JPH1177063A - Treatment of ammonium adipate waste solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly efficiently recover an adipic acid component and an ammonium component by adding a calcium source to an ammonium adipate-containing waste soln. to make the waste soln. weak alkaline and separating generated ammonia gas while subjecting calcium adipate crystallized in a reaction soln. to solid-liquid separation. SOLUTION: Waste solns. containing ammonium adipate are collected in waste soln. storage tanks 1, 2 to be respectively taken out in a predetermined ratio. The taken-out waste solns. are supplied to an RO apparatus 3 to concentrate ammonium adipate and the conc. ammonium adipate waste soln. is guided to a calcium adipate forming tank 4. Cream of lime obtained by emulsifying calcium hydroxide by industrial water or the like is added to the tank 4 and air is blown in the tank 4 from the lower part thereof. By this treatment, ammonia is separated and recovered and calcium adipate hydrate is precipitated in the tank 4. The overflow slurry is sent to a sedimentation tank 5 to be subjected to sedimentation treatment and calcium adipate is separated and recovered from a condensing part by a centrifugal separator 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a waste liquid containing ammonium adipate generated during a chemical conversion treatment or the like in a method for producing an aluminum electrode foil for an electrolytic capacitor, for example.

[0002]

2. Description of the Related Art Conventionally, a method for treating adipic acid waste liquid is disclosed in Japanese Patent Application Laid-Open Nos. 1-224092 and 54-11-11.
Methods described in JP-A-5314 and JP-A-51-32513 are exemplified. In each of these methods, an adipic acid waste liquid is added with an inorganic salt in an acidic state or concentrated to crystallize adipic acid.However, it can be said that the recovery rate of adipic acid is still sufficient. No further improvement was desired. Furthermore, no consideration has been given to an effective treatment of a waste liquid containing ammonium adipate composed of a component having high solubility.

Next, generation of waste liquid containing ammonium adipate from the chemical conversion treatment in the method for producing an aluminum electrode foil for an electrolytic capacitor will be described in detail.
In an aluminum electrolytic capacitor characterized by small size and large capacity, an aluminum foil is subjected to a so-called etching treatment to increase the effective surface area, and then subjected to a chemical treatment to form an insulating aluminum oxide film on the surface. In this chemical conversion treatment,
In the past, a borate-based electrolytic solution (chemical conversion solution) was used, but an ammonium adipate chemical conversion bath was proposed in order to improve characteristics such as withstand voltage, dielectric constant, and insulation properties (German Patent 19).
No. 36267, JP-A-49-81240, etc.). Further, by using it in combination with a chemical conversion treatment using a phosphoric acid-based bath, a higher-performance electrode foil can be obtained (JP-A-52-923).
No. 60), currently, a two-stage chemical conversion treatment using an ammonium adipate chemical conversion bath and a phosphoric acid chemical conversion bath is widely performed.

[0004] In these chemical conversion treatments, impurities accumulate in the chemical conversion bath due to the dissolution of electrochemical reaction products and aluminum materials, and if the chemical conversion treatment is continued as it is, the physical and electrochemical performance of the aluminum electrode foil is reduced. After a predetermined amount of the aluminum material, the chemical conversion treatment is performed in place of a new chemical conversion bath. And the aging chemical bath becomes waste liquid. That is, a waste liquid containing ammonium adipate is generated from this chemical conversion treatment. Further, a phosphoric acid waste liquid is also generated from this chemical conversion treatment.

[0005]

Among the above waste liquids, the phosphoric acid waste liquid is insolubilized as calcium phosphate by adding a generally well-known calcium compound (such as calcium hydroxide), and the calcium phosphate is solidified. 2. Description of the Related Art A wide variety of methods have been widely used in which liquids are separated and collected, used as useful resources, and used as safe wastewater.

However, the waste liquid containing ammonium adipate is composed of an organic acid component having high solubility in water and an ammonia component.
The adipic acid treatment method disclosed in 24092 and the like could not be applied effectively. In other words, there is no definitive method for the treatment of waste liquid containing ammonium adipate, and the actual situation is that environmental problems are avoided by partial treatment such as microbial treatment and ion exchange, and dilution with a large amount of water. is there. Moreover, in the microorganism treatment method, since ammonia must be removed in advance, a huge amount of aeration equipment is required, and there are problems such as sludge treatment. Further, even if the separation of ammonia and the separation of adipic acid are performed by using an ion exchange resin, a secondary problem occurs in the treatment of the eluent and the regenerating solution, and the economic burden is not easy.

An object of the present invention is to provide an effective treatment method capable of almost recovering an adipic acid component and an ammonia component from a waste liquid containing ammonium adipate composed of a component having high solubility in water.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for effectively treating a waste liquid containing ammonium adipate, and as a result, typically using calcium hydroxide, a simple process using adipic acid A method for treating a waste liquid containing ammonium to effectively remove an adipic acid component and an ammonia component and to make it a useful resource has been found.

That is, in the method for treating ammonium adipate waste liquid according to the present invention, a calcium source that reacts with the ammonium adipate to produce calcium adipate is added to the waste liquid containing ammonium adipate, and the mixture is made weakly alkaline to generate. Ammonia gas is separated outside the reaction solution, and calcium adipate crystallized in the reaction solution is subjected to a solid-liquid separation treatment.
According to the present invention, the waste liquid containing ammonium adipate is an organic acid salt having relatively high solubility in water and solid-liquid separation is difficult. However, the calcium source is added to the waste liquid, and the waste liquid is made weakly alkaline and heated. By doing so, it is possible to crystallize calcium adipate having a relatively low solubility and a negative change in solubility due to a temperature rise in the waste liquid after the addition of the calcium source. By solid-liquid separation of the crystallized calcium adipate, it can be separated and recovered at a higher rate than the waste liquid after the addition. At the same time, since the waste liquid after the addition is weakly alkaline and heated, ammonia easily becomes gaseous and is separated out of the waste liquid at a high rate. In this separation, a calcium source is first added to the waste liquid to make it weakly alkaline, and the mixture is aged under stirring while heating.
The generated ammonia gas is first blown into the waste liquid with an air flow to separate and recover the waste gas together with the air flow.Then, the waste liquid is sent to the next tank to precipitate the crystallized calcium adipate, separated from the supernatant liquid, and the sedimented concentrated liquid. If calcium adipate is mechanically separated into solid and liquid by a centrifugal separator or the like and collected, the collection at a high rate can be easily performed.

According to a second aspect of the present invention, in the first aspect of the present invention, a part of the treated wastewater after separating the calcium adipate is returned to the upstream, mixed with the untreated ammonium adipate waste liquid and re-used. It is characterized by processing. According to this invention, a part of the treated wastewater is re-treated together with the untreated wastewater without being drained as it is, so that the separation and recovery rate of adipate ions can be further increased.

[0011] The invention described in claim 3 of the present application is claim 1 or 2.
In the described invention, the calcium source is calcium hydroxide. Calcium hydroxide itself functions as both the calcium source and the alkalizing agent, so that it can be completed with one type of additive as compared to the case where separate agents are used for the calcium source and the alkalizing agent. it can. In addition, it is easy to control and control the amount of addition. Further, calcium hydroxide is economical because it is easy to obtain and handle.

According to a fourth aspect of the present invention, in the first aspect of the invention, the waste liquid containing ammonium adipate is a waste liquid generated in a process of manufacturing an aluminum electrode foil for an electrolytic capacitor. It is a feature. By applying to a waste liquid containing ammonium adipate from such a source, it is possible to reduce the economic and equipment burden for treating the waste liquid generated in the manufacturing process of the electrode foil.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the wastewater after separating calcium adipate is combined with a wastewater containing phosphoric acid generated in another manufacturing process of the aluminum electrode foil for an electrolytic capacitor. And a neutralization treatment with calcium carbonate and / or calcium hydroxide. In the manufacturing process of an aluminum electrode foil for electrolytic capacitors, a phosphoric acid treatment is usually performed after a chemical conversion treatment using an ammonium adipate bath. For example, it has been found that, in the presence of adipate ions, calcium phosphate sludge has the property of capturing adipate ions by chemical reaction or adsorption and maintaining them firmly even in a dilute state. Therefore, the COD in the wastewater can be further reduced by combining the wastewater from which ammonia and calcium adipate are collected with the phosphoric acid wastewater before discharging, and then performing a batch neutralization treatment with one or both of calcium carbonate and calcium hydroxide. .

According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention, the waste liquid containing ammonium adipate is subjected to a concentration treatment of ammonium adipate before adding a calcium source. Is what you do. According to this invention, the crystallization rate of calcium adipate is increased by the concentration treatment, and the calcium adipate can be separated and recovered at a higher recovery rate.

[0015] The invention of claim 7 of the present application is characterized in that, in the invention of claim 6, ammonium adipate is concentrated to 60 g / l or more. By concentrating to such an extent, separation and recovery at a high recovery rate can be performed reliably and easily.

The invention according to an eighth aspect of the present invention is characterized in that, in any one of the first to seventh aspects, the separation of the ammonia gas and the crystallization of calcium adipate are performed at a temperature in the range of 70 ° C to 100 ° C. It is assumed that. Since calcium adipate has the property that the change in solubility due to temperature rise is negative, by performing the crystallization in a temperature range of 70 ° C to 100 ° C, the crystallization rate can be kept high, and after crystallization, Can be prevented from being redissolved.

The ninth aspect of the present invention is characterized in that, in the eighth aspect of the present invention, solid-liquid separation of the crystallized calcium adipate is carried out in a warm state. The heat retention can prevent the crystallized calcium adipate from being redissolved during solid-liquid separation.

[0018] The invention described in claim 10 of the present application is claimed in claims 1 to 9.
In any of the inventions described above, the calcium adipate separated and recovered is oxidized into calcium carbonate. As a result, resources can be reused.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Waste liquids to be treated in the present invention are all waste liquids containing ammonium adipate from various sources. Hereinafter, adipic acid generated in the process of manufacturing aluminum electrode foil for electrolytic capacitors will be described. A waste liquid containing ammonium will be described as an example. Among the waste liquids containing ammonium adipate generated by the chemical conversion treatment, except for dilute waste liquids (usually COD of 4 ppm or less) such as finishing cleaning liquids of, for example, COD of 10 ppm or less, which can be flowed to the drainage system as they are, high concentration aging chemical baths and chemical formation. It treats waste liquid from medium facilities such as waste liquid from ancillary equipment such as a power supply tank in the process and intermediate cleaning liquid. Usually, the main chemical liquid is ammonium adipate 20 to 130 g / l, especially 60 to 110 g / l.
A g / l concentration is widely used, and waste liquid having a concentration of 6 to 15 g / l is generated from the incidental equipment and the intermediate cleaning liquid.

In the present invention, in order to efficiently crystallize ammonium adipate having a solubility of several hundred g / l as calcium adipate having a relatively low solubility to remove adipate ions from the waste liquid, A concentrated ammonium adipate waste liquid is desirable. In particular, the amount of ammonium adipate is at least 60 g / l, preferably 80 g / l.
If it is 1 or more, separation and recovery at a high recovery rate can be performed reliably and easily. The concentration method may be any known method, and includes a reverse osmosis treatment method (hereinafter, referred to as an RO treatment) and an electrolytic dialysis treatment method (hereinafter, referred to as an ED treatment). Ammonium acid can be concentrated to about 110 g / l.

The calcium source is not particularly limited as long as it can crystallize calcium adipate under weak alkalinity. Calcium hydroxide itself can be used as both calcium source and alkalizing agent. In order to work, the two roles can be fulfilled by one type of additive. In addition, it is easy to control and control the amount of addition. Furthermore, it is inexpensive because ordinary industrial calcium hydroxide can be used. It is preferable that calcium hydroxide is uniformly dispersed and added to the waste liquid, and is added in advance as lime milk in order to carry out the reaction efficiently. The higher the concentration of milk of lime, the smaller the amount of liquid phase and the higher the recovery rate of calcium adipate, which is desirable. However, if the concentration is excessive, the supply pipe is likely to be clogged during continuous use. Therefore, the concentration is preferably 30% by weight or less, and practically 10 to 15% by weight.

As the reaction milk base, industrial water is usually used. However, as described above, the amount of liquid phase increases and the concentration of adipate ions decreases accordingly, and the amount of leaked adipate after recovery of calcium adipate increases. Since the rate is reduced, if a part of the diluted calcium adipate wastewater after the recovery of the crystallized calcium adipate is treated with calcium hydroxide and refluxed as lime milk, the recovery rate is further improved.

Calcium adipate has the lowest solubility among adipates, and details of its solubility in a saturated solution of calcium hydroxide are not clear, but according to experiments conducted by the present inventors, it is roughly shown in Table 1. Value. From this Table 1, it is considered that the transformation point between the monohydrate and the anhydrous salt in the aqueous solution is approximately 85 to 95 ° C.

[0024]

[Table 1]

Therefore, in order to efficiently remove adipate ions, it is desirable that the higher the temperature, the lower the solubility. However, in practice, the scale of the apparatus, the total amount of waste water, the presence or absence of post-treatment of the wastewater after the calcium adipate crystal recovery, Is determined by Generally, it is advantageous to set the range of small equilibrium solubility at 95 ° C. or more, since the concentration of dissolved calcium adipate is advantageously reduced, but it is necessary to keep in mind that a large amount of heat energy is required. is there. Practically 70-9
At 0 ° C., monohydrate crystallization occurs, a part of water is taken out as crystallization water, the amount of residual solution is reduced, and as a result, the total amount of leaked adipate ions is reduced, which is advantageous for wastewater treatment. Often.

The calcium hydroxide treatment of ammonium adipate can be carried out by any of a batch method and a continuous method. However, it is possible to prevent variations in the amount of generated ammonia and the properties (sedimentation and filtration) of the produced calcium adipate. Continuous processing is desirable for the temperature stability of the whole system. This is because calcium adipate may be re-dissolved due to a temperature drop and the recovery rate may be reduced. The heating method is
In addition to the method using steam or electric heat, any known method such as an indirect heating method using waste heat from another process, a direct heating method such as blowing in high-temperature air for ammonia carrier, or a method using these methods may be used.

The aging for release of ammonia gas and crystallization of calcium adipate is carried out in a stirring state at a predetermined temperature, but it is 1 to 4 hours in a batch mode, and 2 to 5 hours in a continuous mode even in a single tank treatment. A long residence time is practically sufficient. During the aging, the solution is weakly alkaline and in a heated state, so that ammonia is easily gasified and separated, but the ammonia concentration in the exhaust gas is at least below the explosion limit,
It is necessary to manage so that it is preferably 4 to 10% by volume. Specifically, if industrial air, preferably heated air, is blown into the bottom of the treatment tank, 95% or more of ammonia can be easily recovered during the aging time.

For recovering the crystallized calcium adipate, a known solid-liquid separator can be used. However, since the change in solubility of calcium adipate is negative with respect to the temperature, it is possible to reduce the temperature after aging. If the separation of the crystallized substances is incomplete, the leaked crystallized substances will re-dissolve as the temperature decreases, and the COD in the wastewater will increase. It should be noted. Practically, it is preferable that the solution be introduced into a continuous sedimentation tank having a sufficient heat retaining zone immediately after completion of ripening, the supernatant liquid be discharged, and the dense portion be treated with a centrifugal separator or a heat-resistant pressure filter. Calcium adipate crystallized under heating has an extremely good sedimentation property, and has a residence time of 1 to 3 hours in a normal vertical continuous sedimentation tank. Can be obtained. If calcium adipate leaks during the solid-liquid separation of the dense part, it can be directly returned to the calcium hydroxide tank.

According to the present invention, ammonium adipate in a waste liquid containing ammonium adipate is recovered as ammonia and calcium adipate using calcium hydroxide or the like, respectively, so that waste water containing less ammonia nitrogen and organic components can be obtained. it can. The separated ammonia can be reused as useful ammonia water as it is, and can also be used as an ammonia source when regenerating ammonium adipate by chemically treating recovered calcium adipate. In addition, in order to simplify the scale and operation, the fuel can be burned and made harmless by a known method, and at the same time, the heat of combustion can be used as a heat energy source in the waste liquid treatment method. Calcium adipate can be used as a useful resource for the chemical industry, and it can also be used as a calcium carbonate by burning or oxidizing it to partially neutralize the phosphoric acid waste liquid generated during the manufacturing process of aluminum electrode foil for electrolytic capacitors. Can be used as an agent.

The wastewater after the recovery of ammonia and calcium adipate contains almost no ammonia nitrogen and the amount of organic components is significantly lower than that of the initial ammonium adipate waste liquid (ammonia nitrogen). Is about 1/20 or less of source wastewater, adipate ion is about 1/20
10 or less), if there is dilute wastewater from another step, it can be safely discharged together with the above-mentioned wastewater from another step after pH adjustment for practical use.

In the case where the amount of the diluted wastewater is insufficient in the above, or when there is another environmental restriction such as a restriction on the amount of water used, a part of the recovered wastewater, for example, 30 to 70%
Is combined with the ammonium adipate waste liquid before the treatment, it can be easily concentrated by RO or the like without generating a precipitate of the calcium compound in the waste liquid. By returning to the calcium treatment step of the present invention, The emission amount of acid and ammonia nitrogen is greatly reduced (adipate ion is about 1/15 or less of source wastewater), and the dilution water can be increased, so that it can be discharged without environmental problems.

Further, if a phosphoric acid waste liquid generated in the aluminum electrode foil manufacturing process is used as the dilution water, COD in the wastewater is further reduced by the effect of supplementing the adipate ions by the calcium phosphate sludge in addition to the dilution effect. There are advantages.

As described above, according to the present invention, ammonia and calcium adipate can be recovered from the waste liquid containing ammonium adipate to obtain a sufficiently safe wastewater. Microbial treatment may be used in combination. These treatments do not contain ammonia or other harmful substances in the treatment, and most of them are treated, so that sufficient effects can be obtained with very small-scale facilities.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but it goes without saying that the device and method of each unit operation are not limited to this. FIG.
BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows the method of treating the waste liquid containing ammonium adipate with calcium hydroxide which is the basic of this invention. Low and medium concentrations (hereinafter refer to those with a concentration of 0.06 to 60 g / l) and high concentrations (hereinafter refer to those with a concentration of 60 g / l or more) excluding a dilute waste liquid with a COD of 10 ppm or less that can be directly discharged. The waste liquid containing ammonium adipate is temporarily stored in the waste liquid storage tank 1 in order to make the concentration as uniform as possible.
It is summarized in 2. The capacity of the storage tanks 1 and 2 is determined by the number of source devices, the generation cycle, and the concentration fluctuation state. The amount of the high concentration waste liquid is generally smaller than the amount of the low concentration medium waste liquid. Like the two types of storage tanks 1, 2
If a predetermined ratio is provided and each of them is extracted from each of them, the size can be reduced.

The waste liquid continuously withdrawn from the storage tank is R
Ammonium adipate is 80 to 100 by the O device 3
g / l, preferably to 100 g / l. Here, in the case where there is a partial reflux of the treated wastewater, once it is mixed with the waste liquid before treatment without being separately concentrated, and then subjected to RO treatment,
In many cases, it is possible to smoothly concentrate unnecessary insolubles without crystallization.

The concentrated ammonium adipate waste liquid is continuously led to a calcium adipate tank (hereinafter referred to as an azical tank) 4 provided with a stirring device (not shown) using a steam jacket and rotary blades. On the other hand, calcium hydroxide (eg, industrial slaked lime No. 1, etc.) is emulsified with industrial water or a part of the waste liquid after recovery of calcium adipate to form lime milk of 10 to 15% by weight. The lime milk is continuously added to the azical tank 4, the pH in the tank 4 is kept at 10.5 to 12.0 (however, measured at room temperature after sample cooling), and the liquid temperature is 80 to Maintained at 90 ° C. The residence time of the reaction solution in the azical tank 4 is 1 to 10
The tank capacity, temperature, PH conditions and the like are selected so that the time is appropriate, preferably 2 to 5 hours. During this time, air from the lower part of the tank 4, preferably heated air at 150 to 300 ° C. (for example, air utilizing exhaust heat generated during the combustion processing of the recovered ammonia), is supplied with ammonia generated from the liquid at 4 to 300 ° C.
Blow to 6% by volume.

By this calcium hydroxide treatment, 95% or more of the ammonia is separated and recovered outside the waste liquid system, and white crystals of calcium adipate monohydrate crystallize in the tank 4, and the calcium adipate in the liquid phase is removed. The concentration is 14-16 g / l
(13.7 to 15.7 g in terms of ammonium adipate
/ L) On the other hand, the residual ammonia concentration in the liquid phase is 2.0 g
/ L or less.

The slurry containing the crystallized calcium adipate overflowed or extracted from the appropriate position is:
Immediately, it is sent to the continuous vertical sedimentation tank 5 where the sedimentation treatment is performed for 2 to 3 hours. During this time, in order to prevent the re-dissolution of the crystallized calcium adipate due to the temperature drop of the waste liquid,
The waste liquid is kept warm by a heat retaining zone (not shown) provided in the settling tank 5 so that the temperature does not fall below 70 ° C. or more, preferably 75 ° C.

The supernatant is drained and has a solid concentration of 200 to 3
In the dense portion of 00 g / l, calcium adipate is separated and collected by a centrifugal separator 6 or mechanical means such as a vacuum filter or a pressure filter. In this case, if there is any leakage of the solid content to the filtrate, it is preferable to return the solid content to the azical tank 4 as it is.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. Quantitative numerical values in the examples are obtained by converting experimental results on a scale of 1/10 to 1/20 to actual scales in order to easily understand the effects.

[0041] (Example 1) has a configuration as shown in FIG. 1, January (24 × 30 hours) per about 120 m ³ aging chemical bath containing ammonium adipate 75 g / l, about 8
about 510 m ³ and 0.03 g
g / l of the waste liquid of the dilute cleaning liquid in the chemical conversion step using ammonium adipate in the production of the electrode foil to generate about 2000 m ³ , the dilute cleaning liquid is discharged to the drainage system as it is,
The aging chemical bath and the medium-concentration waste liquid are subjected to RO treatment to obtain about 500
m ³ water, 100 g / l ammonium adipate
Was 130 m ³ .

This concentrated solution was treated with 10% lime milk 5% prepared from 48.0 m ³ of a portion of the supernatant after recovery of calcium adipate and slaked lime JIS No. 5.8 t by pretreatment.
Together with 0.8 m ³ and 47.8 m ³ of leaked slurry during calcium adipate recovery (solids concentration 14 g / l)
It is continuously guided to the azical tank 4.

In the azical tank 4 provided with a stirring device such as a steam jacket, the temperature is always 85 ° C. and the liquid amount (slurry amount) is 0.9.
m ³ , and a nominal residence time of 3 hours with respect to the inflow. 200 from the bottom of the tank 4
Air heated to 0 ° C. is blown in at a rate of 81 Nm ³ / hour, and 2.4 t of ammonia is collected outside the system at a concentration of 5% by volume with respect to air while accompanied by steam. During this time, the double decomposition of ammonium adipate and the crystallization of calcium adipate were simultaneously performed, and the calcium adipate concentration was 15 g / l or less under the above conditions.

The slurry after completion of the crystallization of calcium adipate monohydrate is continuously subjected to sedimentation in a sedimentation tank 5 equipped with a heat insulating zone, and the supernatant liquid 135 m ³ and the dense part 53 m ³ (solid concentration 225 g / l) ) And 48 m ^{3 of} the supernatant
Is refluxed for lime milk adjustment, 87 m ³ is neutralized and combined with wastewater from other processes to become wastewater. Its composition is calcium adipate 15.0 g / l, ammonia 1.9 g
/ L and a trace amount of free calcium hydroxide.

The dense portion was centrifuged by a centrifugal separator 6 to obtain a liquid phase weight of 3
18.7t of calcium adipate sludge containing 0% and solid concentration of leaked calcium adipate monohydrate of 14g / l
Divided into leakage slurry 47.8M ³ including, said leakage slurry is returned to Ajikaru tank 4.

By this treatment, the waste liquid containing 13000 kg of ammonium adipate was treated, and the recovery rate of ammonia was 93% and the recovery rate of adipate ion was 90%. This corresponds to a reduction of ammonia by 1/25 and adipic acid ion by 1/10 in the total amount.

(Example 2) The wastewater of Example 1 is drained in the other step of electrode foil formation (including dilute ammonium adipate waste liquid and permeated water during RO treatment of ammonium adipate).
Combined with 12000m ³ , the final drainage C
OD was 13 ppm and ammonia nitrogen was 13 ppm.

Example 3 13 t of phosphoric acid generated by phosphoric acid treatment following chemical conversion treatment in an ammonium adipate bath
When the phosphoric acid waste liquid 3000m ³ containing water is neutralized using 13.2t of slaked lime and subjected to coagulation sedimentation-solid-liquid separation treatment, the waste water 87m ³ sent to the drainage step of Example 1 is drained as it is. Was mixed with wastewater containing phosphoric acid and subjected to batch neutralization.
The COD in m ³ has dropped to 9 ppm.

Example 4 18.7 t of the calcium adipate sludge obtained in Example 1 was baked at 750 ° C. in a fluidized heating furnace at 750 ° C. using 0.7 kiloliter of heavy oil to 6.5 t. Was obtained, emulsified with water, and charged in the initial stage of the neutralization treatment of the phosphoric acid waste liquid. As a result, 4.7 t of 13.2 t of the usual required slaked lime could be reduced.

(Embodiment 5) As shown in FIG.
120 m of aging chemical bath containing 75 g / l of adipic acid per month
³ and 82.0 g / l of a medium-concentration waste liquid 510 m ³ , and a part of the waste water from which crystallized calcium adipate was recovered by the previous treatment was 72.0 m ³ (calcium adipate was 15.
0g / l, Ca (OH) 2 is 0.3g / l, NH ₃ is 1.
9 g / l), and ammonium adipate was added to the mixture.
5 g / l, calcium adipate 1.6 g / l, NH
₃ is 702 m ³ containing 0.21 g / l,
O treatment and 554 m ³ dehydration, ammonium adipate 87.5 g / l, calcium adipate 7.6 g
/ L, concentrated solution NH ₃ contains 1.0 g / l 147.9
It was m ^3.

This is slaked lime (JIS industrial slaked lime No. 1)
15% lime milk adjusted with 5.8t and water 32.8m ³
And 49.3 m ³ of leaked slurry at the time of recovery of the crystallized calcium adipate by the treatment prior thereto (solid concentration 14%).
g / l), the solution was led to the same azical tank 4 as in Example 1, the liquid temperature was maintained at 85 ° C while stirring, and air at 200 ° C was blown from the bottom of the tank 4 at a rate of 80 Nm ³ / hour.

2.3 tons of ammonia was recovered from the upper part at a ratio of 5% by volume of air, and overflow was set in a continuous settling tank 5
To 133.8 m ^{3 of} supernatant and a solid concentration of 225 g / l.
63.0 m ³ was obtained.

The dense portion was treated with a centrifugal separator 6, and 19.2 t of calcium adipate sludge having a liquid phase weight of 30% was used.
And leaked slurry 49.3m ³ (solid concentration 14g / l)
The leaked slurry was refluxed to the azical tank 4.

The supernatant was 15.0% calcium adipate.
g / l, NH ₃ comprises a free calcium hydroxide 1.9 g / l and trace, of turning the 61.8M ³ to drainage, 72m ³ is discharged from the pretreatment of the chemical conversion device the ammonium adipate waste The mixture was returned to 630 m ³ and mixed to make a total of 702 m ³ .

The waste water 6 after the recovery of calcium adipate 6
1.8m ³ is collected together with the wastewater from other processes, and the total
COD of 00m ³ is 9ppm, ammonia nitrogen is 9p
pm.

(Example 6) Waste water 6 obtained in Example 5
1.8 m ³ was not drained as it was, but was combined with the phosphoric acid waste liquid in the same manner as in Example 3 and subjected to batch treatment.
The COD in the total wastewater of 1200 m ³ was reduced to 5 ppm.

[0057]

According to the method of the present invention, crystallization of calcium adipate and deammonification are simultaneously performed by adding a calcium source such as slaked lime and making the waste liquid containing ammonium adipate weak and alkaline. As a result, organic compounds (COD) and ammonia nitrogen in wastewater can be easily and easily reduced.

[Brief description of the drawings]

FIG. 1 is a basic schematic configuration diagram of a method for treating a waste liquid containing ammonium adipate of the present invention.

FIG. 2 is a basic schematic configuration diagram of a method for treating a waste liquid containing ammonium adipate according to another example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage tank 2 Storage tank 3 RO treatment 4 Azical tank 5 Sedimentation tank 6 Centrifuge

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 9/02 615 B01D 9/02 615Z 625 625A C07C 51/41 C07C 51/41 51/43 51/43 55/14 55/14 (72) Inventor Akira Morita 1-34-1 Kambara, Kambara-cho, Abara-gun, Shizuoka Prefecture Inside the Nippon Light Metal Co., Ltd.Group Technology Center (72) Inventor Noboru Sugiyama 1-34-1, Kambara-cho, Kambara-cho, Abara-gun, Shizuoka Prefecture Nippon Light Metal Group Technology Center Co., Ltd. (72) Yasushi Egami 1-34-1, Kambara, Kambara-cho, Anbara-gun, Shizuoka Prefecture Nippon Light Metal Co., Ltd. Group Technology Center (72) Inventor Hiroshi Ozawa 5-12 Matsubara-cho, Shimizu-shi, Shizuoka Nikkei Sangyo Co., Ltd.

Claims (10)

[Claims] 1. A wastewater containing ammonium adipate is added with a calcium source which reacts with said ammonium adipate to form calcium adipate, is made weakly alkaline, and is heated. A method for treating ammonium adipate waste liquid, wherein calcium adipate separated and crystallized in a reaction solution is subjected to a solid-liquid separation treatment. 2. The adipin according to claim 1, wherein a part of the treated wastewater after separating the calcium adipate is returned upstream, mixed with the untreated ammonium adipate waste liquid, and retreated. Method of treating ammonium acid waste liquid. 3. The method for treating an ammonium adipate waste liquid according to claim 1, wherein the calcium source is calcium hydroxide. 4. The method for treating an ammonium adipate waste liquid according to claim 1, wherein the waste liquid containing ammonium adipate is a waste liquid generated in a process of manufacturing an aluminum electrode foil for an electrolytic capacitor. . 5. The wastewater containing calcium adipate according to claim 4, wherein the wastewater after separating the calcium adipate is combined with a wastewater containing phosphoric acid generated in another manufacturing process of the aluminum electrode foil for an electrolytic capacitor, and the calcium carbonate and / or water is mixed. A method for treating ammonium adipate waste liquid, wherein the waste liquid is neutralized with calcium oxide. 6. The method according to claim 1, wherein the waste liquid containing ammonium adipate is subjected to concentration treatment of ammonium adipate before adding a calcium source. 7. The method for treating ammonium adipate waste liquid according to claim 6, wherein the ammonium adipate is concentrated to 60 g / l or more. 8. The method for treating an ammonium adipate waste liquid according to claim 1, wherein the separation of the ammonium gas and the crystallization of calcium adipate are performed in a temperature range of 70 ° C. to 100 ° C. . 9. The method for treating ammonium adipate waste liquid according to claim 8, wherein solid-liquid separation of the crystallized calcium adipate is performed in a warm state. 10. The method for treating ammonium adipate waste liquid according to claim 1, wherein the calcium adipate separated and recovered is oxidized to calcium carbonate.