JP6863849B2 - How to remove musty odor substances and water treatment equipment that can remove musty odor substances - Google Patents

Description

The present invention relates to a method for removing a musty odor substance and a water treatment device capable of removing the musty odor substance.

Among stagnant waters such as lakes and reservoirs, especially in eutrophic waters, when the water temperature rises, phytoplankton such as blue-green algae and microorganisms such as actinomycetes of the genus Streptomyces may propagate and generate musty odor. Among the blue-green algae, Geosmin is produced when Anabaena macrospora, Oscillatoria animalis, and Afanizomenon floss aqua grow. On the other hand, when Phormidium tenue and Oscillatoria limnetica proliferate, 2-methylisoborneol (2-MIB) is produced.
These geosmin and 2-MIB are known as substances that cause musty odor (moldy odor substance). Geosmin has a strong earthy odor, and 2-MIB has a strong ink odor.

The odor thresholds of these musty substances are said to be 10 ppt for geosmin and 5 ppt for 2-MIB. The upper limit of the water quality standard stipulated by the Waterworks Law is 10 ppt for both geosmin and 2-MIB, and it is required that these concentrations in water be 10 ppt or less.

As a method for removing a musty odor substance, for example, Patent Document 1 discloses a method in which a cyclodextrin supported on a silica gel carrier is used and the musty odor substance is encapsulated with cyclodextrin.
Patent Document 2 discloses a method of oxidatively decomposing a musty odor substance by treating the water to be treated with ozone.
Patent Documents 3 and 4 disclose a method of adsorbing and removing a musty odor substance by treating the water to be treated with activated carbon.

U.S. Pat. No. 6,024,879 Japanese Unexamined Patent Publication No. 6-269786 Japanese Unexamined Patent Publication No. 6-343951 Japanese Unexamined Patent Publication No. 2006-282441

However, in the method described in Patent Document 1, since the amount of cyclodextrin supported on the silica gel carrier is small, the amount of the musty odor substance adsorbed is small, and the musty odor substance cannot be sufficiently removed.
In the method described in Patent Document 2, an expensive ozone generator is required for ozone treatment, and an operating cost is incurred. In addition, it is necessary to decompose it with ultraviolet rays or the like after ozone treatment, which is costly and troublesome.
In the methods described in Patent Documents 3 and 4, the amount of the musty odor substance adsorbed by the activated carbon was small, and the musty odor substance could not be sufficiently removed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for removing a musty odor substance at low cost and easily, and a water treatment device capable of removing the musty odor substance.

The present invention has the following aspects.
[1] A method for removing a musty odor substance that removes at least one of geosmin and 2-MIB contained in water to be treated, and a cyclic compound capable of forming an inclusion compound with at least one of geosmin and 2-MIB, and a subject. A method for removing a musty odor substance, which comprises a mixing step of mixing the treated water and an ion exchange treatment step of bringing the water to be treated mixed with the cyclic compound into contact with an ion exchanger.
[2] The method for removing a musty odor substance according to [1], wherein the cyclic compound is at least one selected from the group consisting of cyclodextrin, calixarene and derivatives thereof.
[3] The method for removing a musty odor substance according to [1] or [2], wherein the cyclic compound has a negative charge and the ion exchanger is an anion exchanger.
[4] The method for removing a musty odor substance according to [1] or [2], wherein the cyclic compound has a positive charge and the ion exchanger is a cation exchanger.
[5] The method for removing a musty odor substance according to any one of [1] to [4], further comprising a regeneration step of regenerating the ion exchanger.
[6] The mixing step is a step of mixing the water to be treated that has not been treated with activated carbon and the cyclic compound, and the ion exchange treatment step is the water to be treated that has not been treated with activated carbon and is a mixture of the cyclic compound. The method for removing a musty odor substance according to any one of [1] to [5], which is a step of bringing the ion exchanger into contact with the ion exchanger.
[7] Further having an activated carbon treatment step of bringing the water to be treated into contact with the activated carbon, the ion exchange treatment step and the activated carbon treatment step are carried out at the same time, or the ion exchange treatment step is carried out after the activated carbon treatment step. 1] The method for removing a musty odor substance according to any one of [5].

[8] A water treatment device capable of removing a musty odor substance that removes at least one of geosmin and 2-MIB contained in the water to be treated, and is a ring capable of forming an inclusion compound with at least one of geosmin and 2-MIB. A water treatment apparatus capable of removing musty odor substances, comprising a mixing means for mixing the compound and water to be treated, and an ion exchange treatment means for bringing the water to be treated mixed with the cyclic compound into contact with an ion exchanger.
[9] The water treatment apparatus capable of removing a musty odor substance according to [8], wherein the cyclic compound is at least one selected from the group consisting of cyclodextrin, calixarene and derivatives thereof.
[10] The water treatment apparatus according to [8] or [9], wherein the cyclic compound has a negative charge and the ion exchanger is an anion exchanger.
[11] The water treatment apparatus according to [8] or [9], wherein the cyclic compound has a positive charge and the ion exchanger is a cation exchanger, which can remove the musty odor substance.
[12] The water treatment apparatus capable of removing the musty odor substance according to any one of [8] to [11], further comprising a regeneration facility for regenerating the ion exchanger.
[13] The mixing means is a means for mixing the water to be treated that has not been treated with activated carbon and the cyclic compound, and the ion exchange treatment means is the water to be treated that has not been treated with activated carbon and is a mixture of the cyclic compound. The water treatment apparatus capable of removing the musty odor substance according to any one of [8] to [12], which is a means for bringing the ion exchanger into contact with the ion exchanger.
[14] The activated carbon treatment means for bringing the water to be treated into contact with the activated carbon is further provided, and the ion exchange treatment means and the activated carbon treatment means are configured as one treatment means, or the ion exchange treatment means is the activated carbon treatment. A water treatment device provided downstream of the means and capable of removing the musty odor substance according to any one of [8] to [12].

According to the method for removing a musty odor substance and the water treatment apparatus capable of removing the musty odor substance of the present invention, the musty odor substance can be easily removed at low cost.

It is the schematic which shows an example of the water treatment apparatus which can remove the musty odor substance of the 1st aspect of this invention. It is the schematic which shows an example of the water treatment apparatus which can remove the musty odor substance of the 2nd aspect of this invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.
In the drawings below, the scale of each member is appropriately changed in order to make each member recognizable.
Further, in FIG. 2, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

The musty odor substance to be removed by the present invention is at least one of geosmin and 2-methylisoborneol (2-MIB).
The water to be treated to be treated in the present invention is water containing a musty odor substance. Examples of such water to be treated include groundwater, well water, river water, water in stagnant water areas, and the like. Examples of stagnant water areas include lakes and marshes and reservoirs. In particular, the present invention is suitable for treating water in which phytoplankton such as blue-green algae and microorganisms such as actinomycetes of the genus Streptomyces propagate and generate a musty odor.

"First aspect"
<Water treatment device that can remove musty odor substances>
FIG. 1 shows an example of a water treatment apparatus capable of removing a musty odor substance according to the first aspect of the present invention.
The water treatment device 1 capable of removing the musty odor substance shown in FIG. 1 includes a water pumping means 10 for pumping the water to be treated W from a stagnant water area or the like, a storage tank 20 for temporarily storing the water W to be treated, and the like. The mixing means 30 that mixes the water to be treated W and the cyclic compound, the ion exchange treatment means 40 that brings the water W to be treated mixed with the cyclic compound into contact with the ion exchanger, and the treated water (hereinafter, "" It is provided with a treated water tank 50 for storing (also referred to as "treated water").

The water pumping means 10 pumps the water to be treated W from an area where the water to be treated exists, such as a stagnant water area, and includes a pump 11 for pumping the water to be treated W and a pumping pipe 12.
One end of the pumping pipe 12 of this example is connected to the pumping pump 11, and the other end is connected to the storage tank 20.

The storage tank 20 temporarily stores the water to be treated W. The water to be treated W passes through the pumping pipe 12 and is stored in the storage tank 20.
The water to be treated W stored in the storage tank 20 passes through the first water pipe 21 and is supplied to the ion exchange treatment means 40.

A mixing means 30 for mixing the water to be treated W and the cyclic compound is connected to the first water pipe 21.
The mixing means 30 includes a scavenger dissolution tank 31 for accommodating the cyclic compound and a scavenger supply pipe 32 for supplying the cyclic compound to the first water pipe 21. In the present embodiment, the trapping agent supply pipe 32 joins in the middle of the first water pipe 21, and the cyclic compound is supplied to the water W to be treated in the first water pipe 21 to be combined with the water W to be treated. It is designed to be mixed with a cyclic compound.

As the cyclic compound, a compound capable of forming a clathrate compound with at least one of geosmin and 2-MIB is used. As such a compound, one or more selected from the group consisting of cyclodextrin, calixarene and derivatives thereof is preferable.
Cyclodextrin, also called Shardinger dextrin, is a D-glucose molecule that forms a cyclic structure with α1 → 4 bonds. Examples of the cyclodextrin include α-cyclodextrin having a degree of polymerization of 6, β-cyclodextrin having a degree of polymerization of 7, and γ-cyclodextrin having a degree of polymerization of 8.
Commercially available products can be used as cyclodextrin and its derivatives, for example, "amino-deoxy-β-cyclodextrin" manufactured by Tokyo Kasei Kogyo Co., Ltd .; "sulfobutoxy-β-cyclodextrin" manufactured by Funakoshi Co., Ltd .; Examples thereof include carboxymethyl-β-cyclodextrin (Cas No .: 218269-34-2).
On the other hand, calixarene is a cyclic oligomer in which a plurality of positions 2 and 6 of a phenol derivative are bonded via crosslinked chains such as a methylene bond, an ether bond, a sulfide bond, and a sulfone bond.

Cyclodextrin, calixarene and their derivatives have a cyclic structure and are compounds that enclose other atoms and molecules in their pores, and play a role in encapsulating and capturing musty odor substances. For example, calixarene and its derivatives are thought to capture the musty odor substance by forming a 1: 1 or 2: 1 inclusion complex with the musty odor substance from the inner pore size of the cyclic compound. Therefore, it is preferable to mix the water to be treated W and the cyclic compound so that the molar concentration of the cyclic compound in the water to be treated is equal to or more than the molar concentration of the musty odor substance.

In addition, cyclodextrin, calix arene and derivatives thereof are chemically modified as compared with other cyclic compounds to have an anionic group (for example, a sulfonic acid group, a carboxy group, a phosphonic acid group, etc.) or a cationic group (for example, an ammonium group, etc.). Amino groups, etc.) can be easily chemically introduced, and musty odor substances can be more easily included.
Among them, calixarene and its derivatives are preferable because they can easily introduce a sulfonic acid group, which is an anionic group, by reaction with sulfuric acid, can be easily purified, and can be obtained at low cost.
The anionic group-introduced cyclic compound has a negative charge, and the cationic group-introduced cyclic compound has a positive charge.

The number of repeating units of cyclodextrin, calixarene and their derivatives is not particularly limited.
In addition, cyclodextrin, calixarene and derivatives thereof include, but are not limited to, those having a crosslinked portion by a methylene bond, a sulfide bond, a sulfone bond, an ether bond and the like. An example is shown below.

Examples of the negatively charged cyclic compound include 4-sulfocalix [4] arene, 4-sulfocalix [6] arene, 4-sulfocalix [8] arene, 4-sulfothiacalix [4] arene, and 4-carboxy. Examples thereof include methyl calix [4] arene and carboxymethyl-β-cyclodextrin.
Examples of the positively charged cyclic compound include dimethylaminomethyl calix [4] arene, trimethylammonium methyl calix [4] arene, amino-deoxy-α-cyclodextrin, amino-deoxy-β-cyclodextrin, and amino-deoxy-. Examples thereof include γ-cyclodextrin.

The ion exchange treatment means 40 brings the water W to be treated mixed with the cyclic compound into contact with the ion exchanger.
The ion exchange processing means 40 of the present embodiment includes an ion exchanger tower 41 filled with an ion exchanger. A filter 42 for preventing the outflow of the ion exchanger is installed in the ion exchanger tower 41.
A first water pipe 21 is connected to the upper part of the ion exchanger tower 41.

The ion exchanger tower 41 is filled with the ion exchanger so as to form a fixed bed or a fluidized bed.
The ion exchanger has an ion exchanger (fixed ion) chemically bonded to the skeletal polymer on the surface and inside of the skeletal polymer (resin matrix). The cyclic compound (that is, the clathrate compound) that encapsulates the musty odor substance is adsorbed by this ion exchange group, and the musty odor substance can be removed from the water W to be treated.
Examples of the skeleton polymer include styrene-based, (meth) acrylic-based, (meth) acrylamide-based, and cellulose-based polymers. Among these, (meth) acrylic and (meth) acrylamide polymers, which are hydrophilic polymers, are preferable from the viewpoint of organic contamination resistance, and styrene polymers are preferable from the viewpoint of cost.

Examples of the ion exchanger include an anion exchanger and a cation exchanger.
When the water to be treated W and the cyclic compound having a negative charge are mixed, it is preferable to use an anion exchanger as the ion exchanger. When the water W to be treated and the cyclic compound having a positive charge are mixed, it is preferable to use a cation exchanger as the ion exchanger.

The anion exchanger may be weakly basic or strongly basic, but a strongly basic anion exchanger is preferable because a cyclic compound encapsulating a musty odor substance is easily adsorbed.
Here, the "strongly basic anion exchanger" is an anion exchanger having a quaternary ammonium group which is in a dissociated state even if it is alkaline as an ion exchange group.

Examples of the strong basic anion exchanger include those having various ion exchange groups. Examples of the ion exchange group include a trimethylammonium group, a triethylammonium group, a tripropylammonium group, a tributylammonium group, a hydroxyethyldimethylammonium group, a dihydroxyethylmethylammonium group and the like. Among these, maximization of static exchange capacity, increase in the amount of organic matter due to elution due to inferior thermal stability of ion exchange groups, generation of odor derived from ion exchange groups, ion exchange groups due to long-term use A trimethylammonium group is preferable as the ion exchange group from the viewpoint of the generation of formaldehyde due to the loss of the ion exchange group and the decomposition of the ion exchange group.

Examples of the anion exchanger include anion exchange resin and anion exchange fiber.
The particle size of the anion exchange resin is preferably large from the viewpoint of suppressing an increase in the pressure loss of the resin. The average particle size of the anion exchange resin is preferably 100 μm or more, more preferably 200 μm or more, and further preferably 300 μm or more.
On the other hand, from the viewpoint of minimizing the adsorption zone length and maximizing the once-through exchange capacity, it is preferable that the particle size of the anion exchange resin is small. The average particle size of the anion exchange resin is preferably 800 μm or less, more preferably 700 μm or less, still more preferably 600 μm or less, and particularly preferably 500 μm or less.
The anion exchange resin may be a resin having a particle size distribution or a resin having a uniform particle size having the same particle size. Further, the anion exchange resin may be a gel type or a porous type. However, when a gel-type anion exchange resin is used, the degree of cross-linking of the gel-type anion exchange resin is preferably low because the molecular weight of the inclusion compound adsorbed on the anion exchange resin is relatively large. Specifically, the degree of cross-linking of the gel-type anion exchange resin is preferably 10% or less, more preferably 6% or less. On the other hand, when a porous type anion exchange resin is used, it is preferable to have a pore diameter capable of diffusing cyclodextrin, calixarene and derivatives thereof inside.
When a strong basic anion exchange resin is used as the anion exchange resin, the strong basic anion exchange resin may be type I or type II.

Commercially available products can be used as the anion exchange resin, for example, Amberlite "IRA402", "IRA901", "XT5007", "IRA958", "IRA458" and Dowex Marathon manufactured by The Dow Chemical Company. "A", "A2", "SBR", "MSA", "MSA-1", "C", "C-1" and Duolite "A132"; Purofine "PFA850" manufactured by Purolite Co., Ltd .; Rebatit "MP500", "M500", "MP504", "A8071" manufactured by Ion Exchange India; "Indion A930" manufactured by Ion Exchange India; Manufactured diamond ions "SA10A", "SA12A", "SA20A", "PA308", rewrites "JA800", "JA810" and the like are suitable.

The fibers constituting the anion exchange fibers may be short fibers or long fibers. The anion exchange fiber may be a graft polymerization type.
The average fiber diameter of the anion exchange fiber is preferably 1 μm or more, more preferably 10 μm or more. The average fiber diameter of the anion exchange fibers is preferably 1 mm or less, more preferably 500 μm or less, still more preferably 100 μm or less, and particularly preferably 50 μm or less.
As the anion exchange fiber, a commercially available product can be used, and for example, "IEF-SA" manufactured by Nichibi Co., Ltd. is suitable.

The cation exchanger may be weakly acidic or strongly acidic, but a strongly acidic cation exchanger is preferable because a cyclic compound encapsulating a musty odor substance is easily adsorbed.
Here, the "strongly acidic cation exchanger" is a cation exchanger having a sulfonic acid group as an ion exchange group.

Examples of the cation exchanger include cation exchange resins and cation exchange fibers.
Commercially available products can be used as the cation exchange resin, for example, Amber Jet "1200", Amber Light "IR120B", "IR112", Dowex "MSC-1", "" manufactured by The Dow Chemical Company. "HCR"; Rebatit "SP112", "S100" manufactured by LANXESS; Diaion "SK1B", "SK104", "PK208", "PK212" manufactured by Mitsubishi Chemical Co., Ltd. are suitable.

The fibers constituting the cation exchange fibers may be short fibers or long fibers. The cation exchange fiber may be a graft polymerization type.
The average fiber diameter of the cation exchange fibers is preferably 1 μm or more, more preferably 10 μm or more. The average fiber diameter of the cation exchange fibers is preferably 1 mm or less, more preferably 500 μm or less, still more preferably 100 μm or less, and particularly preferably 50 μm or less.
As the cation exchange fiber, a commercially available product can be used, and for example, "IEF-SC" manufactured by Nichibi Co., Ltd. is suitable.

The ion exchange processing means 40 of this example is provided with a regeneration facility 60 for regenerating the ion exchanger.
The regenerating facility 60 comprises a regenerating agent supply pipe 61 that supplies the regenerating agent to the ion exchanger tower 41 of the ion exchange processing means 40, a regenerating agent discharge pipe 62 that discharges the regenerating agent from the ion exchanger tower 41, and a regenerating agent. It is provided with a regenerator storage tank 63 for storing. In the present embodiment, one end of the regenerating agent supply pipe 61 is connected to the regenerating agent containing tank 63, and the other end is connected to the upper part of the ion exchanger tower 41. On the other hand, one end of the regenerating agent discharge pipe 62 is connected to the lower part of the ion exchanger tower 41.

Examples of the regenerating agent include aqueous solutions of sodium chloride, potassium chloride, sodium sulfate, ammonium sulfate, sodium hydroxide, sodium bromide, sulfuric acid, hydrochloric acid, seawater and the like. Among these, sodium chloride aqueous solution and potassium chloride aqueous solution are preferable because the counter ion of the anion exchanger becomes chloride ion in the one-stage regeneration. When an aqueous solution of a regenerating agent such as sodium sulfate, sodium hydroxide, sodium bromide, or ammonium sulfate is used as the regenerating agent, the counter ion of the anion exchanger becomes sulfate ion, hydroxide ion, or bromide ion, and thus chloride. In order to convert it into an ionic form, it may be regenerated in two stages using an aqueous sodium chloride solution or an aqueous potassium chloride solution.

The water W to be treated that has passed through the ion exchange treatment means 40 is discharged from the lower end of the ion exchanger tower 41, passes through the second water pipe 43, and is stored in the treatment water tank 50. One end of the second water pipe 43 is connected to the lower part of the ion exchanger tower 41, and the other end is connected to the treatment water tank 50.
A first treated water supply pipe 51 for supplying treated water to a water receiving tank (not shown) is connected to the treated water tank 50.
Further, a second treated water supply pipe 53 provided with a treated water pump 52 is connected to the treated water tank 50. The second treated water supply pipe 53 joins the regenerating agent supply pipe 61.

<How to remove musty odor substances>
Hereinafter, an example of a method for removing a musty odor substance from the water to be treated using the water treatment device 1 capable of removing the musty odor substance shown in FIG. 1 will be described.
First, the pump 11 is operated to pump the water to be treated W from a stagnant water area or the like. The pumped water W to be treated is supplied to the storage tank 20 through the pumping pipe 12 and temporarily stored.

The water to be treated W stored in the storage tank 20 is supplied to the ion exchange treatment means 40 through the first water pipe 21. When the water to be treated W passes through the first water pipe 21, the water to be treated W and the cyclic compound are mixed at the confluence of the first water pipe 21 and the scavenger supply pipe 32 (mixing step). ).
The mixing ratio of the water to be treated W and the cyclic compound is determined according to the concentration of the musty odor substance contained in the water to be treated W. Specifically, it is preferable to mix the water to be treated W and the cyclic compound so that the molar concentration of the cyclic compound in the water to be treated is equal to or more than the molar concentration of the musty odor substance. The larger the ratio of the cyclic compound to the water W to be treated, the easier it is to enclose the musty odor substance, but on the other hand, the amount of the ion exchanger to be treated increases and the adsorption saturation tends to be easily reached. Considering the life and cost of the ion exchanger and the content of organic substances in the water W to be treated, the concentration of the cyclic compound is 1 ppm or less with respect to 1 L of the water W to be treated. It is preferable to mix with the compound, more preferably 100 ppb or less, further preferably 10 ppb or less, and particularly preferably 1 ppb or less.

The water W to be treated mixed with the cyclic compound is supplied to the ion exchange treatment means 40. The water W to be treated passes through the ion exchanger tower 41 of the ion exchange treatment means 40 in a downward flow, and in the meantime, comes into contact with the ion exchanger (ion exchange treatment step).
When the water W to be treated comes into contact with the ion exchanger, the cyclic compound encapsulating the musty odor substance is adsorbed on the anion exchanger, and as a result, the musty odor substance is removed from the water W to be treated.

Liquid permeation speed of the treatment water W is passed through the ion exchanger column 41 varies depending water, but preferably 1～200Hr ^-1, for example, a space velocity (SV), more preferably 5~100hr ^-1, 10~ 50 hr ^-1 is more preferable. When the liquid passing speed is low, the filling amount of the ion exchanger into the ion exchanger tower 41 increases. On the other hand, when the liquid passing speed is high, the adsorption band length becomes long, and the utilization efficiency of the exchange group decreases.
The temperature of the water to be treated W passed through the ion exchanger tower 41 is preferably 4 to 70 ° C, more preferably 5 to 50 ° C, and even more preferably 10 to 35 ° C. When the liquid passing temperature is low, the diffusion rate in the ion-exchanged body becomes low, and the processing amount decreases. On the other hand, when the liquid passing temperature is high, the ion exchanger decomposes or the elution amount increases and deteriorates.

The water to be treated W that has passed through the ion exchange treatment means 40 is supplied to the treated water tank 50 as treated water through the second water pipe 43, and is temporarily stored. Then, it is supplied to the water receiving tank (not shown) through the first treated water supply pipe 51.

When the water W to be treated is continuously treated, it is preferable to periodically regenerate the ion exchanger filled in the ion exchanger tower 41 (regeneration step).
When regenerating the ion exchanger, first, the pump 11 is stopped. Next, the regenerating agent is supplied from the regenerating agent containing tank 63 to the regenerating agent supply pipe 61. The regenerating agent is supplied to the ion exchanger tower 41 through the regenerating agent supply pipe 61. The regenerant supplied to the ion exchanger tower 41 passes through the ion exchanger tower 41 in a downward flow, is discharged from the lower part of the ion exchanger tower 41, and is discharged to the outside of the system through the regenerator discharge pipe 62. Will be done.

Since the regenerating agent contained in the regenerating agent accommodating tank 63 has a relatively high concentration, it is preferable to dilute it before supplying it to the ion exchanger tower 41. It is preferable to use treated water or, depending on the situation, raw water for diluting the regenerant.
When the regenerant is diluted with the treated water, the treated water pump 52 is operated to send the treated water stored in the treated water tank 50 to the second treated water supply pipe 53. The treated water is supplied to the regenerating agent supply pipe 61 through the second treated water supply pipe 53, and the regenerating agent is diluted with the treated water in the regenerating agent supply pipe 61.
The concentration of the regenerating agent passing through the ion exchanger tower 41 is preferably 2 to 25% by mass, more preferably 2 to 20% by mass, further preferably 4 to 20% by mass, and 7 to 7 to the total mass of the regenerating agent. 15% by mass is particularly preferable.

The amount of water flowing through the ion exchanger tower 41 is preferably in the range of 50 to 1000 g with respect to 1 L of the ion exchanger filled in the ion exchanger tower 41. For example, when 500 mL of a sodium chloride aqueous solution having a concentration of 10% by mass with respect to 1 L of the ion exchanger is passed through the ion exchanger tower 41, the input amount of the regenerating agent is 50 g / L-resin, and the regeneration level of the regenerating agent is 50 g. being called.

When an organic substance is adsorbed on the ion exchanger, a water-soluble alcohol such as methanol or ethanol, an aqueous solution thereof, or an electrolyte solution thereof may be used as the regenerating agent.
If the function of the ion exchanger does not recover even after the regeneration operation, replace the ion exchanger.

<Effect>
According to the water treatment apparatus capable of removing the musty odor substance according to the first aspect of the present invention described above and the method for removing the musty odor substance using the water treatment apparatus capable of removing the musty odor substance, the above-mentioned specific cyclic compound. By mixing the water to be treated with the water to be treated, the musty odor substance contained in the water to be treated is supplemented by the cyclic compound. Further, by bringing the water to be treated mixed with the cyclic compound into contact with the ion exchanger, the cyclic compound encapsulating the musty odor substance is adsorbed on the ion exchanger, and the musty odor substance is removed from the water to be treated.
As described above, according to the present invention, the water to be treated has a musty odor by a low-cost and simple method of mixing the water to be treated with the cyclic compound and contacting the water to be treated with the cyclic compound with the ion exchanger. The substance can be removed.

<Other forms>
In the water treatment device 1 capable of removing the musty odor substance shown in FIG. 1, the other end of the first water pipe 21 is connected to the upper part of the ion exchanger tower 41, and one end of the second water pipe 43 is the ion exchanger tower. Although connected to the lower part of 41, the other end of the first water pipe 21 is connected to the lower part of the ion exchanger tower 41, and one end of the second water pipe 43 is connected to the upper part of the ion exchanger tower 41. It may have been. In this case, the water to be treated W passes through the ion exchanger tower 41 in an upward flow. Further, the ion exchanger tower 41 may be installed sideways and the water to be treated W may be passed in a lateral flow. However, from the viewpoint of increasing the adsorption zone length due to the vertical diffusion of the water to be treated W, reducing the treatment amount as a result, and simplifying the process, the water to be treated W is passed through the ion exchanger tower 41 in a downward flow. Is preferable.

Further, in the water treatment apparatus 1 capable of removing the musty odor substance shown in FIG. 1, the cyclic compound and the water to be treated W are mixed in the first water passage pipe 21, but the cyclic compound and the water to be treated W are mixed. It may be mixed in the storage tank 20 or in the ion exchanger tower 41. That is, in FIG. 1, the scavenger supply pipe 32 is connected to the first water passage pipe 21, but even if the scavenger supply pipe 32 is connected to the storage tank 20, it is connected to the upper part of the ion exchanger tower 41. May be good.

The ion exchange processing means 40 shown in FIG. 1 is provided with a regeneration facility 60, and the ion exchanger can be regenerated on the spot. For example, even if the ion exchanger tower 41 is replaced with a new one filled with an anion exchanger, the used ion exchanger tower 41 is moved to another place, and then the ion exchanger is regenerated. Good. In this case, the installation of the reproduction equipment 60 can be omitted.

Further, a sand filtration tower (not shown) filled with sand such as filtered sand, filtered gravel, manganese sand, and manganese dioxide grains may be installed upstream of the ion exchange processing means 40. If the water to be treated contains iron or manganese, the sand filter tower removes iron and manganese. Before supplying the water to be treated to the sand filtration tower, add a coagulant such as polyaluminum chloride (PAC), aluminum sulfate (aluminum sulfate band), an organic polymer flocculant, and an organic coagulant to the water to be treated. Is preferable.
If the water to be treated contains a large amount of iron (II) ions, air is bubbled or press-fitted into the water to be treated before the water to be treated is treated with the sand filtration tower to generate iron (II) ions. May be air-oxidized to iron (III) ions. Alternatively, iron (III) ions may be precipitated by oxidation with sodium hypochlorite.

Further, a membrane separation means (not shown) may be installed between the ion exchange treatment means 40 and the treatment water tank 50. When the water to be treated contains bacteria and suspended solids, the bacteria and suspended solids are removed by the membrane separation means.
The membrane separation means is not particularly limited, and examples thereof include a known membrane module provided with a known separation membrane (filtration membrane). As the type of separation membrane, a microfiltration membrane (MF membrane) and an ultrafiltration membrane (UF membrane) are preferable.

Further, in the first aspect, the water to be treated W is temporarily stored in the storage tank 20, but the water to be treated W may be directly supplied to the ion exchange treatment means 40. In this case, since the pumping pipe 12 also serves as the first water passage pipe 21, the mixing means 30 is connected to the pumping pipe 12.

"Second aspect"
<Water treatment device that can remove musty odor substances>
FIG. 2 shows an example of a water treatment apparatus capable of removing a musty odor substance according to a second aspect of the present invention.
The water treatment device 2 capable of removing the musty odor substance shown in FIG. 2 includes a water pumping means 10 for pumping the treated water W from a stagnant water area or the like, a storage tank 20 for temporarily storing the treated water W, and the like. The activated carbon treatment means 70 that brings the water to be treated W into contact with the activated carbon, the mixing means 30 that mixes the water to be treated W and the cyclic compound, and the ions that bring the water to be treated W mixed with the cyclic compound into contact with the ion exchanger. It includes a replacement treatment means 40 and a treatment water tank 50 for storing treated water.

In the first aspect, as shown in FIG. 1, the activated carbon treatment means is not provided between the storage tank 20 and the ion exchange treatment means 40. That is, in the first aspect, the mixing means 30 is a means for mixing the water W to be treated and the cyclic compound which has not been treated with activated carbon, and the ion exchange treatment means 40 is a means for mixing the cyclic compound and not being treated with activated carbon. This is a means for bringing the treated water W into contact with the ion exchanger.
On the other hand, in the second aspect, as shown in FIG. 2, the activated carbon treatment means 70 is provided between the storage tank 20 and the ion exchange treatment means 40. Further, the mixing means 30 is connected to a third water pipe 72, which will be described later. In these respects, the water treatment device 2 capable of removing the musty odor substance of the second aspect is different from the water treatment device 1 capable of removing the musty odor substance of the first aspect. Other than that, it is the same as the water treatment device 1 capable of removing the musty odor substance of the first aspect, and the preferred embodiment is also the same.

The activated carbon treatment means 70 brings the water to be treated W and the activated carbon into contact with each other.
The activated carbon treatment means 70 of the present embodiment includes an activated carbon adsorption tower 71 filled with activated carbon.
A first water pipe 21 is connected to the upper part of the activated carbon adsorption tower 71.

The water W to be treated that has passed through the activated carbon treatment means 70 is discharged from the lower end of the activated carbon adsorption tower 71, passes through a third water pipe 72, and is supplied to the ion exchange treatment means 40. One end of the third water pipe 72 is connected to the lower part of the activated carbon adsorption tower 71, and the other end is connected to the upper part of the ion exchanger tower 41.
A mixing means 30 for mixing the water to be treated W and the cyclic compound is connected to the third water pipe 72. In the present embodiment, the trapping agent supply pipe 32 joins in the middle of the third water pipe 72, and the cyclic compound is supplied to the water to be treated W in the third water pipe 72 to be combined with the water W to be treated. It is designed to be mixed with a cyclic compound.

<How to remove musty odor substances>
Hereinafter, an example of a method for removing a musty odor substance from the water to be treated using the water treatment device 2 capable of removing the musty odor substance shown in FIG. 2 will be described.
First, the pump 11 is operated to pump the water to be treated W from a stagnant water area or the like. The pumped water W to be treated is supplied to the storage tank 20 through the pumping pipe 12 and temporarily stored.

The water to be treated W stored in the storage tank 20 is supplied to the activated carbon treatment means 70 through the first water pipe 21. The water W to be treated passes through the activated carbon adsorption tower 71 of the activated carbon treatment means 70 in a downward flow, and comes into contact with the activated carbon during this period (activated carbon treatment step).
The musty odor substance may contain trihalomethanes. When the water to be treated W comes into contact with the activated carbon, if trihalomethane is contained in the musty odor substance, the trihalomethane is removed.

The water W to be treated that has passed through the activated carbon treatment means 70 is supplied to the ion exchange treatment means 40 through the third water pipe 72. When the water to be treated W passes through the third water pipe 72, the water to be treated W and the cyclic compound are mixed at the confluence of the third water pipe 72 and the scavenger supply pipe 32 (mixing step). ).
The water W to be treated mixed with the cyclic compound is supplied to the ion exchange treatment means 40, passes through the ion exchanger tower 41 of the ion exchange treatment means 40, and comes into contact with the ion exchanger during this time (ion exchange treatment step).
When the water W to be treated comes into contact with the ion exchanger, the cyclic compound encapsulating the musty odor substance is adsorbed on the anion exchanger, and as a result, the musty odor substance is removed from the water W to be treated.

The water to be treated W that has passed through the ion exchange treatment means 40 is supplied to the treated water tank 50 as treated water through the second water pipe 43, and is temporarily stored. Then, it is supplied to the water receiving tank (not shown) through the first treated water supply pipe 51.

The mixing ratio of the water to be treated W and the cyclic compound, the liquid passing speed and the liquid passing temperature of the water to be treated W passed through the ion exchanger tower 41, and the regeneration of the ion exchanger are the same as those in the first aspect. Therefore, the description thereof will be omitted.
The mixing step in the first aspect is a step of mixing the water to be treated and the cyclic compound which have not been treated with activated carbon, and the ion exchange treatment step is a step of mixing the water to be treated and the cyclic compound which have not been treated with activated carbon and ions. This is a step of contacting the exchange body.

<Effect>
According to the water treatment apparatus capable of removing the musty odor substance according to the second aspect of the present invention described above and the method for removing the musty odor substance using the water treatment apparatus capable of removing the musty odor substance, the above-mentioned specific cyclic compound. By mixing the water to be treated with the water to be treated, the musty odor substance contained in the water to be treated is supplemented by the cyclic compound. Further, by bringing the water to be treated mixed with the cyclic compound into contact with the ion exchanger, the cyclic compound encapsulating the musty odor substance is adsorbed on the ion exchanger, and the musty odor substance is removed from the water to be treated.
As described above, according to the present invention, the water to be treated has a musty odor by a low-cost and simple method of mixing the water to be treated with the cyclic compound and contacting the water to be treated with the cyclic compound with the ion exchanger. The substance can be removed.

Moreover, in the second aspect, the activated carbon treatment means is provided upstream of the ion exchange treatment means, and the activated carbon treatment step is performed before the ion exchange treatment step. Therefore, when trihalomethane is contained in the musty odor substance, the activated carbon treatment step is performed. , Trihalomethane can also be removed.

<Other forms>
In the water treatment apparatus 2 capable of removing the musty odor substance shown in FIG. 2, the ion exchange treatment means 40 is provided downstream of the activated carbon treatment means 70, but the ion exchange treatment means 40 and the activated carbon treatment means 70 are used as one treatment means. It may be configured. That is, one tower may be filled with an ion exchanger and activated carbon. Specifically, in FIG. 2, the ion exchanger may be filled in the activated carbon adsorption tower 71, or the activated carbon may be filled in the ion exchanger tower 41. Such a state is also called a mixed floor. On the other hand, as shown in FIG. 2, the state in which the ion exchanger and the activated carbon are filled in separate towers is also referred to as a single bed. In the case of a mixed bed state of the ion exchanger and activated carbon, the ion exchange treatment step and the activated carbon treatment step are performed at the same time.

Further, in the water treatment device 2 capable of removing the musty odor substance shown in FIG. 2, the other end of the third water pipe 72 is connected to the upper part of the ion exchanger tower 41, and one end of the second water pipe 43 is ion exchanged. Although connected to the lower part of the body tower 41, the other end of the third water pipe 72 is connected to the lower part of the ion exchange body tower 41, and one end of the second water pipe 43 is the upper part of the ion exchange body tower 41. It may be connected to. In this case, the water to be treated W passes through the ion exchanger tower 41 in an upward flow. Further, the ion exchanger tower 41 may be installed sideways and the water to be treated W may be passed in a lateral flow. However, from the viewpoint of increasing the adsorption zone length due to the vertical diffusion of the water to be treated W, reducing the treatment amount as a result, and simplifying the process, the water to be treated W is allowed to pass through the ion exchanger tower 41 in a downward flow. Is preferable.

Further, in the water treatment apparatus 2 capable of removing the musty odor substance shown in FIG. 2, the cyclic compound and the water to be treated W are mixed in the third water passage pipe 72, but the cyclic compound and the water to be treated W are mixed. It may be mixed in the storage tank 20, mixed in the first water passage pipe 21, or mixed in the ion exchanger tower 41. That is, although the scavenger supply pipe 32 is connected to the third water pipe 72 in FIG. 2, the scavenger supply pipe 32 may be connected to the storage tank 20 or the first water pipe 21. , May be connected to the upper part of the ion exchanger tower 41.

The ion exchange processing means 40 shown in FIG. 2 is provided with a regeneration facility 60, and the ion exchanger can be regenerated on the spot. For example, even if the ion exchanger tower 41 is replaced with a new one filled with an anion exchanger, the used ion exchanger tower 41 is moved to another place, and then the ion exchanger is regenerated. Good. In this case, the installation of the reproduction equipment 60 can be omitted.

Further, an acid addition means (not shown) for adding hypochlorite to the water to be treated is provided upstream of the activated carbon treatment means 70, and hypochlorite is added to the water to be treated prior to the activated carbon treatment step. May be good. By adding hypochlorite to the water to be treated, the water to be treated is sterilized.
Examples of hypochlorite include sodium hypochlorite and calcium hypochlorite. Among these, sodium hypochlorite is preferable from the viewpoint of price and distribution.
When the water to be treated contains an organic substance, the organic substance may react with hypochlorite to produce a disinfection by-product such as trihalomethane. However, even if trihalomethane is produced, it is adsorbed on the activated carbon and removed from the water to be treated by the activated carbon treatment means in the subsequent stage. In addition, unreacted organic substances and hypochlorite in the water to be treated are also adsorbed on the activated carbon, so that they are removed from the water to be treated.

Further, a sand filtration tower (not shown) filled with sand such as filtered sand, filtered gravel, manganese sand, and manganese dioxide grains may be installed upstream of the activated carbon treatment means 70. If the water to be treated contains iron or manganese, the sand filter tower removes iron and manganese. Before supplying the water to be treated to the sand filtration tower, add a coagulant such as polyaluminum chloride (PAC), aluminum sulfate (sulfate band), organic polymer flocculant, and organic coagulant to the water to be treated. Is preferable.
When hypochlorite is added to the water to be treated prior to the activated carbon treatment step, it is preferable to install a sand filtration tower downstream of the acid addition means for adding hypochlorite. That is, the sand filtration tower is preferably installed between the acid addition means and the activated carbon treatment means 70.
If the water to be treated contains a large amount of iron (II) ions, air is bubbled or press-fitted into the water to be treated before the water to be treated is treated with the sand filtration tower to generate iron (II) ions. May be air-oxidized to iron (III) ions. Alternatively, iron (III) ions may be precipitated by oxidation with sodium hypochlorite.

Further, a membrane separation means (not shown) may be installed between the ion exchange treatment means 40 and the treatment water tank 50. When the water to be treated contains bacteria and suspended solids, the bacteria and suspended solids are removed by the membrane separation means.
The membrane separation means is not particularly limited, and examples thereof include a known membrane module provided with a known separation membrane (filtration membrane). As the type of separation membrane, a microfiltration membrane (MF membrane) and an ultrafiltration membrane (UF membrane) are preferable.

Further, in the first aspect, the water to be treated W is temporarily stored in the storage tank 20, but the water to be treated W may be directly supplied to the activated carbon treatment means 70. In this case, the pumping pipe 12 also serves as the first water pipe 21.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

"Example 1"
A standard stock solution containing 100 ppm each of geosmin and 2-MIB (“Geosmin 2-methylisoborneol standard stock solution” manufactured by Kanto Chemical Co., Ltd.) is diluted with methanol for HPLC and further diluted with ultrapure water to obtain geosmin and 2-MIB. 500 mL of an aqueous solution having a 2-MIB concentration of 50 ppb was prepared. This aqueous solution was used as water to be treated.
Separately, 500 mL of an aqueous solution containing 0.5 ppm of 4-sulfothia calix [4] arene sodium salt (manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared. This aqueous solution was used as a scavenger solution.

As an ion exchanger, 10 mL of a strongly basic anion exchange resin (manufactured by Mitsubishi Chemical Co., Ltd., "Relite JA810", porous resin) is filled in a glass column with an inner diameter of 13 mm and a height of 50 cm in a water slurry state, and is ultrapure. ^{Water was passed under the conditions of a space velocity of SV20hr-1} and a water flow rate of 40 BV with respect to the volume of the ion exchanger, and the anion exchanger was washed.
Next, after the column was filled with ultrapure water, the water to be treated and the scavenger solution were passed through an HPLC pump under the condition of 1.0 mL / min to treat the water to be treated.
One hour after the start of water flow, the treated water discharged from the outlet of the column was collected and analyzed by a headspace gas chromatograph / mass spectrometer (HS / GC / MS) under the following measurement conditions. The concentration of 2-MIB was measured. The results are shown in Table 1. The lower limit of detection was 10 ppt.

<HS / GC / MS analysis conditions>
-HS device: "Agilent G1888" manufactured by Agilent Technologies.
-GC device: "Agilent 5975C GC-MS" manufactured by Agilent Technologies.
-Sample sample: 1.0 g of sodium chloride was added to 10 mL of treated water and heated to 40 ° C.
-Rising conditions: 50 ° C (holding for 5 minutes) to 250 ° C (holding for 10 minutes), heating rate 10 ° C / min.
-Analysis time: 35 minutes.
-Analytical column: "Agilent DB-5MS" manufactured by Agilent Technologies (30 m x 0.25 mm ID, film thickness 0.25 μm).
-Carrier gas: He.
-Vaporization chamber temperature: 200 ° C.
-Split ratio: 2/1.
-Injection amount: 1.00 μL.

"Example 2"
The water to be treated was treated in the same manner as in Example 1 except that a strong basic anion exchange resin (manufactured by Mitsubishi Chemical Corporation, "Diaion PA308") was used as the ion exchanger, and geosmin and geosmin in the treated water were treated. The concentration of 2-MIB was measured. The results are shown in Table 1.

As is clear from the results in Table 1, in each example, geosmin and 2-MIB were not detected in the treated water.

1 Water treatment device that can remove musty odor substances 2 Water treatment device that can remove musty odor substances 10 Water pumping means 11 Pumping pump 12 Pumping pipe 20 Storage tank 21 First water pipe 30 Mixing means 31 Capture agent dissolution tank 32 Capture agent supply Pipe 40 Ion exchange treatment means 41 Ion exchanger tower 42 Filter 50 Treated water tank 51 First treated water supply pipe 52 Treated water pump 53 Second treated water supply pipe 60 Recycling equipment 61 Reclaiming agent supply pipe 62 Regenerating agent discharge pipe 63 Regenerating agent storage tank 70 Activated charcoal treatment means 71 Activated charcoal adsorption tower 72 Third water pipe W Treated water

Claims (12)

A method for removing a musty odor substance that removes at least one of geosmin and 2-methylisoborneol contained in the water to be treated.
A mixing step of mixing a cyclic compound capable of forming a clathrate compound with at least one of geosmin and 2-methylisoborneol and water to be treated.
An ion exchange treatment step of bringing the water to be treated mixed with the cyclic compound into contact with the ion exchanger,
Have a,
The cyclic compound has an anionic group or a cationic group and has an anionic group or a cationic group.
A method for removing a musty odor substance , wherein the cyclic compound is at least one selected from the group consisting of a cyclodextrin derivative and a calixarene derivative. The cyclic compound has a negative charge and
The method for removing a musty odor substance according to claim 1, wherein the ion exchanger is an anion exchanger. The cyclic compound has a positive charge and
The method for removing a musty odor substance according to claim 1, wherein the ion exchanger is a cation exchanger. The method for removing a musty odor substance according to any one of claims 1 to 3 , further comprising a regeneration step of regenerating the ion exchanger. The mixing step is a step of mixing the water to be treated which has not been treated with activated carbon and the cyclic compound.
The musty odor substance according to any one of claims 1 to 4 , wherein the ion exchange treatment step is a step of bringing the water to be treated, which is a mixture of the cyclic compounds and not treated with activated carbon, into contact with the ion exchanger. Removal method. It further has an activated carbon treatment step in which the water to be treated and the activated carbon are brought into contact with each other.
The method for removing a musty odor substance according to any one of claims 1 to 4 , wherein the ion exchange treatment step and the activated carbon treatment step are carried out at the same time, or the ion exchange treatment step is carried out after the activated carbon treatment step. A water treatment device capable of removing a musty odor substance that removes at least one of geosmin and 2-methylisoborneol contained in the water to be treated.
A mixing means for mixing a cyclic compound capable of forming a clathrate compound with at least one of geosmin and 2-methylisoborneol, and water to be treated.
An ion exchange treatment means for bringing the water to be treated mixed with the cyclic compound into contact with the ion exchanger,
Equipped with a,
The cyclic compound has an anionic group or a cationic group and has an anionic group or a cationic group.
A water treatment apparatus capable of removing a musty odor substance , wherein the cyclic compound is at least one selected from the group consisting of a cyclodextrin derivative and a calixarene derivative. The cyclic compound has a negative charge and
The water treatment device capable of removing a musty odor substance according to claim 7 , wherein the ion exchanger is an anion exchanger. The cyclic compound has a positive charge and
The water treatment device capable of removing a musty odor substance according to claim 7 , wherein the ion exchanger is a cation exchanger. The water treatment apparatus capable of removing the musty odor substance according to any one of claims 7 to 9 , further comprising a regeneration facility for regenerating the ion exchanger. The mixing means is a means for mixing the water to be treated that has not been treated with activated carbon and the cyclic compound.
The musty odor substance according to any one of claims 7 to 10 , wherein the ion exchange treatment means is a means for bringing the water to be treated, which is a mixture of the cyclic compounds, and the water to be treated, which has not been treated with activated carbon, into contact with the ion exchanger. Removable water treatment equipment. Further provided with activated carbon treatment means for bringing the water to be treated into contact with activated carbon,
Any one of claims 7 to 10 , wherein the ion exchange treatment means and the activated carbon treatment means are configured as one treatment means, or the ion exchange treatment means is provided downstream of the activated carbon treatment means. A water treatment device capable of removing the musty odor substance described in 1.

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