JP2021098165A - Water treatment facility operation method and water treatment facility - Google Patents

Abstract

To provide a method for operating a water treatment facility and a water treatment facility.SOLUTION: In a method of operating a water treatment facility, a priority water treatment facility 5 and a non-priority water treatment facility 6 are used in combination, a treated water from both facilities is supplied to a first treatment tank 4, and the treated water from the first treatment tank 4 is distributed downstream via a second treatment tank 13. The priority water treatment facility 5 starts at the priority operation water level set at the medium level of the first treatment tank 4, stops at the first tank upper limit water level set at the high level of the first treatment tank 4, and the non-priority water treatment facility 6 is capable of being operated at the start-up permitted water level set at the low level of the second treatment tank 13.SELECTED DRAWING: Figure 1

Description

The present invention relates to an operation method of a water treatment facility and a technique for using water treatment methods having different treatment methods in combination.

1. 1. Many water purification plants use a single water purification method to deal with raw water with large fluctuations in water quality.

2. A general water purification plant is planned based on the maximum daily water supply, and has a margin for the average water supply.

3. 3. At water purification plants that employ multiple water purification methods, water purification plant staff determine and operate the system operation of each treatment method based on the quality of raw water and the amount of water demand.

4. In many cases, water is sent from a water purification pool installed at a water purification plant to a distribution reservoir at a higher position by a water supply pump, and water is distributed from the distribution reservoir to consumers in a natural flow. In this case, the operation / stop of the water supply pump is controlled by the water level of the distribution reservoir, and the operation / stop of the water purification treatment is controlled by the water level of the water purification reservoir. Furthermore, when the scale of the water purification plant is large, the water supply flow rate may be controlled by controlling the number of water supply pumps or the inverter, or the amount of purified water may be controlled.

5. Patent Document 1 discloses an operation method in which the treatment amount of a plurality of treatment methods is changed in response to fluctuations in the required water supply amount and changes in water quality.

Patent No. 50720050

When a single water purification method is used, it may be difficult to purify the water when the water quality load increases, or conversely, excessive power and chemicals may be consumed when the water quality load decreases, which may be uneconomical.

When planning a facility based on the planned maximum daily water supply, the days that require the planned daily maximum water supply are limited, and on many days it is sufficient to treat the average water supply, so multiple water purifications are required. If the treatment method is adopted, the more suitable method should be preferentially operated according to the condition of the raw water.

In addition, if the water purification plant staff judges and operates the system operation of multiple water purification methods, the number of technical staff is expected to decrease in the future, so the water quality and quantity, especially at night and on holidays, It may be difficult to respond to fluctuations.

In addition, when water is sent from a water purification pond installed at a water purification plant to a distribution reservoir at a higher position with a water supply pump, if the water purification treatment is controlled only by the water level of the water purification reservoir, the water supply pump capacity is superior to the distribution amount, so the necessary water supply is required. The amount and the water level of the water purification pond are not linked, and it becomes difficult to operate the water purification facility according to the required amount of water supply.

What is disclosed in Patent Document 1 is to change the processing amount of each treatment method according to the filtration rate and the membrane filtration flux, which is accompanied by changes in the treated water quality and the operating state. Therefore, appropriate monitoring is required and unmanned operation is required. Not suitable for. A large number of systems is required to change the number of operating systems, and if the scale is small, flexible application becomes difficult.

The present invention solves the above problems, and an object of the present invention is to provide an operation method of a water treatment facility and a water treatment facility.

In order to solve the above problems, in the operation method of the water treatment equipment according to the present invention, the priority water treatment equipment that operates preferentially and the non-priority water treatment equipment that operates non-priority are used in combination, and both water treatments are performed. In the operation method of the water treatment equipment in which the treated water is supplied from the equipment to the first treated water tank and the treated water in the first treated water tank is distributed downstream via the second treated water tank, the priority water treatment equipment is the first. The non-priority water treatment equipment starts at the priority operating water level set to the middle level of the first treated water tank, stops at the upper limit water level of the first tank set to the high level of the first treated water tank, and the non-priority water treatment equipment is the lower level of the second treated water tank. It is characterized in that it can be operated at the start permission water level set to.

In the operation method of the water treatment equipment according to the present invention, the treated water of the first treated water tank is supplied to the second treated water tank via the water supply pump, and the water supply pump is set to the middle of the second treated water tank. It is characterized in that it starts at the starting water level of the water supply pump and stops at the upper limit water level of the second tank set at a high level of the second treatment water tank.

In the operation method of the water treatment equipment according to the present invention, the second treatment water tank is arranged lower than the first treatment water tank, and is treated by natural flow from the first treatment water tank to the second treatment water tank via a valve. Water is supplied, and the valve is opened at the valve open water level set at the middle level of the second treatment water tank and closed at the upper limit water level of the second tank set at the high level of the second treatment water tank.

In the operation method of the water treatment facility according to the present invention, the control device starts the non-priority water treatment facility when the water level of the first treatment water tank is set to a medium level lower than the priority operation water level. The feature is that the non-priority water treatment facility is stopped when the water level of the first treatment water tank exceeds the non-priority stop water level of the same water level as the priority operation water level set to the middle level.

In the operation method of the water treatment equipment according to the present invention, the control device starts the non-priority water treatment equipment when the water level of the first treatment water tank is set to a medium level lower than the priority operation water level. When the water level of the first treated water tank exceeds the upper limit water level of the first tank set to a high level, the non-priority water treatment equipment is stopped.

In the operation method of the water treatment equipment according to the present invention, the control device starts the non-priority water treatment equipment when the water level of the first treatment water tank is the non-priority operation water level equal to the priority operation water level set to the middle level. However, when the water level of the first treated water tank exceeds the upper limit water level of the first tank set to a high level, the non-priority water treatment equipment is stopped.

In the operation method of the water treatment facility according to the present invention, water treatment facilities having different water treatment methods are used in combination, and the value of a specific water quality item contained in the raw water is used as a selection index. The other water treatment facility is used as the priority water treatment facility, the other water treatment facility is operated as the non-priority water treatment facility, and when the selection index exceeds the threshold value, the other water treatment facility is set as the priority water treatment facility. The water treatment facility is operated as a non-priority water treatment facility.

In the operation method of the water treatment equipment according to the present invention, the priority water treatment equipment and the non-priority water treatment equipment are treated with water using membrane separation devices having different membrane areas per unit volume, and the unit in one membrane separation device. It is characterized in that the membrane area per volume is larger than the membrane area per unit volume in the other membrane separation device.

In the operation method of the water treatment equipment according to the present invention, a plurality of water treatment equipments using membrane separation devices having different membrane areas per unit volume are used in combination, and the membrane area per unit volume in one membrane separation device is the other. When the turbidity of the water quality item is larger than the membrane area per unit volume in the membrane separator and the turbidity of the water quality item is below the threshold, the water treatment facility that uses one of the membrane separators with the larger membrane area per unit volume is set as the priority water treatment facility. When the turbidity of the water quality item exceeds the threshold value, the water treatment facility that uses the other membrane separation device having a small membrane area per unit volume is set as the priority water treatment facility.

In the operation method of the water treatment equipment according to the present invention, the priority water treatment equipment and the non-priority water treatment equipment treat water using a film separation device of a different water treatment method, and one of the film separation devices uses a filtration film. It is a casing storage type membrane separator that filters the raw water supplied into the casing of the stored closed space, and the other membrane separator is an open space housing that houses the filtration membrane in the tank that stores the raw water. It is characterized by being a tank immersion type film separating device that is immersed and filters raw water.

In the operation method of the water treatment equipment according to the present invention, the priority water treatment equipment and the non-priority water treatment equipment are treated with water using different water treatment methods, and one of the water treatment equipment is a slow sand filter. The other water treatment facility is a coagulation sedimentation / rapid sand filter.

In the operation method of the water treatment equipment according to the present invention, the priority water treatment equipment and the non-priority water treatment equipment are treated with water using water treatment equipment of different water treatment methods, and one of the water treatment equipment is a slow filtration device. The other water treatment facility is a membrane separator.

In the operation method of the water treatment equipment according to the present invention, the priority water treatment equipment and the non-priority water treatment equipment are treated with water using water treatment equipment of different water treatment methods, and one of the water treatment equipment is coagulated sedimentation / rapid sand filter. It is a filtration device, and the other water treatment facility is a film separation device using a hollow thread film.

The water treatment facility according to the present invention uses a film separation device that treats inflow raw water in parallel and has a different film area per unit volume, and the film area per unit volume in one film separation device is the other film. A plurality of water treatment facilities larger than the membrane area per unit volume in the separation device, a turbidity measuring device for measuring the turbidity of the inflow raw water, a water purification pond for supplying treated water from both water treatment facilities, and a water purification pond. It is equipped with a distribution reservoir that supplies treated water via a water supply pump, a water level measuring device that measures the water level of each of the water purification reservoir and the distribution reservoir, and a control device that controls the start and stop of each water treatment facility and the water supply pump. When the measurement turbidity of the turbidity measuring device is equal to or less than the threshold value, the control device sets the water treatment facility that uses one of the film separation devices having a large film area per unit volume as the priority water treatment facility and measures the turbidity. When the measured turbidity of the device exceeds the threshold, the water treatment facility that uses the other film separation device with a small film area per unit volume is set as the priority water treatment facility, and the priority water treatment facility is the water level of the purification pond. Starts when the water level is below the priority operating water level set to the middle level, stops when the upper limit water level of the water purification reservoir set to the high level of the purification reservoir is exceeded, and the non-priority water treatment facility starts when the water level of the distribution reservoir is set to the low level. It can be operated when the water level is below the permitted water level, and the water supply pump is activated when the water level of the distribution reservoir is set to the middle level or lower than the pump start water level, and when the water level of the distribution reservoir exceeds the upper limit water level of the distribution reservoir set to the high level. It is characterized by stopping.

In the above invention, the non-priority water treatment facility can be started when the water level of the distribution reservoir drops and reaches a low non-priority operating water level, so that the non-priority water treatment equipment can be efficiently operated according to the actual water demand. That is, it is possible to operate all the priority water treatment equipment and make up for the shortage with the non-priority water treatment equipment.

As a result, by preferentially operating the appropriate treatment equipment according to the condition of the raw water, reliable water quality can be ensured, the operation becomes economical, and rational system operation becomes possible.

Schematic diagram showing a water treatment facility according to an embodiment of the present invention Sectional drawing which shows an example of the casing storage type membrane separation apparatus in the same embodiment. Perspective view showing the membrane element of the casing retractable membrane separation device according to the same embodiment. Cross-sectional view showing an example of a tank immersion type membrane separation device in the same embodiment. Schematic diagram showing a control method when operating the casing storage type membrane separation device and the bath immersion type membrane separation device in the same embodiment. Schematic diagram showing the operating state of the water treatment facility according to the water level of the water purification pond in the same embodiment. Schematic diagram showing the operating state of the water treatment facility according to the water level of the distribution reservoir in the same embodiment.

Hereinafter, the water treatment equipment according to the embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 to 7, the main water treatment facility includes a landing well 1 and a mixing well 2, and a plurality of water treatment facilities having different water treatment methods are arranged between the water purification pond 4 for storing purified water. Therefore, in the present embodiment, the casing storage type membrane separation device 5 and the tank immersion type membrane separation device 6 are arranged in parallel and used together. Other water treatment facilities of different water treatment methods include a slow sand filter and a rapid sand filter, which will be described later. The landing well 1 is provided with a turbidity measuring device 11 for measuring the turbidity of raw water.

The water purification reservoir 4 which is the first treatment water tank communicates with the distribution reservoir 13 which is the second treatment water tank via the water supply pump 12.

Further, it is provided with a casing storage type membrane separation device 5 and its auxiliary equipment, a tank immersion type membrane separation device 6 and its auxiliary equipment, and a control device 14 for controlling the operation of the water supply pump 12.

In the present embodiment, one casing housing type membrane separation device 5 is a water treatment facility in which the membrane area per unit volume is larger than the membrane area per unit volume of the other tank immersion type membrane separation device 6. The water purification reservoir 4 and the distribution reservoir 13 are provided with water level measuring devices 15 and 16 for measuring the respective water levels.

The control device 14 uses the value of a specific water quality item contained in the raw water, here the turbidity, as a selection index. As shown in FIG. 5, when the measured turbidity of the turbidity measuring device 11 is equal to or less than the medium threshold value X1, the casing-contained membrane separation device 5 which is one of the membrane separation devices having a large membrane area per unit volume is used. The water treatment equipment to be used is set as the priority water treatment equipment, and the water treatment equipment that uses the tank immersion type membrane separation device 6 which is the other membrane separation device having a small membrane area per unit volume is set as the non-priority water treatment equipment. To do.

When the measured turbidity of the turbidity measuring device 11 exceeds the threshold value X1, the water treatment facility using the tank immersion type membrane separation device 6, which is the other membrane separation device having a small membrane area per unit volume, is used as the priority water treatment facility. The water treatment facility that uses the casing-contained membrane separation device 5, which is one of the membrane separation devices having a large membrane area per unit volume, is set as the non-priority water treatment facility.

Here, the casing storage type membrane separation device 5 is set as the priority water treatment facility, and the tank immersion type membrane separation device 6 is set as the non-priority water treatment facility.

The turbidity measuring device 11 may be provided in the inflow pipe through which the raw water flows into the landing well 1, and when the raw water is taken out by a sampling pump, it can be installed in a remote place such as a management building.

As shown in FIG. 6, the control device 14 is a casing storage type membrane separation device 5 of the priority water treatment facility when the water level of the water purification pond 4 measured by the water level measuring device 15 is set to the middle level and is equal to or lower than the priority operating water level M3. When the priority stop water level (upper limit water level of the first tank) H set at the higher level of the water purification pond 4 is exceeded, the casing storage type membrane separation device 5 of the priority water treatment facility is stopped.

The control device 14 enables the tank immersion type membrane separation device 6 of the non-priority water treatment facility to be operated when the water level of the distribution reservoir 13 measured by the water level measuring device 16 is set to a low level and the start permission water level is M1 or less. Further, when the water level of the water purification pond 4 is set to the medium level, the tank immersion type film separation device 6 of the non-priority water treatment facility is activated when the non-priority operating water level M2 or less is set, and the water level of the water purification pond 4 is set to the medium level. When the non-priority stop water level M3 set to the same water level as the priority operation water level M3 is exceeded, the tank immersion type film separation device 6 of the non-priority water treatment facility is stopped.

The operation of the tank immersion type membrane separation device 6 of the non-priority water treatment facility can also be performed as follows. That is, when the water level of the water purification pond 4 is set to the middle level and the non-priority operating water level is M2 or less, the tank immersion type film separation device 6 of the non-priority water treatment facility is activated, and the water level of the water purification pond 4 is set to a high level. When the non-priority stop water level H, which is set to the same water level as the stop water level (upper limit water level of the first tank) H, is exceeded, the tank immersion type film separation device 6 of the non-priority water treatment facility is stopped.

Further, the operation of the tank immersion type membrane separation device 6 of the non-priority water treatment facility can be performed as follows. That is, when the water level of the water purification pond 4 is set to the middle level, the priority operating water level of the casing storage type membrane separator 5 of the priority water treatment facility M3 is set to the same water level, and the non-priority operating water level is M3 or less. The tank immersion type film separation device 6 is activated, and when the water level of the water purification pond 4 exceeds the priority stop water level (first tank upper limit water level) H set to the same water level as the non-priority stop water level H, the non-priority water treatment is performed. The tank immersion type film separation device 6 of the equipment is stopped.

The control device 14 starts the water supply pump 12 when the water level of the distribution reservoir 13 is set to the middle level, and the water supply pump is stopped when the water level of the distribution reservoir 13 is set to a high level (second tank). When the upper limit water level) H is exceeded, the water supply pump 12 is stopped.
(Casing storage type membrane separation device)
The casing storage type membrane separation device 5 comprises a casing storage type membrane separation device that filters the entire amount of supplied raw water supplied into the casing of the closed space containing the filtration membrane, and has, for example, the structures shown in FIGS. 2 and 3. It has and is composed of a plurality of basic membrane units. In the present embodiment, ceramics will be described as an example of the film material, but the present invention is not limited to the film material and the shape. Further, there is no limitation depending on the form such as so-called internal pressure type or external pressure type.

Here, the film element 101 is composed of a plurality of ceramic molded bodies 101a having a substantially rectangular parallelepiped shape, and the porous ceramic molded bodies 101a are joined to each other via a bonding material layer 101b. A plurality of through-passage paths 104 are formed in the membrane element 101 so as to penetrate between a pair of opposite end faces 102 and 103. The inner surface side of the through flow path 104 forms the primary side, and the outer surface side of the membrane element 101 forms the secondary side.

A plurality of slits 105 are formed in the film element 101. The slit 105 extends in the axial direction of the through-flow path 104, has a groove shape that opens on the side surface 106 of the membrane element 101, and both ends of the slit 105 are closed in the vicinity of the end faces 102 and 103 of the membrane element 101. ..

The film element 101 is housed inside the casing 112. The casing 112 has an upper primary chamber 114 formed at the upper portion and a lower primary chamber 115 formed at the lower portion. The upper end of the membrane element 101 is exposed in the upper primary chamber, the lower end of the membrane element 101 is exposed in the lower primary chamber 115, and the through flow path 104 communicates with the upper primary chamber 114 and the lower primary chamber 115.

The raw water supply system 130 communicates with the raw water inflow port 109 of the lower primary chamber 115 of the casing 112 via the first valve 116, and the backwash water discharge system 131 communicates with the raw water discharge system 131 via the second valve 118. ..

The casing 112 has a treated water outlet 110 on its side, and the treated water outlet 110 communicates with a space surrounding the secondary side of the membrane element 101. The treated water system 132 communicates with the treated water outlet 110 via the third valve 117, and the backwash water supply system 133 communicates with the treated water outlet 110 via the fourth valve 119.

A pressurized gas supply system 134 communicates with the pressurized gas inflow port 111 of the upper primary chamber 114 of the casing 112 via a fifth valve 120.

The casing storage type film separation device 5 generally consumes less power than the bath immersion type film separation device 6.
(Tank immersion type membrane separation device)
The tank immersion type membrane separation device 6 immerses a housing in an open space containing a filtration membrane in a tank for storing raw water, circulates the raw water in the tank inside and outside the housing, and surrounds the membrane surface of the filtration membrane. This is a tank immersion type membrane separation device that filters a solid-liquid mixed phase flow flowing in a so-called cross flow, and has a structure shown in FIG. 4, for example. Although FIG. 4 discloses one tank immersion type membrane separation device 6 as an example. In the present embodiment, a plurality of tank immersion type membrane separation devices 6 are arranged inside the treatment tank 7. As described above, the present invention is not limited by the film material or shape, and is not limited by the so-called internal pressure type, external pressure type, or the like.

Here, the tank immersion type membrane separation device 6 has a plurality of tubular membrane elements 51 and a membrane case 52 as a housing for accommodating these membrane elements 51. The membrane case 52 has a rectangular cross section, and the upper and lower ends are open to form an open space.

Each membrane element 51 has a filtration membrane 54 attached to the surface of a porous tubular support 53 made of ceramics, and the inside communicates with a treated water lead-out system (not shown) for leading out treated water.

The film elements 51 are arranged along the horizontal direction in the axial direction (length direction), and are arranged in parallel with a predetermined interval. A flow path 56 open to both the upper and lower sides is formed between the membrane surfaces of the filtration membranes 54 of the membrane elements 51 facing each other. Below the membrane element 51, an air diffuser 57 capable of adjusting the amount of air diffuser is provided.

The tank immersion type membrane separation device 6 can generally treat raw water having a higher turbidity than the casing storage type membrane separation device 5.

The operation in the above configuration will be described below.

The turbidity of the raw water flowing into the landing well 1 is measured by the turbidity measuring device 11. The control device 14 determines the priority water treatment equipment and the non-priority water treatment equipment using the turbidity as a selection index. Here, the casing housing type membrane separation device 5 is set as the priority water treatment equipment, and the tank immersion type membrane separation device 6 is set as the non-priority water treatment equipment, with the measured turbidity set to a medium threshold value X1 or less.

When the water level of the distribution reservoir 13 is equal to or lower than the water supply pump starting water level M2, the control device 14 activates the water supply pump 12 to send the treated water of the water purification reservoir 4 to the distribution reservoir 13.

When the water level of the water purification pond 4 drops to the priority operating water level M3 or less, the casing storage type membrane separation device 5 of the priority water treatment facility is activated to treat the raw water of the mixing pond 2 and supply it to the water purification pond 4.

If the water level of the distribution reservoir 13 continues to decrease and the water level of the distribution reservoir 13 is lower than the water pump start water level M2 and higher than the non-priority water treatment facility start permission water level M1, the tank immersion type membrane of the non-priority water treatment facility The separation device 6 is not operated, and the operation of the water supply pump 12 is continued while the operation of the casing storage type membrane separation device 5 of the priority water treatment facility is continued.

Further, when the water level of the distribution reservoir 13 drops and becomes lower than the start permission water level M1, the start of the tank immersion type membrane separation device 6 of the non-priority water treatment facility is permitted. In the water purification pond 4, when the water level becomes lower than the non-priority operating water level M2 of the non-priority water treatment facility, the tank immersion type membrane separation device 6 of the non-priority water treatment facility is added to the casing storage type membrane separation device 5 of the priority water treatment facility. To drive.

When the water supply amount of the water supply pump 12 exceeds the water distribution amount, the water level of the distribution reservoir 13 rises, and when the water level reaches the water supply pump stop water level H, the water supply pump 12 is stopped. During this period, even if the water level of the distribution reservoir 13 rises and exceeds the start permission water level M1 of the non-priority water treatment facility, the operation of the tank immersion type membrane separation device 6 of the non-priority water treatment facility continues.

In the control device 14, the water level of the water purification pond 4 rises due to the operation of the casing storage type membrane separation device 5 of the priority water treatment facility and the tank immersion type membrane separation device 6 of the non-priority water treatment facility, and the water level of the water purification pond 4 is medium. When the non-priority stop water level M3 set to the same as the priority operation water level M3 set to the position is exceeded, the tank immersion type membrane separation device 6 of the non-priority water treatment facility is stopped.

Further, the control device 14 is a casing storage type of the priority water treatment facility when the water level of the water purification pond 4 measured by the water level measuring device 15 exceeds the priority stop water level (first tank upper limit water level) H set to the higher level of the water purification pond 4. The membrane separation device 5 is stopped.

The operation of the tank immersion type membrane separation device 6 of the non-priority water treatment facility can also be performed as follows. That is, when the water level of the water purification pond 4 is set to the middle level and the non-priority operating water level is M2 or less, the tank immersion type film separation device 6 of the non-priority water treatment facility is activated, and the water level of the water purification pond 4 is set to a high level. When the non-priority stop water level H, which is set to the same water level as the stop water level (upper limit water level of the first tank) H, is exceeded, the tank immersion type film separation device 6 of the non-priority water treatment facility is stopped.

Further, the operation of the tank immersion type membrane separation device 6 of the non-priority water treatment facility can be performed as follows. That is, when the water level of the water purification pond 4 is set to the middle level, the priority operating water level of the casing storage type membrane separator 5 of the priority water treatment facility M3 is set to the same water level, and the non-priority operating water level is M3 or less. The tank immersion type film separation device 6 is activated, and when the water level of the water purification pond 4 exceeds the priority stop water level (first tank upper limit water level) H set to the same water level as the non-priority stop water level H, the non-priority water treatment is performed. The tank immersion type film separation device 6 of the equipment is stopped.

As described above, the tank immersion type membrane separation device 6 of the non-priority water treatment facility can be started when the water level of the distribution reservoir 13 drops and reaches the low non-priority operating water level M1, so that the water flows out from the distribution reservoir 13. Efficient operation can be performed according to the actual water demand. That is, it is possible to operate the casing-contained membrane separation device 5 of the priority water treatment facility in its entirety and make up for the shortage by the operation of the tank immersion type membrane separation device 6 of the non-priority water treatment facility. As a result, the tank immersion type membrane separation device 6, which consumes more power than the casing storage type membrane separation device 5, can be used only for the shortage of water demand while ensuring reliable water quality according to the raw water turbidity. By operating, it becomes economical operation and rational system operation becomes possible.

In the above description, when the turbidity exceeds the threshold value X1, the settings of the priority water treatment equipment and the non-priority water treatment equipment are changed, the tank immersion type membrane separation device 6 is used as the priority water treatment equipment, and the casing storage type membrane separation device 5 is used. The above-mentioned operation is performed as a non-priority water treatment facility. The casing storage type membrane separation device 5 stops when the turbidity X2 is reached. In this case, the tank immersion type membrane separation device 6 can cope with a higher raw water turbidity than the casing storage type membrane separation device 5, so that the operation is safer.

In the above embodiment, it is also possible to use a valve instead of the water supply pump 12. In this case, the distribution reservoir 13 is arranged at a position lower than the purification reservoir 4, the valve opening / closing operation is performed with the water supply pump stop water level as the valve open water level and the water supply pump start water level as the valve closing water level.

Other combinations of different water treatment methods include, for example, a combination of a slow sand filter and a coagulation sedimentation / rapid sand filter. In this case, for example, when the turbidity is 10 degrees or less (preferably turbidity is 5 degrees or less), the slow speed filtration device is used as the priority water treatment equipment, and the coagulation sedimentation / rapid filtration device is used as the non-priority water treatment equipment. .. When the turbidity exceeds 10 degrees, the slow sand filter is used as a non-priority water treatment facility, and the coagulation sedimentation / rapid filtration device is used as a priority water treatment facility.

Further, as a combination of other different water treatment methods, for example, there is a combination of a slow sand filter and a membrane separation device. In this case, for example, when the turbidity is 10 degrees or less (preferably, the turbidity is 5 degrees or less), the slow sand filter is used as the priority water treatment equipment, and the membrane separation device is used as the non-priority water treatment equipment. When the turbidity exceeds 10 degrees, the slow sand filter is used as a non-priority water treatment facility, and the membrane separation device is used as a priority water treatment facility. If the turbidity exceeds 100 degrees, it is difficult to operate the membrane separation device alone, and pretreatment for the purpose of turbidity is required.

Further, as a combination of other different water treatment methods, for example, there is a combination of a coagulation sedimentation / rapid filtration device and a membrane separation device using a hollow fiber membrane. In this case, for example, a film separation device using a hollow fiber membrane at a turbidity of 5 degrees or less is used as a priority water treatment facility, and a coagulation sedimentation / rapid sand filter device is used as a non-priority water treatment facility. When the turbidity exceeds 5 degrees, a film separation device using a hollow fiber membrane is used as a non-priority water treatment facility, and a coagulation sedimentation / rapid sand filter device is used as a priority water treatment facility.

1 Reservoir 2 Mixing pond 4 Water purification pond 5 Casing storage type membrane separation device 6 Tank immersion type membrane separation device 11 Turbidity measurement device 12 Water supply pump 13 Reservoir 14 Control device 15, 16 Water level measurement device

Claims (14)

A priority water treatment facility that operates preferentially and a non-priority water treatment facility that operates non-priority are used in combination, and treated water is supplied from both water treatment facilities to the first treated water tank. In the operation method of the water treatment facility that distributes the treated water downstream through the second treated water tank,
The priority water treatment facility starts at the priority operating water level set to the middle level of the first treatment water tank, stops at the first tank upper limit water level set to the high level of the first treatment water tank, and then stops.
The non-priority water treatment equipment is a method of operating the water treatment equipment, which is characterized in that the non-priority water treatment equipment can be operated at the start permission water level set to the lower level of the second treatment water tank. The treated water in the first treated water tank is supplied to the second treated water tank via a water pump.
According to claim 1, the water supply pump starts at the water supply pump starting water level set to the middle level of the second treated water tank and stops at the second tank upper limit water level set to the high level of the second treated water tank. The operation method of the described water treatment equipment. The second treated water tank is arranged lower than the first treated water tank, and the treated water is supplied from the first treated water tank to the second treated water tank by a natural flow through a valve.
The first aspect of the present invention, wherein the valve is opened at the valve open water level set to the middle level of the second treatment water tank and closed at the upper limit water level of the second tank set to the high level of the second treatment water tank. How to operate the water treatment facility. The control device activates the non-priority water treatment facility when the water level in the first treated water tank is set to a medium level lower than the priority operating water level, and the water level in the first treated water tank is set to a medium level. The operation method of the water treatment facility according to claim 1, wherein the non-priority water treatment facility is stopped when the non-priority stop water level of the same water level as the priority operation water level is exceeded. The control device activates the non-priority water treatment equipment when the water level of the first treated water tank is set to a medium level lower than the priority operating water level, and sets the water level of the first treated water tank to a high level. The method for operating a water treatment facility according to claim 1, wherein the non-priority water treatment facility is stopped when the upper limit water level of the first tank is exceeded. The control device activates the non-priority water treatment facility when the water level of the first treatment water tank is the same as the priority operation water level set to the middle level and the non-priority operation water level is the same, and the water level of the first treatment water tank becomes high. The method for operating a water treatment facility according to claim 1, wherein the non-priority water treatment facility is stopped when the set upper limit water level of the first tank is exceeded. Using water treatment equipment with different water treatment methods
The value of a specific water quality item contained in raw water is used as a selection index, and when the selection index is below the threshold, one water treatment facility is used as a priority water treatment facility and the other water treatment facility is operated as a non-priority water treatment facility. The claim is characterized in that, when the selection index exceeds the threshold value, the other water treatment facility is used as the priority water treatment facility and the one water treatment facility is operated as the non-priority water treatment facility. The method for operating a water treatment facility according to any one of 1 to 6. Priority water treatment equipment and non-priority water treatment equipment treat water using membrane separation devices with different membrane areas per unit volume, and the membrane area per unit volume in one membrane separation device is in the other membrane separation device. The method for operating a water treatment facility according to any one of claims 1 to 7, wherein the membrane area is larger than the membrane area per unit volume. Multiple water treatment facilities that use membrane separation devices with different membrane areas per unit volume are used together, and the membrane area per unit volume in one membrane separation device is larger than the membrane area per unit volume in the other membrane separation device. ,
When the turbidity of the water quality item is below the threshold, the water treatment equipment that uses one of the membrane separation devices with the larger membrane area per unit volume is set as the priority water treatment equipment.
The water according to claim 7, wherein the water treatment equipment using the other membrane separation device having a small membrane area per unit volume as the priority water treatment equipment when the turbidity of the water quality item exceeds the threshold value. How to operate the processing equipment. Priority water treatment equipment and non-priority water treatment equipment treat water using membrane separation devices of different water treatment methods, and one membrane separation device supplies raw water into the casing of a closed space containing a filtration membrane. The other membrane separator is a tank-immersed membrane separator that filters raw water by immersing a housing in an open space containing the filter membrane in a tank that stores raw water. The water purification treatment method according to any one of claims 1 to 7, wherein the device is an apparatus. Priority water treatment equipment and non-priority water treatment equipment treat water using water treatment equipment of different water treatment methods, one water treatment equipment is a slow sand filter, and the other water treatment equipment is coagulated and settled. The water purification treatment method according to any one of claims 1 to 7, wherein the water purification device is a rapid filtration device. Priority water treatment equipment and non-priority water treatment equipment treat water using water treatment equipment of different water treatment methods, one water treatment equipment is a slow filtration device, and the other water treatment facility is a membrane separator. The water purification treatment method according to any one of claims 1 to 7, wherein the water purification method is characterized by the above. Priority water treatment equipment and non-priority water treatment equipment treat water using water treatment equipment of different water treatment methods, one water treatment equipment is a coagulation sedimentation / rapid sand filter, and the other water treatment equipment is hollow. The water purification treatment method according to any one of claims 1 to 7, wherein the membrane separating device uses a thread film. Inflow raw water is treated in parallel, and membrane separation devices with different membrane areas per unit volume are used, and the membrane area per unit volume in one membrane separation device is the membrane area per unit volume in the other membrane separation device. With multiple larger water treatment facilities,
A turbidity measuring device that measures the turbidity of the inflowing raw water,
A water purification pond that supplies treated water from both water treatment facilities,
A distribution reservoir that supplies treated water from a water purification pond via a water supply pump,
A water level measuring device that measures the water level of each of the purified water reservoir and the distribution reservoir,
Equipped with a control device that controls the start and stop of each water treatment facility and water pump
When the measured turbidity of the turbidity measuring device is equal to or less than the threshold value, the control device sets the water treatment facility that uses one of the film separating devices having a large film area per unit volume as the priority water treatment facility.
When the measured turbidity of the turbidity measuring device exceeds the threshold value, the water treatment facility that uses the other membrane separation device with a small membrane area per unit volume is set as the priority water treatment facility.
The priority water treatment facility starts when the water level of the water purification pond is below the priority operating water level set to the middle level, and stops when the water level of the water purification pond exceeds the upper limit water level of the water purification pond set to the high level.
The non-priority water treatment facility can be operated when the water level of the distribution reservoir is below the start permission water level set to a low level.
The water treatment pump is a water treatment facility that starts when the water level of the distribution reservoir is set to the middle level or lower than the pump start water level, and stops when the water level of the distribution reservoir exceeds the upper limit water level of the distribution reservoir set to the high level. ..

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