WO2011105566A1

WO2011105566A1 - Seawater desalting system

Info

Publication number: WO2011105566A1
Application number: PCT/JP2011/054354
Authority: WO
Inventors: 晃治陰山; 直樹原; みさき隅倉; 隆広舘; 浩人横井; 周一菅野
Original assignee: 株式会社日立製作所
Priority date: 2010-02-26
Filing date: 2011-02-25
Publication date: 2011-09-01
Also published as: JP2011177601A; JP5577113B2

Abstract

Provided is a seawater desalting system comprising: a reverse osmosis membrane type seawater desalting facility (18) using a reverse osmosis membrane; an activated carbon adsorption processing facility (14) provided upstream or downstream of the reverse osmosis membrane type seawater desalting facility (18); and a high-temperature fluid pouring facility (22) for pouring a high-temperature fluid into the activated carbon adsorption processing facility (14) to clean the activated carbon. Alternatively provided is a seawater desalting system comprising: a reverse osmosis membrane type seawater desalting facility (18) using a reverse osmosis membrane; an activated carbon adsorption processing facility (14) provided upstream or downstream of the reverse osmosis membrane type seawater desalting facility (18); a water quality measuring device (36) provided downstream of the activated carbon adsorption processing facility (14); a cleaning trigger calculation unit (32) for obtaining by calculation the time of cleaning of the activated carbon adsorption processing facility (14) on the basis of a water quality measurement value outputted from the water quality measuring device (36); and a high-temperature fluid pouring facility (22) for pouring a high-temperature fluid into the activated carbon adsorption processing facility (14) on the basis of a cleaning trigger signal outputted from the cleaning trigger calculation unit (32).

Description

Seawater desalination system

The present invention relates to a seawater desalination system including a seawater desalination facility using a reverse osmosis membrane for obtaining freshwater from seawater and pretreatment / posttreatment facilities.

In recent years, seawater desalination apparatuses that use reverse osmosis membranes and perform filtration have been increasing. Reverse osmosis membranes are made of materials such as cellulose and polyamide. Applying pressure to the reverse osmosis membrane more than twice the osmotic pressure of seawater, salt does not permeate the membrane, allowing water to permeate the fresh water. Obtainable.

While the boron concentration in seawater is about 4.5-5 mg / L, the water quality standard value of WHO drinking water is 0.5 mg / L, so the boron rejection should be about 90%. It is. However, in general, the boron rejection of one reverse osmosis membrane module is 50 to 70%, which requires two-stage treatment of high-pressure reverse osmosis membrane and low-pressure reverse osmosis membrane. Increase. In order to reduce running costs as much as possible, there are two systems for producing one-stage treated water and two-stage treated water, and the one-stage treated water and Although blending water of two-stage treatment has been implemented, there has been a problem that initial cost and running cost increase.

[Patent Document 1] discloses a fresh water producing apparatus for removing boron contained in seawater using a reverse osmosis membrane (semi-permeable membrane). The fresh water producing apparatus described in [Patent Document 1] temporarily stores pretreatment such as a filter for pretreatment of raw water (seawater), a first semipermeable membrane unit for treating pretreatment water, and primary permeate. An intermediate water tank, a second semipermeable membrane unit for treating the primary permeated water stored in the intermediate water tank, a high-pressure pump provided in front of the first semipermeable membrane unit, and a second semipermeable membrane unit. In addition to the booster pump provided at the front stage of the permeable membrane unit, the first alkali addition means provided at the front stage of the high-pressure pump, and the second alkali for increasing the pH of the primary permeate in the intermediate water tank It is a fresh water production apparatus equipped with an addition means and an acid addition means for lowering the pH of secondary permeated water. In short, the pH is controlled by utilizing the fact that the removal rate of components such as boron changes depending on the pH. It produces fresh water efficiently.

JP 2006-187719 A JP 2003-326251 A JP-A-10-225682

The conventional techniques described in [Patent Document 2] and [Patent Document 3] have a problem that the apparatus becomes complicated and it is necessary to always add chemicals. Improvement is demanded. Furthermore, chemical components remain in the waste liquid after the reverse osmosis membrane treatment, which has a problem of affecting the ecosystem in the sea area where it is discharged.

An object of the present invention is to provide a seawater desalination system that can reduce the running cost of the entire system.

In order to achieve the above object, a seawater desalination system of the present invention is provided on the upstream or downstream side of a reverse osmosis membrane type seawater desalination facility using a reverse osmosis membrane and the reverse osmosis membrane type seawater desalination facility. Activated carbon adsorption treatment equipment, and high temperature fluid injection equipment for injecting high temperature fluid into the activated carbon adsorption treatment equipment to wash the activated carbon.

Moreover, a reverse osmosis membrane type seawater desalination facility using a reverse osmosis membrane, an activated carbon adsorption treatment facility provided upstream or downstream of the reverse osmosis membrane type seawater desalination facility, and a downstream side of the activated carbon adsorption treatment facility A water quality measuring device provided in the apparatus, a cleaning trigger calculating unit for calculating a cleaning time of the activated carbon adsorption treatment facility based on a water quality measurement value output from the water quality measuring device, and a cleaning output from the cleaning trigger calculating unit And a high-temperature fluid injection facility for injecting a high-temperature fluid into the activated carbon adsorption processing facility based on a trigger signal.

According to the present invention, the concentration of the soluble component contained in the treated water of the seawater desalination system, particularly the boron concentration, can be suppressed to a reference value or less, so that water that is not problematic even when used for drinking can be supplied, and high safety is achieved. Can be secured. In addition, since no chemicals are used, the environmental load on the discharge destination of the concentrate is small.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the seawater desalination system provided with the activated carbon adsorption processing equipment of Example 1 of this invention in the front | former stage of the reverse osmosis membrane type seawater desalination equipment. It is another block diagram of the seawater desalination system provided with the activated carbon adsorption processing equipment of Example 1 in the back | latter stage of the reverse osmosis membrane type seawater desalination equipment. It is a block diagram of the seawater desalination system regarding the washing | cleaning signal in Example 1. FIG. It is a block diagram of the activated carbon adsorption treatment equipment in the seawater desalination system of a present Example. It is another structural drawing of the activated carbon adsorption treatment equipment in the seawater desalination system of a present Example. It is a structural diagram of the activated carbon adsorption treatment equipment in the seawater desalination system of Example 2 of the present invention. It is a structural diagram of the activated carbon adsorption treatment equipment in the seawater desalination system of Example 3 of the present invention.

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a seawater desalination system according to a first embodiment of the present invention.

The seawater 12 is treated by the activated carbon adsorption treatment facility 14 before flowing into the reverse osmosis membrane type seawater desalination facility 18. Although not shown in FIG. 1, when the reverse osmosis membrane type seawater desalination facility 18 is provided with a pretreatment facility such as a two-layer filtration device, a UF membrane filtration device, or an MF membrane filtration device, activated carbon The adsorption treatment facility 14 may be on the upstream side or downstream side of the pretreatment facility.

Generally, since activated carbon has an adsorption capacity for boron, the concentration of boron in the treated water 16 of the activated carbon facility flowing out from the activated carbon adsorption treatment facility 14 is lowered. Therefore, the concentration of boron in the water obtained by desalinating the activated carbon equipment treated water 16 with the reverse osmosis membrane type seawater desalination equipment 18 is low, and the fresh water 20 can be supplied even if used for drinking. Concentrated water 26 generated at the same time is discharged from the reverse osmosis membrane type seawater desalination facility 18.

However, activated carbon has a limit in the amount of adsorption, and if it is used continuously, the adsorption capacity decreases as it approaches the saturated adsorption amount. In general, the amount of saturated adsorption increases as the temperature decreases, and conversely decreases as the temperature increases. Accordingly, when hot water having a high water temperature is supplied to activated carbon that has adsorbed boron under low water temperature conditions, the boron once adsorbed is desorbed from the activated carbon. As a result, the adsorption ability of the activated carbon is recovered.

In the example shown in FIG. 1, the high-temperature fluid 10 is injected from the high-temperature fluid injection facility 22 in order to supply high-temperature hot water to the activated carbon. The high-temperature fluid 10 may be anything as long as it is a high-temperature fluid, and may be fresh water, seawater, water vapor, or air. The temperature should just be 40 degreeC or more, for example. As the high-temperature fluid injection facility 22, it is efficient to use exhaust heat from a power generation facility provided in a seawater desalination system, hot water produced by a solar water heater, or cooling water from a photovoltaic power generation cell.

Especially, IWPP (Independent Water and Power Production) equipment equipped with both seawater desalination equipment and power generation equipment is efficient because it can obtain a large amount of exhaust heat from a gas turbine or nuclear power generation.

Since the high-temperature fluid 10 of this embodiment is necessary for recovering the adsorptive capacity of the activated carbon, high-temperature water can be obtained by heating equipment such as a boiler and a heater each time without using exhaust heat or natural energy from a gas turbine or nuclear power generation. It may be.

Boron and other substances once adsorbed on the activated carbon are desorbed to the high-temperature fluid 10 given to the activated carbon adsorption treatment facility 14 and discarded as a waste liquid 24. This waste liquid 24 contains only substances such as boron and organic substances originally present in the taken seawater 12, and the load on the water environment does not increase. However, the waste liquid 24 is warmed, and if the waste liquid 24 having a high temperature is discharged, there is a possibility of adversely affecting the environmental ecosystem. Therefore, it is desirable to dispose of the waste liquid 24 of the high-temperature fluid 10 containing the substance desorbed from the activated carbon after releasing the thermal energy into the atmosphere to reduce the temperature to about the seawater temperature.

In the example shown in FIG. 1, the activated carbon adsorption treatment facility 14 is installed upstream of the reverse osmosis membrane type seawater desalination facility 18. In this case, the activated carbon also adsorbs organic substances and fine particles in addition to boron. As a result, fouling and clogging of the reverse osmosis membrane are reduced. Further, when the seawater 12 is continuously passed through the activated carbon adsorption treatment facility 14, microorganisms that originally lived in the seawater 12 may adhere to the activated carbon surface and propagate. As a result, the reverse osmosis membrane may be fouled or clogged by organic matter discharged from the body by the microorganisms.

In the present embodiment, as in the configuration shown in FIG. 1, by supplying the high temperature fluid 10 to the activated carbon adsorption treatment facility 14, the growth of microorganisms can be suppressed or the microorganisms can be killed. This is because the microorganisms are damaged by giving an environment different from the normal breeding condition, and the protein contained in the microorganisms is thermally denatured.

FIG. 2 shows an example in which the activated carbon adsorption treatment facility 14 is installed on the downstream side of the reverse osmosis membrane type seawater desalination facility 18 opposite to the case of FIG. Since activated carbon has the ability to adsorb various substances, if it is in front of the reverse osmosis membrane type seawater desalination facility 18, organic matter and fine particles contained in the seawater 12 will also adhere to the activated carbon surface in the same manner as boron. Therefore, a desorption process using the high-temperature fluid 10 is required.

The configuration in FIG. 2 aims to reduce this frequency. The water that has passed through the reverse osmosis membrane-type seawater desalination facility 18 contains almost no organic matter or fine particles, and only a part of dissolved components such as boron. Therefore, by guiding the fresh water 20 flowing out from the reverse osmosis membrane type seawater desalination facility 18 to the activated carbon adsorption treatment facility 14, the remaining boron can be adsorbed and removed more efficiently.

However, in this case, since there is no facility for adsorbing organic matter or fine particles before the reverse osmosis membrane type seawater desalination facility 18, compared to the case of FIG. 1, fouling or clogging of the reverse osmosis membrane is likely to occur. there is a possibility. However, if other pretreatment facilities are provided upstream of the reverse osmosis membrane type seawater desalination facility 18 and have sufficient performance to suppress fouling and clogging, the configuration of FIG.

FIG. 3 shows an apparatus configuration for supplying a signal for cleaning by supplying the high temperature fluid 10 from the high temperature fluid injection facility 22 to the activated carbon adsorption treatment facility 14 at an appropriate time. In this case, the activated carbon adsorption treatment facility 14 may be upstream or downstream of the reverse osmosis membrane seawater desalination facility 18.

The water quality of the activated carbon equipment treated water 16 flowing out from the activated carbon adsorption treatment equipment 14 is measured by the water quality measuring device 36. This measurement item includes any one of boron concentration, adenosine triphosphate, and ultraviolet absorbance. Among these, boron concentration can evaluate the remainder of the adsorptive capacity of activated carbon. Adenosine triphosphate is an indicator of the amount of microorganisms that are propagated in the activated carbon adsorption treatment facility 14. Although the ultraviolet absorbance varies depending on the wavelength, the remainder of the adsorption ability of the activated carbon can be evaluated and can be an index of the amount of microorganisms that are propagated in the activated carbon adsorption treatment facility 14.

The water quality measurement values 30 of these components are given to the washing trigger calculation unit 32. The cleaning trigger calculation unit 32 obtains an appropriate cleaning time based on the analysis of the water quality measurement value 30 and a preset threshold value or temporal change data, and gives a cleaning trigger signal 34 to the high-temperature fluid injection facility 22. The high-temperature fluid injection facility 22 injects the high-temperature fluid 10 into the activated carbon adsorption processing facility 14 based on the cleaning trigger signal 34.

At that time, in order to prevent the desorbed components from flowing out to the downstream side together with the activated carbon equipment treated water 16, the valve on the activated carbon equipment treated water 16 side is first closed and the discharge valve of the waste liquid 24 is opened. The high temperature fluid 10 raises the temperature of the activated carbon in the activated carbon adsorption treatment facility 14, desorbs boron and other components once attached, and is discharged as a waste liquid 24.

Thus, by having the structure provided with the washing trigger calculation unit 32, the washing frequency of the activated carbon adsorption treatment facility 14 can be optimized, boron outflow to the downstream side due to insufficient washing can be suppressed, and fresh water generation efficiency due to excessive washing And the increase of the waste liquid 24 can be suppressed.

According to Example 1, by using the activated carbon adsorption treatment facility 14 having a function of washing with the high temperature fluid 10, boron contained in the seawater 12 can be removed without using chemicals. Since the waste liquid 24 does not contain artificially added components such as chemicals, no problems other than the water temperature occur even when the water is returned to the sea area.

In addition, by installing the activated carbon adsorption treatment facility 14 upstream of the reverse osmosis membrane type seawater desalination facility 18, fouling and clogging of the reverse osmosis membrane can be suppressed. As a result, it is possible to extend the life of the reverse osmosis membrane, reduce the power cost, and reduce the amount of chemical used for chemical cleaning of the reverse osmosis membrane.

FIG. 4 is an example of the structure of the activated carbon adsorption treatment facility 14. Since the activated carbon 42 is worn and crushed with its use, the refined activated carbon 42 may flow into the treated water 16 of the activated carbon facility. When the reverse osmosis membrane type seawater desalination facility 18 is provided on the downstream side, the refined activated carbon 42 may cause the blockage of the reverse osmosis membrane. The activated carbon adsorption treatment facility 14 shown in FIG. 4 includes an activated carbon tank 40 and an outlet-side inorganic film 38 at the outlet of the activated carbon tank 40. With this configuration, the refined activated carbon 42 does not flow out. With this configuration, adverse effects on the reverse osmosis membrane type seawater desalination facility 18 can be suppressed.

Since the high temperature fluid 10 desorbs boron and other components, there is a problem of heat resistance in the organic film, so it needs to be an inorganic film. The material of the inorganic film may be a metal such as stainless steel or a ceramic.

In this configuration, the activated carbon 42 does not flow out even if the particle size of the activated carbon 42 is originally small even if the activated carbon is not worn or crushed. Therefore, even activated carbon powder having a particle diameter smaller than that of granular activated carbon can be provided in the activated carbon tank 40. Powdered activated carbon having a particle size of 150 μm, 100 μm, or 75 μm or less is generally used, but the range of the particle size of the powdered activated carbon in this example does not have to be 150 μm, 100 μm, or 75 μm or less, and is larger. Activated carbon having a particle size may be used.

When the particle size is small, the specific surface area of the activated carbon 42 is large, so that the adsorption rate and the amount of adsorption increase, and the scale of the activated carbon adsorption treatment facility 14 can be reduced. As a result, the amount of the high-temperature fluid 10 supplied from the high-temperature fluid injection facility 22 may be small, and an efficient desorption process is possible. However, depending on the particle diameter, powdered activated carbon is preferably used in an upward flow tank because it may become consolidated and increase resistance when used in a downward flow.

If the activated carbon 42 has a small particle size, it is easy to flow on the water flow and does not settle easily. Even if it is an upward flow, if the flow velocity is fast, the powdered activated carbon adheres to the outlet side inorganic film 38 provided on the upper surface and is consolidated. there is a possibility. Therefore, as shown in FIG. 5, a taper is provided so that the upward flow velocity is lower in the lower portion and the upward flow velocity is lower in the vicinity of the upper outlet portion. It is possible to suppress the powdered activated carbon from adhering to and compacting. The taper need not be linear as shown in FIG. 5, but may be on a curved line or stepped, as long as the upper cross-sectional area is larger than the lower cross-sectional area.

In this embodiment, since the activated carbon and fine particles that have been refined do not flow out to the subsequent stage of the activated carbon adsorption treatment facility 14, even if the reverse osmosis membrane type seawater desalination facility 18 is provided immediately downstream, blockage of the flow path is suppressed. be able to.

Further, since the activated carbon 42 does not flow downstream even if the particle size of the activated carbon 42 is small, it is possible to use powdered activated carbon having a small particle size. As a result, the adsorption rate and the amount of adsorption increase, and the activated carbon adsorption treatment equipment 14 Thus, the initial cost and running cost can be reduced.

Further, the activated carbon tank 40 is set as an upward flow, and by providing a portion where the upper cross-sectional area is larger than the lower cross-sectional area, the fine activated carbon 42 adheres to the outlet-side inorganic film 38 provided on the upper surface and is consolidated. Therefore, long-term continuous operation is possible.

Embodiment 2 of the present invention will be described with reference to FIG.

FIG. 6 is an example of the structure of the activated carbon adsorption treatment facility 14 of Example 2, and shows a cross-sectional view thereof. In the second embodiment, an inorganic film is provided on both the outlet side and the inlet side of the activated carbon tank 40 so that the activated carbon 42 does not flow out of the activated carbon tank 40. The activated carbon adsorption treatment facility inflow water 28 is an upward flow, flows in from the activated carbon adsorption treatment facility inlet 44, and coarse organic substances and fine particles are separated and removed on the lower surface of the inlet-side inorganic membrane 48. Subsequently, the incoming water comes into contact with the activated carbon 42 of the activated carbon tank 40 in an upward flow. When the particle size of the activated carbon 42 such as powdered activated carbon is small, the inside of the activated carbon tank 40 becomes a fluidized bed. Here, fine organic substances and fine particles are adsorbed and separated together with boron. Coarse organic matter and fine particles that cannot pass through the inlet-side inorganic film 48 cannot flow into the activated carbon tank 40.

Therefore, since the substance adsorbed on the activated carbon surface is reduced and the surface of the activated carbon 42 is effectively used, the period until the boron adsorption capacity reaches saturation can be lengthened, and the frequency of cleaning with the high temperature fluid 10 can be reduced.

On the upper part of the activated carbon tank 40, an outlet side inorganic membrane 38 is provided, and the activated carbon 42 is separated and removed here. When the activated carbon particles have a very small particle size and poor sedimentation, activated carbon 42 may adhere to the lower side of the outlet-side inorganic film 38 due to the upward flow and may be consolidated. In order to suppress it, it is preferable to use activated carbon that can keep the upward flow velocity low and has good sedimentation.

The activated carbon facility treated water 16 filtered by the outlet side inorganic membrane 38 flows out from the activated carbon adsorption treatment facility outlet 46.

When cleaning the activated carbon 42 of the activated carbon tank 40 with the high temperature fluid 10, the high temperature fluid 10 is allowed to pass through the activated carbon adsorption treatment facility outlet 46 in a descending manner. Since the inflow side inorganic film 48 is provided, the activated carbon 42 does not flow out of the activated carbon tank 40.

During washing, the water flow is in the opposite direction to that during normal adsorption, so that the substances adhering to the lower side of the outlet side inorganic film 38, mainly the fine activated carbon 42, are peeled off and returned to the activated carbon tank 40. As a result, the filtration performance of the outlet-side inorganic membrane 38 is recovered. Since it is the high temperature fluid 10, it has a high cleaning effect compared with a low temperature fluid.

The high-temperature fluid 10 warms the activated carbon 42, desorbs the substances adsorbed on the activated carbon 42, mainly boron, organic matter, and fine particles and moves them into the liquid. The component that has moved is originally a substance that has flowed in and passed through the inlet-side inorganic film 48 in an upward flow, and conversely, it flows through the inlet-side inorganic film 48 and flows out even in the downward flow of the cleaning process. The waste liquid generated by the cleaning is discharged from a discharge port 50 provided on the upstream side of the inflow side inorganic film 48.

It is desirable that the pore diameter of the inlet-side inorganic membrane 48 be a size that prevents the fine activated carbon 42 from flowing out. However, since there is a possibility that the organic matter adsorbed in the activated carbon tank 40 is combined with other organic substances to form a large organic substance, the organic substance of that size can be removed from the activated carbon tank 40 during cleaning. The hole diameter of 48 may be larger than the hole diameter of the outlet side inorganic membrane 38. By this downward flow, coarse organic substances and fine particles adhering to the lower surface of the inlet-side inorganic film 48 are back-washed and separated, and the filtration performance of the inlet-side inorganic film 48 is restored. Since it is the high temperature fluid 10, it has a high cleaning effect compared with a low temperature fluid.

In this embodiment, since the inlet side inorganic membrane 48 is also provided on the side of the activated carbon adsorption treatment equipment inlet 44, the seawater 12 from which coarse organic substances and fine particles are separated comes into contact with the activated carbon surface. The period until the boron adsorption capacity reaches saturation can be lengthened, and the frequency of cleaning with the high temperature fluid 10 can be reduced.

Further, the cleaning with the high temperature fluid 10 is directed from the activated carbon adsorption treatment facility outlet 46 to the activated carbon adsorption treatment facility inlet 44, and even if the cleaning is performed in the reverse direction in this way, the activated carbon 42 does not flow out and is adsorbed on the surface. The material that has been released flows out. Due to the cleaning effect of the high-temperature fluid 10, the filtration performance of the inlet side inorganic membrane 48 and the outlet side inorganic membrane 38 is also efficiently recovered.

Embodiment 3 of the present invention will be described with reference to FIG.

FIG. 7 is an example of the structure of the activated carbon adsorption treatment facility 14 of Example 3, and shows a cross-sectional view thereof. In the activated carbon adsorption treatment facility 14 of the third embodiment, the activated carbon adsorption treatment facility inflow water 28 flows as a downward flow from the activated carbon adsorption treatment facility inlet 44 into the inlet-side inorganic film 48. Coarse organic matter and particles contained in the activated carbon adsorption treatment facility inflow water 28 are separated on the upper surface of the inlet-side inorganic film 48. The activated carbon adsorption treatment facility inflow water 28 that has passed through the inflow-side inorganic membrane 48 contacts the activated carbon 42 in the activated carbon tank 40, and boron, fine organic matter, and fine particles are adsorbed and removed. Thereafter, the fine activated carbon 42 is separated at the outlet-side inorganic membrane 38, and a liquid from which coarse organic substances, particles, boron, fine organic substances, and fine particles are removed flows out as the activated carbon facility treated water 16.

When the activated carbon 42 of the activated carbon tank 40 is washed with the high temperature fluid 10, the high temperature fluid 10 is injected vertically downward from the activated carbon adsorption treatment facility outlet 46. Since the inflow side inorganic film 48 is provided, the activated carbon 42 does not flow out of the activated carbon tank 40. At the time of cleaning, the water flow is in the opposite direction to that during normal use. Therefore, substances adhering to the lower side of the outlet-side inorganic film 38, mainly fine activated carbon 42, are peeled off and returned to the activated carbon tank 40. As a result, the filtration performance of the outlet-side inorganic membrane 38 is recovered. Since it is the high temperature fluid 10, it has a high cleaning effect compared with a low temperature fluid.

The high-temperature fluid 10 heats the activated carbon 42, and the substances adsorbed on the activated carbon 42, mainly boron, organic matter, and fine particles are desorbed and move into the liquid. The components that have moved originally are substances that have flowed in and flowed up through the inlet-side inorganic film 48, and therefore flow out through the inlet-side inorganic film 48 even in the upward flow of the cleaning process.

It is desirable that the pore diameter of the inlet-side inorganic membrane 48 be a size that prevents the fine activated carbon 42 from flowing out. However, since the organic substance adsorbed in the activated carbon tank 40 may be combined with other organic substances to form a large organic substance, the pore size of the inflow-side inorganic membrane so that the organic substance of that size can be removed from the activated carbon tank 40 during cleaning. May be larger than the pore diameter of the outflow side inorganic membrane.

This upward flow causes coarse organic matter and fine particles adhering to the upper surface of the inlet-side inorganic membrane 48 to be backwashed and separated, and the filtration performance of the inlet-side inorganic membrane 48 is restored. Since it is the high temperature fluid 10, it has a high cleaning effect compared with a low temperature fluid.

6, unlike the structure shown in FIG. 6, in the activated carbon adsorption treatment facility 14 of this embodiment, the high temperature fluid 10 flows in an upward flow with respect to the inlet-side inorganic film 48 during cleaning. By maintaining the flow velocity of the upward flow low and using the activated carbon 42 having good sedimentation properties, it is possible to suppress a decrease in the filtration performance of the inlet-side inorganic membrane 48 during cleaning.

According to the present embodiment, since the high temperature fluid 10 is applied in an upward flow to the inlet-side inorganic film 48 at the time of cleaning, it is possible to suppress a decrease in filtration resistance at the time of cleaning, and shorten the cleaning time. It is possible to reduce clogging of the inlet side inorganic film 48.

DESCRIPTION OF SYMBOLS 10 High temperature fluid 12 Seawater 14 Activated carbon adsorption treatment equipment 16 Activated carbon equipment treated water 18 Reverse osmosis membrane type seawater desalination equipment 20 Fresh water 22 High temperature fluid injection equipment 24 Waste liquid 26 Concentrated sea water 28 Activated carbon adsorption treatment equipment inflow water 30 Water quality measurement value 32 Cleaning trigger Calculation unit 34 Cleaning trigger signal 36 Water quality measuring device 38 Outlet side inorganic membrane 40 Activated carbon tank 42 Activated carbon 44 Activated carbon adsorption treatment facility inlet 46 Activated carbon adsorption treatment facility outlet 48 Inlet side inorganic membrane 50 Outlet

Claims

A reverse osmosis membrane type seawater desalination facility using a reverse osmosis membrane, an activated carbon adsorption treatment facility provided upstream or downstream of the reverse osmosis membrane type seawater desalination facility, and a high temperature fluid is injected into the activated carbon adsorption treatment facility And a high-temperature fluid injection facility for cleaning activated carbon, and a seawater desalination system.
A reverse osmosis membrane type seawater desalination facility using a reverse osmosis membrane, an activated carbon adsorption treatment facility provided upstream or downstream of the reverse osmosis membrane type seawater desalination facility, and a downstream side of the activated carbon adsorption treatment facility Water quality measuring device, a cleaning trigger calculation unit for calculating the cleaning time of the activated carbon adsorption treatment facility based on a water quality measurement value output from the water quality measurement device, and a cleaning trigger signal output from the cleaning trigger calculation unit And a high temperature fluid injection facility for injecting a high temperature fluid into the activated carbon adsorption treatment facility.
The seawater desalination system according to claim 2, wherein the component measured by the water quality measuring device includes at least one of boron, adenosine triphosphate, and ultraviolet absorbance.
The activated carbon adsorption treatment facility comprises an activated carbon tank in which activated carbon is provided, and an outlet-side inorganic membrane having a pore diameter formed so that activated carbon provided at the outlet of the activated carbon tank does not flow out. The seawater desalination system according to any one of Items 1 to 3.
An exhaust port for discharging cleaning waste liquid from the activated carbon tank to the outside during the activated carbon cleaning of the activated carbon tank is provided upstream from the inlet of the activated carbon adsorption treatment equipment so that the activated carbon does not flow out to the inlet of the activated carbon adsorption treatment equipment. The seawater desalination system according to claim 4, further comprising an inlet-side inorganic membrane having a formed pore diameter.
The seawater desalination system according to claim 5, wherein powdered activated carbon is used as the activated carbon in the activated carbon tank, and the water flow during adsorption is an upward flow.
The seawater desalination system according to claim 6, wherein the high-temperature fluid for cleaning the activated carbon is structured to pass through the outlet-side inorganic membrane in a downward flow.
Powdered activated carbon is used as the activated carbon in the activated carbon tank, and the structure is configured to flow downward from the inlet-side inorganic membrane of the activated carbon adsorption treatment facility to the activated carbon tank, and from the activated carbon tank of the activated carbon adsorption treatment facility to the outlet. The high temperature fluid for cleaning the activated carbon is configured to flow down the inorganic membrane on the outlet side, and the high temperature fluid for cleaning the activated carbon is on the inlet side. The seawater desalination system according to claim 5, wherein the inorganic membrane is structured to pass upward.