JP2021065802A - Water treatment system and water treatment method - Google Patents

Abstract

To provide a water treatment system and a water treatment method that enable efficient use of equipment in a water treatment system including water treatment equipment.SOLUTION: Raw water is supplied to an irrigation water treatment facility 2 by a pipe 1 for treatment, and treated water is supplied to a use point 4 by a pipe 3. Discharged water of the use point 4 is supplied to a wastewater treatment facility 6 by a pipe 5, and treated water is discharged by a pipe 7. A reserve water treatment facility 2A having substantially the same configuration as the water treatment facility 2 is provided, and if necessary, a part of the wastewater discharged from the use point 4 or the wastewater treatment facility 6 is received and treated, and returned to the water treatment facility 2 or the use point 4.SELECTED DRAWING: Figure 2

Description

The present invention relates to a water treatment system and a water treatment method for treating and using water.

A water treatment device is used to treat raw water and supply water of a predetermined water quality to a water-using facility that uses pure water, ultrapure water, or the like.

For example, in various manufacturing plants, in the processes of water treatment, wastewater treatment, and wastewater recovery, devices having a configuration suitable for each process are independently designed for each process. Therefore, the equipment configuration is inconsistent, and there is a tendency for design costs to increase and field tests to be lengthened.

Japanese Patent Application Laid-Open No. 9-192643 describes recovery system wastewater using units having the same device configuration in two systems, a system that separates wastewater using pure water and reuses it for pure water, and a system that reuses it for miscellaneous water. It is described that the processing is performed.

Further, in JP-A-2018-171578, JP-A-2018-158310, JP-A-2017-140557, and JP-A-2017-170275, the same as aggregation-> turbidity-> desalting for water treatment and wastewater recovery. It is described to use the conceptual water treatment unit.

However, in this case as well, once the unit was determined to be used for water treatment, wastewater recovery, etc., it was fixed to this use and was not changed to another use on the way. Therefore, there have been cases of inefficiency such as the required amount of water cannot be obtained, or the demand is low and some water treatment units are not used.

Japanese Unexamined Patent Publication No. 9-192643 Japanese Unexamined Patent Publication No. 2018-171578 JP-A-2018-158310 Japanese Unexamined Patent Publication No. 2017-140577 JP-A-2017-170275

An object of the present invention is to provide a water treatment system and a water treatment method that enable efficient use of the equipment in a water treatment system including a water treatment equipment.

The water treatment system of the present invention is a water treatment system having a main series equipped with a water treatment facility for treating raw water, and is provided with a reserve water treatment facility having substantially the same configuration as the water treatment facility. Is characterized in that it can be incorporated into the main series.

In one aspect of the present invention, the water treatment equipment and the reserve water treatment equipment include at least a coagulation device, a decontamination device, and a desalting device.

In one aspect of the present invention, the main series includes the water treatment facility to which raw water is supplied by the first pipe, a use point in which the treated water from the water treatment facility is supplied by the second pipe, and the use point. It is provided with a wastewater treatment facility in which the wastewater discharged from the wastewater is supplied by a third pipe, and a fourth pipe for flowing the outflow water of the wastewater treatment facility.

In one aspect of the present invention, each of the first, second, third, and fourth pipes is provided with a pipe connection portion.

The water treatment method of the present invention is a water treatment method using the water treatment system of the present invention.

In one aspect of the method of the present invention, a part of the discharged water from the use point is treated by the reserve water treatment facility, and the treated water of the reserve water treatment facility is returned to the water treatment facility or the use point.

In one aspect of the method of the present invention, a part of the discharged water from the pipe is treated by the reserve water treatment facility, and the treated water of the reserve water treatment facility is returned to the water treatment facility or the use point.

In one aspect of the method of the present invention, a part of the discharged water from the use point is branched, a part of the branched water is returned to the water treatment facility, and the rest of the branched water is treated with the preliminary water. It is treated by the equipment and the treated water of the reserve water treatment equipment is returned to the water treatment equipment or the use point.

In one aspect of the method of the present invention, a part of the discharged water from the wastewater treatment facility is branched, a part of the branched water is returned to the water treatment facility, and the rest of the branched water is the reserve water. It is treated by the treatment facility and the treated water of the reserve water treatment facility is returned to the water treatment facility or the use point.

The water treatment system of the present invention includes a reserve water treatment facility that can be incorporated into a main series having a water treatment facility and has substantially the same configuration as the water treatment facility. This reserve water treatment facility can be used properly as a water treatment, a wastewater recovery treatment, and a preliminary standby, depending on the request.

It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment. It is a block diagram of the water treatment system which concerns on embodiment.

FIG. 1 shows the configuration of the water treatment system according to the embodiment. In this water treatment system, raw water is supplied to the water treatment facility 2 via the pipe 1 and treated to be produced water, and the produced water is sent to the use point 4 via the pipe 3. The water used in the use point 4 is supplied to the wastewater treatment facility 6 via the pipe 5 for treatment, and the treated water is discharged from the pipe 7.

In addition to the main sequence consisting of these pipes 1, 3, 5, 7, the water treatment facility 2, the use point 4, and the wastewater treatment facility 6, a reserve water treatment facility 2A that can be connected to the main sequence is provided.

The pipes 1, 3, 5, and 7 are provided with pipe connection portions 1a, 3a, 5a, and 7a for incorporating the reserve water treatment facility 2A. The inlet side of the reserve water treatment equipment 2A can be connected to the connection portions 1a, 5a, 7a by piping, and the outlet side can be connected to the connection portions 1a, 3a, 7a by piping.

The irrigation water treatment equipment 2 and the reserve water treatment equipment 2A have substantially the same configuration. The fact that the irrigation water treatment equipment 2 and the reserve water treatment equipment 2A are substantially the same means that the configurations of the main water treatment equipment of each equipment are the same, or that one equipment is the main water treatment equipment of the other equipment. It means to have all of them and to have other water treatment equipment.

In this embodiment, the water treatment facility 2 and the reserve water treatment facility 2A each include a plurality of water treatment devices a ₁ , a ₂ , and a ₃ . a ₁ is, for example, a coagulation device, a ₂ is a decontamination device, and a ₃ is a desalination device.

The decontamination device is, for example, one of the following.
-UF membrane device-filter-pressurized levitation device and subsequent stage filter-pressurized levitation device and subsequent stage UF membrane device-precipitator and subsequent stage filter / sedimentation device and subsequent stage UF membrane device removal Among the above, the turbidizer is preferably an ultrafiltration membrane device. The decontamination membrane device may be a cross-flow type or a total filtration type.

The decontamination treatment step using the dehumidifying membrane preferably includes water flow, air bubbling, backwashing, and water filling steps. The filtration water flow time is preferably 20 to 40 minutes (usually 30 minutes), and the differential pressure (inlet pressure-outlet pressure) is preferably about 0.02 to 0.04 MPa. When the differential pressure reaches 0.07 to 0.10 MPa, it is preferable to perform clean-in-place cleaning. The material of the dehumidifying film is preferably PVDF having excellent chemical resistance, and the pore size is preferably 0.02 μm or more.

As the desalting apparatus, an RO membrane apparatus, an electrodialysis apparatus and the like are suitable. As the desalination device, an ion exchange resin tower using an ion exchange resin or an electrodialyzed deionizer can also be used, but since it is difficult to condition the one used for wastewater treatment for water treatment, RO A membrane device or an electrodialysis device is more preferable. However, an electrodeionizer or an ion exchange resin tower may be installed on the rear side of the RO membrane device or the like.

Among the above, the RO membrane device is preferable as the desalting device. In this case, it is preferable to secure a line amount of 3.6 m ^{3 / h or more.}

There are no restrictions on the reverse osmosis membrane. It is also possible to use an ultra-low pressure film with a standard pressure of 0.735 MPa. The membrane area is ^{preferably about 35 to 41 m 2} , the initial pure water flux at 0.735 MPa: about 1.0 m / d (25 ° C.) or more, and the initial desalting rate: 98% or more.

It is preferable to set the recovery rate so that the calcium hardness Langeria index is 0 or less.

It is preferable to set the recovery rate of silica so that the brine water is within the solubility. The recovery rate is usually 50 to 80%.

A slime control agent may be added to the raw water to prevent fouling of the RO membrane. The slime control agent may be a bound chlorine-based oxidizing agent such as chloramine or sodium chlorosfufamate, or an isothiazolone-based compound. The slime control agent may be used alone or in combination of two or more.

In the case of a bound chlorine-based oxidizing agent, it is preferable to add it so _{as to be 0.3 to 1.0 mg / La as Cl 2.}

Examples of the sodium chlorosulfamate oxidant include a chlorine-based oxidant having an effective chlorine concentration of 1 to 8% by weight, preferably 3 to 6% by weight, and 1.5 to 9% by weight, preferably 4.5 to 8% by weight. An aqueous solution having a pH of ≧ 12 containing% sulfamic acid compound can be used.

In addition, a scale dispersant may be added.

The water treatment facility 2 and the reserve water treatment facility 2A are provided with a discharge unit d for discharging backwash drainage and concentrated wastewater (including drawn sludge) from the decontamination device and the desalination device.

In normal times, as shown in FIG. 1, production water is produced and use point discharged water is treated using a main sequence that does not incorporate the reserve water treatment facility 2A. When repairing the main sequence water treatment equipment 2, the water treatment equipment 2 and the reserve water treatment equipment 2A can be replaced.

When collecting wastewater, increasing water demand at use points, restricting the intake of raw water, reducing the capacity of wastewater treatment equipment, etc., the reserve water treatment equipment 2A is incorporated into the main series, and the reserve water treatment equipment 2A is used. Also treats water.

The connection of the reserve water treatment facility 2A is performed by, for example, one of the following.
-Remove the water flow pipe from the main sequence side, move the reserve water treatment equipment 2A closer to the main series, and connect the water flow pipe.
-Remove the water flow pipe from the main sequence side and reconnect the water flow pipe to the reserve water treatment equipment 2A side.
-Both the water treatment equipment 2 side and the wastewater treatment equipment 6 side and the reserve water treatment equipment 2A are connected in advance by a valve or the like (not shown) with a water flow pipe to switch the water flow direction.

When switching the water flow to use the common water treatment unit used for wastewater treatment for water treatment and wastewater recovery, check in advance whether the functional material is dirty, and if it is dirty, clean the inside of the system. After that, after confirming that the treated water quality achieves the target, preliminary conditioning is completed and water flow is started.

An example in which the reserve water treatment facility 2A is incorporated is shown in FIGS. 2 to 12.

2 and 3 show an example in which the reserve water treatment facility 2A is incorporated in order to recover a part of the treated water from the wastewater treatment facility 6.

In FIG. 2a, a part of the outflow water of the use point 4 is supplied from the pipe 5 to the inlet side of the reserve water treatment equipment 2A by the pipe 10, the treated water is returned to the pipe 1 by the pipe 11, and the water treatment equipment is used together with the raw water. Send water to 2.

In FIG. 2b, a part of the outflow water of the use point 4 is supplied from the pipe 5 to the inlet side of the reserve water treatment facility 2A by the pipe 10. Since the quality of the treated water (produced water) of the reserve water treatment facility 2A is good, the treated water (produced water) is returned to the pipe 3 instead of the pipe 1 and used together with the produced water from the water treatment facility 2. Water is sent to point 4.

Other configurations of FIGS. 2a and 2b are the same as those of FIG. 2a and 2b are adopted when the cleanliness of the effluent of use point 4 is relatively high.

Use point When the cleanliness of the effluent is low, as shown in FIGS. 3a and 3b, a part of the treated water of the wastewater treatment equipment 6 is sent from the pipe 7 to the inlet side of the reserve water treatment equipment 2A via the pipe 10. .. When the quality of the treated water (produced water) of the reserve water treatment facility 2A is low, the treated water is returned to the pipe 1 as shown in FIG. 3a, and when the water quality is good, the treated water is piped as shown in FIG. 3b. Return to 3.

Other configurations of FIGS. 3a and 3b are the same as those of FIGS. 2a and 2b.

FIGS. 4 and 5 show an example in which the amount of wastewater recovered is increased because the intake of raw water is restricted and the flow rate of raw water is reduced. For example, normally 70% of the permissible amount of raw water is taken in, but when the water intake is restricted to 50% due to drought, 20% of the shortfall is supplemented with wastewater recovered water. In FIGS. 4 and 5, since the amount of wastewater recovered was increased, a part of the recovered wastewater was treated by the reserve water treatment facility 2A, and the rest was returned to the pipe 1.

That is, in FIG. 4a, in FIG. 2b, a part of the use point outflow water branched from the pipe 5 to the pipe 10 is treated by the reserve water treatment facility 2A, and the rest is piped through the pipe 12 branched from the pipe 10. Return to 1. In this case, when the quality of the treated water (produced water) of the reserve water treatment facility 2A is good, the treated water (produced water) is returned to the pipe 3 by the pipe 11. Other configurations of FIG. 4a are the same as those of FIG. 2b.

FIG. 4b shows a case where the quality of the treated water from the reserve water treatment facility 2A is inferior in FIG. 4a. In this case, the treated water of the reserve water treatment facility 2A is merged with the use point outflow water from the branch pipe 12 by the pipe 11, and is returned to the pipe 1 via the merging pipe 13. Other configurations of FIG. 4b are the same as those of FIG. 4a.

In FIGS. 4a and 4b, since the quality of the effluent of use point 4 is relatively good, the effluent of use point is sent to the reserve water treatment facility 2A, but the quality of the effluent of use point is relatively inferior. As shown in FIGS. 5a and 5b, a part of the treated water of the wastewater treatment facility 6 is branched from the pipe 7 to the pipe 10. The other configurations of FIG. 5a are the same as those of FIG. 4a, and the other configurations of FIG. 5b are the same as those of FIG. 4b.

FIG. 6 shows that a part of the effluent from the use point 4 is branched into the pipe 10 and supplied to the reserve water treatment facility 2A due to a malfunction in the wastewater treatment facility 6. The other configurations of FIG. 6a are the same as those of FIG. 4a, and the other configurations of FIG. 6b are the same as those of FIG. 4b.

In FIGS. 1 to 6 above, the water treatment facility 2 is installed independently, but a water treatment facility having the same configuration as the water treatment facility 2 may be installed in parallel with the water treatment facility 2.

FIG. 7 shows an example of securing the amount of treated water (produced water) for irrigation treatment when the amount of water demand at use point 4 increases during the operation of FIG.
In FIG. 7, a part of the raw water is supplied from the pipe 1 to the inlet side of the reserve water treatment equipment 2A through the pipe 12, and the treated water (produced water) is returned to the pipe 3 through the pipe 13 from the water treatment equipment 2. It is sent to use point 4 together with the produced water.
Other configurations of FIG. 7 are the same as those of FIG.
Note that FIG. 7 can also be applied to reduce the load per unit of the irrigation water treatment equipment when the quality of raw water deteriorates, especially when the turbidity increases due to heavy rain or the like.

FIG. 8 shows the case where the raw water quality deteriorates, especially when the seawater flows back into the river due to the drought of the river and the ionic strength increases, or when the humus derived from the fallen leaves on the ground surface flows into the well and the TOC increases. Shows an example of ensuring the quality of treated water for water treatment.
In FIG. 8, at least a part of the raw water is supplied from the pipe 1 to the inlet side of the reserve water treatment facility 2A through the pipe 12, and the treated water is supplied through the pipe 14 to the branch point of the pipe 1 and the inlet side of the irrigation water treatment facility 2. I will return it in the meantime.
Other configurations of FIG. 8 are the same as those of FIG.
It is desirable that the higher the raw water load, the higher the flow rate ratio to the reserve water treatment facility 2A.

In the present invention, the raw water may be pretreated in the front stage of the water treatment facility 2.

The present invention is not limited to the above-described embodiment, and may be further used.

2 Water treatment equipment 2A Reserve water treatment equipment 4 Use points 6 Wastewater treatment equipment

Claims (8)

In a water treatment system with a main sequence equipped with water treatment equipment for treating raw water
It is equipped with a reserve water treatment facility that has substantially the same configuration as the water treatment facility.
A water treatment system characterized in that the reserve water treatment equipment can be incorporated into the main sequence. The water treatment system according to claim 1, wherein the water treatment equipment and the reserve water treatment equipment include at least a coagulation device, a decontamination device, and a desalination device. In the main series, the irrigation water treatment facility to which raw water is supplied by the first pipe, the use point to which the treated water from the irrigation water treatment facility is supplied by the second pipe, and the discharge water from the use point are the third. The water treatment system according to claim 1 or 2, further comprising a wastewater treatment facility supplied by a pipe and a fourth pipe for flowing outflow water of the wastewater treatment facility. The water treatment system according to claim 3, wherein each of the first, second, third, and fourth pipes is provided with a pipe connection portion. A water treatment method using the water treatment system according to claim 3 or 4.
A water treatment method characterized in that a part of the discharged water from the use point is treated by the reserve water treatment facility, and the treated water of the reserve water treatment facility is returned to the water treatment facility or the use point. A water treatment method using the water treatment system according to claim 3 or 4.
A water treatment method characterized in that a part of the discharged water from the wastewater treatment facility is treated by the reserve water treatment facility, and the treated water of the reserve water treatment facility is returned to the water treatment facility or a use point. A water treatment method using the water treatment system according to claim 3 or 4.
A part of the discharged water from the use point is branched, a part of the branched water is returned to the water treatment facility, and the rest of the branched water is treated by the reserve water treatment facility to prepare the reserve. A water treatment method characterized in that the treated water of a water treatment facility is returned to the water treatment facility or a point of use. A water treatment method using the water treatment system according to claim 3 or 4.
A part of the discharged water from the wastewater treatment facility is branched, a part of the branched water is returned to the water treatment facility, and the rest of the branched water is treated by the reserve water treatment facility. A water treatment method characterized in that the treated water of the reserve water treatment facility is returned to the water treatment facility or the point of use.

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