JPH11169851A - Water filter and its operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water filter and a method of operating it in which the quantity of treated water by membrane filtration is stably secured and also the proceeding of clogging is restrained to enable continuous operation of the membrane filtration for a long time. SOLUTION: This water filter is a device for filtering water to be treated by a membrane module 2. It is provided with a control means 12 for changing the physical washing frequency of the membrane module 2 by a physical washing means 11, based on differential pressure across the membrane by supply water pressure detected by a supply water pressure sensor 3 installed on the supply side of water to be treated to the membrane module 2 and permeated water pressure obtained by detecting the pressure of filtered water from the membrane module 2 by a permeated water pressure sensor 4. By the control means 12, the differential pressure across membrane is calculated. By changing the physical washing frequency of the membrane module 2 according to the differential pressure across membrane, sludge or the like stuck on the membrane module 2 is removed and the differential pressure across membrane is made relatively stable one and the filtered water is quantitatively supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water filtration treatment apparatus in a water purification plant and a method for operating the same, and more particularly, to a water filtration treatment apparatus for controlling the frequency of physical cleaning by a transmembrane pressure difference of a membrane module and a method for operating the same. Things.

[0002]

2. Description of the Related Art Referring to FIG. 6, a flow of water purification treatment in a water purification plant using general membrane filtration will be described. In the figure, after raw water such as river water is received by a landing well 13, suspended components and bacteria in the raw water are removed by a pretreatment device 14 and a membrane filtration treatment device 15. As the pretreatment device 14, a simple rotary solid-liquid separator such as a coagulant addition device or an autostrainer is used for the purpose of removing impurities, and for the purpose of removing soluble organic matters in raw water. For example, advanced treatment apparatuses such as biological treatment, ozone treatment, and activated carbon treatment are used. Chlorine disinfection is performed on the membrane filtration water obtained in the membrane filtration treatment device 15 and supplied as tap water.

[0003] In the membrane filtration treatment device 15 in the water purification plant,
The membrane module of the membrane filtration apparatus 15 is periodically cleaned, and the membrane cleaning wastewater is stored in a drainage pond 16, and the supernatant water is returned to the landing well 13. Then, the sludge from the drainage pond 16 is sent to the concentration tank 18. The supernatant water of the concentration tank 18 is sent to the landing well 13, and the concentrated sludge is sent to the dehydrator 17 and discharged as dry sludge.

The processing flow of the membrane filtration apparatus 15 is shown in FIG.
And FIG. FIG. 7 shows the case of dead-end (total) filtration, and FIG. 8 shows the case of cross-flow filtration. Explaining with reference to the dead end filtration of FIG. 7, the water to be treated is sent to the membrane module 2 by the supply pump 1 to obtain the membrane filtered water. A supply water pressure sensor 3 is provided in a supply pipe 7 for the water to be treated, and a transmission pipe 8
Is provided with a permeated water pressure sensor 4, which is used as an index of the clogging of the filtration membrane and the accumulation amount of solid matter by the transmembrane pressure difference calculated as the difference between them. Most of the clogging substances and deposited solid matter of the filtration membrane are removed by physically cleaning the membrane module 2 periodically. The filtration water treatment is continuously performed while continuing such a physical cleaning operation. In the case of the cross-flow filtration shown in FIG. 8, the supply water pressure sensor 3 is provided in the supply pipe 7 of the water to be treated, the permeate pressure sensor 4 is provided in the permeation pipe 8, and the circulation water pressure sensor 5 is provided in the circulation pipe 9. Then, the transmembrane pressure, which is calculated as the difference between the average value of the supply water pressure and the circulation water pressure (true supply water pressure) and the permeate water pressure, is used as an index of the clogging of the filtration membrane and the accumulation amount of solids.

[0005] In a membrane filtration apparatus using the above-mentioned membrane module, backwashing (backwashing or backpressure washing) of the membrane is performed in order to eliminate clogging of the membrane. One example is shown with reference to FIG. FIG.
No. 475 discloses a washing water system using a filtration membrane module. The wash water system shown in the figure includes a check valve 20, a pump 21, a hollow fiber UF membrane module 22, an automatic permeate water valve 23, an automatic valve for discharge of wash water 24, a permeate tank 27 for accumulating permeate, a backwash. A pump 28 which sometimes pressurizes the backwash water, a backwash path 30 including a backwash automatic valve 29, a chemical tank 31 as a means for injecting a bactericide into the backwash path 30, a chemical pump 32, and a check valve 33. It is composed of a germicide injection route and the like.

[0006] The operation of this water purification system is performed as follows. In the cross-flow filtration operation, the permeated water automatic valve 23 is opened, the concentrated water discharge automatic valve 24 and the backwash automatic valve 29 are both closed, and the pump 28 is stopped. In this way, the raw water introduced through the check valve 20 is pressurized by the pump 21 and supplied to the hollow fiber UF membrane module 22. In the hollow fiber UF membrane module 22, the permeated water from which turbid components have been removed by the filtration action of the filtration membrane is accumulated in the permeated water tank 27 through the permeated water automatic valve 23.

At the time of back washing, the supply of raw water is stopped, the automatic permeated water valve 23 is closed, the automatic flush water discharge valve 24 and the automatic back wash valve 29 are both opened, the pump 21 is stopped, and the pump 28 is stopped. To drive. In this way, the hollow fiber UF membrane module 22 is backwashed by using a part of the permeated water accumulated in the permeated water tank 27, and the turbidity peeled off from the inner surface of the hollow fiber membrane by the backwash. The quality components are discharged out of the system as cleaning water through a cleaning water discharge automatic valve 24. When performing the backwashing treatment of the filtration membrane module with respect to the fluctuation of the monitored flux, the pressure of the pump 28 is adjusted to perform the backwashing pressure corresponding to the flux level, and the backwashing time is performed as described above. This is executed by extending or shortening the set time of the automatic valve and the pump. When using a chemical such as a bactericide in the permeated water,
In addition to the setting of the automatic valve and the pump, the backwash with the chemical pump 32 opened is executed.

[0008]

In the conventional water purification treatment using a membrane module, the progress of membrane clogging is small as at the beginning of the continuous operation of the water filtration treatment, or a long time has elapsed after the start of the continuous operation. Even if film clogging progresses, a method of periodically performing physical cleaning is employed. As a result, even when the clogging is small at the beginning of the continuous operation, the physical cleaning is performed unnecessarily, the cost of the pump power for the physical cleaning is increased, and the damage of the membrane due to the reverse cleaning is accelerated, which is not preferable. Further, even if continuous operation has been performed for a long period of time and membrane clogging has progressed, it is periodically performed at a predetermined cycle, and if sufficient membrane clogging is not eliminated by the physical cleaning, the transmembrane pressure difference increases. Since it rises rapidly, the chemical cleaning is frequently repeated to recover. If the clogging of the membrane still cannot be recovered, the membrane module needs to be replaced, resulting in a high running cost, which is not preferable.

The water filtration method shown in FIG.
The permeation flow rate from 2 is detected by the flux measuring device 34 and measured by the arithmetic and control unit 35, and the physical cleaning water amount is changed according to the magnitude of the permeation flow rate. As described above, in this water filtration treatment method, the permeation flow rate obtained from the membrane module 22 is not constant because it is not an operation method for making the permeation flow rate constant, that is, a constant flow filtration operation method. Therefore, there is a problem that the method is not suitable for a processing flow in which a stable and continuous amount of water is to be treated and a water supply amount must be secured, such as in a water purification plant.

Further, in the water filtration method shown in FIG. 9, when clogging progresses and the permeation flow rate decreases, the amount of water obtained from the membrane module 22 further decreases in order to increase the amount of water for physical cleaning. This cleaning method has a problem that the water recovery rate is reduced. Also,
There is also a method of changing the physical cleaning frequency according to the reduction rate of the permeation flow rate.However, since this method is not a constant flow filtration operation, the permeation flow rate obtained from the membrane module is not constant, and it is continuously stable in a water purification plant. There is a problem that it is not suitable for a processing flow in which a large amount of water is processed to secure a water supply amount.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to stably secure an amount of water to be treated by a membrane filtration process and suppress the progress of clogging so that a long-term membrane filtration process can be performed. It is an object of the present invention to provide a water filtration treatment device that enables continuous operation and a method of operating the same.

[0012]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention of claim 1 is a water filtration apparatus for filtering water to be treated by a membrane module. Based on the pressure difference between the membrane indicated by the difference between the supply water pressure on the side to which the water to be treated is supplied and the permeated water pressure on the side through which the filtered water permeates from the membrane module. A water filtration treatment device comprising control means for changing the physical cleaning frequency of the water filtration. According to this configuration, the transmembrane pressure is calculated by the control means and the physical cleaning frequency of the membrane module is changed, thereby removing sludge and the like adhering to the membrane module, and making the transmembrane pressure relatively stable. In this case, it is intended to supply the filtered water at a constant flow rate.

The second aspect of the present invention is directed to various wastewaters such as sedimentation basin sludge, sand filtration backwash wastewater, activated carbon backwash wastewater, and membrane filtration backwash wastewater generated in river water, groundwater, lake water or a water purification plant. The water filtration treatment device according to claim 1, wherein the water filtration treatment device is a water filtration treatment device that performs membrane filtration treatment of the water to be treated. In this configuration, the water recovery rate can be improved by applying the present invention to the treatment of each wastewater from the water purification plant.

The invention according to claim 3 is characterized in that the membrane module used in the membrane filtration apparatus is a microfiltration membrane or an ultrafiltration membrane. It is. In this configuration, by using a microfiltration membrane or an ultrafiltration membrane as a membrane module,
When applied to a water purification plant, the diameter of the membrane hole is 10 to 1000
Since the holes are 孔 or smaller, extremely high quality water can be supplied as drinking water.

According to a fourth aspect of the present invention, the control means includes a damage detecting means for detecting a damage of the membrane module by a supply water pressure and / or a transmembrane pressure difference. 4. A water filtration treatment device according to 2 or 3. With this configuration, the control unit has a function of detecting damage to the membrane module, and can maintain the quality of drinking water.

According to a fifth aspect of the present invention, the control means can program the frequency of physical cleaning of the membrane module by the cleaning means by an arbitrary transmembrane pressure. , 3 or 4. In this configuration, since the transmembrane pressure can be measured and an arbitrary physical cleaning frequency can be set,
The membrane module can function for as long as possible.

According to a sixth aspect of the present invention, there is provided a water filtration method for filtering water to be treated by a membrane module, comprising: a supply water pressure at a side where the water to be treated is supplied to the membrane module; Finding the transmembrane pressure from the permeated water pressure of water, based on the transmembrane pressure, physically cleaning the membrane module by changing the physical cleaning frequency by the cleaning means, to obtain membrane filtered water. This is an operation method of the water filtration treatment device. In this configuration, the control means calculates the transmembrane pressure and changes the physical cleaning frequency of the membrane module, thereby removing sludge and the like adhering to the membrane module and preventing the transmembrane pressure from rising rapidly. Suppress and stable,
This is a water filtration method for supplying a constant flow rate of the filtered water.

[0018] In the invention according to claim 7, the method of operating the membrane filtration apparatus is characterized in that the membrane module is physically washed by changing a physical washing frequency to reduce the transmembrane pressure to a predetermined value or less. The method for operating a water filtration treatment device according to claim 6, wherein quantitatively filtered water is obtained from the product. In this configuration, by changing the physical cleaning frequency based on the transmembrane pressure, the water to be treated is quantitatively filtered, and the membrane filtered water as drinking water can be stably supplied.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a water filtration treatment apparatus and an operation method thereof according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a processing flow of an embodiment of a water filtration treatment device according to the present invention. The figure shows
This shows a case of dead-end (total) filtration processing. This water filtration apparatus mainly includes a membrane module 2 to which water to be treated is supplied by a supply pump 1, a supply water pressure sensor 3 for measuring supply water pressure, A permeate pressure sensor 4 for measuring water pressure, a physical cleaning means 11 for taking in an output signal of each pressure sensor and cleaning the membrane module 2 in accordance with a transmembrane pressure calculated from each pressure value are respectively defined. A control device 12 for executing the program at a predetermined frequency and other pipes 7 and 8 are provided.

The water to be treated is river water or various kinds of wastewater such as sedimentation tank sludge generated in a water purification plant, sand filtration backwash wastewater, activated carbon backwash wastewater, and membrane filtration reverse wastewater. That is, this water filtration treatment device is used in each wastewater treatment step of a water purification plant or the like, and is subjected to quantitative filtration in order to secure a stable amount of treated water.

As the filtration membrane of the membrane module 2, a microfiltration membrane or an ultrafiltration membrane is used.
孔 1000 ° or smaller pores. The form of the membrane module 2 may be any one of a plate and frame type (flat membrane type), a pleated type, a spiral type (spiral type), a tubular type (tubular type) or a hollow fiber type, if physical cleaning is possible. Although it may be selected, a hollow fiber membrane module is most preferred.

Subsequently, the water filtration treatment apparatus according to the present invention employs a quantitative filtration method. When clogging of the filtration membrane or accumulation of solid matter occurs, the difference is represented by a difference in water pressure between the supply side and the permeation side of the membrane module. The transmembrane pressure will increase. Outputs from the supply water pressure sensor 3 provided in the pipe 7 and the permeated water pressure sensor 4 provided in the pipe 8 are input to the control device 12, respectively. In the control device 12, the calculating section calculates the transmembrane pressure, and the physical cleaning interval for activating the physical cleaning means 11 can be changed according to the transmembrane pressure.

For example, at the beginning of the continuous operation of the water filtration process, since the clogging of the filtration membrane is small, the rising speed of the transmembrane pressure difference is small, and the filtration can be continued for a long time without performing physical cleaning. , Reduce the frequency of physical cleaning. Then, the physical cleaning frequency of the membrane module 2 is increased as the continuous operation is extended for several months to several years. Furthermore, as the time of continuous operation elapses,
As the clogging of the membrane progresses, the transmembrane pressure immediately after the physical cleaning does not sufficiently recover, the transmembrane pressure increases, and the rate of increase of the transmembrane pressure increases. Therefore, physical cleaning is performed by changing the physical cleaning time of the membrane module 2 according to the continuous operation time of the water filtration process.

The physical cleaning frequency of the membrane module 2 is set by receiving signals output from the various pressure sensors 3 and 4 by the controller 12 and calculating the supply water pressure and the permeate water pressure of the membrane module 2. The physical cleaning frequency (the number of physical cleanings per unit time) is determined using the calculated value. Based on the physical cleaning frequency, the cleaning of the membrane module 2 by the physical cleaning means 11 is performed. The specific physical cleaning time performed at one time is based on whether air is used for physical cleaning, water is used, or both are used together, and the physical cleaning method and the amount of water used in the physical cleaning process are used. It changes with. Alternatively, it varies depending on the physical cleaning method such as whether or not both are used in combination, the amount of water used in the physical cleaning step, and the like.
The time is set in the range of about minutes to several tens of hours, preferably about 30 minutes to about 10 hours. As described above, by changing the cycle of performing the efficient physical cleaning by the transmembrane pressure difference of the membrane module, it is possible to perform a stable water filtration process for a long time.

FIG. 2 is a diagram showing a processing flow of another embodiment of the water filtration treatment device according to the present invention, which will be described with reference to FIG. This figure shows the case of the cross-flow filtration process. This water filtration treatment device is mainly
A membrane module 2 to which water to be treated is supplied via a pipe 7 by a supply pump 1, a supply water pressure sensor 3 provided on the pipe 7 for measuring the pressure of the supply water, and a pipe for measuring the pressure of the permeated water. 8, a circulating water pressure sensor 5 provided in a pipe 9 for measuring the pressure of circulating water, a circulating tank 6 for temporarily storing water to be treated, and for physically cleaning the membrane module 2. The physical cleaning means 11 takes in the output signal of each pressure sensor, calculates the supply water pressure and the permeate water pressure from each pressure value, and calculates and calculates the transmembrane pressure from the supply water pressure and the permeate water pressure to obtain the physical cleaning means 11 respectively. It comprises a control device 12 for executing at a predetermined frequency.

As the filtration membrane of the membrane module 2, a microfiltration membrane or an ultrafiltration membrane is used in the same manner as in the above embodiment.
Various wastewater such as physical washing wastewater, activated carbon backwashing wastewater, and membrane filtration backwashing wastewater will be treated. And dead end filtration,
Quantitative filtration can be applied to both cross-flow filtration and stable water treatment. In the filtration process, as described above, as time elapses, when clogging of the filtration membrane or accumulation of solids occurs, the transmembrane pressure expressed by the difference between the supply side and the permeation side of the membrane increases. Will be. At the beginning of the continuous operation of the water filtration process, since the clogging of the filtration membrane is small, the rate of increase of the transmembrane pressure difference is low, and the filtration can be continued for a long time without physical cleaning.

However, as in the above-described embodiment, when continuous operation is performed for a long period of several months to several years, clogging of the membrane proceeds, and the transmembrane pressure immediately after the physical cleaning is sufficiently reduced. It is high without recovery, and the rate of increase of the transmembrane pressure is also increasing. In the water filtration treatment device by the cross flow filtration treatment, the output from the supply water pressure sensor 3, the permeation water pressure sensor 4, and the circulating water pressure sensor 5 is received by the control device 12, and the supply water pressure, the permeation water pressure, and the circulating water pressure are measured. Calculate,
Furthermore, the transmembrane pressure difference is calculated, and the physical cleaning frequency (the number of times of physical cleaning per unit time) is determined using the calculated value. Thus, the physical cleaning of the membrane module 2 can be effectively performed. Needless to say, in the above embodiment, the pressure sensor is provided in the pipe. However, without being limited to this embodiment, each pressure sensor may be provided in the membrane module.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a water filtration apparatus according to the present invention will be described based on the following embodiments. Further, a water filtration treatment device will be described by comparing the present embodiment with a conventional example. It is needless to say that the present invention is not limited by these examples.

(Embodiment 1) In Embodiment 1, the water filtration apparatus of FIG. 1 is used in the treatment equipment of a water purification plant shown in FIG. The membrane module 2 is based on the specifications in Table 1 below.
A membrane module was used. In Table 2, the physical cleaning conditions of the water filtration treatment apparatus of the present invention and the conventional example, and the physical cleaning intervals of the membrane modules are set in relation to the pressure difference between the membranes of the membrane module 2 and the physical cleaning intervals. In the control method of the physical cleaning interval, for example, the operation was performed according to the flowchart shown in FIG. FIG. 5 compares the water filtration treatment apparatus of the present invention with a conventional example, and shows the change with time of the transmembrane pressure difference. River water was used as the water to be treated in the water filtration treatment device.

[0030]

[Table 1]

[0031]

[Table 2]

The water filtration apparatus shown in FIG. 1 is used in the water purification apparatus shown in FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals. The control device 12 includes, for example, a CPU (Central Processing Unit) and a storage device. A program for executing the relationship between the transmembrane pressure and the physical cleaning interval shown in Table 2 is stored in the storage device. This program for setting the physical cleaning interval can be arbitrarily switched according to the characteristics, season, and the like of the water purification treatment device to which the water filtration treatment device is applied.

Next, referring to the flowchart of FIG.
An operation method of the water filtration treatment device will be described. The water to be treated that has been treated by the pretreatment device 14 is sent to the membrane module 2 by the water supply pump 1 provided in the pipe 7. The membrane filtered water that has passed through the membrane module 2 is discharged from the pipe 8 to the next processing step. Since the membrane module 2 is clogged with the passage of time, a physical cleaning step is performed.

The physical cleaning step will be described with reference to FIG. First, in step S1, the supply water pressure sensor 3 detects the supply water pressure of the water to be treated to the membrane module 2, and inputs the output to the control device 12 to supply the supply water pressure Va.
Is measured. Subsequently, in step S2, the pressure of the permeated water discharged from the membrane module 2 of the water to be treated is detected by the permeated water pressure sensor 4, and its output is input to the control device 12 to measure the permeated water pressure Vb. In step S3, the calculation unit of the control device 12 calculates and calculates the transmembrane pressure difference Vd of the membrane module 2. Subsequently, the process proceeds to step S4, and it is determined whether or not the transmembrane pressure Vd is in the range of 0 to 40 KPa. When step S4 is satisfied, the process proceeds to step S9, in which the membrane module 2 is physically cleaned by the physical cleaning means 11 at time intervals of 2 hours. Subsequently, after waiting for a predetermined time, step S is performed again.
Returning to step 1, the same operation is repeated. The operation of the water filtration treatment device has been performed for about one month, and the transmembrane pressure difference Vd is generally 40 to 6 months.
If it is within the range of 0 kPa, if the process proceeds from step S4 to step S5, step S5 is satisfied, so the physical cleaning interval is set to one hour. After waiting for a predetermined time again, the steps from step S1 to step S3 are executed, and the steps from step S4 to step S7 are executed to set the physical cleaning interval.

On the other hand, if the step from step S3 to step S7 is NO, the process proceeds to step S8, and the controller 12 is provided with a film damage detecting means.
It is determined whether the membrane module 2 is damaged. If the supply water pressure drops sharply in normal use, it indicates that the membrane module 2 is significantly damaged.
Perform the replacement work. Damage to the membrane module 2 may be detected by a change in the transmembrane pressure difference Vd. In addition, in the water filtration treatment apparatus by the cross flow filtration of FIG. 2, the physical cleaning interval and the membrane damage detection can be performed by the feed water pressure, the circulating water pressure, and the permeate water pressure.

FIG. 5 is a diagram showing a comparison between the embodiment of FIG. 4 and a conventional example. As is clear from FIG. 5, at the initial stage after the start of operation, the increase in the transmembrane pressure of the conventional example is Although it is smaller than that of the present invention, the transmembrane pressure increases from around the 100th day. The time required for the transmembrane pressure to finally reach 100 KPa was about 120 days in the conventional example, but was about 150 days in the present invention, which was longer than the conventional example. Further, the water recovery rate of the present invention up to an average water recovery rate of 100 kPa is about 94%, and it has been proved that a value having no practical problem can be secured.

[0037]

As described above, according to the present invention, the physical cleaning time of the membrane module is changed in accordance with the continuous operation time, and the filtration is carried out stably. In addition to this, there is an effect that a long-term continuous operation of the membrane filtration process can be performed by suppressing the progress of clogging. Therefore, the present invention has the effect of suppressing the running cost required for chemical cleaning of the membrane module or replacement of the membrane module.

Further, according to the present invention, the control unit calculates and calculates the transmembrane pressure difference, and changes the physical cleaning frequency of the membrane module to separate sludge and the like adhering to the membrane module. With a relatively stable pressure differential over the long term,
Accordingly, there is an advantage that the filtration treatment water can be supplied at a constant flow rate, and the water recovery rate can be improved by applying the filtration treatment water to each wastewater treatment.

According to the present invention, by using a microfiltration membrane or an ultrafiltration membrane as a membrane module, when applied to a water purification plant, it is possible to stably supply extremely high quality water as drinking water. it can.

Further, according to the present invention, the membrane filtration processing apparatus is provided with a control device, and by measuring the transmembrane pressure difference and changing the program, it is possible to set an arbitrary physical cleaning frequency. In addition, there is an advantage that the membrane module can function as long as possible.

According to the present invention, the control device is used to detect damage to the membrane module and to prevent the water to be treated from being mixed into the membrane filtered water, thereby improving the quality of drinking water. There are advantages that can be maintained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a processing flow of an embodiment of a water filtration treatment device according to the present invention.

FIG. 2 is a diagram showing a processing flow of another embodiment of the water filtration treatment device according to the present invention.

FIG. 3 is a diagram showing a processing flow of a water purification treatment device to which the water filtration treatment device of the present invention is applied.

FIG. 4 is a diagram showing a flowchart for setting a physical cleaning interval.

FIG. 5 is a diagram comparing the present invention with a conventional example.

FIG. 6 is a view showing a processing flow of a conventional water purification treatment apparatus.

FIG. 7 is a diagram showing an example of a conventional water filtration treatment device.

FIG. 8 is a diagram showing another example of a conventional water filtration treatment device.

FIG. 9 is a diagram showing an example for explaining a washing step of a conventional water filtration treatment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water supply pump 2 Membrane module 3 Supply water pressure sensor 4 Permeate water pressure sensor 5 Circulation water pressure sensor 6 Circulation tank 7-10 Piping 11 Physical cleaning means 12 Control device 13 Water landing well 14 Pretreatment device 16 Drainage pond 17 Dehydrator 18 Concentration tank 19 Membrane Filtration processing equipment

Claims (7)

[Claims] 1. A water filtration apparatus for filtering water to be treated by a membrane module, comprising: a supply water pressure at a side where the water to be treated is supplied to the membrane module; and a water pressure at a side where filtered water permeates from the membrane module. A water filtration treatment apparatus comprising a control unit for changing a physical cleaning frequency of the membrane module by a physical cleaning unit based on a transmembrane pressure difference indicated by a difference from a permeated water pressure. 2. The water to be treated, which is various wastewater such as sedimentation basin sludge, sand filtration backwash wastewater, activated carbon backwash wastewater, and membrane filtration backwash wastewater generated in river water, groundwater, lake water, or a water purification plant, is subjected to membrane treatment. The water filtration treatment device according to claim 1, which is a water filtration treatment device for performing a filtration treatment. 3. The water filtration apparatus according to claim 1, wherein the membrane module used in the membrane filtration apparatus is a microfiltration membrane or an ultrafiltration membrane. 4. The water according to claim 1, wherein said control means comprises a damage detecting means for detecting damage to the membrane module by a supply water pressure and / or a transmembrane pressure difference. Filtration processing equipment. 5. The method according to claim 1, wherein the control means can program the frequency of physical cleaning of the membrane module by the cleaning means by an arbitrary transmembrane pressure. Water filtration treatment equipment. 6. A water filtration method for filtering water to be treated by a membrane module, comprising: a membrane comprising: a supply water pressure on a side where the water to be treated is supplied to the membrane module; and a permeated water pressure of filtered water from the membrane module. Operating the water filtration treatment apparatus, wherein the membrane module is physically washed by changing the physical washing frequency of the washing means based on the membrane pressure difference to obtain membrane filtration water. Method. 7. The method of operating the membrane filtration treatment device, wherein the membrane module is physically washed by changing the physical washing frequency, the transmembrane pressure is reduced to a predetermined value or less, and quantitative filtered water is obtained from the membrane module. The method for operating the water filtration treatment device according to claim 6, wherein: