Adsorption treatment method and adsorption treatment system

Abstract

To provide an adsorption treatment method and the like capable of easily and efficiently adsorbing target substances onto an adsorbent.SOLUTION: An adsorption treatment method of the embodiment includes an adsorption treatment step that performs adsorption treatment to adsorb target substances from the water to be treated onto an adsorbent, and a precipitation treatment step that performs precipitation treatment to precipitate adsorption-inhibiting substances by adding a precipitating agent to the water to be treated prior to performing the adsorption treatment. The water to be treated contains both sulfate ions and bicarbonate ions as adsorption-inhibiting substances, and also contains oxo acid ions other than sulfate ions and bicarbonate ions as substances to be adsorbed. The precipitating agent is a water-soluble metal salt that reacts with and precipitates both the sulfate ions and bicarbonate ions contained in the water to be treated as adsorption-inhibiting substances.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to an adsorption treatment method and an adsorption treatment system. [Background technology]

[0002] There is a need to remove oxoanions (oxoacid ions) from water that contains oxoanions that are harmful to the environment. For example, in nuclear power facilities, iodate ions (IO3 - ) and other substances are required to be removed. In general environments, arsenate ions (AsO3 3- ,AsO4 3- There is a need to remove oxoacid ions, etc., from river water. Removal of oxoacid ions is carried out, for example, by adsorption treatment using an adsorbent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-127990 [Patent Document 2] Japanese Patent Application Publication No. 2018-23952 Summary of the Invention [Problem to be solved by the invention]

[0004] The water to be treated by adsorption treatment contains multiple ion components in addition to the substances to be adsorbed, such as iodate ions. For example, if the water to be treated contains seawater or groundwater, the water to be treated contains sulfate ions (SO4 2- In addition, carbon dioxide and other substances dissolve from the air into the water being treated, so the water being treated contains a large amount of bicarbonate ions (HCO3 - ) is often contained.

[0005] FIG. 4 shows the results of evaluating the adsorption performance of the adsorbent when the water to be treated, which contains iodate ions as the substance to be adsorbed, also contains sulfate ions and bicarbonate ions.

[0006] In Figure 4, the vertical axis represents the ratio (DB / DA) of the inlet concentration DA when the water to be treated is introduced into an adsorption tower containing an adsorbent to the outlet concentration DB when the water to be treated is discharged from the adsorption tower. The horizontal axis represents the cumulative flow rate BV (Bed volume: cumulative water flow rate / adsorbent fill volume) of the water to be treated introduced into the adsorption tower relative to the adsorbent fill volume. Figure 4 shows two cases: a high concentration condition where the concentrations of sulfate ions and bicarbonate ions are high (equivalent to the concentrations of sulfate ions and bicarbonate ions in raw seawater), and a low concentration condition where the concentrations of sulfate ions and bicarbonate ions are low (equivalent to the concentrations of sulfate ions and bicarbonate ions when seawater is diluted 250 times).

[0007] As shown in Figure 4, the adsorption performance of the adsorbent is lower when the concentrations of sulfate ions and bicarbonate ions are high than when they are low. This confirms that sulfate ions and bicarbonate ions act as adsorption inhibitors that inhibit the adsorption performance of the adsorbent.

[0008] It has been proposed to remove adsorption inhibitors from the water to be treated by adding a precipitating agent to the water to be treated before the adsorption treatment, thereby precipitating the adsorption inhibitors.

[0009] However, conventionally, sulfate ions (SO4 2- ) and bicarbonate ions (HCO3 - ) from the water to be treated before the adsorption treatment is carried out. As a result, it is not easy to efficiently adsorb the substances to be adsorbed onto the adsorbent when the adsorption treatment is carried out.

[0010] Therefore, the problem to be solved by the present invention is to provide an adsorption treatment method and an adsorption treatment system that can easily realize efficient adsorption of a target substance onto an adsorbent. [Means for solving the problem]

[0011] An adsorption treatment method according to an embodiment includes an adsorption treatment step in which an adsorption target substance is adsorbed onto an adsorbent from water to be treated, the water further containing adsorption inhibitors that inhibit the adsorption performance of the adsorbent for the adsorption target substance. The adsorption treatment method according to an embodiment also includes a precipitation treatment step in which, prior to the adsorption treatment, a precipitating agent is added to the water to be treated to precipitate the adsorption inhibitors. The water to be treated contains at least sulfate ions and bicarbonate ions as adsorption inhibitors, as well as oxoacid ions other than sulfate ions and bicarbonate ions as adsorption target substances. The precipitating agent is a water-soluble metal salt that reacts with and precipitates both sulfate ions and bicarbonate ions contained as adsorption inhibitors in the water to be treated. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an adsorption treatment method and an adsorption treatment system that can easily realize efficient adsorption of a target substance to be adsorbed onto an adsorbent. [Brief explanation of the drawings]

[0013] [Figure 1A] FIG. 1A is a functional block diagram schematically showing an adsorption treatment system according to a first embodiment. [Figure 1B] FIG. 1B is a flow chart showing the adsorption treatment method of the first embodiment. [Figure 2A] FIG. 2A is a functional block diagram schematically showing an adsorption treatment system according to a second embodiment. [Figure 2B] FIG. 2B is a flow chart showing the adsorption treatment method of the second embodiment. [Figure 3] FIG. 3 shows the results of the example. [Figure 4] FIG. 4 shows the results of evaluating the adsorption performance of the adsorbent when the water to be treated, which contains iodate ions as the substance to be adsorbed, also contains sulfate ions and bicarbonate ions. DETAILED DESCRIPTION OF THE INVENTION

[0014] First Embodiment

[0015] [A] Adsorption treatment system configuration FIG. 1A is a functional block diagram schematically showing an adsorption treatment system according to a first embodiment.

[0016] 1A, the adsorption treatment system of this embodiment has a treatment target water storage section 20, a precipitating agent storage section 21, a precipitating treatment section 30, an adsorption treatment section 50, and an adsorption-treated water storage section 70. The adsorption treatment system of this embodiment is configured to perform an adsorption treatment in which the adsorption target substance is adsorbed from the treatment target water onto the adsorbent 501, and also to perform a precipitating treatment in which a precipitating agent that precipitates adsorption-inhibiting substances in the treatment target water is added to the treatment target water before the adsorption treatment is performed.

[0017] Each component of the adsorption treatment system will be described in turn.

[0018] [A-1] Treatment target water storage unit 20 The treatment target water storage unit 20 includes, for example, a tank, and is configured to store the treatment target water.

[0019] As will be described in detail later, the water to be treated contains adsorption inhibitors in addition to the substances to be adsorbed.

[0020] [A-2] Precipitating agent storage section 21 The precipitating agent storage unit 21 includes, for example, a tank, and is configured to store the precipitating agent.

[0021] The precipitating agent is a water-soluble metal salt that reacts with adsorption inhibitors contained in the water to be treated and precipitates them during the precipitation treatment, as will be described in detail later.

[0022] [A-3] Precipitation treatment section 30 The precipitation treatment unit 30 includes, for example, a tank, and is configured to perform precipitation treatment by introducing the water to be treated from the water to be treated storage unit 20 via a supply pipe L20, and by introducing a precipitation agent from the precipitation agent storage unit 21 via a supply pipe L21 into the precipitation treatment unit 30.

[0023] As will be described in detail later, a reaction occurs between the adsorption inhibitors and the precipitating agent when the precipitation treatment is performed in the precipitation treatment unit 30, producing a precipitate. As a result, the adsorption inhibitors are removed from the water to be treated in the precipitation treatment unit 30. The precipitates that have precipitated as a result of the reaction with the adsorption inhibitors are then discharged outside the tank system from a removal device (not shown) that passes through a filter, strainer, etc. and discharges them out of the system via piping.

[0024] [A-4] Adsorption processing unit 50 The adsorption treatment unit 50 is, for example, an adsorption tower having an internal space containing an adsorbent 501. The adsorption treatment unit 50 is configured to perform adsorption treatment by introducing the treatment target water, from which adsorption inhibitors have been removed by precipitation treatment, from the precipitation treatment unit 30 via a supply pipe L30.

[0025] Although details will be described later, the adsorption treatment is carried out in the adsorption treatment unit 50, whereby the substances to be adsorbed are removed from the water to be treated.

[0026] [A-5] Adsorption-treated water storage section 70 The adsorption-treated water storage unit 70 includes, for example, a tank. The adsorption-treated water storage unit 70 stores the treatment target water (adsorption-treated water) from which the adsorption target substances have been removed by adsorption treatment, which is introduced from the adsorption treatment unit 50 via the supply pipe L50.

[0027] [B] Adsorption treatment method An adsorption treatment method for removing a target substance from treatment target water containing the target substance using the above-described adsorption treatment system (see FIG. 1A) will be described.

[0028] FIG. 1B is a flow chart showing the adsorption treatment method of the first embodiment.

[0029] In the adsorption treatment method of this embodiment, a precipitation treatment step (ST10) and an adsorption treatment step (ST20) are performed sequentially, as shown in Fig. 1B. The precipitation treatment step (ST10) and the adsorption treatment step (ST20) may be performed sequentially in a batch system or in a flow system.

[0030] Each step will be described in detail below.

[0031] [B-1] Precipitation treatment step (ST10) In the precipitation treatment step (ST10), precipitation treatment is carried out in a precipitation treatment section 30 (see FIG. 1A).

[0032] [B-1-1] Water to be treated When carrying out the precipitation treatment, a predetermined amount of water to be treated is introduced into the precipitation treatment unit 30 from the water to be treated storage unit 20. The water to be treated introduced from the water to be treated storage unit 20 contains adsorption inhibitors as well as the substances to be adsorbed.

[0033] [B-1-1-1] Substances to be adsorbed The adsorption target substance is a substance that is adsorbed by the adsorbent 501 during the adsorption treatment. Here, the water to be treated contains oxoacid ions other than adsorption inhibitors as the adsorption target substance. In this embodiment, the adsorption target substance is, for example, iodate ions (IO3 - The substances to be adsorbed are halide ions such as iodate ions (XO3 - ;X=I, F, Cl, Br, At), ruthenate ion (RuO4 2- ), arsenate ion (AsO3 3- , AsO4 3- ), technetate ion (TcO4 - ), borate ion (BO33- ), phosphate ions (PO4 3- ) is at least one of the following:

[0034] [B-1-1-2] Adsorption inhibitors The adsorption inhibitor is a substance that inhibits the adsorption performance of the adsorbent 501 to adsorb the target substance during the adsorption process. In this embodiment, sulfate ions (SO4 2- ) and bicarbonate ions (HCO3 - ) are contained in the water to be treated as adsorption inhibitors.

[0035] [B-1-2] Precipitating agent A predetermined amount of precipitating agent is introduced into the precipitating treatment section 30 from the precipitating agent storage section 21 together with the water to be treated.

[0036] The precipitating agent introduced from the precipitating agent storage section 21 is a water-soluble metal salt that reacts with and precipitates both sulfate ions and bicarbonate ions contained as adsorption inhibitors in the water to be treated during the precipitation treatment.

[0037] The precipitating agent preferably has low solubility of the product produced by reaction with sulfate ions and low solubility of the product produced by reaction with bicarbonate ions, so that precipitates are efficiently produced in the water to be treated. Furthermore, the precipitating agent is preferably a substance other than sulfates and bicarbonates. When the precipitating agent is a substance other than sulfates and bicarbonates, the addition of the precipitating agent can prevent an increase in sulfate ions and bicarbonate ions, which act as adsorption inhibitors.

[0038] For example, the precipitating agent is preferably at least one of barium chloride (BaCl2), barium hydroxide (Ba(OH)2), lead chloride (PbCl2), strontium chloride (SrCl2), and strontium hydroxide (Sr(OH)2).

[0039] [B-1-3] Precipitation treatment In the precipitation treatment process, for example, sulfate ions (SO4 2-) and divalent metal ions M produced by dissolving the precipitant in the water to be treated. 2+ The precipitation treatment is carried out by the reaction between the following (reaction formula 1). - ) and divalent metal ions M produced by dissolving the precipitant in the water to be treated. 2+ The precipitation treatment is carried out by the reaction between and as shown in the following (reaction formula 2). 2+ However, it is not limited to divalent ions, and other valences that cause a precipitation reaction are also acceptable.

[0040] SO4 2- +M 2+ →MSO4 (Reaction 1) CO3 2- +M 2+ →MCO3 (Reaction 2)

[0041] As mentioned above, by carrying out the precipitation treatment, sulfate ions (SO4 2- The reaction between the precipitation agent and the bicarbonate ion (HCO3 - A reaction occurs between the additive and the precipitating agent, producing a precipitate. As a result, the adsorption inhibitors are removed from the water to be treated, which contains both the adsorption target substance and the adsorption inhibitors. Note that, depending on the additive, precipitation occurs in the form of phosgenite (Pb2(CO3)Cl2), so the formulas shown in Reactions 1 and 2 are only examples, and sulfate ions and carbonate ions can also be precipitated using other reaction formulas.

[0042] [B-2] Adsorption treatment process (ST20) In the adsorption treatment step (ST20), adsorption treatment is carried out in the adsorption treatment unit 50 (see FIG. 1A).

[0043] The adsorption treatment is carried out by introducing the water to be treated, from which adsorption inhibitors have been removed by the precipitation treatment, into the adsorption treatment unit 50. By carrying out the adsorption treatment, the substances to be adsorbed contained in the water to be treated are adsorbed onto the adsorbent 501, and the substances to be adsorbed are removed from the water to be treated. The water to be treated from which the substances to be adsorbed have been removed by the adsorption treatment (adsorption-treated water) is discharged to and stored in the adsorption-treated water storage unit 70.

[0044] [C] Summary As described above, in this embodiment, the water to be treated contains sulfate ions (SO4 2- ) and bicarbonate ions (HCO3 - ) as adsorption inhibitors. However, in this embodiment, a precipitation treatment is performed by adding a precipitating agent to the water to be treated before the adsorption treatment is performed, in which the adsorption inhibitors are precipitated. The precipitating agent in this embodiment is a water-soluble metal salt that reacts with and precipitates both sulfate ions and bicarbonate ions contained as adsorption inhibitors in the water to be treated. Therefore, in this embodiment, it is possible to sufficiently and efficiently remove both sulfate ions and bicarbonate ions from the water to be treated before the adsorption treatment is performed. As a result, in this embodiment, the adsorption target substances can be efficiently adsorbed onto the adsorbent during the adsorption treatment. This is also clear from the results shown in Figure 4 above.

[0045] In addition, sulfate ions (SO4 2- ) and divalent metal ions M produced by dissolving the precipitant in the water to be treated. 2+ When the precipitation treatment is carried out by the reaction between and as shown in the above (reaction formula 1), sulfate ions (SO4 2- ) and the amount of substance n1 (mol) of metal ion M 2+ It is preferable that the amount of substance n2 (mol) of the saturation ion (SO4) satisfies the molar equivalent (n2 / n1) relationship shown in the following formula A. By satisfying the lower limit of the following formula A, the amount of sulfate ions (SO4 2- In addition, by satisfying the upper limit of the following formula A, the divalent metal ions M 2+This reduces the amount of residual substances remaining in the water to be treated, allowing each treatment to be carried out stably.

[0046] 1≦n2 / n1≦1.2 (Formula A)

[0047] Second Embodiment [A] Adsorption treatment system configuration FIG. 2A is a functional block diagram schematically showing an adsorption treatment system according to a second embodiment.

[0048] As shown in Fig. 2A, the adsorption treatment system of this embodiment differs from the first embodiment (see Fig. 1A) in that it includes an adsorption inhibitor concentration measurement unit 200 and a precipitating agent addition amount adjustment unit 210. Except for this and related points, this embodiment is similar to the above-mentioned embodiment. Therefore, explanations of overlapping matters will be omitted as appropriate.

[0049] [A-1] Adsorption inhibitor concentration measuring unit 200 The adsorption inhibitor concentration measuring unit 200 includes a concentration measuring device and is configured to measure the concentration of adsorption inhibitors contained in the water to be treated that is introduced from the water to be treated storage unit 20 to the precipitating agent storage unit 21. When the adsorption inhibitor concentration measuring unit 200 measures the concentration of the adsorption inhibitors, the concentration data of the adsorption inhibitors is output to the precipitating agent addition amount adjusting unit 210.

[0050] [A-2] Precipitating agent addition amount adjusting unit 210 The precipitating agent addition amount adjustment unit 210 includes, for example, an arithmetic unit (computer) and a memory device, and is configured such that the arithmetic unit adjusts the amount of precipitating agent introduced from the precipitating agent storage unit 21 to the precipitating treatment unit 30 using a program stored in the memory device.

[0051] The precipitating agent addition amount adjustment unit 210 uses, for example, a lookup table that associates the concentration of adsorption inhibitors contained in the water to be treated with the amount of precipitating agent to be introduced into the precipitation treatment unit 30, to determine the amount of precipitating agent corresponding to the concentration data of adsorption inhibitors input from the adsorption inhibitor concentration measurement unit 200. Naturally, if the amount of water to be treated introduced from the water to be treated storage unit 20 to the precipitation treatment unit 30 is changed from a predetermined amount, the amount of precipitating agent is changed according to the changed amount.

[0052] [B] Adsorption treatment method An adsorption treatment method for removing a target substance from treatment target water containing the target substance using the above-described adsorption treatment system (see FIG. 2A) will be described.

[0053] FIG. 2B is a flow chart showing the adsorption treatment method of the second embodiment.

[0054] In the adsorption treatment method of this embodiment, as shown in FIG. 2B, unlike the first embodiment (see FIG. 1B), an adsorption inhibitor concentration measurement step (ST1) is performed before the precipitation treatment step (ST10) and the adsorption treatment step (ST20) are performed sequentially.

[0055] [B-1] Adsorption inhibitor concentration measurement process (ST1) The adsorption inhibitor concentration measurement step (ST1) is performed by the adsorption inhibitor concentration measurement unit 200 (see FIG. 2A). As described above, the adsorption inhibitor concentration measurement unit 200 measures the concentration of adsorption inhibitors contained in the water to be treated.

[0056] [B-2] Precipitation treatment process (ST10) and adsorption treatment process (ST20) Then, in the precipitation treatment step (ST10), a precipitating agent is added to the treatment target water based on the concentration measured in the adsorption inhibitor concentration measurement step (ST1). In this embodiment, as described above, the amount of precipitating agent corresponding to the measured concentration data of the adsorption inhibitor is determined in the precipitating agent addition amount adjustment unit 210. Then, based on the determined amount of precipitating agent, the precipitating agent is supplied from the precipitating agent storage unit 21 to the precipitation treatment unit 30. Thereafter, the adsorption treatment step (ST20) is performed as in the first embodiment.

[0057] [C] Summary As described above, in this embodiment, the concentration of adsorption inhibitors in the water to be treated is measured before the precipitation treatment is performed. Then, based on the measured concentration, a precipitating agent is added to the water to be treated, thereby performing the precipitation treatment. Therefore, in this embodiment, the precipitation treatment can be performed efficiently. [Example]

[0058] FIG. 3 shows the results of the example.

[0059] In Figure 3, the vertical axis represents the total amount of dissolved S and C in the sulfate ion (SO4 2- ), bicarbonate ion (HCO 3- The figure shows the ratio (D1 / D0) of the concentration of adsorption inhibitors after precipitation treatment [D1] to the concentration of adsorption inhibitors (dissolved S concentration, dissolved C concentration [D0]) before precipitation treatment, assuming that the concentration is 0.005. The horizontal axis lists the type of precipitating agent used in the precipitation treatment for each example. Figure 3 shows the results when precipitation treatment was performed under conditions where the molar equivalent (n2 / n1) shown in (Equation A) was 1.2 (n2 / n1 = 1.2). In Figure 3, the [*] mark indicates that D1 / D0 ≦ 0.005.

[0060] As shown in Figure 3, in each of (Ex. 1) to (Ex. 5), the precipitation treatment was carried out using barium chloride (BaCl2), barium hydroxide hydrate (Ba(OH)2·8H2O), lead chloride (PbCl2), strontium chloride (SrCl2), and strontium hydroxide (Sr(OH)2) as the precipitating agent. In each of (Ex. 1) to (Ex. 5), the concentrations of dissolved S and dissolved C, which are adsorption inhibitors, were significantly reduced by the precipitation treatment. In each of (Ex. 1) to (Ex. 5), it was possible to efficiently remove adsorption inhibitors from the target water before adsorption treatment, allowing the target substances to be efficiently adsorbed onto the adsorbent during adsorption treatment. In particular, when precipitation treatment was carried out using barium hydroxide hydrate (Ba(OH)2·8H2O) as the precipitating agent, as in (Ex. 2), sulfate ions (SO4 2- ) and bicarbonate ions (HCO3 - ) can be sufficiently removed, and is therefore preferable.

[0061] In (Ex.6) and (Ex.7), precipitation treatment was carried out by using radium chloride hydrate (RaCl2·2H2O) and calcium chloride (CaCl2) as precipitating agents, respectively. In (Ex.6), sulfate ions (SO4 2- ) was significantly reduced by the precipitation treatment, but the amount of hydrogen carbonate ions (HCO3 - ) showed almost no decrease even after precipitation treatment. In (Ex. 7), sulfate ions (SO4 2- ), bicarbonate ion (HCO3 - The concentration of sulfate ions (SO4 2- ) and bicarbonate ion (HCO3 - ) are not sufficiently removed at the same time.

[0062] From the above results, it was found that when carrying out the precipitation treatment, it is preferable to use barium chloride (BaCl2), barium hydroxide (Ba(OH)2), lead chloride (PbCl2), strontium chloride (SrCl2), and strontium hydroxide (Sr(OH)2) as the precipitation agent.

[0063] [Table 1]

[0064] Table 1 shows the results when the molar equivalent (n2 / n1) of the precipitating agent was changed in each of (Ex.1) to (Ex.5). Here, the precipitating agent was added under the condition that the molar equivalent (n2 / n1) of the precipitating agent was 1.2 or 37. The precipitating treatment was carried out by adding the precipitating agent under the condition that the molar equivalent (n2 / n1) of the precipitating agent was 1.2 or 37. The precipitating treatment was carried out by adding the sulfate ions (SO4 2- ) and bicarbonate ion (HCO3 - The experiment was carried out under conditions where the concentration of ) was the same as that of raw seawater.

[0065] After precipitation treatment, the concentration of iodine ions contained as an adsorption target substance in the water to be treated that underwent adsorption treatment was 1 ppm. In the adsorption treatment, the water to be treated after precipitation treatment was passed through the column so that the space velocity SV, which is the water flow rate [ml / h] to the column divided by the adsorbent volume [ml], was as follows:

[0066] SV=30[1 / h]

[0067] Table 1 shows the percentage of the supply amount of water to be treated that, when adsorption treatment was performed in each of (Ex. 1) to (Ex. 5), resulted in the outlet concentration at the outlet of the adsorption tower being the same as the inlet concentration at the inlet of the adsorption tower (based on the case where no precipitation treatment was performed (n2 / n1 = 0)).

[0068] As can be seen from Table 1, when the precipitation treatment is performed under conditions where the molar equivalent (n2 / n1) of the precipitating agent is 1.2 or higher, the adsorption performance is equivalent to that of the adsorption treatment. If the molar equivalent (n2 / n1) of the precipitating agent exceeds 1.2, the metal ions from the precipitating agent will be present in excess, which may lead to the inhibition of adsorption performance. For this reason, as already mentioned, it is preferable that the molar equivalent (n2 / n1) of the precipitating agent satisfies the relationship shown in (Equation A).

[0069] <Other> Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0070] 20: storage unit for water to be treated, 21: storage unit for precipitating agent, 30: precipitating treatment unit, 50: adsorption treatment unit, 70: storage unit for adsorption-treated water, 200: unit for measuring concentration of adsorption inhibitors, 210: unit for adjusting amount of precipitating agent added, 501: adsorbent, L20: supply pipe, L21: supply pipe, L30: supply pipe, L50: supply pipe

Claims

1. an adsorption treatment step of performing an adsorption treatment in which the adsorption target substance is adsorbed onto an adsorbent from the treatment target water containing the adsorption target substance; and the water to be treated further contains an adsorption inhibitor that inhibits the adsorption performance of the adsorbent to adsorb the target substance; An adsorption treatment method, comprising: a precipitation treatment step in which a precipitation agent is added to the water to be treated before the adsorption treatment to precipitate the adsorption inhibitors; and the water to be treated contains at least both sulfate ions and bicarbonate ions as the adsorption inhibitors, and also contains oxoacid ions other than sulfate ions and bicarbonate ions as the adsorption target substances; The precipitating agent is a water-soluble metal salt that reacts with both sulfate ions and bicarbonate ions contained as the adsorption inhibitors in the water to be treated to cause precipitation. Adsorption treatment method.

2. an adsorption inhibitor concentration measurement step of measuring the concentration of the adsorption inhibitor in the water to be treated before the precipitation treatment is performed; and In the precipitation treatment step, the precipitating agent is added to the treatment target water based on the concentration measured in the adsorption inhibitor concentration measurement step. The adsorption treatment method according to claim 1 .

3. The precipitating agent is a water-soluble metal salt other than sulfates and bicarbonates. The adsorption treatment method according to claim 1 .

4. In the precipitation treatment step, the adsorption inhibitor, sulfate ion SO ４ ２－ and divalent metal ions M produced by dissolving the precipitating agent in the water to be treated. ２＋ The precipitation treatment is carried out by the reaction between and as shown in the following (Reaction Formula 1), The precipitation treatment is carried out to remove sulfate ions SO , which are the adsorption inhibitors. ４ ２－ and the amount of substance n1 (mol) of sulfate ions SO ４ ２－ Metal ions M react with ２＋ The amount of substance n2 (mol) is carried out so that the relationship shown in the following (Equation A) is satisfied. The adsorption treatment method according to claim 3. SO ４ ２－ +M ２＋ →MSO ４ ... (Reaction Scheme 1) 1≦n2 / n1≦1.2 (Formula A)

5. an adsorption treatment unit that performs an adsorption treatment in which the adsorption target substance is adsorbed onto an adsorbent from the treatment target water containing the adsorption target substance; and the water to be treated contains an adsorption inhibitor that inhibits the adsorption performance of the adsorbent to adsorb the target substance; 1. An adsorption treatment system comprising: a precipitation treatment unit that performs a precipitation treatment by adding a precipitating agent to the water to be treated, which causes the adsorption inhibitors to precipitate in the water to be treated, before the adsorption treatment is performed; and the water to be treated contains at least both sulfate ions and bicarbonate ions as the adsorption inhibitors, and also contains oxoacid ions other than sulfate ions and bicarbonate ions as the adsorption target substances; The precipitating agent is a water-soluble metal salt that reacts with both sulfate ions and bicarbonate ions contained as the adsorption inhibitors in the water to be treated to cause precipitation. Adsorption treatment system.

Images