filtration apparatus according to claim 1, characterised in that it further comprises an initial step d) of supplying and flowing in said membrane filtration apparatus, for a fourth predetermined period time, a detergent solution comprising at least one sequestering agent and/or at least one dispersant and/or at least one wetting agent.

5. Method for treating a membrane filtration apparatus according to claim 1, characterised in that it further comprises at least one step of effecting a jump in pH implemented in order to achieve a pH of between 9 and 10 by adding an alkaline compound in said membrane filtration apparatus, said jump in pH being performed: before steps a) and/or b), or after steps a) and/or b), or after steps d) and/or c), steps d) and/or c), a) and/or b) then being carried out sequentially.

6. Method for treating a membrane filtration apparatus according to claim 1, characterised in that it further comprises a final additional step of increase in pH in order to achieve a pH of between 10 and 11 by adding an alkaline compound in said membrane filtration apparatus.

7. Method for treating a membrane filtration apparatus according to claim 1, characterised in that said first, second, third and fourth predetermined periods of time have a duration of between 5 and 60 minutes, preferably between 20 and 30 minutes.

8. Method for treating a membrane filtration apparatus according to claim 1, characterised in that at least said step a) is performed at a temperature of between 20 and 60 C., preferably between 40 and 50 C.

9. Method for treating a membrane filtration apparatus according to claim 1, characterised in that said enzyme solutions comprise a detergent phase as a solvent.

10. Method for treating a membrane filtration apparatus according to claim 1, characterised in that an additional identification of the presence of biofilms implemented by supplying and flowing in said membrane filtration apparatus a composition comprising at least one detergent component and at least one enzyme component, said enzyme component comprising at least one laccase and/or at least one polysaccharidase and/or at least one protease and said detergent component comprising at least one sequestering compound, a dispersing compound and a wetting compound.

11. Method for treating a membrane filtration apparatus according to claim 1, characterised in that an additional identification of the presence of metal ions is implemented by supplying and flowing a composition comprising a sequestering agent and/or a dispersant.

12. Kit for identifying the nature of clogging present in a membrane filtration apparatus, said kit comprising at least: c) a first enzyme solution comprising at least one protease; d) a second enzyme solution comprising at least one enzyme other than a protease.

13. Kit for identifying the nature of clogging present in a membrane filtration apparatus according to claim 12, characterised in that said at least one enzyme other than a protease is chosen from the group consisting of -polysaccharidases (lactase, amylase, alpha-glucosidase, etc.), -polysaccharidases (-N-acetylglucosaminidase, cellulase, hemicellulase, -glucanase, arabanase, pectinase, chitinase, xylanase, dextranase, lysozyme, pullulanase, -glucisidase, mannanase, etc.), oxidoreductases (laccase, etc.), lyases (pectate lyase, etc.), transferases, lipases and esterases (lysophospholipase, phospholipase, etc.) and mixtures thereof.

14. Kit for identifying the nature of clogging present in a membrane filtration apparatus according to claim 12, characterised in that it further comprises a third enzyme solution comprising at least one enzyme chosen from the group consisting of -polysaccharidases (lactase, amylase, alpha-glucosidase, etc.), -polysaccharidases (-N-acetylglucosaminidase, cellulase, hemicellulase, -glucanase, arabanase, pectinase, chitinase, xylanase, dextranase, lysozyme, pullulanase, -glucisidase, mannanase, etc.), oxidoreductases (laccase, etc.), lyases (pectate lyase, etc.), transferases, proteases and peptidases (metallo-protease, serine-proteases, exo-peptidase, endo-protease, cystine-protease, etc.), and lipases and esterases (lysophospholipase, phospholipase, etc.) and mixtures thereof.

15. Kit for identifying the nature of clogging present in a membrane filtration apparatus according to claim 12, further comprising a detergent solution comprising at least one sequestering agent and/or at least one dispersing agent and/or at least one wetting agent.

16. Kit for identifying the nature of clogging present in a membrane filtration apparatus according to claim 12, further comprising a detergent solution comprising at least one detergent component and at least one enzyme component, said enzyme component comprising at least one laccase and/or at least one polysaccharidase and/or at least one protease and said detergent component comprising at least one sequestering compound, a dispersing compound and a wetting compound.

17. Kit for identifying the nature of clogging present in a membrane filtration apparatus according to claim 12, further comprising a detergent solution comprising a composition comprising a sequestering agent and/or a dispersing agent.

Description

EXAMPLES

Example 1

[0051] In order to determine the nature o f the clogging present in an ultrafiltration apparatus (300 litre volume) for extracting lupines, the method according to the invention was implemented according to the steps set out in the following table:

TABLE-US-00001 pH after Dura- injection Flow rate tion Product Volume T of at Step (min) injected (litres) ( C.) product outlet (l/h) Organic clogging Detergent 20 A6 + 0.5 (A6) + 47.6 5.5 280 base + D2 0.15 acidification (D2) Cellulase 20 K4 0.15 47.5 5.1 426 Jump in pH 10 K2 0.2 47.5 9.8 356 Protease 20 K1 0.8 48 9.8 518 Lipase 20 K3 0.15 48.5 9.8 521 Rinsing 10 H.sub.2O n.a.* 48.5 7 521 Metal clogging Acidification 15 A3 0.25 41 3 760 Sequestering 20 A4 0.3 42 3 917 agent + dispersant A6 = detergent base comprising a sequestering agent, a dispersing agent and a wetting agent D2 = acid solution (phosphoric acid + nitric acid) K4 = aqueous enzyme solution based on cellulase K2 = alkaline solution (caustic soda + caustic potash) K1 - aqueous enzyme solution based on protease K3 = aqueous enzyme solution based on lipase A3 = acid solution (HCl) A4 = solution comprising a sequestering agent and a dispersing agent n.a.* = not applicable: lost-flow circulation continuously for 10 minutes.

[0052] Implementation of the method according to the invention according to the first example showed that the clogging of the ultrafiltration apparatus is essentially due to the presence of particles having an affinity with cellulases and proteases but also because of the presence of metal ions. As can be seen from this example, a first step of injecting a detergent solution was performed, in order to at least partially detach the particles (soiling) from the filter and to keep them in suspension. A pH of 5.5 was imposed at the start of audit so that the cellulase is situated in a medium having a pH favourable to its enzyme activity. Furthermore, a jump in pH was effected before the successive injections of the enzyme solutions based on protease and lipase so that these enzymes are situated in a medium having a pH favourable to the enzyme activity. Moreover, acidification was effected before the injection of a solution comprising a sequestering agent and a dispersing agent, in order to promote the action of these agents in the possible attachment of metal ions. More specifically, the acidification was performed in order to effect a detachment of iron.

[0053] In this test, since higher flow rates at the discharge from the filtration apparatus were observed following the injection of the solution containing cellulase, the injection of the solution contained protease and the injection of the solution comprising a sequestering agent and a dispersing agent, it could be concluded that the nature of the clogging is essentially cellulosic and proteinic but that the clogging is also due to the presence of metal ions. Following this audit, a suitable solution comprising cellulases, proteases and agents for detaching the metal ions could be formulated in order to be able to act specifically against particles actually responsible for clogging.

Example 2

[0054] In order to determine the nature of clogging present in a nanofiltration and reverse osmosis filtration apparatus (1500 litre volume) for processing milk, the method according to the invention was implemented in accordance with the steps set out in the following table:

TABLE-US-00002 pH Flow after rate injection at Duration Injected Volume T of outlet Step (min) product (litres) ( C.) product (l/h) Organic clogging Detergent 20 A6 3 45 7.57 6000 base Lactase 20 R1 0.9 30 7.57 6000 Protease 20 R2 0.9 35 7.01 7000 Lipase 20 R3 0.9 37.2 6.87 6500 Jump in pH 10 K2 3 40.2 11.05 9000 Rinsing 10 H.sub.2O n.a.* 45 7 6500 Metal clogging Sequestering 25 A4 4.5 34 10.76 9000 agent + dispersant + K2 A6 = detergent base comprising a sequestering agent, a dispersing agent and a wetting agent R1 = aqueous enzymatic solution based on lactase K2 = alkaline solution (caustic soda + caustic potash in a ratio 1:1) R2 = aqueous enzyme solution based on protease R3 = aqueous enzyme solution based on lipase A4 = solution comprising a sequestering agent and a dispersing agent n.a.* = not applicable: lost-flow circulation continuously for 10 minutes

[0055] The implementation of the method according to the invention according this second example showed that the clogging of the nanofiltration and reverse-osmosis filtration apparatus is essentially due to the present of particles having an affinity with lipases and proteases. As can be seen from this example, a first step of injecting a detergent solution was carried out in order to at least partially detach the particles from the filter and to keep them in suspension. Furthermore, a jump in pH was carried out following the successive injections of the enzyme solutions based on protease and lipase so that these enzymes are each situated in a medium having a pH favourable to their enzyme activity.

[0056] From this test, since higher flow values at the discharge from the filtration apparatus were observed following the injection of the solution containing protease and the injection of the solution containing lipase, in association with a subsequent jump in pH, it could be concluded that the nature of the clogging is essentially proteinic and lipidic. A suitable solution comprising proteases and lipases could be formulated in order to be able to act specifically against the particles actually responsible for the clogging.

Example 3

[0057] In order to determine the nature of the clogging present in a reverse-osmosis filtration apparatus (3000 litre volume) for treating milk, the method according to the invention was implemented according to the steps set out in the following table:

TABLE-US-00003 pH Flow after rate injection at Duration Injected Volume T of outlet Step (min) product (litres) ( C.) product (l/h) Organic clogging Detergent 20 A6 3.2 47.2 6.8 18 base + Lactase 20 R1 0.8 47.2 6.6 18 Protease 20 R2 0.8 47.2 6.6 18 Lipase 20 R3 0.8 47.2 6.6 18 Jump in pH 10 K2 1.5 47.2 9.9 26 Rinsing 10 H.sub.2O n.a.* 47.2 7 26 Biofilm clogging Biorem 45 B 4 47.2 7 26 Rinsing 10 H.sub.2O n.a.* 47.2 7 26 Metal clogging Sequestering 25 A4 3.7 47.2 10.1 35 agent + dispersant + K2 A6 = detergent base comprising a sequestering agent, a dispersing agent and a wetting agent R1 = aqueous enzymatic solution based on lactase K2 = alkaline solution (caustic soda + caustic potash in a ratio 1:1) R2 = aqueous enzyme solution based on protease R3 = aqueous enzyme solution based on lipase A4 = solution comprising a sequestering agent and a dispersing agent B = composition comprising a detergent component comprising a sequestering agent, a dispersing agent and a wetting agent and an enzyme component comprising a polysaccharidase, a laccase and protease n.a.* not applicable: lost-flow circulation continuously for 10 minutes.

[0058] The implementation of the method according to the invention according to this third example made it possible to show that the clogging of the reverse-osmosis filtration apparatus is essentially due to the presence of particles having an affinity with lipases and proteases but also because of the presence of metal ions. As can be seen from this example, a first step of injecting a detergent solution is performed, in order to at least partly detach the particles from the filter and to keep them in suspension. Furthermore, a jump in pH was effected following the successive injections of enzyme solutions based on protease and lipase so that these enzymes are situated in an environment having a pH favourable to their enzyme activity. As can be seen, the injection of a solution for showing the presence of clogging due to the presence of biofilm did not make it possible to observe a greater flow at the discharge, which results in an almost absence of biofilm in the filtration apparatus.

[0059] From this test, since the higher flow values at the discharge from the filtration installation were observed following the injection of the solution containing lipase, the injection of the solution containing the protease and the injection of the solution comprising a sequestering agent and a dispersant, it could be concluded that the nature of the clogging is essentially lipidic and proteinic but also that the clogging is due to the presence of metal ions. Following this audit, a suitable solution comprising lipases, proteases and agents for detaching the metal ions could be formulated in order to be able to act specifically against the particles actually responsible for the clogging.

[0060] Naturally the present invention is in no way limited to the embodiments described above and many modifications can be made thereto without departing from the scope of the accompanying claims.