JP6533056B2 - Filtration treatment system and filtration treatment method - Google Patents

Description

  The present invention relates to a filtration treatment system and a filtration treatment method for performing reverse osmosis membrane treatment of water to be treated containing organic matter.

  In water treatment using reverse osmosis membranes of treated water containing organic matter, the generation of slime is often a problem, and at present, by the addition of organic slime inhibitors and intermittent addition of oxidizing agents such as hypochlorous acid It corresponds. However, the addition of the organic slime inhibitor causes an increase in running cost and deterioration of total organic carbon (TOC) of the permeate, and although the use of hypochlorous acid is intermittent addition, deterioration of the polyamide-based reverse osmosis membrane May occur.

  Techniques for monitoring the quality of raw water or treated water and changing the amount of the organic slime inhibitor or bactericide have been proposed. For example, in patent document 1 and patent document 2, the method of calculating the addition amount of a microbicide from the microbial cell count of raw water is proposed. However, the number of cells is measured off-line, and it is difficult to quickly control the amount of addition according to the water quality of the raw water.

  Patent Document 3 proposes a method for detecting the generation of microorganisms online and controlling the amount of slime inhibitor added. However, since it is control after sensing the generation of microorganisms, it is difficult to cope with the generation of microorganisms.

Japanese Patent Application Publication No. 2002-143849 JP, 2014-171988, A JP 2012-101194 A

  An object of the present invention is to provide a filtration treatment system and a filtration treatment method capable of appropriately supplying a slime inhibitor in water treatment for reverse osmosis membrane treatment of treated water containing organic matter.

The present invention relates to a reverse osmosis membrane treatment means for performing reverse osmosis membrane treatment using a reverse osmosis membrane for treated water containing high molecular organic matter, and TOC measurement for measuring TOC of concentrated water from the reverse osmosis membrane treatment means And slime suppression for supplying at least one of hypochlorous acid-based slime inhibitor and hypobromous acid-based slime inhibitor to the water to be treated when the measured TOC exceeds a predetermined value. filtration system comprising a agent supply means, in front of the front Kigyaku osmosis membrane treatment the TOC measuring device to a subsequent unit, and a UF membrane or MF membrane as the polymer organic substance removing means for removing the polymer organic material It is.

  In the filtration system, it is preferable that the slime inhibitor supply means supply the slime inhibitor to the water to be treated when the measured TOC becomes 0.5 mg / L or more.

In the filtration treatment system, the hypobromous acid slime inhibitor, bromine-based oxidizing agent, Moshiku comprises a reaction product of a bromine compound and chlorine-based oxidizing agent, a sulfamic acid compound, the, or, bromine-based oxidizing agent, Moshiku preferably contains a reaction product of a bromine compound and chlorine-based oxidizing agent, the reaction product of sulfamic acid compound.

  In the filtration system, the hypochlorous acid-based slime inhibitor preferably contains a chlorine-based oxidizing agent and a sulfamic acid compound, or preferably contains a reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound. .

The present invention relates to a reverse osmosis membrane treatment step of performing reverse osmosis membrane treatment using a reverse osmosis membrane for treated water containing high molecular weight organic matter, and TOC measurement for measuring TOC of concentrated water from the reverse osmosis membrane treatment step. And slime suppression to supply at least one of hypochlorous acid-based slime inhibitor and hypobromous acid-based slime inhibitor to the water to be treated when the measured TOC exceeds a predetermined value. agent supplying step, in front of the front Kigyaku osmosis membrane treatment the TOC measurement step a subsequent step, a filtration comprising a polymeric organic substance removing step of removing the polymeric organic material by using a UF membrane or MF membrane It is a processing method.

  In the slime inhibitor supply step of the filtration method, it is preferable to supply the slime inhibitor to the water to be treated when the measured TOC is 0.5 mg / L or more.

In the filtration treatment method, the hypobromous acid slime inhibitor, bromine-based oxidizing agent, Moshiku comprises a reaction product of a bromine compound and chlorine-based oxidizing agent, a sulfamic acid compound, the, or, bromine-based oxidizing agent, Moshiku preferably contains a reaction product of a bromine compound and chlorine-based oxidizing agent, the reaction product of sulfamic acid compound.

  In the filtration method, the hypochlorous acid-based slime inhibitor preferably contains a chlorine-based oxidizing agent and a sulfamic acid compound, or preferably contains a reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound. .

  ADVANTAGE OF THE INVENTION In the water treatment which performs the reverse osmosis membrane process of the to-be-processed water containing an organic substance, this invention can provide the filtration processing system and the filtration processing method which can supply a slime inhibitor appropriately.

It is a schematic block diagram which shows an example of the filtration processing system which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the filtration processing system which concerns on embodiment of this invention. It is a figure which shows the measurement result of LC-OCD of the waste_water | drain processed by the polymeric organic substance removal apparatus in an Example.

  Embodiments of the present invention will be described below. The present embodiment is an example for implementing the present invention, and the present invention is not limited to the present embodiment.

<Filtration treatment system and filtration treatment method>
An outline of an example of a filtration system according to an embodiment of the present invention is shown in FIG. 1, and the configuration thereof will be described. The filtration processing system 1 includes a reverse osmosis membrane processing device 12 as reverse osmosis membrane processing means, and a slime inhibitor storage tank 14 as slime inhibitor supply means. The filtration system 1 may include a raw water tank 10.

  In the filtration system 1 of FIG. 1, the raw water pipe 22 is connected to the inlet of the raw water tank 10, and the outlet of the raw water tank 10 and the inlet of the reverse osmosis membrane treatment apparatus 12 are connected by the raw water supply pipe 24 via the pump 16. It is done. A permeated water pipe 26 is connected to the permeated water outlet of the reverse osmosis membrane treatment apparatus 12, and a concentrated water pipe 28 is connected to the concentrated water outlet. The outlet of the slime inhibitor storage tank 14 and the downstream side of the pump 16 of the raw water supply piping 24 are connected by a slime inhibitor supply piping 30 via a pump 18. A TOC measurement meter 20 as a TOC measurement unit may be installed in the concentrated water pipe 28, and the TOC measurement meter 20 and the pump 18 may be connected by an electrical connection unit or the like via a control device or the like (not shown).

  The filtration processing method and the operation of the filtration processing system 1 according to the present embodiment will be described.

  Raw water, which is water to be treated containing organic matter, is stored in the raw water tank 10 through the raw water pipe 22 if necessary, and is then supplied to the reverse osmosis membrane treatment device 12 through the raw water supply pipe 24 by the pump 16. In the reverse osmosis membrane treatment device 12, reverse osmosis membrane treatment of the water to be treated is performed by the reverse osmosis membrane (reverse osmosis membrane treatment step).

  The permeated water obtained by the reverse osmosis membrane treatment is discharged through the permeated water pipe 26, and the concentrated water is discharged through the concentrated water pipe 28.

  Here, in the concentrated water pipe 28, the TOC of the concentrated water is measured by the TOC measuring meter 20 (TOC measuring step). And when measured TOC becomes more than a predetermined value, the pump 18 is controlled by the control apparatus etc. which is not shown in figure, and the slime inhibitor of hypochlorous acid type from the slime inhibitor storage tank 14 through the slime inhibitor supply piping 30 And at least one of the hypobromous acid-based slime inhibitors is supplied to the water to be treated (a slime inhibitor supply step).

  Thereby, in the water treatment which performs the reverse osmosis membrane process of the to-be-processed water containing an organic substance, a slime inhibitor can be supplied appropriately. The TOC, which can be a nutrient source of microorganisms in the concentrated water, can be measured, and the appropriate supply amount of slime inhibitor can be determined based on the measured value of the TOC. Since the TOC component is concentrated in the concentrated water and the risk of slime formation on the concentrated water side is further increased, the TOC of the concentrated water is measured, and based on the measured value of the TOC, the appropriate slime inhibitor is selected. It is important to decide the supply amount.

  The “predetermined value” may be set based on the system to be treated, the property of the treated water (permeated water) to be obtained, and the like, and is not particularly limited. For example, the lower limit value of TOC may be determined in advance by obtaining the relationship between TOC and the number of bacteria. For example, when the measured TOC becomes 0.5 mg / L or more, at least one of a hypochlorous acid-based slime inhibitor and a hypochlorous acid-based slime inhibitor may be supplied to the water to be treated .

  Examples of hypochlorous acid-based slime inhibitors include hypochlorous acid and hypochlorous acid-stabilized compositions of hypochlorous acid and a sulfamic acid compound. Examples of hypobromous acid-based slime inhibitors include hypobromous acid and the following hypobromous acid-stabilized compositions. When an organic slime inhibitor is used, it is detected as TOC in concentrated water, so appropriate control can not be performed.

  In the filtration treatment method and the filtration treatment system according to the present embodiment, a drug containing hypochlorous acid, hypochlorous acid and sulfamine as raw water in a reverse osmosis membrane treatment apparatus 12 as a drug for blocking or preventing slime formation, etc. An agent containing an acid compound or an agent containing a reaction product of hypochlorous acid and a sulfamic acid compound is supplied. It is believed that the “hypochlorous acid” and the “sulfamic acid compound” produce a hypochlorous acid stabilized composition in the raw water.

  For example, in the raw water tank 10 or the raw water supply pipe 24, "hypochlorous acid", or "hypochlorous acid" and "sulfamic acid compound", or their reaction products are injected into the raw water by a chemical pump or the like. do it. The “hypochlorous acid” and the “sulfamic acid compound” may be added separately, or may be added after being mixed with the stock solution.

In filtration method and filtration treatment system according to the present embodiment, as a reverse osmosis membrane treatment apparatus 12 agents such as for preventing clogging and slime generation suppression, the raw water, the agent comprising a hypobromite, bromine-based oxidizing agent, also properly is a reaction product of a bromine compound and chlorine-based oxidizing agent, the agent comprising a sulfamic acid compound, the, or, bromine-based oxidizing agent, Moshiku is a reaction product of a bromine compound and chlorine-based oxidizing agent, sulfamate An agent is provided that comprises a reaction product with a compound.

  That is, in the filtration processing method and the filtration processing system according to the present embodiment, “bromine-based oxidizing agent” or “reactant of bromine compound and chlorine-based oxidizing agent” and “sulfamic acid compound” are used as the above-mentioned agents. Use drugs that contain it. This is believed to produce a hypobromous acid stabilized composition in the raw water.

  Further, in the filtration method and the filtration system according to the present embodiment, “the reaction product of a bromine-based oxidizing agent and a sulfamic acid compound” or “the reaction product of a bromine compound and a chlorine-based oxidizing agent” as the agent , A reaction product of a sulfamic acid compound and a hypobromous acid stabilizing composition.

  Specifically, in the filtration treatment method and the filtration treatment system according to the present embodiment, for example, “bromine”, “bromine chloride” or “reactant of sodium bromide and hypochlorous acid” in raw water; "Sulfamic acid compound" is supplied.

  Further, in the filtration method and the filtration system according to the present embodiment, for example, “reaction product of bromine and sulfamic acid compound”, “reaction product of bromine chloride and sulfamic acid compound”, or raw water in the raw water "The reaction product of the reaction product of sodium bromide and hypochlorous acid and the sulfamic acid compound" is supplied.

  For example, in the raw water tank 10 or the raw water supply pipe 24, the raw water may contain “hypobromous acid”, “bromine-based oxidizing agent” or “reactant of bromine compound and chlorine-based oxidizer”, and “sulfamic acid compound” Or these reaction products may be injected by a chemical pump or the like. The "bromine-based oxidizing agent" or the "reactant of a bromine compound and a chlorine-based oxidizing agent" and the "sulfamic acid compound" may be added separately, or they may be added after mixing in the stock solution and then added. Good.

  According to the filtration treatment method and the filtration treatment system according to the present embodiment, “bromine-based oxidizing agent” or “reactant of bromine compound and chlorine-based oxidant” and “sulfamic acid compound” are made to be present in raw water The presence of these reaction products can prevent blockage and slime formation of the reverse osmosis membrane processing apparatus 12. Also for treated water containing an organic substance, membrane filtration can be performed by suppressing deterioration of the separation membrane.

  The organic substance is not particularly limited, and examples thereof include isopropyl alcohol and monoethanolamine.

  The ratio of the equivalent of “sulfamic acid compound” to the equivalent of “bromine-based oxidizing agent” or “reactant of bromine compound and chlorine-based oxidizing agent” is preferably 1 or more, and is in the range of 1 or more and 2 or less. Is more preferred. If the ratio of the equivalent of "sulfamic acid compound" to the equivalent of "bromine-based oxidizing agent" or "reactant of bromine compound and chlorine-based oxidizing agent" is less than 1, the active ingredient may not be stabilized sufficiently. If more than 2, the manufacturing cost may increase.

  It is preferable that the addition amount of the microbicide in to-be-processed water is 0.01-10 mg / L in conversion of an effective chlorine concentration as an effective halogen concentration. If it is less than 0.01 mg / L, sufficient slime suppression effect may not be obtained, and if it is more than 10 mg / L, corrosion of metal materials such as piping may be caused.

  Bromine-based oxidizing agents include bromine (liquid bromine), bromine chloride, hypobromous acid, bromate, bromate and the like.

  Among these, formulations of "bromine and sulfamic acid compound" or "reaction product of bromine and sulfamic acid compound" using bromine are formulations of "hypochlorous acid and bromine compound and sulfamic acid" and "bromine chloride And sulfamic acid, it is more preferable because it has less chloride ions and is less likely to cause corrosion of metal materials such as piping.

  That is, in the filtration method and the filtration system according to the present embodiment, it is preferable to make bromine and a sulfamic acid compound exist in the raw water, or to make a reaction product of bromine and a sulfamic acid compound.

  Examples of bromine compounds include sodium bromide, potassium bromide, lithium bromide, ammonium bromide and hydrobromic acid. Among these, sodium bromide is preferable in terms of formulation cost and the like.

  As the chlorine-based oxidizing agent, for example, chlorine gas, chlorine dioxide, hypochlorous acid or its salt, chlorous acid or its salt, chloric acid or its salt, perchloric acid or its salt, chlorinated isocyanuric acid or its salt Etc. Among these, as salts, for example, alkali metal hypochlorite such as sodium hypochlorite and potassium hypochlorite, calcium hypochlorite, alkaline earth hypochlorite such as barium hypochlorite and the like Metal salts, alkali metal chlorite such as sodium chlorite and potassium chlorite, alkaline earth metal chlorite such as barium chlorite, and other metal chlorite such as nickel chlorite And alkali metal salts of chlorate such as ammonium chlorate, sodium chlorate and potassium chlorate, and alkali earth metal chlorates such as calcium chlorate and barium chlorate. One of these chlorine-based oxidizing agents may be used alone, or two or more thereof may be used in combination. As a chlorine-based oxidizing agent, sodium hypochlorite is preferably used in terms of handleability and the like.

The sulfamic acid compound is a compound represented by the following general formula (1).
R ₂ NSO ₃ H (1)
(Wherein, R is independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms)

  As a sulfamic acid compound, for example, in addition to sulfamic acid (amidosulfuric acid) in which both of two R groups are hydrogen atoms, N-methylsulfamic acid, N-ethylsulfamic acid, N-propylsulfamic acid, N- A sulfamic acid compound in which one of two R groups such as isopropyl sulfamic acid and N-butyl sulfamic acid is a hydrogen atom and the other is an alkyl group having 1 to 8 carbon atoms, N, N-dimethyl sulfamic acid, N, Two R groups such as N-diethylsulfamic acid, N, N-dipropylsulfamic acid, N, N-dibutylsulfamic acid, N-methyl-N-ethylsulfamic acid, N-methyl-N-propylsulfamic acid, etc. One of two R groups such as sulfamic acid compounds and N-phenylsulfamic acid, both of which are alkyl groups of 1 to 8 carbon atoms An atom, the other is sulfamic acid compound or a salt thereof, such as an aryl group having 6 to 10 carbon atoms. Examples of sulfamate salts include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts, strontium salts and barium salts, manganese salts, copper salts, zinc salts, iron salts, cobalt salts, Other metal salts such as nickel salts, ammonium salts and guanidine salts can be mentioned. The sulfamic acid compounds and their salts may be used alone or in combination of two or more. As the sulfamic acid compound, sulfamic acid (amidosulfuric acid) is preferably used from the viewpoint of environmental load and the like.

  In the filtration method and the filtration system according to the present embodiment, an alkali may be further present. Examples of the alkali include alkali hydroxides such as sodium hydroxide and potassium hydroxide. Sodium hydroxide and potassium hydroxide may be used in combination from the viewpoint of product stability at low temperature and the like. Further, the alkali is not solid but may be used as an aqueous solution.

  The filtration treatment method and the filtration treatment system according to the present embodiment can be suitably applied to, in particular, a polyamide-based polymer membrane that is currently mainstream as a reverse osmosis membrane (RO membrane). The polyamide-based polymer membrane has a relatively low resistance to an oxidizing agent, and when free chlorine and the like are continuously brought into contact with the polyamide-based polymer membrane, the membrane performance significantly decreases. However, in the filtration method and the filtration system according to the present embodiment, such a remarkable decrease in the membrane performance hardly occurs even in the polyamide polymer membrane.

  In the filtration method and the filtration system according to the present embodiment, the pH of the raw water which is the water to be treated is preferably in the range of 5 to 12, and more preferably in the range of 6.5 to 12. When the pH of the raw water is less than 5, the flux may decrease. In addition, when the pH of the raw water exceeds 12, the membrane may be degraded.

  In the reverse osmosis membrane treatment apparatus 12, when scale is generated at pH 5 or more of the raw water, a dispersant is used for scale inhibition, a hypochlorous acid-based scale inhibitor and a hypobromous acid-based scale inhibitor You may use together with at least one. Examples of the dispersant include polyacrylic acid, polymaleic acid, phosphonic acid and the like. The amount of the dispersant added to the feed water (pre-filtered water) is, for example, in the range of 0.1 to 1,000 mg / L as the concentration in the concentrated water.

  Also, in order to suppress the generation of scale without using a dispersant, for example, the reverse osmosis membrane so that the concentration of silica in the concentrated water is less than the solubility and the Langeria index, which is an indicator of calcium scale, is less than 0. Adjusting the operating conditions such as the recovery rate of the processing apparatus 12 can be mentioned.

  The filtration processing method and the filtration processing system according to the present embodiment treat, for example, treated water containing organic substances such as semiconductor factory drainage and liquid crystal factory drainage. The TOC of the water to be treated is, for example, in the range of 0.01 to 10 mg / L.

  The schematic configuration of another example of the filtration system according to the embodiment of the present invention is shown in FIG. In the filtration processing system 3 of FIG. 2, it is a subsequent stage of the reverse osmosis membrane processing apparatus 12 and is a previous stage of the TOC measuring meter 20 that measures the TOC of the concentrated water from the reverse osmosis membrane processing apparatus 12. A high molecular weight organic substance removing device 32 is installed between the branch point and the TOC measurement meter 20 as a high molecular weight organic substance removing means.

  When the water to be treated contains a high molecular weight organic substance (for example, with a molecular weight of 100,000 to 2,000,000) and the high molecular weight organic substance that is unlikely to be a nutrient source of the microorganism is detected by the TOC measurement meter 20 Preferably, as shown in FIG. 2, the high molecular weight organic substance is removed by the high molecular weight organic substance removal device 32 (high molecular weight organic substance removal step). The high molecular organic matter can be blocked upstream of the TOC measuring meter 20, and the control accuracy of the slime inhibitor supply amount based on the measured TOC is improved.

  Examples of the high molecular weight organic substance removing apparatus 32 include a UF film, an MF film, and the like.

<Composition for filtration processing>
The composition for filtration processing of the hypobromous acid stabilization composition system according to the present embodiment is, for example, a "bromine-based oxidizing agent" or a "reactant of a bromine compound and a chlorine-based oxidant", and a "sulfamic acid compound". And may further contain an alkali.

  Moreover, the composition for the filtration process of the hypobromous acid stabilization composition type | system | group based on this embodiment is, for example, "a reaction product of a bromine-based oxidizing agent and a sulfamic acid compound", or "a bromine compound and a chlorine-based oxidation "A reaction product of a reactant with an agent and a sulfamic acid compound" and may further contain an alkali.

  The bromine-based oxidizing agent, the bromine compound, the chlorine-based oxidizing agent and the sulfamic acid compound are as described above.

  The composition for filtration processing according to the present embodiment contains bromine and a sulfamic acid compound, from the viewpoint of low corrosiveness to metal materials such as piping and little by-production of bromic acid, or Those containing a reaction product of bromine and a sulfamic acid compound are preferred.

  The composition for filtration processing according to the present embodiment has a high oxidizing power and a remarkably high slime suppressing power and slime peeling power, as compared with a combined chlorine-based slime inhibitor such as chlorosulfamic acid.

  Unlike the oxidizing agent such as hypochlorous acid, the composition for filtration treatment according to the present embodiment hardly degrades the reverse osmosis membrane. Moreover, since the concentration can be measured on site in the same manner as hypochlorous acid etc., more accurate concentration control is possible.

  The pH of the composition is, for example, more than 13.0, more preferably more than 13.2. When the pH of the composition is 13.0 or less, the effective halogen in the composition may become unstable.

  The concentration of bromate in the composition for filtration is preferably less than 5 mg / kg. When the concentration of bromic acid in the composition for filtration treatment is 5 mg / kg or more, the water quality of the treated water may be deteriorated.

<Method of producing composition for filtration treatment>
The composition for filtration processing of the hypobromous acid stabilization composition system according to the present embodiment is, for example, a mixture of a bromine-based oxidizing agent and a sulfamic acid compound, or a reaction product of a bromine compound and a chlorine-based oxidizing agent. It may be obtained by mixing with a sulfamic acid compound, and may further be mixed with an alkali.

  Water, an alkali and a sulfamic acid compound can be used as a method for producing a filtration processing composition containing bromine and a sulfamic acid compound, or a filtration processing composition containing a reaction product of bromine and a sulfamic acid compound. It is preferable to include a step of adding bromine to the mixed solution containing it under an inert gas atmosphere to cause a reaction. Addition and reaction under an inert gas atmosphere lowers the bromate ion concentration in the composition, which is preferable.

Used but are not limited to inert gas, at least one and preferably one in terms of nitrogen and argon, such as production, nitrogen is particularly preferred from the viewpoint of production cost and the like.

  The oxygen concentration in the reactor at the time of addition of bromine is preferably 6% or less, more preferably 4% or less, still more preferably 2% or less, and particularly preferably 1% or less. If the oxygen concentration in the reactor during the reaction of bromine exceeds 6%, the amount of bromic acid produced in the reaction system may increase.

  The addition rate of bromine is preferably 25% by weight or less based on the total amount of the composition, and more preferably 1% by weight or more and 20% by weight or less. If the addition rate of bromine exceeds 25% by weight with respect to the total amount of the composition, the amount of bromic acid produced in the reaction system may increase. When it is less than 1% by weight, the bactericidal activity may be poor.

  The reaction temperature at the time of bromine addition is preferably controlled in the range of 0 ° C. or more and 25 ° C. or less, but is more preferably controlled in the range of 0 ° C. or more and 15 ° C. or less from the viewpoint of production cost. When the reaction temperature at the time of bromine addition exceeds 25 ° C., the amount of bromic acid produced in the reaction system may increase, and when it is less than 0 ° C., freezing may occur.

  Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited to the following examples.

[Preparation of stabilized hypobromous acid composition]
Liquid nitrogen: 16.9 wt% (wt%), sulfamic acid: 10.7 wt%, sodium hydroxide: 12.9 wt%, potassium hydroxide: 3.94 wt%, water under a nitrogen atmosphere The ingredients were mixed to prepare a composition. The pH of the composition was 14, and the effective halogen concentration (effective chlorine equivalent concentration) was 7.5% by weight. The detailed preparation method of the stabilized hypobromous acid composition is as follows.

  Add 1436 g of water, 361 g of sodium hydroxide to a 2-liter 4-neck flask sealed by continuous injection while controlling the flow rate of nitrogen gas with a mass flow controller so that the oxygen concentration in the reaction vessel is maintained at 1% Mix, then add 300 g of sulfamic acid and mix, then add 473 g of liquid bromine while maintaining cooling so that the temperature of the reaction solution becomes 0 to 15 ° C., and then add 230 g of 48% potassium hydroxide solution An objective composition was obtained in which the ratio by weight of the total composition was 10.7% sulfamic acid, 16.9% bromine, and the equivalent ratio of sulfamic acid to equivalent of bromine was 1.04. The pH of the resulting solution was 14 as measured by the glass electrode method. The bromine content of the resulting solution is 16.9% as determined by a redox titration method using sodium thiosulfate after converting bromine to iodine with potassium iodide, and the theoretical content (16.9% 100.0% of the Moreover, the oxygen concentration in the reaction container in the case of a bromine reaction was measured using "oxygen monitor JKO-02 LJDII" made by Dicor Corporation. The bromate concentration was less than 5 mg / kg.

[Correlation measurement of TOC and number of bacteria]
The TOC of the retentate of the reverse osmosis membrane and the number of bacteria were measured by the following method to determine the correlation between the TOC and the number of bacteria. The number of general bacteria was measured by Bio Checker TTC (manufactured by San-Ai Oil Co., Ltd.), and TOC was measured by a TOC measuring device (manufactured by Sivas, Sievers 900 type). The results are shown in Table 1.

Thus, there is a correlation between TOC and the number of bacteria. For example, when TOC becomes 0.5 mg / L or more, the number of bacteria becomes 10 ³ (CFU / mL) or more, and the risk of slime generation It can be seen that From this, when the TOC of the concentrated water from the reverse osmosis membrane treatment means reaches 0.5 mg / L or more, a slime inhibitor such as the above-mentioned stabilized hypobromous acid composition is supplied to the water to be treated It can be understood that it should be controlled.

[Removal of high molecular organic matter by UF membrane]
The following wastewater was treated using a UF membrane (LH3-6Cd type, manufactured by Rising), and it was confirmed that the high molecular organic matter was blocked by the UF membrane (turbidizing membrane) and the low molecular weight organic matter passed through.

(Experimental conditions)
Raw water: electronics factory drainage (TOC: 1.1 mg / L)
Operating pressure: 1.5MPa
Raw water pH: 6.2
Test temperature: 25 ± 1 ° C

(Analysis conditions)
The analysis of the TOC component in the permeated water which permeated the UF membrane was performed using LC-OCD apparatus (made by DOC-LABOR, model 2007). LC-OCD is an analyzer which fractionates the TOC component in a sample for every molecular weight, and shows it as a chromatogram. On the chromatogram, the higher the molecular weight and the more hydrophilic the organic substance, the faster the retention time tends to be displayed (on the left). For example, in the case of an organic substance having the same molecular weight, the organic substance having high hydrophilicity tends to exhibit a peak on the left side. The results are shown in FIG.

  As can be seen from FIG. 3, the high molecular weight organic substance (molecular weight 100,000 or more) was blocked by the UF film (turbidizing film), and the low molecular weight organic substance (molecular weight less than 350) passed.

  Thus, in water treatment which performs reverse osmosis membrane processing of the to-be-processed water containing an organic substance by measuring TOC in concentrated water and determining the supply amount of an appropriate slime inhibitor based on the measured value of TOC, It has been suggested that slime inhibitors can be provided appropriately.

  1, 3 filtration system, 10 raw water tank, 12 reverse osmosis membrane treatment device, 14 slime inhibitor storage tank, 16, 18 pump, 20 TOC measuring meter, 22 raw water piping, 24 raw water piping, 26 permeated water piping, 28 concentration Water piping, 30 slime inhibitor supply piping, 32 polymer organic substance removal equipment.

Claims (8)

Reverse osmosis membrane treatment means for performing reverse osmosis membrane treatment using a reverse osmosis membrane for treated water containing high molecular weight organic matter;
TOC measurement means for measuring TOC of the concentrated water from the reverse osmosis membrane treatment means;
A slime inhibitor supply means for supplying at least one of a hypochlorous acid-based slime inhibitor and a hypobromous acid-based slime inhibitor to the water to be treated when the measured TOC exceeds a predetermined value When,
In front of the TOC measuring device to a subsequent stage before Kigyaku osmosis membrane treatment unit, the UF membrane or MF membrane as the polymer organic substance removing means for removing the polymer organic material,
A filtration processing system comprising: The filtration system according to claim 1, wherein
The slime inhibitor supply means supplies the slime inhibitor to the water to be treated when the measured TOC reaches 0.5 mg / L or more. A filtration system according to claim 1 or 2, wherein
The hypobromous acid-based slime inhibitor comprises a bromine-based oxidizing agent, or a reaction product of a bromine compound and a chlorine-based oxidizing agent, and a sulfamic acid compound, or a bromine-based oxidizing agent or a bromine compound What is claimed is: 1. A filtration system comprising a reaction product of a reactant with a chlorine-based oxidizing agent and a sulfamic acid compound. A filtration system according to claim 1 or 2, wherein
The filtration processing system, wherein the hypochlorous acid-based slime inhibitor contains a chlorine-based oxidizing agent and a sulfamic acid compound, or contains a reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound. A reverse osmosis membrane treatment step of performing reverse osmosis membrane treatment using a reverse osmosis membrane to be treated water containing high molecular weight organic matter
A TOC measurement step of measuring TOC of the concentrated water from the reverse osmosis membrane treatment step;
Slime inhibitor supply step of supplying at least one of hypochlorous acid-based slime inhibitor and hypobromous acid-based slime inhibitor to the water to be treated when the measured TOC exceeds a predetermined value When,
In front of the front Kigyaku osmosis membrane treatment the TOC measurement step a subsequent step, the polymer organic substance removing step of removing the polymeric organic material by using a UF membrane or MF membrane,
A filtration treatment method characterized in that It is the filtration processing method according to claim 5,
The slime inhibitor supply process WHEREIN: The said slime inhibitor is supplied to to-be-processed water, when the measured TOC becomes 0.5 mg / L or more, The filtration process method characterized by the above-mentioned. It is the filtration processing method according to claim 5 or 6,
The hypobromous acid-based slime inhibitor comprises a bromine-based oxidizing agent, or a reaction product of a bromine compound and a chlorine-based oxidizing agent, and a sulfamic acid compound, or a bromine-based oxidizing agent or a bromine compound What is claimed is: 1. A filtration method comprising a reaction product of a reactant with a chlorine-based oxidizing agent and a sulfamic acid compound. It is the filtration processing method according to claim 5 or 6,
The hypochlorous acid-based slime inhibitor contains a chlorine-based oxidizing agent and a sulfamic acid compound, or contains a reaction product of a chlorine-based oxidizing agent and a sulfamic acid compound.

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