Water treatment apparatus and water treatment method

Abstract

To provide a water treatment apparatus and a water treatment method capable of reducing the frequency of maintenance required for replacing consumables.SOLUTION: A water treatment apparatus 1A for treating water to be treated containing organic matter and ammoniacal nitrogen includes an ion exchange resin tower 2 filled with anion exchange resin 3, in which a microbial layer is formed on the surface of the anion exchange resin 3 within the ion exchange resin tower 2. According to one example, the ion exchange resin tower 2 may additionally be filled with cation exchange resin in addition to the anion exchange resin 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water treatment device and a water treatment method. [Background technology]

[0002] Patent Documents 1 and 2 disclose the use of activated carbon carrying microorganisms to treat water containing organic matter and ammonia nitrogen. Activated carbon essentially functions as an adsorbent for impurities such as organic matter. When water treatment is carried out using activated carbon carrying microorganisms such as nitrifying bacteria, the action of the microorganisms can be utilized to oxidize the ammonia nitrogen in the water. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-23961 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-154064 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when water treatment is performed using activated carbon as an adsorbent as in Patent Documents 1 and 2, it is common to replace the activated carbon with new one when the impurity adsorption capacity of the activated carbon is exceeded, which results in frequent maintenance for replacing consumables after water treatment.

[0005] The present invention provides a water treatment device and a water treatment method that can reduce the number of maintenance operations required for replacing consumables. [Means for solving the problem]

[0006] The present invention has the following aspects. [1] A water treatment device for treating water containing organic matter and ammonia nitrogen, an ion exchange resin tower packed with an anion exchange resin; A water treatment device, wherein a microbial layer is formed on the surface of the anion exchange resin in the ion exchange resin tower. [2] The water treatment device has a plurality of the ion exchange resin towers, The water treatment device according to [1], wherein at least one of the plurality of ion exchange resin towers is regenerated while the remaining ion exchange resin towers are used to treat the water to be treated. [3] The water treatment device has a plurality of the ion exchange resin towers, a water-to-be-treated pipe for supplying the water to be treated to each of the primary sides of the plurality of ion exchange resin towers; a treated water pipe for extracting treated water flowing out from each of the secondary sides of the plurality of ion exchange resin towers; a connecting pipe that supplies the treated water flowing out from the secondary side of at least one of the plurality of ion exchange resin towers to the primary side of the other ion exchange resin towers; The water treatment device according to [1] or [2], further comprising: [4] The water treatment device has a plurality of the ion exchange resin towers, a reclaimed water pipe for supplying reclaimed water to the primary sides of the plurality of ion exchange resin towers; a wastewater pipe for discharging wastewater generated when regenerating the plurality of ion exchange resin towers; The water treatment device according to any one of [1] to [3], further comprising: [5] The water treatment device according to any one of [1] to [4], wherein at least one of the plurality of ion exchange resin towers further contains a cation exchange resin in addition to the anion exchange resin, and has a mixed bed which is a mixture of the anion exchange resin and the cation exchange resin. [6] Among the plurality of ion exchange resin towers, at least one tower is further packed with a cation exchange resin in addition to the upper or lower layer of the anion exchange resin, The water treatment device according to any one of [1] to [4], which has a multi-layer structure in which the anion exchange resin layer and the cation exchange resin layer are stacked. [7] The water treatment device according to [5] or [6], wherein the volume ratio of the cation exchange resin to the anion exchange resin (cation exchange resin / anion exchange resin) is 2 / 1 to 10 / 1. [8] The water treatment device according to any one of [1] to [7], wherein the microbial layer contains nitrifying bacteria.

[0007] [9] A water treatment method for treating water containing organic matter and ammonia nitrogen, comprising: A water treatment method comprising passing the water to be treated through an ion exchange resin tower packed with an anion exchange resin having a microbial layer formed on the surface thereof.

[10] The water treatment method according to [9], further comprising growing microorganisms in the microbial layer to form the microbial layer.

[11] The water treatment method according to [9] or

[10] , further comprising regenerating the anion exchange resin in the ion exchange resin tower when the TOC concentration of the treated water flowing out from the secondary side of the ion exchange resin tower exceeds 30 to 50% of the TOC concentration of the water to be treated.

[12] The ion exchange resin tower is further filled with a cation exchange resin in addition to the anion exchange resin, The water treatment method according to any one of [9] to

[11] , wherein the ion exchange resin tower has a mixed bed which is a mixture of the anion exchange resin and the cation exchange resin.

[13] The ion exchange resin tower is further filled with a cation exchange resin in addition to the anion exchange resin, The water treatment method according to any one of [9] to

[12] , wherein the ion exchange resin tower has a multi-layer structure in which a layer of the anion exchange resin and a layer of the cation exchange resin are stacked.

[14] The water treatment method according to

[12] or

[13] , wherein the volume ratio of the cation exchange resin to the anion exchange resin (cation exchange resin / anion exchange resin) is 2 / 1 to 10 / 1.

[15] The water treatment method according to any one of

[12] to

[14] , further comprising regenerating the cation exchange resin in the ion exchange resin tower when the ammonia nitrogen concentration in the treated water flowing out from the secondary side of the ion exchange resin tower exceeds 30 to 50% of the ammonia nitrogen concentration in the water to be treated.

[16] The water treatment method according to any one of [9] to

[15] , wherein the microbial layer contains nitrifying bacteria. [Effects of the Invention]

[0008] According to the present invention, the number of maintenance operations required for replacing consumables can be reduced. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of a water treatment device. [Figure 2] FIG. 2 is a schematic diagram showing another example of the water treatment device. [Figure 3] FIG. 3 is a schematic diagram showing another example of the configuration of a water treatment device. [Figure 4] FIG. 4 is a schematic diagram showing another example of the configuration of a water treatment device. DETAILED DESCRIPTION OF THE INVENTION

[0010] The meanings of the terms are as follows: The "primary side" refers to the upstream side in the direction of flow of the water to be treated and the treated water. The "secondary side" refers to the downstream side in the direction of flow of the water to be treated and the treated water. Therefore, the water to be treated and the treated water flow from the primary side to the secondary side. The symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0011] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. However, the following description is for representative examples, and the present invention is not limited to the following description. The dimensional ratios in the drawings are for the convenience of explanation and may differ from the actual ones. In the following drawings, the same components are indicated by the same reference numerals, and descriptions of overlapping components may be omitted.

[0012] [First embodiment] The water treatment device 1A shown in FIG. 1 is for treating water containing ammonia nitrogen. The water to be treated is not particularly limited as long as it contains organic matter and ammonia nitrogen. Examples of the water to be treated include raw water such as groundwater, well water, lake water, river water, industrial water, sewage, and wastewater. However, the raw water is not limited to these examples. The water to be treated may also be water that has been subjected to some kind of treatment on the raw water.

[0013] Examples of the main organic components in the water to be treated include humic acid and fulvic acid. However, the water to be treated may contain organic matter other than these exemplified components. The TOC concentration of the water to be treated is not particularly limited, but is preferably 1 to 5 mg / L, and more preferably 1 to 3 mg / L. If the TOC concentration of the water to be treated is within the above numerical range, the technical significance of applying the present invention is greater, and this is preferable.

[0014] The ammonia nitrogen concentration of the water to be treated is not particularly limited, but is preferably 0.1 to 5 mg / L, more preferably 0.5 to 2 mg / L. If the ammonia nitrogen concentration is within the above range, the technical significance of applying the present invention is greater, and therefore it is preferable.

[0015] In addition to ammonia nitrogen and organic matter, the water to be treated may further contain impurities such as anions such as carbonate ions, bicarbonate ions, nitrate ions, sulfate ions, and chloride ions, cations such as iron ions, manganese ions, calcium ions, and magnesium ions, microorganisms such as nitrifying bacteria, suspended solids, and turbidity. However, the components of the water to be treated are not limited to these.

[0016] A water treatment device 1A shown in FIG. 1 includes an ion-exchange resin tower 2 filled with an anion-exchange resin 3, a pipe 4 for water to be treated, and a pipe 5 for treated water.

[0017] The untreated water pipe 4 is used to supply the untreated water to the primary side of the ion exchange resin tower 2. A first end (not shown) of the untreated water pipe 4 is connected to a supply source of the untreated water such as a raw water tank, and a second end of the untreated water pipe 4 is connected to the top of the ion exchange resin tower 2. Although not shown in Fig. 1, the ion exchange resin tower 2 has a dispersion mechanism for dispersing the untreated water at the upper side inside the ion exchange resin tower 2. As the dispersion mechanism, a dispersion plate, branch pipes, and spray nozzles are used.

[0018] The treated water pipe 5 is used to extract treated water flowing out from the secondary side of the ion exchange resin tower 2. A first end of the treated water pipe 5 is connected to the bottom of the ion exchange resin tower 2, and a second end of the treated water pipe 5 is connected to a treated water tank (not shown) or a downstream treatment facility (not shown). Although not shown in FIG. 1, the ion exchange resin tower 2 has a water collection mechanism at the bottom inside the ion exchange resin tower 2 for separating the treated water from the ion exchange resin and collecting only the treated water.

[0019] The anion exchange resin 3 is used to remove organic matter from the water to be treated. When the water to be treated is supplied to the primary side of the ion exchange resin tower 2 from the water to be treated pipe 4, the water to be treated is passed through the anion exchange resin 3. As a result, the organic matter in the water to be treated is adsorbed by the anion exchange resin 3 and removed.

[0020] The anion exchange resin 3 may be a commercially available product, such as Purolite A860, Purofine PFA850 (Purolite products), DIAION SA10A, SA12A, SA20A, PA308, Rewrite JA800, JA810 (Mitsubishi Chemical products), Lewatit MP500, M500, MP504, A8071 (Lanxess products), and Amberlite IRA402, IRA901, XT5007, IRA958, IRA458 (DuPont products).

[0021] A microbial layer (not shown) is formed on the surface of the anion exchange resin 3 in the ion exchange resin tower 2. Because the water to be treated may contain microorganisms such as nitrifying bacteria, as the water to be treated continues to pass through the ion exchange resin tower 2, a microbial layer is formed on the surface of the anion exchange resin 3 in the ion exchange resin tower 2. Ammonia nitrogen in the water to be treated is treated by the anion exchange resin 3 with this microbial layer formed on its surface. More specifically, ammonia nitrogen in the raw water is oxidized to nitrate nitrogen such as nitrite and nitrate by the action of nitrifying bacteria such as ammonia-oxidizing bacteria and nitrite-oxidizing bacteria, and is then biologically removed (nitrification reaction).

[0022] An example of a water treatment method will be described with reference to Figure 1. Water to be treated is passed through an ion exchange resin tower 2 filled with anion exchange resins 3 having a microbial layer (not shown) formed on the surface thereof, whereby organic matter in the water to be treated is removed by the anion exchange resins 3. In addition, ammonia nitrogen in the water to be treated is biologically removed by the microbial layer formed on the surface of the anion exchange resins 3.

[0023] In one example, when the TOC concentration of the treated water flowing out from the secondary side of the ion exchange resin tower 2 exceeds 30 to 50% of the TOC concentration of the water to be treated, the anion exchange resin in the ion exchange resin tower 2 may be regenerated. The TOC concentration of the treated water, which is the guideline for starting regeneration of the anion exchange resin in the ion exchange resin tower 2, can be determined based on the TOC concentration of the water to be treated and the TOC concentration of the treated water. If the load on the ion exchange resin is too large, the leakage of organic matter into the treated water after regeneration increases. For example, if the TOC concentration of the water to be treated is 1 to 3 mg / L, the ion exchange resin is regenerated when it exceeds 50% of the TOC concentration of the water to be treated.

[0024] After treating a certain amount of water, the anion exchange resin's ability to remove organic matter gradually decreases. In this case, the anion exchange resin can be regenerated with a regenerant to restore its ability to remove organic matter. A preferred example of the water treatment method may further include regenerating the anion exchange resin with a regenerant.

[0025] For example, in the case of two or more stages of regeneration, the regenerant in the first stage is not particularly limited as long as it is easy to exchange organic matter, and examples thereof include aqueous solutions of sodium sulfate, ammonium sulfate, sodium hydroxide, sodium bromide, sulfuric acid, hydrochloric acid, etc. As the regenerant for the final stage, an aqueous solution of sodium chloride or an aqueous solution of potassium chloride is preferred because the counter ion of the anion exchanger becomes a chloride ion.

[0026] After regeneration of the anion exchange resin, the activity of the microbial layer (not shown) may be lost, but when water is passed through after regeneration is complete, the microorganisms grow and a microbial layer is reformed. The period for the formation of the microbial layer is not particularly limited as it depends on the growth conditions, but it can be about one week to one month. The flow rate of the water to be treated when forming the microbial layer is, for example, preferably SV1 to SV10, and more preferably SV1 to SV5.

[0027] When restarting the anion exchange resin, the ammonia nitrogen concentration in the anion exchange resin-treated water is measured to see if it has reached a standard value or less. For example, if it has reached a standard value or less, it can be determined that the proliferation process is complete. The standard value can be determined depending on the desired quality of the treated water. For example, when producing drinking water, it is preferable to continue the proliferation process until the ammonia nitrogen concentration in the anion exchange resin-treated water reaches 1 mg / L or less, more preferably 0.5 mg / L or less, and even more preferably 0.1 mg / L or less.

[0028] The quality of the treated water from the water treatment device 1A can be determined depending on the intended use. For example, if the water is intended for drinking water, the ammonia concentration should be 0.5 mg / L or less, and 0.1 mg / L or less is more preferable, to reduce the consumption of sodium hypochlorite used for sterilization. On the other hand, the TOC of organic matter should be 1.5 mg / L or less, and 1.0 mg / L or less is more preferable, to ensure that the disinfection by-products generated by the reaction with sodium hypochlorite used for sterilization are below drinking water standards.

[0029] As shown in the examples of Figures 2 and 3, the ion exchange resin tower 2 may be filled with a cation exchange resin 6 in addition to the anion exchange resin 3. The cation exchange resin is used to remove ammonia nitrogen from the water to be treated through an ion exchange reaction. When the water to be treated is supplied to the primary side of the ion exchange resin tower 2 from the water to be treated pipe 4, the ammonia nitrogen in the water to be treated is adsorbed onto the cation exchange resin 6 and removed. By using the cation exchange resin 6 in combination with the anion exchange resin 3 in this way, it becomes possible to adsorb and remove organic matter and ammonia nitrogen from the water to be treated. In the case of a mixed bed or multiple bed structure, the cation exchange resin can remove ammonia nitrogen during the initial water flow or at the start of water flow after regeneration is completed, until a microbial layer is formed large enough to allow the nitrification reaction to proceed sufficiently.

[0030] The cation exchange resin 6 may be a commercially available product, such as SK1B and SK110 (manufactured by Mitsubishi Chemical Corporation), Lewatit S100 and S110 (manufactured by Lanxess), Purolite C-100 (manufactured by Purolite), IR120 and IR122 (manufactured by DuPont), and HCR-S (manufactured by Dow Chemical Company).

[0031] In the example shown in Fig. 2, the ion exchange resin tower 2 has a mixed bed 7 which is a mixture of anion exchange resin 3 and cation exchange resin 6. In the example shown in Fig. 3, the ion exchange resin tower 2 has a multi-layer 8 in which a layer of anion exchange resin 3 and a layer of cation exchange resin 6 are stacked. In both examples, a microbial layer is formed on the surface of the anion exchange resin 3. In addition, a microbial layer (not shown) may also be formed on the surface of the cation exchange resin 6.

[0032] The volume ratio of the cation exchange resin to the anion exchange resin (cation exchange resin / anion exchange resin) is not particularly limited, and may be determined depending on the quality of the water to be treated and the quality of the treated water discharged from the ion exchange resin tower. In the case of the TOC concentration and ammonia nitrogen concentration of the water to be treated described above, if the water is intended for drinking, the volume ratio may be 2 / 1 to 10 / 1, 2 / 1 to 5 / 1, or 1 / 1 to 3 / 1.

[0033] In one example, when the ammonia nitrogen concentration in the treated water flowing out from the secondary side of the ion exchange resin tower 2 exceeds 30 to 50% of the water to be treated, the cation exchange resin 6 in the ion exchange resin tower 2 may be regenerated. The regenerant for regenerating the cation exchange resin is not particularly limited, but may be the same as the regenerant for regenerating the anion exchange resin. In the case of a mixed bed or multiple beds as shown in Figures 2 and 3, the regeneration of the cation and anion exchange resins is carried out simultaneously.

[0034] (Mechanism of action) In the embodiment described above, the anion exchange resin 3 can be used as an adsorbent for organic matter and as a carrier for the microbial layer. This allows for efficient removal of organic matter and ammonia nitrogen from the water being treated. Furthermore, when the organic matter adsorption capacity of the anion exchange resin is exceeded, the anion exchange resin can be regenerated. This reduces the frequency of maintenance work for replacing consumables. In addition, ammonia nitrogen can also be removed from the water being treated through a nitrification reaction by the microbial layer.

[0035] [Second embodiment] A water treatment device 1D shown in FIG. 4 includes a plurality of ion-exchange resin towers 2A and 2B, a pipe 4 for water to be treated, a pipe 5 for treated water, a connecting pipe 10, a pipe 11 for reclaimed water, and a pipe 12 for wastewater. It has.

[0036] The ion exchange resin towers 2A and 2B are filled with anion exchange resins 3A and 3B, respectively. A microbial layer (not shown) is formed on the surface of each of the anion exchange resins 3A and 3B. When the water to be treated is supplied to the primary side of the ion exchange resin towers 2A and 2B, organic matter in the water is adsorbed onto the anion exchange resins 3A and 3B and removed. In addition, ammonia nitrogen in the water to be treated is biologically removed by the microbial layer formed on the surface of the anion exchange resins 3A and 3B.

[0037] In the second embodiment, the untreated water pipe 4 is for supplying the untreated water to the primary sides of the multiple ion exchange resin towers 2A, 2B. A first end (not shown) of the untreated water pipe 4 is connected to a source of the untreated water, such as a raw water tank, and a second end of the untreated water pipe 4 branches into branch supply pipes 4A, 4B. The branch supply pipes 4A, 4B at the branched second ends are connected to the tops of the ion exchange resin towers 2A, 2B, respectively. The branch supply pipes 4A and 4B are provided with flow path switching valves V1A and V1B, respectively. In addition, the branch supply pipe 4B is provided with an on-off valve V5 on the primary side (upstream side) of the connection point with the connecting pipe 10.

[0038] In the second embodiment, treated water piping 5 is used to extract treated water flowing out from the secondary sides of multiple ion exchange resin towers 2A, 2B. A first end of treated water piping 5 branches into branch treated water piping 5A, 5B, and a second end of treated water piping 5 is connected to a treated water tank (not shown) or a downstream treatment facility (not shown). Branch treated water piping 5A, 5B at the branched first end are connected to the bottoms of ion exchange resin towers 2A, 2B, respectively. The branch treated water pipes 5A and 5B are provided with flow path switching valves V2A and V2B, respectively. In addition, the branch treated water pipe 5A is provided with an on-off valve V6 on the secondary side (downstream side) of the connection point with the connecting pipe 10.

[0039] The connecting pipe 10 is used to supply treated water flowing out from the secondary side of the ion exchange resin tower 2A, one of the multiple ion exchange resin towers 2A, 2B, to the primary side of the other ion exchange resin tower 2B. A first end of the connecting pipe 10 is connected to the branch treated water pipe 5A on the primary side (upstream side) of the on-off valve V6, and a second end of the connecting pipe 10 is connected to the branch supply pipe 4B on the secondary side (downstream side) of the on-off valve V5. The connecting pipe 10 is provided with an on-off valve V4.

[0040] The reclaimed water pipe 11 is used to supply reclaimed water to the primary sides of the multiple ion exchange resin towers 2A and 2B. A first end (not shown) of the reclaimed water pipe 11 is connected to a reclaimed water supply source, and a second end of the reclaimed water pipe 11 branches into branched reclaimed water pipes 11A and 11B. The branched reclaimed water pipes 11A and 11B at the second branched ends are connected to flow path switching valves V1A and V1B, respectively. The branched reclaimed water pipes 11A and 11B are provided with on-off valves V3A and V3B, respectively.

[0041] The wastewater pipe 12 is used to discharge wastewater generated when regenerating the multiple ion exchange resin towers 2A, 2B. A first end of the wastewater pipe 12 branches into branch wastewater pipes 12A, 12B. The branch wastewater pipes 12A, 12B at the branched first end are connected to flow path switching valves V2A, V2B, respectively. A second end of the wastewater pipe 12 is not shown, but its connection destination is not particularly limited.

[0042] 4, water treatment equipment 1D can treat water to be treated using at least one of the ion exchange resin towers while regenerating the other ion exchange resin towers. For example, to treat water to be treated using ion exchange resin tower 2B while regenerating ion exchange resin tower 2A, open on-off valves V3A and V5 and close on-off valves V3B, V4, and V6. Also, flow path switching valve V1A is connected to branch reclaimed water pipe 11A, flow path switching valve V1B is connected to branch supply pipe 4B, flow path switching valve V2A is connected to branch wastewater pipe 12A, and flow path switching valve V2B is connected to branch treated water pipe 5B.

[0043] At this time, wastewater is generated when the regenerated water regenerates the anion exchange resin 3A in the ion exchange resin tower 2A. The wastewater is discharged from the wastewater pipe 12 via the branch wastewater pipe 12A. Meanwhile, the water to be treated is passed through the anion exchange resin 3B in the ion exchange resin tower 2B. Therefore, organic matter and ammonia nitrogen in the water to be treated are treated by the anion exchange resin 3B. The treated water from the ion exchange resin tower 2B flows through the treated water pipe 5 via the branch treated water pipe 5B.

[0044] Subsequently, after the regeneration of the ion exchange resin tower 2A is completed, it is preferable to pass the water to be treated in series through the ion exchange resin towers 2A and 2B using the connecting pipe 10. More specifically, this is achieved by closing the on-off valve V5 and opening the on-off valve V4. Furthermore, the flow path switching valve V1A is connected to the branch supply pipe 4A, and the flow path switching valve V2A is connected to the branch treated water pipe 5A. At this time, the water to be treated is passed through the anion exchange resin 3A of the ion exchange resin tower 2A and then the anion exchange resin 3B of the ion exchange resin tower 2B in that order. By treating the water to be treated successively through the anion exchange resins 3A and 3B of the ion exchange resin towers 2A and 2B in this way, the removal of organic matter and ammonia nitrogen can be improved.

[0045] After the regeneration of the ion exchange resin tower 2A is complete, the activity of the microbial layer (not shown) on the surface of the anion exchange resin 3A may be lost. However, when water is passed through after the regeneration is complete, the microorganisms grow and the microbial layer is reformed. It is preferable to reform the microbial layer to such an extent that the nitrification reaction by the microbial layer proceeds sufficiently. The period, temperature conditions, and water passing conditions for reforming the microbial layer are not particularly limited, but the same conditions as those described for the first embodiment can be applied.

[0046] Furthermore, if water treatment continues after regenerating the anion exchange resin 3A in the ion exchange resin tower 2A, the organic matter removal capacity of the anion exchange resin 3B in the ion exchange resin tower 2B may gradually decrease. In this case, it is preferable to treat the water to be treated using the ion exchange resin tower 2A while regenerating the ion exchange resin tower 2B. More specifically, this is achieved by opening the on-off valve V6 and closing the on-off valves V4 and V5. Furthermore, the flow path switching valve V1B is connected to the branch regenerated water pipe 11B, and the flow path switching valve V2B is connected to the branch wastewater pipe 12B. After regenerating the anion exchange resin 3B in the ion exchange resin tower 2B, wastewater is generated. The wastewater is discharged from the wastewater pipe 12 via the branch wastewater pipe 12B. Meanwhile, the water to be treated is passed through the anion exchange resin 3A in the ion exchange resin tower 2A. Therefore, organic matter and ammonia nitrogen in the water to be treated are treated by the anion exchange resin 3A. The treated water from the ion-exchange resin tower 2A flows through the treated water pipe 5 via the branch treated water pipe 5A.

[0047] After the regeneration of the ion exchange resin tower 2B is completed, it is preferable to pass the water to be treated in series through the ion exchange resin towers 2A and 2B using the connecting pipe 10. More specifically, this can be achieved by closing the on-off valve V6 and opening the on-off valve V4. Furthermore, the flow path switching valve V1B is connected to the branch supply pipe 4B, and the flow path switching valve V2B is connected to the branch treated water pipe 5B. At this time, the water to be treated is passed through the anion exchange resin 3A of the ion exchange resin tower 2A and then through the anion exchange resin 3B of the ion exchange resin tower 2B in that order. By treating the water to be treated successively through the anion exchange resins 3A and 3B of the ion exchange resin towers 2A and 2B in this way, the removal of organic matter and ammonia nitrogen can be improved.

[0048] After regeneration of the ion exchange resin tower 2B is complete, the activity of the microbial layer (not shown) on the surface of the anion exchange resin 3B may be lost. However, when water is passed through the tower after regeneration is complete, the microorganisms grow and the microbial layer is reformed. It is preferable to reform the microbial layer to the extent that the nitrification reaction proceeds sufficiently. The period, temperature conditions, and water passing conditions for reforming the microbial layer are not particularly limited, but the same conditions as those described for the first embodiment can be applied.

[0049] In the second embodiment, water treatment may be performed so that the quality of the treated water falls within the standard range. For example, the TOC concentration of the treated water is preferably 1.5 mg / L or less, more preferably 1.0 mg / L or less, and even more preferably 0.5 mg / L or less. The ammonia nitrogen concentration of the treated water is preferably 0.5 mg / L or less, more preferably 0.2 mg / L or less, and even more preferably 0.1 mg / L or less. For drinking water applications, when the nitrate nitrogen concentration in the treated water reaches, for example, 10 mg / L or more, it is necessary to remove the nitrate nitrogen by denitrification or using a reverse osmosis membrane.

[0050] [Mechanism of action] According to the second embodiment described above, the water to be treated can be treated using one ion exchange resin tower while the other ion exchange resin tower is being regenerated. Therefore, after the anion exchange resin is regenerated, there is no need to stop the water treatment until the microbial layer is regenerated. In addition, the timing of regenerating the anion exchange resin can be adjusted depending on the activity of the microbial layer. In this way, while one of the multiple ion exchange resin towers is being regenerated, the other ion exchange resin towers can treat the water to be treated, so that organic matter and ammonia nitrogen in the water to be treated can be continuously treated. Furthermore, when water is passed through the tower after regeneration is complete, organic matter and ammonia nitrogen in the water to be treated can be continuously treated in the same manner as described above, even during the period until a microbial layer is formed.

[0051] [Other embodiment examples] Although one embodiment has been described above by showing one example embodiment, the present invention is not limited to the example embodiment disclosed in this specification and can be appropriately modified and implemented without departing from the spirit of the invention. The embodiment disclosed in this specification can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[0052] For example, the mixed bed shown in Fig. 2 or the multi-layer structure shown in Fig. 3 can also be applied to a water treatment device having multiple ion exchange resin towers as shown in Fig. 4. In this case, it is sufficient that at least one ion exchange resin tower has a mixed bed or multi-layer structure. It is believed that the performance of removing ammonia nitrogen can be further improved by using a cation exchange resin and an anion exchange resin in combination and passing water through multiple ion exchange resin towers in series. In addition, the number of ion exchange resin towers is not particularly limited and may be one, two, three or more.

[0053] The treated water flowing through the treated water pipe 5 may be used as final treated water as is, or may be subjected to additional post-treatment before being used as final treated water. Examples of post-treatment include, but are not limited to, ultraviolet treatment, coagulant treatment, oxidant treatment, sand filter tower treatment, membrane filtration treatment, and disinfectant treatment. The use of the final treated water is also not particularly limited. Examples include, but are not limited to, use as domestic water, drinking water, etc. [Industrial Applicability]

[0054] According to the present invention, the number of maintenance operations required for replacing consumables can be reduced. [Explanation of symbols]

[0055] 1. Water treatment equipment 2. Ion exchange resin tower 3 Anion exchange resin 4. Treated water piping 5 Treated water piping 6. Cation exchange resin 7 mixed bed 8 Multi-layer

Claims

1. A water treatment device for treating water to be treated containing organic matter and ammonia nitrogen, an ion exchange resin tower packed with an anion exchange resin; A water treatment device, wherein a microbial layer is formed on the surface of the anion exchange resin in the ion exchange resin tower.

2. The water treatment device includes a plurality of the ion exchange resin towers, The water treatment device according to claim 1 , wherein the water to be treated is treated using at least one of the plurality of ion exchange resin towers while the other ion exchange resin towers are being regenerated.

3. The water treatment device includes a plurality of the ion exchange resin towers, a water-to-be-treated pipe for supplying the water to be treated to each of the primary sides of the plurality of ion exchange resin towers; a treated water pipe for extracting treated water flowing out from each of the secondary sides of the plurality of ion exchange resin towers; a connecting pipe for supplying the treated water flowing out from the secondary side of at least one of the ion exchange resin towers to the primary side of the other ion exchange resin towers; The water treatment device according to claim 1 or 2, further comprising:

4. The water treatment device includes a plurality of the ion exchange resin towers, a reclaimed water pipe for supplying reclaimed water to the primary sides of the plurality of ion exchange resin towers; a wastewater pipe for discharging wastewater generated when regenerating the plurality of ion exchange resin towers; The water treatment device according to claim 1 or 2, further comprising:

5. Among the plurality of ion exchange resin towers, at least one tower further contains a cation exchange resin in addition to the anion exchange resin, The water treatment device according to claim 1 or 2, comprising a mixed bed which is a mixture of the anion exchange resin and the cation exchange resin.

6. Among the plurality of ion exchange resin towers, at least one tower is further packed with a cation exchange resin in addition to the upper or lower layer of the anion exchange resin, The water treatment device according to claim 1 or 2, comprising a multi-layer structure in which the anion exchange resin layer and the cation exchange resin layer are stacked.

7. 6. The water treatment device according to claim 5, wherein a volume ratio of the cation exchange resin to the anion exchange resin (cation exchange resin / anion exchange resin) is 2 / 1 to 10 / 1.

8. The water treatment device according to claim 1 or 2, wherein the microbial layer contains nitrifying bacteria.

9. A water treatment method for treating water to be treated containing organic matter and ammonia nitrogen, comprising: A water treatment method comprising passing the water to be treated through an ion exchange resin tower packed with an anion exchange resin having a microbial layer formed on the surface thereof.

10. The water treatment method according to claim 9 , further comprising growing microorganisms in the microbial layer to form the microbial layer.

11. 11. The water treatment method according to claim 9, further comprising regenerating the anion exchange resin in the ion exchange resin tower when the TOC concentration of the treated water flowing out from the secondary side of the ion exchange resin tower exceeds 30 to 50% of the TOC concentration of the water to be treated.

12. The ion exchange resin tower is further filled with a cation exchange resin in addition to the anion exchange resin, The water treatment method according to claim 9 or 10, wherein the ion exchange resin tower has a mixed bed which is a mixture of the anion exchange resin and the cation exchange resin.

13. The ion exchange resin tower is further filled with a cation exchange resin in addition to the anion exchange resin, The water treatment method according to claim 9 or 10, wherein the ion exchange resin tower has a multi-layer structure in which a layer of the anion exchange resin and a layer of the cation exchange resin are stacked.

14. The water treatment method according to claim 12, wherein the volume ratio of the cation exchange resin to the anion exchange resin (cation exchange resin / anion exchange resin) is 2 / 1 to 10 / 1.

15. 13. The water treatment method according to claim 12, further comprising regenerating the cation exchange resin in the ion exchange resin tower when the ammonia nitrogen concentration of the treated water flowing out from the secondary side of the ion exchange resin tower exceeds 30 to 50% of the ammonia nitrogen concentration of the water to be treated.

16. The water treatment method according to claim 9 or 10, wherein the microbial layer contains nitrifying bacteria.

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