KR100987221B1 - Maintenance chemical cleaning method of high pressure filtration and device using the same - Google Patents

Abstract

PURPOSE: The lifetime of the high pressure film is extended. The cumulative processing quantity is maximized. The maintenance management cost can be reduced according to save the chemicals usage etc. Provided is the oil-and-fat chemistry cleaning solution and the high pressure membrane filtration equipment using method of the high pressure process of membrane filtration. CONSTITUTION: The oil-and-fat chemistry cleaning solution of the high pressure process of membrane filtration. In the high pressure film consisting of the polyamide system chemical, the oil-and-fat chemistry cleaning solution of the high pressure process of membrane filtration where the treated water is filtered to the pressure of 10 ~ 85bar.

Description

Maintenance chemical cleaning method of high pressure filtration and device using the same}

The present invention relates to a maintenance chemical cleaning method used in a membrane filtration process, particularly a high pressure membrane filtration process, which is a kind of water treatment. More specifically, the present invention is filtered at a high pressure membrane made of polyamide (PA) -based chemicals, and in a maintenance chemical cleaning method of a high pressure membrane filtration process filtered at 10 to 85 bar, at least once a week in a reversible membrane contamination state. It relates to a maintenance chemical cleaning method of a high pressure membrane filtration process comprising the step of maintaining the chemical cleaning of the high pressure membrane.

Membrane filtration process, which is a kind of water treatment, is a low pressure membrane filtration process operated at low pressure such as MF (microfiltration), UF (ultrafiltration, ultrafiltration), NF (nanofiltration, nanofiltration), RO (reverse osmosis). It can be divided into high pressure membrane filtration process operated at high pressure such as reverse osmosis. Pores are formed in the separator used in the membrane filtration process, and contaminants are filtered out.

Separation membranes used in membrane filtration process may cause organic fouling, inorganic fouling, particle fouling, bio-fouling, etc. Its performance continues to decrease. Therefore, cleaning in place (CIP) is performed through chemicals to restore the permeation performance of the membrane reduced with use.

It is reported that the cycle of chemical cleaning is about 1 to 2 years after treatment water production operation, but when it is actually used, it is generally appropriate to perform about 1 to 2 times a year. However, several times a year, due to fluctuations in inflow load of target water, unoptimized process configuration of pretreatment process, unoptimized operating condition of membrane filtration process as main process, and unoptimized cleaning condition of chemical cleaning, etc. Even many applications have been reported several times a month.

In addition, the typical chemical cleaning time is at least 8 hours to 24 hours when using a single chemical cleaning agent, and rinsing and flushing, which are intermediate stages of chemical cleaning, when a plurality of chemical cleaning agents are used. Including time, it takes from 24 hours to 48 hours. It goes without saying that the treated water is not produced and stopped during this time.

The chemical cleaning function is to restore the permeation performance of the membrane, but if the chemical cleaning is frequently performed as above, the productivity of the membrane filtration process may be deteriorated due to the stop of production of the treated water by the chemical cleaning treatment, and the cost of using the chemicals may be increased. Problems such as problems such as economic loss such as problems of treatment and cleaning waste, poor maintenance performance, deterioration of the rejection performance of the used separator, and deformation and aging of the separator ultimately reduce the life of the membrane.

In particular, chemical cleaning is generally applied in the presence of more irreversible "reversible membrane contamination" rather than "reversible membrane contamination" that can be recovered by physical cleaning such as backwashing, air scribing, and water washing. In the case of chemical cleaning (CIP) in reversible membrane fouling, the chemical cleaning is performed in a time and chemical manner in order to ensure the stability of the process at the point of need or unexpected change in inflow load during operation of the membrane filtration water treatment process. There is a problem that the drug is excessively consumed.

Therefore, the optimization of chemical cleaning is an important process directly related to the stability and economics of the membrane filtration process. Therefore, from the late 1990s, the physico-cleaning process such as back washing in low pressure membrane filtration processes such as MF and UF has been applied worldwide. And researches for optimizing chemical cleaning are being actively conducted, and the concept of maintenance chemical cleaning is emerging as one of such aspects.

Regarding optimization of chemical cleaning, Japanese Patent Application No. 2004-171256, Korean Application No. 10-2007-0054770 (Automatic chemical cleaning control system and method using membrane fouling rate), Korean Application No. 10-1997-0706463 (Filtration monitoring and control system), Korean Application No. 10-2008-0046564 (Method for Cleaning Immersion Membrane and Membrane Filter), and Korean Application No. 10-2007-0109624 (Method for High Efficiency Membrane Cleaning) It is.

In particular, Korean Application No. 10-2007-0109624 (high efficiency membrane cleaning method) and Korean Application No. 10-2007-0054770 (automatic chemical cleaning control system and method using membrane fouling rate) in the low pressure membrane filtration process In order to complement and improve the chemical cleaning process, Asahi Kasei's enhanced flux maintenance (EMF) technique, Xenon's membrane maintenance cleaning (MMC) technique or CEB (chemical) are mainly used with chemicals such as NaOCl, NaOH and H ₂ SO ₄ . Maintenance chemical cleaning, an enhanced backwashing technique, is optimized and applied according to the characteristics of each process.

However, these research trends are limited to low pressure membrane filtration processes, and high pressure membrane filtration processes such as NF and RO have not been actively studied.

In particular, there are few high-pressure membrane manufacturers in Korea, and the unit process technology of the high-pressure membrane and the high-pressure membrane filtration process can be said to be an initial stage.

In addition, chemical cleaning technology has also been established in general for low pressure membrane filtration processes such as organic and inorganic chemical cleaners for membrane pollutants, but general guidelines for high pressure membrane filtration processes are shown in Table 1 below. Even advanced membrane manufacturers offer different chemical cleaners for membrane pollutants, and commercial chemical cleaners manufactured by combining single chemical cleaners whose composition and ratio are covered by veils are distributed. The situation is not presented.

Unlike the chemical cleaning process of the low pressure membrane filtration process, the chemical cleaning process of the high pressure membrane filtration process does not provide general cleaning guidelines. Therefore, the paradigm of maintenance chemical cleaning technique, which has been applied in the low pressure membrane filtration process, Through the expansion, it is applied to high pressure membrane filtration process of 10 to 85 bar for brackish water, seawater and sewage / wastewater containing high salt, and improved operation performance of process The company intends to develop the element process technology of competitive chemical cleaning process to secure stability.

In addition, by performing the maintenance chemical cleaning method in the "reversible membrane contamination" state, which is less advanced "reversible membrane pollution", it is possible to extend the life of the high-pressure membrane, maximize the cumulative production volume, save the use of chemicals, etc. To reduce management costs.

In one embodiment for solving the above problems, the present invention is filtered in a high pressure membrane made of a polyamide (PA) -based chemical, and in the maintenance chemical cleaning method of the high pressure membrane filtration process is filtered at 10 to 85 bar In the reversible membrane fouling state provides a maintenance chemical cleaning method of the high pressure membrane filtration process comprising the step of maintaining the chemical cleaning of the high pressure membrane at least once a week.

In addition, a chemical is used in the maintenance chemical cleaning step, and the chemical is NaOH, HCl, EDTA-4Na, EDTA-2Na, NaOH (+) EDTA-4Na, HCl (+) EDTA-2Na, and HCl (+ It is preferably any one selected from the group consisting of citric acid.

In addition, the concentration of the chemical is preferably 0.01% (w) to 0.5% (w).

In addition, the cleaning time of the maintenance chemical cleaning step is preferably 30 minutes to 4 hours.

In another embodiment for solving the above problems, the present invention is a pre-processing unit, a main processing unit, a post-processing unit; And a chemical washing unit communicating with the main processing unit, wherein the main processing unit includes a high pressure pressurized membrane filter unit, and the high pressure pressurized membrane filter unit comprises a high pressure film made of polyamide (PA) -based chemicals. Including, and operating at 10 to 85bar, the chemical cleaning unit may perform a chemical cleaning (CIP) process and maintenance chemical cleaning process, the maintenance chemical cleaning process is the high pressure at least once a week in a reversible membrane contamination state Provided is a high pressure membrane filter, characterized in that the membrane is cleaned.

In addition, the chemical cleaning unit includes a chemical cleaning tank unit, the chemical cleaning tank chemicals (CIP) and maintenance chemical cleaning chemicals may be input, and the maintenance chemical cleaning chemicals Preferred is any one selected from the group consisting of NaOH, HCl, EDTA-4Na, EDTA-2Na, NaOH (+) EDTA-4Na, HCl (+) EDTA-2Na, and HCl (+) citric acid.

By applying the maintenance chemical cleaning method for the high pressure membrane filtration process according to the present invention it is possible to delay the performance of the chemical cleaning process at the time when the "non-reversible membrane fouling" is advanced. In other words, the process is performed at least once a week in a state of less "reversible membrane contamination", that is, "reversible membrane contamination," thereby ultimately extending the membrane life of the high pressure membrane, maximizing the cumulative production volume, and using chemicals. The maintenance cost can be reduced by saving the back.

In addition, the chemicals used are NaOH, HCl, EDTA-4Na, EDTA-2Na, NaOH (+) EDTA-4Na, HCl, which are less types of chemical cleaning processes than non-chemical cleaning agents used in high pressure membrane filtration. By using only one selected from the group consisting of (+) EDTA-2Na and HCl (+) citric acid as a single chemical, the concentration of the chemical is not only applied at 50% or less compared to the chemical cleaning process, but also the cleaning time. It can be reduced to less than 20% compared to chemical cleaning process.

In addition, in order to use the maintenance chemical cleaning method in the high pressure membrane filtration process according to the present invention, it is not necessary to add a separate device, and thus, the same effect as described above may be obtained by only changing the process without the burden of additional equipment. Can be.

1a and 1b show a conceptual diagram of a high pressure membrane filtration apparatus, in particular the steps of the high pressure membrane filtration process according to the invention are shown in bold arrows.
2A and 2B are graphs comparing the effects of the high pressure membrane filtration process according to the prior art and the high pressure membrane filtration process according to the present invention.

Definition of Terms

As used herein, the term "low pressure membrane filtration process" means a membrane filtration process made of low pressure, such as MF (microfiltration), UF (ultrafiltration, ultrafiltration). The membrane used therein is referred to as a "low pressure membrane".

As used herein, "high pressure membrane filtration process" means a membrane filtration process made of high pressure, such as NF (nanofiltration), RO (reverse osmosis). The operating pressure of the high pressure membrane filtration process is generally about 10 to 85 bar. The membrane used therein is also referred to as "high pressure membrane".

As used herein, "CIP (cleaning in place)" refers to a technique for cleaning a membrane by chemical action using chemicals, and "physical cleaning" refers to backwashing, air scribing, and water washing. It refers to the technique of cleaning the membrane by physical action.

As described herein, "non-reversible membrane fouling" refers to membrane fouling that is firmly fixed by long-term accumulation of contaminants on the membrane surface and is not cleaned by the cleaning process, and "reversible membrane fouling" refers to irreversible membrane fouling. On the contrary, it refers to membrane contamination which can be cleaned by physical cleaning or maintenance chemical cleaning process to restore its membrane function. In general, reversible membrane fouling develops into irreversible membrane fouling over a long period of time.

As described herein, "maintenance cleaning" is a concept of cleaning the contaminants at once in a long-term cycle such as 6 months to 1 year or more, that is, a concept opposite to "chemical cleaning", once a month to once a week Or shorter cycles mean cleaning to maintain the membrane's original function. Maintenance cleaning is also possible for chemical cleaning and physical cleaning, especially when using chemical cleaning as maintenance cleaning is referred to as "maintenance chemical cleaning". In addition, a cleaning liquid to which chemicals are added for use therein is referred to as a "maintenance chemical cleaning liquid".

Comparison of low pressure membrane filtration and high pressure membrane filtration

The low pressure membrane, which is a membrane for low pressure membrane filtration process, has a pore size and can be backwashed, but the high pressure membrane, which is a separator for high pressure membrane filtration process, does not have a pore size, and thus the filtration mechanism is different. The difference between the low pressure membrane filtration process and the high pressure membrane filtration process grasped by the present inventors is as follows.

First, unlike the low pressure film, the shape of the high pressure film is generally limited to a hollow-fiber type and a spiral type, and the material is mainly made of polyamide (PA, polyamide) -based chemicals. The high pressure membranes of polyamide (PA) chemicals are very susceptible to chlorine (Cl), so they can use chlorine-based NaOCl, the basic chemical for low pressure membrane filtration process cleaning, which is applied to the prior art, such as the cited patents mentioned above. none. In addition, unlike low pressure membranes having pore diameters, backwashing as physical cleaning or maintenance chemical cleaning through chemical cleaning chemicals cannot be applied in high pressure membrane filtration processes operated with NF and RO membranes.

In addition, the main purpose of the high pressure membrane filtration process is to remove the dissolved organic and dissolved inorganic substances. Therefore, when performing maintenance chemical cleaning, the membrane fouling is different from that of the low pressure membrane filtration process, and thus NaOH, HCl, EDTA-4Na, EDTA- It is effective to use only one selected from the group consisting of 2Na, NaOH (+) EDTA-4Na, HCl (+) EDTA-2Na, and HCl (+) citric acid as chemicals.

The optimum conditions for the chemical cleaning process used in the high pressure membrane filtration process, and more specifically, chemical cleaning chemicals are different depending on the fouling type. For example, the chemical cleaning chemicals provided by each manufacturer are shown in Table 1 below. Is the same as

Foule Type of membranes typeDuPont Film tec
(DOW chemicals) Fluid System Nitto Denko (Hydranautics) Toyobo Toray CaCO ₃ -HCl at pH4
citric acid (2% w), pH 4 (NH ₄ OH)
-Nutek-NT600 (5% w)
citricacid (2% w) + Na ₂ EDTA (2% w)
-pH ₄ (NH ₄ OH) -HCl (0.2% w) H ₃ PO ₄ (0.5% w)
citric acid (2% w) pH4
-Na ₂ S ₂ O ₄ (0.2% w) -citric acid (1% w) pH2.5 citric acid (2% w) pH4 (NaOH) citric acid (1-2% w)
pH2.5-4
(NaOHor NH ₄ )
-ultrasil70 (0.5%) pH2-2.5
-peracetic acid 100-200ppm CaSO ₄
/ BaSO ₄
/ SrSO ₄
/ CaF ₂ -citric acid (2% w) + pH8 (NH ₄ OH)
EDTA (1.5% w)
-pH7-8 (NaOH / HCl)
-Na ₂ S ₂ O ₄ (1% w) -HCl (0.2% w)
-H ₃ PO ₄ (0.5% w)
citric acid (2% w) pH4
-Na ₂ S ₂ O ₄ (0.2% w) -STP (2% w) + Na ₄ EDTA (0.85% w) pH 10 (H ₂ SO ₄ ) SiO ₂ NaOH pH11
-Biz (0.5% w)
-pH11 (NaOH) -NaOH (0.1% W) + Na ₂ EDTA (0.1% w) pH12 max 30 ℃ citric acid (2% w)
pH4 (NaOH) Metal oxides citric acid (2% w)
-pH ₄ (NH ₄ OH)
-Na ₂ S ₂ O ₄ (1% w)
citricacid (2% w) + Na ₂ EDTA (2% w)
-pH ₄ (NH ₄ OH) -H ₃ PO ₄ (0.5% w)
-Na ₂ S ₂ O ₄ (1% w)
NH ₂ SO ₃ H (0.2% w) -citric acid (1% w) pH2.5 citric acid (2% w) pH4 (NaOH) citric acid (2% w) pH4 (NaOH) Inorganic
colloids NaOH pH11
-Biz (0.5% w)
-pH11 (NaOH)
-SHMP (1% w) -NaOH (0.1% W) + sodium dodecylsulfate
[Na-DSS] (0.05% w), pH12 max 30 ° C -STP (2% w) + Na ₄ EDTA (0.85% w)
-pH10 (H ₂ SO ₄ ) citric acid (2% w) pH4 (NaOH) Biological
matter -Formal (0.25 ~ 2% w) followed by Biz (0.25% w) NaOH (0.1% W)
+ Na ₂ EDTA (0.1% w), pH12 max 30 ° C
NaOH (0.1% W)
+ sodiumdodecylsulfate [Na-DSS] (0.05% w), pH12max 30 ° C
-STP (1% w) + TSP (1% w) + EDTA (1% w) -STP (1% w) + TSP (1% w) + EDTA (1% w), pH 10-11 (HCl) -STP (2% w) + Na ₄ EDTA (0.85% w)
-pH10 (H ₂ SO ₄ )
-STP (2% w) + sodium dodecyl benzene sulfonate (0.25%)
-pH10 (H ₂ SO ₄ ) -1-5ppm chlorine pH6.5-7.5
-Formalin (0.5-2%) -Sodium lauryl sulfate 0.2% pH 10-11 (by NaOH)
-ultrasil10 0.7% pH10-11 Organic NaOH pH11
-Biz (0.5% w)
-pH11 (NaOH)
-SHMP (1% w) NaOH (0.1% W)
+ Na ₂ EDTA (0.1% w), pH12 max 30 ° C
NaOH (0.1% W)
+ sodiumdodecylsulfate [Na-DSS] (0.05% w), pH12 max30 ℃
-STP (1% w) + TSP (1% w) + EDTA (1% w) -STP (1% w) + TSP (1% w) + EDTA (1% w), pH 10-11 (HCl) -STP (2% w) + Na ₄ EDTA (0.85% w)
-pH10 (H ₂ SO ₄ )
-STP (2% w) + sodium dodecyl benzene sulfonate (0.25%)
-pH10 (H ₂ SO ₄ ) -1-5ppm
chlorine p H6.5-7.5
-Formalin (0.5-2%)

Detailed Description of One Embodiment of the Present Invention

Hereinafter, a maintenance chemical cleaning method according to the present invention will be described in detail with reference to the accompanying drawings.

As described above, the maintenance chemical cleaning method of the high pressure membrane filtration process according to the present invention can be implemented as a process change without additional equipment to the apparatus of the existing high pressure membrane filtration process.

1A shows a conceptual diagram of a conventional high pressure membrane filter.

In the existing high pressure membrane filtration apparatus, treated water such as seawater, brackish water, sewage / wastewater is treated through the pretreatment unit 100, the main treatment unit 200, and the aftertreatment unit 300, and finally discharged as treated water. In the main processing unit 200, NF or RO processing may be performed as described above.

Most existing high pressure membrane filters further comprise a chemical cleaner (400). As described above, according to the conventional high pressure membrane filtration process, the high pressure membrane of the main processing unit 200 is chemically cleaned once or twice a year through the chemical washing unit 400.

FIG. 1B shows the “A” portion of FIG. 1A in more detail.

It looks at the membrane filtration process of the existing main processing unit 200 in detail. Pre-treatment water in which a suitable chemical is introduced from the chemical input unit 205 into the pretreatment water pretreated in the pretreatment unit 100, and the chemical is introduced into the high pressure pressurized membrane filter unit 220 by the main treatment high pressure pump unit 210. Is filtered, and the main treatment water thus treated is stored in the main treatment water tank 230 and is led to the after treatment unit 300.

Examine the existing chemical treatment (CIP) of the main processing unit in detail. When the treatment water production performance of the main treatment process is deteriorated, the chemical cleaning process is performed, in which case the main treatment water treated in the main treatment unit 200 is used (arrow 10). The main treatment water is transferred to the chemical cleaning tank 410 and is applied to the high pressure pressurized membrane filter 220 by the chemical cleaning pump 420. The chemical cleaning tank unit 410 is injected with a suitable chemical for chemical cleaning, as shown in Table 1, various chemicals may be added according to the type of contamination, membrane type, and the like.

Next, the maintenance chemical cleaning method of the high pressure membrane filtration process according to the present invention will be described in detail. In FIG. 1b the process of the method is shown as a thick arrow.

Maintenance chemical cleaning of the high pressure membrane filtration process according to the present invention, as described above can be made by utilizing a conventional high pressure membrane filter as it is. Of course, the specific criteria such as the cycle of maintenance chemical cleaning, the type of chemicals used for chemical cleaning, the concentration and processing time of the maintenance chemical cleaning solution are different from the conventional chemical cleaning (CIP).

The high pressure membrane filtration process according to the invention is preferably carried out in a reversible membrane fouling state. That is, if the reversible membrane fouling state is left for a long time to reach the irreversible membrane fouling state should be made in a reversible membrane fouling state to deteriorate the performance and life of the high pressure membrane as in the prior art. The inventors have found that the optimal cycle for maintenance chemical cleaning in reversible membrane contamination is at least once a week through a number of experiments.

In addition, it is not only cumbersome to use different chemicals depending on the complicated situation as described in Table 1, but also can cause a great economic loss. As in the present invention, when the maintenance chemical cleaning is performed in a reversible membrane contamination state, it is sufficient to use only one chemical agent. The inventors have made a number of experiments to select only one selected from the group consisting of NaOH, HCl, EDTA-4Na, EDTA-2Na, NaOH (+) EDTA-4Na, HCl (+) EDTA-2Na, and HCl (+) citric acid. In the case of using an oil-based chemical cleaning solution, it was confirmed that the high-pressure membrane in the reversible membrane fouling state could be effectively cleaned. In particular, note that chlorine is not used.

In this way, by carrying out the maintenance chemical cleaning in a short cycle at least once a week, the concentration of the maintenance chemical cleaning liquid and the processing time of the maintenance chemical cleaning are also high concentrations, as in the chemical cleaning which is performed once or twice a year, and a long time of 24 to 48 hours. no need. The inventors have confirmed that, through a number of experiments, high pressure membranes in a reversible membrane fouling state can be effectively cleaned even at a cleaning concentration of 0.01% (w) to 0.5% (w) and a cleaning time of 30 minutes to 4 hours.

By minimizing chemicals, lowering their concentrations, and shortening the treatment time, the chemicals can be used more effectively while using less chemicals. The effect is doubled.

The bold arrows of FIG. 1B will specifically describe the maintenance chemical cleaning process of the high pressure membrane filtration process according to the present invention.

Maintenance chemical cleaning can be started if the treatment water production performance of the main treatment process deteriorates according to predetermined criteria.

The treated water used for the maintenance chemical cleaning is from the main treated water (arrow 10) produced in the main treatment process or the main treated water (arrow 20) or the post-treated water (arrow 30) stored in the main treated water tank 230. Can be obtained.

The treated water is transferred to the chemical cleaning tank unit 410 and mixed with the chemicals of the optimum conditions and the concentration of the optimum conditions, and transferred to the high pressure pressurized membrane filter unit 220 through the chemical cleaning pump unit 420. After that, maintenance and chemical cleaning are performed by circulation or stationary method. Optimum chemicals, concentrations, etc. are as described above.

Detailed description of the effects of the present invention

Referring to Figures 2a and 2b will be described in detail the maintenance chemical cleaning effect of the high pressure membrane filtration process according to the present invention. FIG. 2B shows the detail “B” of FIG. 2A in detail.

2A means the operating time (t) of the high pressure membrane filter device, and the vertical axis means the treated water F to be treated in the high pressure membrane filter device. That is, the vertical axis can be referred to as processing performance as processing water quantity. Graph (1) is the result of periodically performing the maintenance chemical cleaning according to the present invention, graph (2) is the result of performing a chemical cleaning (CIP) without the maintenance chemical cleaning according to the prior art.

First, the graph 2 as a result according to the prior art will be described.

According to the prior art, the proper chemical cleaning is performed at a time when the initial treatment amount F ₀ falls to the chemical cleaning time treatment point F _{c which} is predetermined as the chemical cleaning time point. The predetermined amount of chemical cleaning point F _c is generally set to be reduced by 10 to 15% relative to the initial amount of water F _0. Accordingly, as described above, chemical cleaning is usually performed once or twice a year. Is carried out. Since the reduction in the amount of treatment occurs due to complex membrane sources, chemical cleaning is usually carried out with complex chemicals. (See Table 1)

The chemical cleaning is carried out after the high-pressure membrane filtration unit operations, the processing quantity is chemical cleaning process time quantity (F _c) with the reduced time (t _1). Ideally, the treated water of the high pressure membrane filter subjected to chemical cleaning reaches the initial treatment water (F ₀ ), but in fact, as membrane fouling continues for a long time, reversible membrane fouling proceeds to irreversible membrane fouling. Treated water is not recovered. Accordingly, after one time of chemical cleaning, the treated water amount reaches a lower treated water amount (F ₁ ) than the initial treated water amount (F ₀ ), which means a decrease in performance and lifespan.

Thereafter, the amount of treatment is reduced according to the operation, and chemical cleaning is performed again at the time point t ₂ when the amount of treatment at the chemical cleaning point F _c is reduced. Also, irreversible membrane fouling, which corresponds to the difference between F ₀ and F ₁ , proceeds, and the amount of treated water reaches the amount of treated water (F ₂ ).

Thus, according to the prior art, even if the economics due to the use of the complex chemicals, apart from irreversible membrane contamination proceeds continuously, the life of the high-pressure membrane is shortened and productivity is greatly reduced.

The graph 1 according to the present invention will be described with reference to FIG. 2B.

The maintenance chemical cleaning according to the invention is carried out before reversible membrane fouling proceeds to irreversible membrane fouling, i.e. in a reversible membrane fouling state. That is, the slope, which means the amount of treatment water decrease according to operating time under the same conditions, is the same as that of the graph (2) and the graph (3), but the reversible membrane contamination is periodically reduced as a periodic maintenance chemical cleaning at least once a week. The overall slope of (1) is lower than the slope of the graph (3).

In particular, due to the maintenance of chemical cleaning for reversible membrane fouling, membrane contaminants are periodically cleaned and condensation and compression bonding, which is a combination of contaminants that form irreversible membrane fouling, greatly reduces the occurrence of irreversible membrane fouling. The time can be greatly reduced. This, in turn, means an increase in the lifespan and productivity of the high pressure membrane.

While preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described specific embodiments. That is, those skilled in the art to which the present invention pertains can make many changes and modifications to the present invention without departing from the spirit and scope of the appended claims, and all such appropriate changes and modifications are possible. Equivalents should be considered to be within the scope of the present invention.

100: preprocessing unit 200: main processing unit
205: chemical injection unit 210: main treatment high pressure pump
220: high pressure pressurized membrane filter 230: main treatment water tank
300: post-processing unit 400: chemical tax government
410: chemical cleaning tank unit 420: chemical cleaning pump unit

Claims (6)

In the maintenance chemical cleaning method of the high pressure membrane filtration process in which the water to be treated is filtered at a pressure of 10 to 85 bar in a high pressure membrane made of polyamide (PA) -based chemicals,
And maintaining and chemically cleaning the high pressure membrane at least once a week in a reversible membrane contamination state.
Maintenance chemical cleaning method of high pressure membrane filtration process.
The method of claim 1,
The maintenance chemical cleaning step is used to maintain a chemical cleaning solution containing a chemical,
The chemical agent is any one selected from the group consisting of NaOH, HCl, EDTA-4Na, EDTA-2Na, NaOH (+) EDTA-4Na, HCl (+) EDTA-2Na, and HCl (+) citric acid doing,
Maintenance chemical cleaning method of high pressure membrane filtration process.
The method of claim 2,
The concentration of the maintenance chemical cleaning solution is characterized in that 0.01% (w) to 0.5% (w),
Maintenance chemical cleaning method of high pressure membrane filtration process.
The method of claim 2,
The cleaning time of the maintenance chemical cleaning step is characterized in that 30 minutes to 4 hours,
Maintenance chemical cleaning method of high pressure membrane filtration process.
Pre-processing unit, main processing unit, post-processing unit; And
In the high pressure membrane filter comprising a chemical washing unit in communication with the main processing unit,
The main processing unit includes a high pressure pressurized membrane filtration unit,
The high pressure pressurized membrane filtration unit includes a high pressure membrane made of polyamide (PA) -based chemicals, and operates at 10 to 85 bar,
The chemical tax administration may perform a chemical cleaning (CIP) process and maintenance chemical cleaning process,
The maintenance chemical cleaning process is characterized in that the cleaning of the high pressure membrane at least once a week in a reversible membrane fouling state,
High pressure membrane filtration device.
The method of claim 5, wherein
The chemical cleaner includes a chemical cleaning tank unit,
The chemical cleaning tank unit may be injected with chemical cleaning (CIP) chemicals and maintenance chemical cleaning chemicals,
The chemical cleaning agent for oils and fats is any one selected from the group consisting of NaOH, HCl, EDTA-4Na, EDTA-2Na, NaOH (+) EDTA-4Na, HCl (+) EDTA-2Na, and HCl (+) citric acid It is characterized by
High pressure membrane filtration device.

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