WO2015005186A1

WO2015005186A1 - Water treatment method and water treatment device

Info

Publication number: WO2015005186A1
Application number: PCT/JP2014/067610
Authority: WO
Inventors: 長谷川　進; 三浦　雅彦; 島田　光重; 草介小野田; 秀人松山; 太郎三好; 政宏安川; 智輝高橋
Original assignee: 株式会社神鋼環境ソリューション; 国立大学法人神戸大学
Priority date: 2013-07-08
Filing date: 2014-07-02
Publication date: 2015-01-15
Also published as: JP2015016392A

Abstract

A water treatment method provided with an anaerobic treatment step for anaerobically treating water to be treated containing organic matter is characterized by being further provided with a concentration step for concentrating the water to be treated before the anaerobic treatment by bringing a draw solution formed to produce osmotic pressure by penetration of moisture from the water to be treated through a semipermeable membrane and the water to be processed into contact with each other with the semipermeable membrane therebetween, and supplying the water to be treated after the concentration step to the anaerobic treatment step to perform the anaerobic treatment.

Description

Water treatment method and water treatment apparatus

Cross-reference of related applications

This application claims priority based on Japanese Patent Application No. 2013-142998 and is incorporated herein by reference.

The present invention relates to a water treatment method and a water treatment apparatus for anaerobically treating water to be treated containing organic matter.

Various methods have been proposed as water treatment methods for treating treated water containing organic substances such as sewage, river water, and seawater. For example, in the aerobic activated sludge method, the water to be treated is mixed with the activated sludge, so that the organic matter in the treated water is aerobically decomposed by the action of aerobic microorganisms in the activated sludge. To be removed as carbon dioxide. For this reason, in such an activated sludge method, in order to maintain the activity of microorganisms in the activated sludge, aeration of mixed water in which treated water and activated sludge are mixed is performed.

Also, anaerobic treatment is applied to water to be treated that is relatively unsuitable for treatment by the aerobic activated sludge method, such as wastewater from factories such as food processing plants and pulp factories. Has been proposed. In such a method, the sludge containing anaerobic bacteria and the water to be treated are mixed, so that the organic matter in the water to be treated is decomposed anaerobically by the action of the anaerobic bacteria in the sludge. It is removed as methane gas. In such anaerobic treatment, aeration of mixed water in which treated water and sludge are mixed is usually not performed while organic matter is decomposed.

Incidentally, in addition to the above water treatment, in recent years, a technique for desalinating seawater has been proposed for the purpose of securing drinking water and the like. For example, a draw liquid configured to receive permeation of water from seawater by osmotic pressure when it comes into contact with seawater through a semipermeable membrane, and the draw liquid and seawater are separated from the semipermeable membrane. A method has been proposed in which fresh water is obtained by drawing water from the seawater to the draw liquid side and separating the water from the draw liquid containing the water from the seawater (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-183492

However, since the aerobic activated sludge method described above requires equipment such as a blower when aeration is performed, power is required to operate it, and energy consumption is relatively large. On the other hand, anaerobic treatment does not require aeration as in the activated sludge method, so that energy consumption can be reduced, but for treated water with low organic matter content (ie, low BOD). It is difficult to apply because the activity of anaerobic bacteria becomes unstable. Even if it is applied, the energy recovery rate as methane gas is low, which is not practical.

Therefore, the present invention is a water treatment method that can apply anaerobic treatment to treated water with low organic matter content (that is, low BOD) and efficiently recover methane gas, Another object is to provide a water treatment device.

A water treatment method according to the present invention is a water treatment method for treating water to be treated containing an organic substance, and is configured such that moisture is permeated from the water to be treated by osmotic pressure through a semipermeable membrane. And a water to be treated are brought into contact with each other through a semipermeable membrane, and a concentration step for concentrating the water to be treated and an anaerobic treatment step for performing an anaerobic treatment of the water to be treated after the concentration step are performed. .

The draw liquid preferably contains seawater or a liquid containing magnetic fine particles.

A water treatment apparatus according to the present invention is a water treatment apparatus for treating water to be treated containing an organic substance, a concentration apparatus for concentrating the water to be treated, and an anaerobic treatment of the water to be treated that has been concentrated by the concentration apparatus. An anaerobic treatment tank for performing the treatment, and the concentrating device includes a draw liquid supply unit to which a draw liquid configured to allow moisture to permeate from the treated water by osmotic pressure through the semipermeable membrane and the treated water A treated water supply unit that is supplied, and configured so that the treated water supplied to the treated water supply unit and the draw liquid supplied to the draw liquid supply unit are in contact with each other through the semipermeable membrane. It is characterized by that.

Schematic which showed the water treatment apparatus which concerns on 1st embodiment. The schematic diagram which showed the concentration apparatus of the water treatment apparatus which concerns on the same embodiment. The schematic diagram which showed the concentration apparatus of the water treatment apparatus which concerns on 2nd embodiment. The schematic diagram which showed the concentration apparatus of the water treatment apparatus which concerns on other embodiment. Furthermore, the schematic which showed the water treatment apparatus which concerns on other embodiment.

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

The water treatment apparatus 1 according to the present embodiment is configured such that water to be treated containing organic matter is subjected to anaerobic treatment. Specifically, the water treatment apparatus 1 includes an anaerobic treatment tank 2 that is supplied with treated water and is anaerobically treated, and a BOD adjustment unit 3 that adjusts the BOD of the treated water supplied to the anaerobic treatment tank 2. And a sludge separation unit 4 for separating sludge from the water to be treated discharged from the anaerobic treatment tank 2.

The water to be treated is not particularly limited, but water having a relatively low content of organic matter (ie, low BOD) such as sewage, river water, seawater, etc. is applied. Specifically, the BOD of the water to be treated may be 1000 mg / L or more, may be less than 1000 mg / L, and may be 200 mg / L or less.

The anaerobic treatment tank 2 is not particularly limited. For example, the anaerobic treatment tank 2 is configured to be capable of decomposing organic matter in the water to be treated by a methane fermentation method. The anaerobic treatment tank 2 is supplied with sludge containing anaerobic bacteria that decomposes organic matter anaerobically (hereinafter also referred to as anaerobic sludge). In other words, the water to be treated and the anaerobic sludge are mixed to form a mixed solution. The BOD to be treated supplied to the anaerobic treatment tank 2 is not particularly limited and is preferably 1000 mg / L or more, more preferably 2000 mg / L or more.

The BOD adjustment unit 3 is configured to be able to concentrate the water to be treated so that the water to be treated before being supplied to the anaerobic treatment tank 2 becomes a predetermined BOD. Specifically, the BOD adjustment unit 3 includes a pretreatment unit 3a that removes impurities contained in the water to be treated (raw water) and a concentrator 3b that concentrates the water to be treated. In the pretreatment unit 3a, the temperature, pH, flow rate, and the like of the water to be treated may be adjusted along with the removal of impurities, and the nutrient components necessary for the decomposition of the organic matter in the anaerobic treatment tank 2 are contained in the water to be treated. It may be added. Examples of added nutrients include trace essential metals such as nickel and cobalt.

As shown in FIG. 2, the concentrating device 3b includes an internal space partitioned by a semipermeable membrane 3c. Thereby, the concentration apparatus 3b was comprised so that a water | moisture content might permeate | transmit from a to-be-processed water by osmotic pressure through the to-be-processed water supply part 3d which has an internal space to which to-be-processed water is supplied, and the semipermeable membrane 3c. And a draw liquid supply unit 3e having an internal space to which the draw liquid is supplied. And the concentration apparatus 3b is comprised so that the to-be-processed water and draw liquid which are supplied may contact via the semipermeable membrane 3c. That is, the concentrating device 3b of this embodiment is configured such that the internal space of the treated water supply unit 3d and the internal space of the draw liquid supply unit 3e are provided side by side through the semipermeable membrane 3c (outside tank type ). The semipermeable membrane 3c is not particularly limited, and a general forward osmosis membrane or reverse osmosis membrane can be used.

The treated water supply unit 3d is fluidly connected to the anaerobic treatment tank 2. Specifically, the treated water supply unit 3d includes a treated water introduction unit 31d that is fluidly connected to the pretreatment unit 3a and introduces treated water into the treated water supply unit 3d, and an anaerobic treatment tank 2. And a to-be-treated water discharge part 32d for discharging the to-be-treated water from the inside of the to-be-treated water supply part 3d.

The draw liquid supply unit 3e is fluidly connected to a draw liquid supply source to introduce the draw liquid into the draw liquid supply unit 3e, and is fluidly connected to a discharge destination of the draw liquid. And a draw liquid discharge part 32e for discharging the draw liquid from the draw liquid supply part 3e.

The draw liquid is not particularly limited, and seawater is used in this embodiment. That is, in this embodiment, the ocean S can be used as the supply source and the discharge destination of the draw liquid.

The sludge separation unit 4 is configured to be able to separate the anaerobic sludge from the treated water treated in the anaerobic treatment tank 2. Specifically, since the treated water discharged from the anaerobic treatment tank 2 contains anaerobic sludge that has flowed out of the anaerobic treatment tank 2, the sludge separation unit 4 separates the anaerobic sludge from the anaerobic treated water. In addition, the separated anaerobic sludge can be returned to the anaerobic treatment tank 2.

Next, a method for treating water to be treated using the water treatment apparatus 1 configured as described above will be described.

The treated water (raw water) is supplied to the pretreatment unit 3a to remove impurities. In addition, the water to be treated is adjusted in temperature, pH, flow rate, and the like in the pretreatment unit 3a as necessary, thereby suppressing fouling. The treated water treated by the pretreatment unit 3a is supplied to the concentrating device 3b (specifically, the treated water supply unit 3d). Along with this, seawater is supplied as the draw liquid to the draw liquid supply unit 3e.

In this way, the water to be treated is supplied to the treated water supply unit 3d and the draw liquid is supplied to the draw liquid supply unit 3e, so that the water to be treated and seawater in the concentrator 3b pass through the semipermeable membrane 3c. The water to be treated permeates through the semipermeable membrane 3c and permeates into the seawater side (forward osmosis). Thereby, in the to-be-processed water supply part 3d, to-be-processed water is concentrated and BOD of to-be-processed water rises (concentration process). On the other hand, in the draw liquid supply unit 3e, seawater is diluted by receiving moisture permeation from the water to be treated.

In this embodiment, the to-be-processed water discharge part 32d and the draw liquid discharge part 32e are provided in the vicinity of the semipermeable membrane 3c, and the to-be-processed water and the draw liquid are supplied at an appropriate flow rate to the concentrator 3b. Water to be treated (ie, concentrated water to be treated) and seawater (ie, diluted seawater) in the vicinity of the semipermeable membrane 3c are quickly discharged to the outside of the concentration device 3b. Thereby, it is prevented that to-be-processed water and seawater remain in the vicinity of the semipermeable membrane 3c and the permeation efficiency is lowered.

The treated water discharged from the treated water supply unit 3d is supplied to the anaerobic treatment tank 2. In the anaerobic treatment tank 2, the water to be treated whose BOD is adjusted by the concentrator 3b and anaerobic sludge are mixed and maintained under conditions suitable for anaerobic treatment (methane fermentation, specifically, pH, temperature, etc.). Is done. Thereby, the organic substance in to-be-processed water is anaerobically treated and decomposed | disassembled, and methane gas is produced | generated (anaerobic treatment process). The generated methane gas is separated from the water to be treated and discharged from the anaerobic treatment tank 2. The methane gas discharged from the anaerobic treatment tank 2 can be recovered and used as fuel or raw material.

On the other hand, the water to be treated from which methane gas has been separated (that is, the water to be treated from which organic substances have been removed) is discharged from the anaerobic treatment tank 2 and supplied to the sludge separation unit 4. In the sludge separation unit 4, anaerobic sludge is separated from the water to be treated, and at least a part thereof is returned to the anaerobic treatment tank 2. The treated water separated from the anaerobic sludge in the sludge separation unit 4 can be released into the environment without further water treatment if it is water quality that can be released into the environment such as rivers and oceans. Further, the water may be discharged into the environment after being treated to have a desired water quality. The seawater discharged from the draw liquid supply unit 3e (that is, seawater diluted with water from the water to be treated) is discharged to the ocean S.

As described above, according to the water treatment method and the water treatment apparatus according to the present invention, anaerobic treatment can be applied even to water to be treated with a small amount of organic matter (that is, low BOD). Methane gas can be efficiently recovered.

That is, in the concentration step, moisture permeates through the semipermeable membrane from the treated water to the draw liquid side by osmotic pressure (forward osmosis). Thereby, the amount of water to be treated can be reduced and the water to be treated can be concentrated without using power for applying pressure or reducing pressure as in reverse osmosis. For this reason, even if the water to be treated has a low organic content (ie, low BOD) and is difficult to apply anaerobic treatment, it can be concentrated and supplied to the anaerobic treatment step in a state where the BOD is increased. Anaerobic treatment can be applied.

In other words, since the anaerobic treatment can be applied even to the treated water that is conventionally treated by the aerobic activated sludge method (that is, it is difficult to apply the anaerobic treatment), the activated sludge method with aeration. As a result, the power is reduced as compared with the case of applying water and energy consumption in the treatment of the water to be treated can be suppressed. Moreover, in the activated sludge method, since the carbon component removed as carbon dioxide can be recovered as methane gas and used as fuel or raw material, the emission of carbon dioxide can be suppressed.

The water treatment device 1 includes the concentrating device 3b, so that the water to be treated supplied to the treated water supply unit 3d and the draw liquid supplied to the draw liquid supply unit 3e are passed through the semipermeable membrane 3c. Because of contact, moisture permeates from the treated water to the draw liquid side through the semipermeable membrane 3c by the osmotic pressure (forward osmosis). Thereby, the amount of water to be treated can be reduced and the water to be treated can be concentrated without using power for applying pressure or reducing pressure as in reverse osmosis. And the to-be-processed water supply part 3d and the anaerobic treatment tank 2 are fluidly connected, The concentrated to-be-processed water is supplied to the anaerobic treatment tank 2, and an anaerobic process is performed. For this reason, even if the water to be treated is low in content of organic matter (that is, BOD is low) and it is difficult to apply anaerobic treatment, it can be supplied to the anaerobic treatment tank 2 in a state where the BOD is increased by concentration. Anaerobic treatment can be applied (anaerobic treatment step).

That is, conventionally, since the anaerobic treatment can be applied even to the treated water that is treated by the activated sludge method (that is, it is difficult to apply the anaerobic treatment), the activated sludge method with aeration is applied. However, the power is reduced and the consumption of energy in the treatment of the water to be treated can be suppressed. Moreover, since the carbon component removed as carbon dioxide in the activated sludge method can be recovered as methane gas and used as fuel or raw material, the discharge of carbon dioxide can be suppressed.

こと Since the draw liquid is composed of seawater, the draw liquid can be easily released into the environment. Specifically, when the draw liquid is seawater, only moisture moves from the treated water to the draw liquid side, and the other solutes are generally concentrated by the semipermeable membrane to prevent movement to the draw liquid side. It remains on the side (that is, the treated water side). For this reason, the draw liquid in which moisture has permeated from the water to be treated is obtained by diluting seawater. For this reason, there is no need to perform a process for draining into the environment (for example, pH adjustment or removal of unnecessary components) on the draw liquid after the concentration process, and the draw liquid after the concentration process is directly sent to the ocean. It becomes possible to release.

That is, when the draw liquid is composed of seawater, the draw liquid in which moisture has permeated from the water to be treated is obtained by diluting seawater. For this reason, it is not necessary to perform processing for draining into the environment (for example, pH adjustment or removal of unnecessary components) with respect to the draw liquid (after the concentration step) discharged from the concentration device 3b. It becomes possible to discharge the draw liquid (after the concentration step) discharged from the apparatus 3b directly to the ocean S.

<Second embodiment>
Next, a second embodiment of the present invention will be described with reference to FIG. Compared with the water treatment method and the water treatment apparatus 1 according to the first embodiment, the water treatment method and the water treatment apparatus 1 according to the second embodiment mainly differ in the configuration of the concentration apparatus 300b. Specifically, the concentrating device 300b is different from the concentrating device 3b according to the first embodiment mainly in the configurations of the treated water supply unit 300d and the draw liquid supply unit 300e. Therefore, below, it demonstrates centering on a different point from 1st embodiment, and abbreviate | omits description by attaching | subjecting the same code | symbol to the same structure.

The concentrating device 300b is configured such that the treated water supply unit 300d is disposed in the internal space for supplying the draw liquid in the draw liquid supply unit 300e. The treated water supply unit 300d includes an internal space for supplying the treated water, and the internal space is partitioned from the internal space of the draw liquid supply unit 300e by the semipermeable membrane 3c. That is, the treated water supply unit 300d is at least partially configured from the semipermeable membrane 3c, and at least the portion configured from the semipermeable membrane 3c is located in the internal space of the draw liquid supply unit 300e. The draw liquid supply unit 300e does not include the draw liquid discharge unit 32e unlike the outside tank type.

In the concentrating device 300b having such a configuration, the draw water is supplied to the draw liquid supply unit 300e (specifically, from the equipment X that supplies the draw liquid), so that the treated water supply unit 300d (specifically, , A portion constituted by the semipermeable membrane 3c) is immersed in the draw liquid (immersion type). And by supplying the to-be-processed water to the to-be-processed water supply part 300d, it will be in the state which the to-be-processed water and the draw liquid contacted via the semipermeable membrane 3c, and the water osmosis | permeation from a to-be-processed water to a draw liquid Occurs. According to such a configuration, the to-be-treated water supply unit 300d is immersed in the draw liquid, so that moisture that has permeated into the draw liquid side is easily diffused into the draw liquid supply unit 300e. For this reason, in the vicinity of the semipermeable membrane 3c, the difference between the concentration on the treated water side and the concentration on the draw liquid side is reduced and it is prevented that the osmotic pressure does not easily occur. Thereby, since the penetration | infiltration of the water | moisture content from the to-be-processed water to a draw liquid is performed efficiently, to-be-processed water can be concentrated efficiently. The draw liquid in the draw liquid supply unit 300e is discharged from the draw liquid supply unit 300e by overflowing. Further, in order to efficiently make contact between the draw liquid and the water to be treated through the semipermeable membrane 3c (in other words, contact with the semipermeable membrane 3c), the draw liquid is used using a stirring device or the like (not shown). The inside of the supply unit 300e may be agitated to adjust the flow rate (the amount of discharge of the draw liquid from the draw liquid supply unit 300e).

In addition, the water treatment method and the water treatment apparatus according to the present invention are not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. Further, the configurations and methods of the plurality of embodiments described above may be arbitrarily adopted and combined (even if the configurations and methods according to one embodiment are applied to the configurations and methods according to other embodiments). Of course, it is of course possible to arbitrarily select configurations, methods, and the like according to various modifications described below and employ them in the configurations, methods, and the like according to the above-described embodiments.

For example, in the concentration apparatus 3b of the first embodiment, the flow direction of the water to be treated and the draw liquid is configured to be a parallel flow, but is not limited to this, for example, a reverse flow is performed. May be configured. Specifically, the treated water is introduced from the treated water introduction part 31d (or treated water discharge part 32d) to the treated water supply part 3d, and the treated water discharge part 32d (or treated water introduction part 31d). And the draw liquid is introduced into the draw liquid supply part 3e from the draw liquid discharge part 32e (or the draw liquid introduction part 31e) and discharged from the draw liquid introduction part 31e (or the draw liquid discharge part 32e). Therefore, it may be configured to have a reverse flow.

In the second embodiment, the drawing liquid is discharged from the drawing liquid supply unit 300e when the drawing liquid overflows, but the invention is not limited to this, and the drawing liquid supply unit 300e discharges the drawing liquid. A portion 32e may be provided, and the draw liquid may be discharged from the draw liquid discharge portion 32e.

Moreover, it may replace with the concentration apparatus 3b of the said embodiment, and the concentration apparatus 301b of a structure shown in FIG. 4 may be employ | adopted. Compared with the

concentration apparatuses

3b and 300b according to the above embodiment, the concentration apparatus 301b mainly differs in the configuration of the treated water supply unit 301d and the draw liquid supply unit 301e. Accordingly, the following description will be focused on differences from the above-described embodiment, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 4, the concentrator 301b is configured by arranging a plurality of draw liquid supply units 301e so as to penetrate the treated water supply unit 301d. The draw liquid supply unit 301e has a tubular shape extending in one direction. And the draw liquid supply part 301e is formed using the semipermeable membrane 3c in the area located in the internal space of the treated water supply part 301d, and the draw liquid introduction part 31e and the draw liquid discharge part are formed in the area outside the internal space. 32e is formed.

In the concentrating device 301b having such a configuration, the internal space of the draw liquid supply unit 301e is filled with the draw liquid, and the entire region formed by the semipermeable membrane 3c in the draw liquid supply unit 301e is immersed in the water to be treated. The treated water is supplied to the treated water supply unit 301d. Thereby, the to-be-processed water and the draw liquid will be in the state which contacted through the semipermeable membrane 3c.

In the above embodiment, seawater is used as the draw liquid, but it is not particularly limited as long as it is configured so that moisture from the water to be treated permeates by osmotic pressure. For example, as the draw liquid, a liquid containing any one of an inorganic salt, a sugar, a water-soluble low-boiling gas, a magnetic fine particle, an organic solvent and the like as a solute can be used. When the draw liquid is composed of a liquid containing magnetic fine particles, the magnetic fine particles can be separated from the draw liquid by magnetic force. For this reason, discharge | release to an environment can be easily performed by performing the process which removes magnetic body fine particles with respect to the draw liquid after a concentration process. Furthermore, seawater and other solutes may be combined as the draw liquid, for example, seawater and magnetic fine particles. When these draw liquids are used, it is necessary to remove the solute from the used draw liquid since it cannot be directly released into the environment after use, like seawater. For this reason, it is preferable to select a solute of the draw liquid that can be easily separated from moisture. In such a case, the solute separated from the draw liquid can be recovered and used again as a component of the draw liquid.

Moreover, in the said embodiment, although the to-be-processed water discharged | emitted from the concentration apparatus 3b is supplied to the anaerobic processing tank 2, it is not limited to this, The to-be-processed water concentrated with the concentration apparatus 3b is It may be concentrated again. For example, the water to be treated may be concentrated stepwise by using a plurality of concentrating devices 3b or using a concentrating device different from the concentrating device 3b on at least one of the front and rear sides of the concentrating device 3b.

In addition, the pretreatment unit 3a in the above embodiment is not particularly limited. For example, as shown in FIG. 5, sediment and the like are precipitated and separated from water to be treated (specifically, sewage and the like). The quality of water to be treated is adjusted using a sedimentation basin 30a, a sedimentation basin 31a that separates and removes precipitating organic substances in the water to be treated by gravity settling using a specific gravity difference, and a microfiltration membrane or an ultrafiltration membrane. You may provide the adjustment tank 32a. Moreover, as the sludge separation part 4 in the water treatment apparatus 1, while using what is equipped with a nanofiltration membrane, while anaerobic sludge is isolate | separated from anaerobic treated water in such a sludge separation part 4, the separated anaerobic sludge is You may be comprised so that return to the anaerobic treatment tank 2 is possible. In the sludge separation unit 4, a microfiltration membrane or an ultrafiltration membrane may be applied in addition to the nanofiltration membrane.

Further, as a configuration of the water treatment apparatus 1, a final treatment unit 5 may be provided which filters the water to be treated separated from the anaerobic sludge by the sludge separation unit 4 through a semipermeable membrane. The final treatment unit 5 is configured such that the water to be treated from which the anaerobic sludge has been separated and seawater come into contact with each other through the semipermeable membrane, so that moisture permeates from the water to be treated to the seawater side. . Thereby, the dissolved component in to-be-processed water is removed from to-be-processed water. The removed dissolved components are returned to the anaerobic treatment tank 2 and the final treatment unit 5, and the water to be treated treated in the final treatment unit 5 is discharged into the environment.

Moreover, in the water treatment apparatus in each of the above embodiments, in order to stabilize the anaerobic treatment by suppressing fluctuations in the organic matter concentration of the water to be treated supplied to the anaerobic treatment tank 2, a TDS meter or a conductive material is provided after the concentrator 3b. A rate meter, TOC meter, etc. may be installed. For example, by checking the correlation between TDS and conductivity and organic matter (COD and BOD), and determining the set TDS and conductivity, in the case of concentrated water to be treated, the concentration rate is lowered and the water to be treated is thin. Increases the concentration rate. Thereby, the concentration rate of the concentration apparatus 3b can be controlled, and the organic substance density | concentration of the to-be-processed water sent to the anaerobic processing tank 2 can be maintained at the desired density | concentration.

DESCRIPTION OF SYMBOLS 1 ... Water treatment apparatus, 2 ... Anaerobic treatment tank, 3 ... BOD adjustment part, 3a ... Pretreatment part, 3b, 300b, 301b ... Concentration apparatus, 3c ... Semipermeable membrane, 3d, 300d, 301d ... Water supply part to be treated 31d ... treated water introduction part, 32d ... treated water discharge part, 3e, 300e, 301e ... draw liquid supply part, 31e ... draw liquid introduction part, 32e ... draw liquid discharge part, 4 ... sludge separation part, S ... Ocean

Claims

A water treatment method for treating water to be treated containing organic matter,
A concentration step of concentrating the water to be treated by bringing the water to be treated and the water to be treated into contact with each other through the semipermeable membrane through the semipermeable membrane, the water being permeated from the water to be treated by osmotic pressure;
An anaerobic treatment step of performing anaerobic treatment of water to be treated after the concentration step.
The water treatment method according to claim 1, wherein the draw liquid contains seawater or a liquid containing magnetic fine particles.
A water treatment device for treating water to be treated containing organic matter,
A concentration device for concentration of the water to be treated;
An anaerobic treatment tank for anaerobic treatment of the water to be treated concentrated by the concentrator,
The concentrator includes a draw liquid supply unit to which a draw liquid is configured to permeate water from the treated water by osmotic pressure through a semipermeable membrane, and a treated water supply unit to which the treated water is supplied. The water treatment apparatus is characterized in that the water to be treated supplied to the treated water supply unit and the draw liquid supplied to the draw liquid supply unit are in contact with each other through a semipermeable membrane.
The water treatment apparatus according to claim 3, wherein the draw liquid includes seawater or a liquid containing magnetic fine particles.