JP5324382B2 - Apparatus and method for treating waste liquid containing basic substance having volatility - Google Patents

Description

  The present invention relates to a waste liquid treatment apparatus and a treatment method for separating a volatile basic substance from a waste liquid containing a volatile basic substance by evaporation concentration.

  When evaporating and concentrating waste liquid containing ammonia and hydrazine, if the pH is treated on the alkali side, most of the ammonia and hydrazine components contained in the stock solution are transferred to and mixed in the condensed water. And ammonia / hydrazine was fixed to the concentrated solution and then concentrated by evaporation (see, for example, paragraph 0005 of Patent Document 1).

In the above prior art, since the treatment is performed on the acid side, when a substance that corrodes stainless steel, such as chloride ions, is included, the life of the apparatus is remarkably reduced. Therefore, it is necessary to select a material in consideration of corrosion resistance.
As material selection, it is conceivable to (1) adopt a corrosion-resistant material or (2) construct a lining. However, since (1) is expensive, the initial cost of the apparatus becomes high. Moreover, (2) has a limited service life and has a drawback that maintenance costs such as periodic repairs and re-working of the lining are increased.
Note that the above-described problem exists not only in waste liquids containing ammonia and hydrazine, but also in waste liquids containing other volatile basic substances.

JP 2005-262004 A

  In view of this, there has been a demand for an apparatus for treating a waste liquid containing a basic substance having volatility that is excellent in economic efficiency, because it is possible to use an ordinary metal material, and it is not necessary to use an expensive corrosion-resistant material or to perform lining construction.

  The present invention has been conceived in view of the above problems, and its purpose is to eliminate the need for expensive corrosion-resistant materials and lining construction, and to contain a basic substance having volatility that is excellent in economy. It is to provide a waste liquid treatment apparatus and a treatment method.

In order to achieve the above object, the gist of the present invention is an apparatus for treating a waste liquid containing a basic substance having volatility, wherein the waste liquid containing a basic substance having volatility has a pH of alkaline side. The basic substance-containing vapor and the basic substance-containing steam produced by the first evaporator are generated by evaporating and concentrating in a state to produce a concentrated liquid from which the basic substance and the basic substance have been removed. Neutralizing means for generating a neutralized salt solution by summing treatment, and neutralizing by neutralizing the neutralized salt solution generated by the neutralizing means as an evaporation-concentration target solution by evaporating and concentrating in a state where the pH is on the acid side e Bei a second evaporator to produce a salt solution, wherein the neutralizing means is provided between the second evaporator and the first evaporator, the basicity produced by the first evaporator Neutralized salt solution and basic substances are removed by contacting substance-containing vapor with acid. The vapor-liquid contact means for generating the generated vapor, wherein the gas-liquid contact means supplies the neutralized salt solution generated by the gas-liquid contact means to the second evaporator as the evaporation-concentration target liquid, and the gas-liquid contact The vapor from which the basic substance generated by the means is removed is supplied to the second evaporator and used as a heating source of the second evaporator .

With the above configuration, when the waste liquid containing a volatile basic substance is evaporated and concentrated in a state where the pH is on the alkali side in the first evaporator, most of the volatile basic substance components contained in the waste liquid are obtained. Mix in steam. This basic substance-containing steam is neutralized by a neutralizing means to produce a neutralized salt solution. Then, in the second evaporator, the neutralized salt solution is evaporated and concentrated as an evaporation and concentration target solution. At this time, since the evaporative concentration target liquid does not contain a substance that corrodes stainless steel such as chloride ions, it is not necessary to select a material considering corrosion resistance as in the conventional example. As a result, it is possible to configure the apparatus by using a normal metal material, and it is not necessary to use an expensive corrosion-resistant material and lining work as in the conventional case, and it is possible to realize a waste liquid processing apparatus that is excellent in economy. In addition, since the basic substance having volatility contained in the waste liquid can be recovered as a concentrated neutralized salt solution, the waste liquid treatment apparatus according to the present embodiment has extremely good separation performance.
Moreover, if the basic substance contained in the vapor | steam produced | generated with the 1st evaporator is a small amount, even if it supplies a basic substance containing vapor | steam as it is to a 2nd evaporator, there is no problem as heating steam. However, when the basic substance contained in the steam is sufficient to affect the heating steam, it is preferable to provide the gas-liquid contact means as described above.

  The present invention comprises a steam generating device for generating steam, and an ejector connected to the steam generating device for supplying steam to the first evaporator, wherein the ejector is discharged from the steam generating device. A part of the steam discharged from the second evaporator is sucked by the flow of the steam to generate a mixed steam having a temperature higher than that of the sucked steam and supplied to the first evaporator. Sometimes it is. By using the ejector, heat can be efficiently recovered.

Another aspect of the present invention is a method for treating a waste liquid containing a volatile basic substance, and evaporating and concentrating the waste liquid containing a volatile basic substance in a state where the pH is on the alkali side. The basic substance-containing vapor and the first evaporative concentration step for producing the concentrated liquid from which the basic substance has been removed, and the basic substance-containing vapor produced in the first evaporative concentration step are neutralized. A neutralization step for producing a neutralized salt solution, and a neutralized salt solution produced in the neutralization step as a target solution for evaporation and concentration to produce a concentrated neutralized salt solution by evaporating and concentrating in a state where the pH is on the acid side a second evaporation step, the Bei example that, the neutralization step, the by contacting the first evaporation acid wherein the basic substance-containing steam generated by the concentration step, neutralized salt solution and the basic substance This is a gas-liquid contact process that produces the removed vapor, In the gas-liquid contact process, the neutralized salt solution generated in the gas-liquid contact process is supplied to the second evaporative concentration process as a liquid to be evaporated and concentrated, and the basic substance generated in the gas-liquid contact process is removed. The steam is supplied to the second evaporative concentration step and used as a heat source for evaporative concentration in the second evaporative concentration step .

  With the configuration described above, the same functions and effects as those of the first aspect of the invention can be achieved.

  According to the waste liquid treatment apparatus and treatment method containing a basic substance having volatility according to the present invention, it is not necessary to select a material in consideration of corrosion resistance, and the apparatus can be configured by using a normal metal material. Employing expensive corrosion-resistant materials and lining work as in the past are not required, and a waste liquid treatment apparatus with excellent economy can be realized.

1 is an overall system diagram of a waste liquid treatment apparatus according to an embodiment. The system diagram of the whole waste-liquid processing apparatus which concerns on an Example.

Hereinafter, the present invention will be described in detail based on embodiments. Note that the present invention is not limited to the following embodiments.
FIG. 1 is an overall system diagram of a waste liquid treatment apparatus containing a volatile basic substance (hereinafter abbreviated as a basic substance) according to an embodiment. The waste liquid processing apparatus 1 includes a first evaporator 2 that generates a concentrated liquid from which the basic substance-containing vapor and the basic substance have been removed by evaporating and concentrating the waste liquid in a pH-alkaline state, and a first evaporation. Neutralizing means 100 for neutralizing the basic substance-containing steam produced in the vessel 2 to produce a neutralized salt solution, and using the neutralized salt solution produced by the neutralizing means 100 as a target liquid for evaporation concentration, pH Is provided with a second evaporator 4 that produces a concentrated neutralized salt solution by evaporating and concentrating in a state of acid side. Here, examples of the volatile basic substance include ammonia and hydrazine, but the present invention is not limited to this, and the volatile basic substance is applied to a waste liquid processing apparatus containing other volatile basic substances. The

  With the above configuration, when the waste liquid containing a volatile basic substance is evaporated and concentrated in the first evaporator 2 in a state where the pH is on the alkali side, the most volatile basic substance component contained in the waste liquid is obtained. Is mixed with steam. This basic substance-containing vapor is neutralized by the neutralizing means 100 to produce a neutralized salt solution. Then, the second evaporator 4 evaporates and concentrates the neutralized salt solution as an evaporation concentration target solution. At this time, since the evaporative concentration target liquid does not contain a substance that corrodes stainless steel such as chloride ions, it is not necessary to select a material considering corrosion resistance as in the conventional example. As a result, it is possible to configure the waste liquid treatment apparatus 1 by using a normal metal material, which eliminates the need for the conventional expensive corrosion-resistant material and lining construction, and realizes an economical waste liquid treatment apparatus. it can. In addition, since the volatile basic substance contained in the waste liquid can be recovered as a concentrated neutralized salt solution, the waste liquid treatment apparatus 1 according to the present embodiment has extremely good separation performance.

  In the present invention, the neutralization means 100 may be provided separately from the second evaporator 4, and the neutralization treatment in the neutralization means 100 may be performed in the previous stage treatment of the second evaporator 4. The means 100 may be provided in the circulation line of the second evaporator 4, and the neutralization process in the neutralization means 100 may be performed during the process of the second evaporator 4. Moreover, the structure for double effect which supplies the basic substance containing vapor | steam produced | generated with the 1st evaporator 2 to a 2nd evaporator, and utilizes it as a heat source may be sufficient.

  FIG. 2 is a system diagram of the entire waste liquid treatment apparatus according to the embodiment. In this embodiment, as an example of the waste liquid treatment apparatus 1, an apparatus for separating ammonia, hydrazine and methanol from waste liquid containing ammonia, hydrazine and methanol will be described as an example. Further, gas-liquid contact means 80 is used as an example of the neutralization means 100.

  The waste liquid treatment apparatus 1 includes a first evaporator 2, a gas-liquid contact means 80, a second evaporator 4, an extraction scrubber 5, and the like. The first evaporator 2 and the second evaporator 4 are double effect evaporations that supply the steam generated by the first evaporator 2 to the second evaporator 4 and use it as a heating source for the second evaporator 4. Configure the vessel.

  The first evaporator 2 is a horizontal tube evaporator and includes an evaporator 6. The evaporator 6 is formed in a cylindrical shape and can store a processing liquid therein. A pipe 7 for supplying a processing liquid such as a waste liquid is connected to the evaporator 6. A heater 8 comprising a pair of left and right headers 8a and 8b and a plurality of horizontal heat transfer tubes 8c connecting the headers 8a and 8b is provided on the top of the evaporator 6. A steam supply pipe 9 is connected to the header 8a and is formed so that steam from the ejector 10 enters the header 8a. The header 8b is disposed on the side from which the steam is discharged. A pipe 60 for discharging the condensed water of the heating steam is connected to the header 8b, and the condensed water is discharged to the liquid storage of the condenser 11 through the pipe 60.

  The 1st evaporator 2 in a present Example contains the circulation flow path of a process liquid. A circulation pump 12 and a spreader 13 are disposed in the circulation channel. The circulation pump 12 is connected to the bottom of the evaporator 6. The circulation pump 12 is formed so that the treatment liquid 15 stored in the evaporator 6 can be transferred to the spreader 13 through the pipe 14. The circulation pump 12 is formed so that a part of the concentrated processing liquid (concentrated liquid) 15 can be discharged out of the system through the pipe 16. The spreader 12 is formed so as to spread the treatment liquid 15 from above the horizontal heat transfer tube 8c toward the horizontal heat transfer tube 8c.

  The gas-liquid contact means 80 includes the steam scrubber 3, the pH adjusting tank 20, and the like. The steam scrubber 3 is an apparatus that dissolves and recovers ammonia / hydrazine components contained in steam by gas-liquid contact in dissolving water (in this embodiment, an acidic aqueous solution in the pH adjusting tank 20). In this embodiment, A spray type scrubber is used in which the acidic aqueous solution for dissolution is sprayed downward from the plurality of spray nozzles 21 to countercurrently contact the vapor containing the ammonia / hydrazine component and the acidic aqueous solution for dissolution. Other types of scrubbers may be used as the scrubber.

  The steam scrubber 3 is accommodated in the water washing tower 22, the steam supply pipe 23 that supplies the steam (steam containing ammonia / hydrazine component) generated in the first evaporator 2 to the water washing tower 22, and the water washing tower 22. A supply pipe 24 for supplying a solution in which ammonia and hydrazine components are dissolved to the pH adjusting tank 20, and a spray for transferring the neutralized salt solution adjusted in the pH in the pH adjusting tank 20 to the spray nozzle 21 as an acidic aqueous solution for dissolving. A pipe 25, a steam supply pipe 26 for supplying the vapor from which the ammonia / hydrazine component has been removed to the second evaporator 4, and a condensed water of the steam from which the ammonia / hydrazine component has been removed supplied to the second evaporator 4. And a return pipe 27 to be supplied to the water washing tower 22. A steam scrubber pump 28 is disposed in the supply pipe 24, and a solution in which the ammonia and hydrazine components contained in the washing tower 22 are dissolved is supplied to the pH adjusting tank 20 by the steam scrubber pump 28. A predetermined amount of a pH adjusting acid (for example, sulfuric acid) is supplied to the pH adjusting tank 20, and a solution in which the ammonia / hydrazine component is dissolved and the pH adjusting acid are stirred and mixed to neutralize a salt solution (ammonium sulfate and ammonium sulfate). Hydrazine sulfate solution). A pump 29 and a chiller 30 are arranged in the spray tube 25. Cold water is supplied to the cooler 30. The neutralized salt solution which is stirred and mixed in the pH adjusting tank 20 is cooled by heat exchange with cold water in the cooler 30 and is cooled and sprayed downward from the spray nozzle 21 through the spray tube 25 as an acidic aqueous solution for dissolution. It has become so. A part of the neutralized salt solution in the pH adjusting tank 20 is supplied to the second evaporator 4 via the pipe 31.

  The second evaporator 4 is a horizontal tube evaporator and includes an evaporator 35. The evaporator 35 is formed in a cylindrical shape, and can store a processing solution (neutralized salt solution) therein. A pipe 31 for supplying neutralized salt solution from the pH adjusting tank 20 is connected to the evaporator 35. A heater 36 comprising a pair of left and right headers 36a and 36b and a plurality of horizontal heat transfer tubes 36c connecting the headers 36a and 36b is provided on the top of the evaporator 35. A steam supply pipe 26 is connected to the header 36a, and is formed so that steam from the steam scrubber 3 enters the header 36a. The header 36b is disposed on the side from which the steam is discharged. A return pipe 27 for supplying condensed water of heating steam to the steam scrubber 3 is connected to the header 36b.

  The 2nd evaporator 4 in a present Example contains the circulation flow path of a process liquid. A circulation pump 37 and a spreader 38 are disposed in the circulation channel. The circulation pump 37 is connected to the bottom of the evaporator 35. The circulation pump 37 is formed so that the processing liquid (neutralized salt solution) stored in the evaporator 35 can be transferred to the sprayer 38 through the pipe 70. The circulation pump 37 is formed so that a part of the concentrated treatment liquid (neutralized salt solution) can be discharged out of the system through the pipe 39. The spreader 38 is formed to spray the processing liquid (neutralized salt solution) stored in the evaporator 35 from above the horizontal heat transfer pipe 36c toward the horizontal heat transfer pipe 36c.

  The second evaporator 4 includes an ejector 10. An inlet of the ejector 10 is connected to a steam generating device (not shown) that generates steam, and an outlet of the ejector 10 is connected to the first evaporator 2 via a steam supply pipe 9. The ejector 10 sucks a part of the steam generated by the second evaporator 4 through the pipe 40 by the flow of the steam discharged from the steam generating device (not shown), so that it is more than the sucked steam. A high-temperature mixed steam is generated and supplied to the first evaporator 2. A pipe 41 that guides the vapor in the evaporator 35 to the condenser 11 is connected to the upper part of the evaporator 35. The condenser 11 is supplied with cold water, and the condensed water obtained by condensing the vapor led to the condenser 11 is condensed together with the condensed water from the first evaporator 2 supplied via the pipe 60. It is discharged from the bottom of the liquid storage of the vessel 11 by the condensed water pump 42.

  The extraction scrubber 5 is provided for recovering methanol contained in the waste liquid. That is, steam containing methanol is extracted from the condenser 11 and supplied to the extraction scrubber 5 through the pipe 43 to recover the methanol. More specifically, the extraction scrubber 5 is a spray-type scrubber similar to the steam scrubber 3, and includes a flush tower 50, a pipe 43 for extracting steam from the condenser 11, and water for dissolution accommodated in the flush tower 50. And a spray pipe 52 for transporting the liquid to the spray nozzle 51. In the spray pipe 52, an extraction scrubber pump 53 and a cooler 54 are arranged. Cold water is supplied to the cooler 54, and this cold water exchanges heat with the dissolving water passing through the spray pipe 52 so that the dissolving water is cooled. The methanol solution in which the methanol component is dissolved by contact with the dissolving water is discharged out of the system by the extraction scrubber pump 53. Further, a vacuum pump 55 is connected to the water washing tower 50, and the extraction scrubber 5, the condenser 11, the evaporator 35, the steam scrubber 3, and the evaporator 6 are held in a reduced pressure state.

  Next, the processing operation of the waste liquid processing apparatus 1 configured as described above will be described. A treatment liquid such as a waste liquid (raw solution) containing ammonia, hydrazine and methanol is supplied into the evaporator 6 through the pipe 7. Next, when the circulation pump 12 is driven, the processing liquid 15 stored in the evaporator 6 is supplied to the spreader 13 through the pipe 14 and is spread from the spreader 13 toward the heat transfer pipe 8c. The processing liquid spread by the spreader 13 evaporates in a thin film on the surface of the horizontal heat transfer tube 8c. The vapor evaporated on the surface of the horizontal heat transfer tube 8 c contains ammonia, hydrazine and methanol, and is supplied to the steam scrubber 3. On the other hand, the heated steam that has entered the header 8a through the steam supply pipe 9 is guided to the inside of the horizontal heat transfer pipe 8c, and condenses at the same time as the circulating liquid sprayed to the outside of the heat transfer pipe 8c is evaporated to become condensed water. It flows into the header 8b. Then, the condensed water is guided from the header 8 b to the condenser 11 and is discharged out of the system by the condensed water pump 42. By repeating such a process, the circulating liquid is concentrated, and is discharged out of the system by the circulating pump 12 as a concentrated liquid that hardly contains ammonia, hydrazine, and methanol.

  Next, in the steam scrubber 3, the acidic aqueous solution for dissolution is sprayed downward from the spray nozzle 21, thereby bringing the vapor containing the ammonia / hydrazine component into countercurrent contact with the acidic aqueous solution for dissolution. As a result, a solution in which the ammonia / hydrazine component is dissolved is generated and stored in the washing tower 22. The solution in which the ammonia and hydrazine components are dissolved is supplied to the pH adjusting tank 20 by the steam scrubber pump 28, and is stirred and mixed with the pH adjusting acid in the pH adjusting tank 20 to be neutralized salt solution (ammonium sulfate and sulfuric acid). Hydrazine solution). This neutralized salt solution is supplied to the spray nozzle 21 by a pump 29 as an acidic aqueous solution for dissolution. A part of the neutralized salt solution is supplied to the evaporator 35 of the second evaporator 4 by the pump 29 as the evaporation target liquid. The vapor from which the ammonia / hydrazine component has been removed is supplied to the second evaporator 4. In this manner, the steam scrubber 3 generates neutralized salt solution (ammonium sulfate and hydrazine sulfate solution) by contacting the steam generated in the first evaporator 2 with an acid, and removes ammonia and hydrazine components. Produced steam. Then, the neutralized salt solution is supplied to the second evaporator 4 as a liquid to be evaporated and concentrated, and the vapor from which the ammonia / hydrazine component has been removed is supplied to the second evaporator 4 to serve as a heating source for the second evaporator 4. Use.

  Next, in the second evaporator 4, the processing liquid (neutralized salt solution) stored in the evaporator 35 is supplied to the spreader 38 through the pipe 70 by driving the circulation pump 37, and the horizontal heat transfer pipe from the spreader 38. It spreads toward 36c. The treatment liquid (neutralized salt solution) spread by the spreader 38 evaporates in a thin film on the surface of the horizontal heat transfer tube 36c. A part of the vapor evaporated on the surface of the heat transfer tube 36 c is sucked into the ejector 10 through the tube 40. From the outlet of the ejector 10, a part of the steam generated inside the evaporator 35 is sucked and the mixed steam whose temperature is higher than the suction steam is discharged. In the ejector 10, the steam is compressed and the temperature at the outlet is increased. For this reason, high temperature steam can be supplied to the 1st evaporator 2, and a process with good thermal efficiency is realizable.

  On the other hand, the heated steam that has entered the header 36a through the steam supply pipe 26 is guided to the inside of the horizontal heat transfer pipe 36c, and condenses at the same time as the circulating liquid sprayed outside the horizontal heat transfer pipe 36c is evaporated. And flows into the header 36b. The condensed water is supplied from the header 36b to the steam scrubber 3 via the return pipe 37. By repeating such an evaporation concentration process, the circulating solution (neutralized salt solution) is concentrated and discharged as a concentrated neutralized salt solution to the outside by the circulation pump 37.

  A part of the steam generated inside the evaporator 35 is guided to the condenser 11 to become condensed water, and is discharged out of the system by the condensed water pump 42 together with the condensed water supplied from the pipe 60. The

  Although the vapor generated inside the evaporator 35 contains a methanol component, the methanol component is not condensed in the condenser 11. Therefore, the methanol in the steam extracted from the condenser 11 is supplied to the extraction scrubber 5 and comes into contact with the dissolving water. Then, the methanol solution in which the methanol component is dissolved by the contact of the dissolving water is discharged out of the system by the extraction scrubber pump 53. In this way, the methanol component is recovered.

(Other matters)
(1) Although the waste liquid treatment apparatus containing ammonia and hydrazine has been described in the above embodiment, the present invention is not limited to this, and is applied to a waste liquid treatment apparatus containing other basic substances having volatility. The

  (2) Although the extraction scrubber pump 53 is provided in the above embodiment, the extraction scrubber pump 53 may be omitted when the waste liquid does not contain methanol.

  (3) Although the steam scrubber 3 is provided in the above embodiment, if the ammonia / hydrazine component contained in the steam generated by the first evaporator 2 is small, the steam scrubber 3 is omitted, and the first evaporator The steam generated in 2 may be supplied to the second evaporator 4 as it is. In this case, the vapor supplied to the second evaporator 4 is circulated through the condensate condensed by heat exchange on the surface of the horizontal heat transfer pipe 36c provided in the second evaporator 4, and in the circulation line. In addition, a pH adjusting means may be provided and neutralized.

  (4) In the above embodiment, the first evaporator 2 and the second evaporator 4 have a double effect configuration, but the present invention is not limited to this. That is, in the above embodiment, the steam generated by the first evaporator 2 is supplied to the second evaporator 4 via the steam scrubber 3, but the raw steam is supplied to the second evaporator 4 as heating steam. It may be configured to. Moreover, the vapor | steam produced | generated by the 1st evaporator 2 is condensed with a condenser etc., The neutralization salt liquid produced | generated by neutralizing a condensate with an acid is thrown into the 2nd evaporator 4 as an evaporation concentration object liquid. It may be configured to evaporate and concentrate.

  (5) Although the horizontal evaporator was used for the 1st evaporator 2 and the 2nd evaporator 4 in the said Example, this invention is not limited to this, Arbitrary evaporators can be employ | adopted. For example, a flash type evaporator may be employed. Further, both the first evaporator 2 and the second evaporator 4 may be the same type of evaporator, and different types of evaporators (for example, the first evaporator 2 is a horizontal tube evaporator, the second evaporator). 4 may be a flash type evaporator).

  INDUSTRIAL APPLICABILITY The present invention can be applied to a treatment apparatus and a treatment method for waste liquid containing ammonia / hydrazine and other waste liquid containing basic substances having volatility.

1: Waste liquid treatment device 2: First evaporator 3: Steam scrubber 4: Second evaporator 6, 35: Evaporator 8, 36: Heater 8c, 36c: Horizontal heat transfer tube 10: Ejector 20: pH adjustment tank 80: Gas-liquid contact means 100: Neutralization means

Claims (3)

A first evaporator for producing a concentrated liquid from which the basic substance-containing vapor and the basic substance have been removed by evaporating and concentrating a waste liquid containing a volatile basic substance in a state where the pH is on the alkali side; ,
Neutralizing means for neutralizing the steam containing the basic substance generated in the first evaporator to generate a neutralized salt solution;
A second evaporator that produces a concentrated neutralized salt solution by evaporating and concentrating the neutralized salt solution generated by the neutralization means as a target solution for evaporation and concentration while the pH is on the acid side;
Bei to give a,
The neutralization means is provided between the first evaporator and the second evaporator, and the neutralized salt solution is obtained by bringing the basic substance-containing vapor generated in the first evaporator into contact with an acid. And a gas-liquid contact means for generating steam from which basic substances have been removed,
The gas-liquid contact means supplies the neutralized salt solution generated by the gas-liquid contact means to the second evaporator as a liquid to be evaporated and concentrated, and the vapor from which the basic substance generated by the gas-liquid contact means is removed An apparatus for treating a waste liquid containing a basic substance having volatility, wherein the second evaporator is supplied to be used as a heating source for the second evaporator . Steam generating equipment for generating steam;
An ejector connected to the steam generating device for supplying steam to the first evaporator;
With
The ejector sucks a part of the steam discharged from the second evaporator by the flow of steam discharged from the steam generating device, and generates a mixed steam having a higher temperature than the sucked steam. The waste liquid treatment apparatus containing a basic substance having volatility according to claim 1, wherein the waste liquid treatment apparatus is configured to be supplied to the first evaporator. A first evaporative concentration step for generating a concentrated liquid from which the basic substance-containing vapor and the basic substance are removed by evaporating and concentrating a waste liquid containing a volatile basic substance in a state where the pH is on the alkali side When,
A neutralization step of generating a neutralized salt solution by neutralizing the steam containing the basic substance generated in the first evaporation concentration step;
A second evaporative concentration step of generating a concentrated neutralized salt solution by evaporating and concentrating the neutralized salt solution generated in the neutralization step as a target solution for evaporation and concentration while the pH is on the acid side;
Bei to give a,
The neutralization step is a gas-liquid contact step of generating a vapor from which the neutralized salt solution and the basic substance have been removed by bringing the basic substance-containing vapor generated in the first evaporative concentration step into contact with an acid. And
In the gas-liquid contact step, the neutralized salt solution generated in the gas-liquid contact step is supplied to the second evaporation / concentration step as a liquid to be evaporated and concentrated, and the basic substance generated in the gas-liquid contact step is removed. Of waste liquid containing a basic substance having volatility , wherein the vapor is supplied to the second evaporative concentration step and used as a heat source for evaporative concentration in the second evaporative concentration step Method.

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