JP2019051452A - Apparatus and method for treating liquid to be treated - Google Patents

Abstract

To provide an apparatus and a method for treating liquid to be treated that can sufficiently remove calcium.SOLUTION: A treatment apparatus X includes a reaction tank 21 and a post-stage filtration device 30. The reaction tank 21 includes a partition member 22 that partitions an area into a first area Z1 and a second area Z2, a supply port 24 for liquid D to be treated, means 23 for blowing carbon dioxide, and a discharge port 25 for the liquid D to be treated. The liquid D to be treated supplied from the supply port 24 comes in contact with carbon dioxide, and flows along the partition member 22 through the first area Z, and then flows into the second area Z2 and is discharged from the discharge port 25. Further, in a treating method, the treatment apparatus X includes an ion concentration meter 43 for measuring calcium ion concentration of the liquid D to be treated discharged from the post-stage filtration device 30, and when a measured value is equal to or greater than a predetermined value, the liquid D to be treated is returned to the reaction tank 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a processing apparatus and processing method for a liquid to be processed. In particular, the present invention relates to a treatment apparatus and a treatment method for a treatment liquid suitable when the treatment liquid is wastewater containing calcium such as water jet drainage, road cutter drainage, and waste treatment plant drainage.

At present, the water jet method (WJ method) is widely used in cutting concrete structures, turning work, and the like. In this water jet method, waste water containing calcium is generated. This wastewater has SS of 1000 to 3000 mg / L, calcium of 1000 mg / L or more, and pH of 11 or more. Therefore, it cannot be discharged into the sea or river as it is. Moreover, since calcium in the waste water is precipitated and granulated, there is a possibility that the ultra-high pressure (for example, 300 MPa) pump may break down, so that it cannot be reused in the water jet method as it is. Therefore, in the water jet construction method, tap water is currently used, which causes the cost to increase due to water charges, transportation costs, and the like. In addition, it costs money to transport and purify wastewater. These costs are about 3000 yen / m ^{2 for} water supply treatment (water charges and transportation costs), and about 5000 yen / m ² for wastewater treatment (recovery / transport costs and purification costs), so 80 m ³ / day Then, it becomes 640000 yen / day. Therefore, for example, in the bridge concrete flooring work, the water usage fee during the construction period is 6000 m ³ , so the cost related to the use of water alone is 48000000 yen. Of course, if the water supply place or the drainage place becomes far away, the cost will increase accordingly.

  In addition, the quality standards of tap water are, for example, SS 2 mg / L or less, hardness 300 mg / L or less, and pH 5.8 to 8.6. On the other hand, the water quality standard used for the water jet method is SS 1 mg / L or less, calcium 50 mg / L or less (magnesium is about 10 mg / L although there are differences depending on the region), and pH around 7 is recommended. . Therefore, even tap water may not be used as it is for water jet construction.

  Then, the processing apparatus of the water jet waste water aiming at reusing water jet waste water by a water jet construction method is proposed (refer patent document 1). This treatment apparatus is characterized by including a water jet wastewater neutralizing device and a solid matter removing device. Moreover, in the neutralization apparatus with which this processing apparatus is provided, water jet waste water and sulfuric acid are mixed.

  However, according to the knowledge of the present inventors, there is a possibility that this treatment apparatus cannot sufficiently remove calcium. Moreover, since this processing apparatus uses sulfuric acid, there is room for improvement in terms of safety.

JP-A-11-33549

  The main problem to be solved by the present invention is to provide a treatment apparatus and a treatment method for a liquid to be treated that can sufficiently remove calcium.

  First, the present inventors examined a method for removing calcium in a liquid to be treated using sulfuric acid as in the prior art. By reacting calcium with sulfuric acid to form calcium sulfate, the calcium sulfate is removed by a filtration device to remove calcium. However, calcium sulfate has a high solubility in water (about 2.4 g / L). Therefore, it has been found that according to the method using sulfuric acid, the pH of the liquid to be treated becomes neutral, but calcium cannot be sufficiently removed.

  Then, the method of removing the calcium in a to-be-processed liquid using a carbon dioxide was examined. It is based on a trial calculation that calcium carbonate produced by the reaction between calcium and carbon dioxide has low solubility (0.015 g / L) and becomes a crystal of several μm, and can be sufficiently removed by a filtration device. However, calcium cannot be sufficiently removed by simply reacting calcium with carbon dioxide. As a result of investigating the cause, when carbon dioxide is used, as the reaction proceeds, calcium carbonate becomes calcium hydrogen carbonate, and this calcium hydrogen carbonate is dissolved in water (solubility 16.6 g / L). It was discovered.

Therefore, the present invention has been created based on these examinations and findings.
That is, the means for solving the above problems are as follows:
A reaction tank for the liquid to be treated, and a filtration device for the liquid to be treated discharged from the reaction tank;
The reaction tank includes a partition material for partitioning the inside of the reaction tank into a first region and a second region, a supply port for supplying a liquid to be processed to the first region, and carbon dioxide to the first region. And a discharge means for discharging the liquid to be processed from the second region,
The liquid to be treated supplied from the supply port comes into contact with the carbon dioxide, flows through the first region along the partition material, then flows into the second region, and is discharged from the discharge port. ,
This is an apparatus for processing a liquid to be processed.

In addition, using the treatment apparatus provided with an ion concentration meter that measures the calcium ion concentration of the liquid to be treated discharged from the latter-stage filtration device,
When the measured value of this ion concentration meter is a predetermined value or more, return the liquid to be treated to the reaction vessel,
It is the processing method of the to-be-processed liquid characterized by the above-mentioned.

  According to the present invention, a processing apparatus and a processing method for a liquid to be processed that can sufficiently remove calcium.

It is an equipment figure of the processing device of the liquid to be processed of the 1st form. It is a modification of a reaction tank. It is the equipment figure of the processing apparatus of the to-be-processed liquid of a 2nd form.

  Next, the form for implementing this invention is demonstrated. This form is an example of the present invention. The scope of the present invention is not limited to the scope of this embodiment.

(First form)
FIG. 1 shows a processing apparatus X of this embodiment. The processing apparatus X of this form is an apparatus for removing calcium from the waste water (treatment liquid D) containing calcium, such as water jet waste water, road cutter waste water, and waste disposal site waste water. Therefore, the purified water C processed by the processing apparatus X can be reused by the water jet method, for example, and can be discharged into the sea, rivers, or the like.

  The processing apparatus X of this embodiment is mainly composed of a reaction vessel 21 and a filtration device, and as a filtration device, it is provided with a pre-stage filtration device 10 provided in the front stage (upstream) of the reaction tank 21 and a rear stage (downstream) of the reaction tank 21. A post-stage filtration device 30 is provided. In addition, although mentioned later for details, the 2nd processing apparatus X2 mentioned later is provided with only the front | former stage filtration apparatus 10 as a filtration apparatus, and this point (1st form) has a big difference in this point.

  The liquid D to be treated is first sent to the pre-filtration device 10 by the pump P1. This pre-stage filtration apparatus 10 is an apparatus for removing foreign matters such as sand, cement, and dust contained in the liquid D to be treated. By removing the foreign matters in the previous stage of the reaction tank 21, the reaction tank 21 is less likely to become dirty, and maintenance is facilitated. Moreover, by removing the cement from the liquid D to be treated, the reaction between the cement and carbon dioxide in the reaction tank 21 can be avoided, and the consumption (administration) amount of carbon dioxide can be reduced. In this regard, when the dose of carbon dioxide increases, the problem of simply increasing costs does not arise. As the dose of carbon dioxide increases, the possibility that calcium carbonate will change to calcium bicarbonate increases accordingly. Therefore, the benefit of reducing the dose of carbon dioxide is great.

  As the pre-stage filtration device 10, various filtration devices equipped with a filtration membrane such as a UF membrane (ultrafiltration membrane), an MF membrane (microfiltration membrane), and an RO membrane (reverse osmosis membrane) can be used. However, it is preferable to use a filtration device capable of removing particles of 0.3 μm or more.

The liquid D to be treated filtered by the pre-stage filtration apparatus 10 is sent to the reaction tank 21 through the flow path 81 and the flow path 82. This reaction tank 21 is a tank for causing carbon dioxide to react with calcium contained in the liquid D to be treated. This reaction vessel 21 is characterized in that it is designed to prevent carbon dioxide overreaction. Specifically, the reaction tank 21 is provided with a partition member 22, a supply port 24 for the liquid D to be processed, a blowing means 23 for carbon dioxide CO ₂ , and a discharge port 25 for the liquid D to be processed.

  The partition member 22 is a member that partitions the inside of the reaction tank 21 into a first region Z1 and a second region Z2. For example, as shown in (1) of FIG. 2, the partition member 22 can have a flat plate shape extending upward from the bottom surface 21 a of the reaction vessel 21. However, the partition material 22 of the present embodiment is cylindrical and is provided on the bottom surface 21a of the central portion of the reaction vessel 21, and extends upward from the central bottom surface 21a. In this embodiment, the inner side (inner side) of the cylindrical partition member 22 corresponds to the first region Z1, and the outer side (outer side) corresponds to the second region Z2.

  In this embodiment, the upper end edge 22 b of the partition member 22 is designed to be positioned below the liquid surface of the liquid D to be processed in the reaction tank 21. On the other hand, although the lower end part 22a of the partition material 22 protrudes below the floor surface 21a of the reaction tank 21, the form which does not protrude can also be considered. Moreover, although the partition material 22 of this form is made into the cylindrical shape, it can also be considered as a rectangular tube shape. However, from the viewpoint of a uniform reaction (contact) between the liquid D to be treated and carbon dioxide, a cylindrical shape is preferable.

  The liquid D to be processed sent to the reaction tank 21 through the flow path 81 and the flow path 82 is supplied into the reaction tank 21 through the supply port 24. The supply port 24 of this embodiment is an opening and is formed on the side wall of the lower end portion 22 a of the partition member 22. Accordingly, the supply port 24 is positioned at the bottom of the first region Z1, and the liquid D to be treated is first supplied to the first region Z1 in the reaction vessel 21. Note that the supply port 24 may be formed in a member other than the partition member 22 as long as the liquid D to be treated can be supplied to the first region Z1 first.

  The carbon dioxide blowing means 23 is a means for blowing carbon dioxide into the first region Z1. The blowing means 23 is located at the bottom of the first region Z1. Accordingly, first, carbon dioxide is blown into the liquid D to be treated supplied to the first region Z1.

  Various forms can be considered as the blowing means 23. However, in this embodiment, the blowing means 23 is configured by an injection nozzle that injects carbon dioxide as fine bubbles such as microbubbles, micronanovalves, and nanovalves. By injecting carbon dioxide as fine bubbles, the reaction efficiency between calcium and carbon dioxide contained in the liquid D to be treated is improved. In this regard, when the reaction efficiency is poor, a part of calcium has been completely reacted to calcium carbonate, but the rest of calcium is not yet completely reacted to calcium carbonate. Therefore, it is necessary to proceed with the reaction of calcium that has not been completed, and when the reaction proceeds, the reaction of calcium that has completed the reaction further proceeds and changes from calcium carbonate to calcium hydrogen carbonate. It will dissolve. Therefore, improvement of reaction efficiency is extremely important.

As described above, it is extremely important to control the reaction between calcium and carbon dioxide. In this embodiment, the amount of carbon dioxide blown from the blowing means 23 is controlled as follows, and the accuracy (excess Prevention of administration).
That is, first, as equipment relating to the supply of carbon dioxide, a storage tank 50 filled with carbon dioxide, a pressure regulating valve 51 for adjusting the pressure of carbon dioxide, and a flow valve (control means) 52 for controlling the flow rate of carbon dioxide, Is provided. Further, a flow meter 41 for measuring the flow rate of the liquid D to be processed and a pH meter 42 for measuring the pH of the liquid D to be processed are provided between the pre-stage filtration device 10 and the supply port 24. Furthermore, the values (flow rate and pH) measured by the flow meter 41 and the pH meter 42 are configured to be sent to the flow valve 52 as a signal S1. The flow rate valve 52 is controlled to open and close (flow rate) in accordance with the value of the signal S1, thereby controlling the flow rate of carbon dioxide blown into the first region Z1. The carbon dioxide is mixed with the liquid D to be treated that is taken in through the flow path 83 prior to being blown into the first region Z1. The channel 83 is branched from the channel 81 and the channel 82, and includes, for example, a transport pipe, a duct, and the like. The flow of the liquid D to be processed in the flow paths 81 to 83 is performed by the pump P3.

  In the test conducted by the present inventors, the flow rate of carbon dioxide was 0.4 L / min, the mixing ratio of the liquid D to be treated and the carbon dioxide from the flow path 83 was 10: 1, and the treatment in the reaction tank 21 was performed. The test was performed by setting the volume of the liquid D to 16.3 L and the residence time of the liquid D to be treated in the reaction tank 21 to 5 minutes. As a result, it was found that the reaction to calcium carbonate can be sufficiently performed while avoiding overreaction (change to calcium bicarbonate).

  When carbon dioxide is blown in as described above, the liquid D to be treated supplied to the first region Z1 comes into contact with the carbon dioxide, and the first region Z1 is separated along the partition material 22 (in this embodiment). Flows in the partition 22. During this time, the reaction between calcium and carbon dioxide proceeds. In order to ensure this reaction, the following devices have been devised in this embodiment.

  First, in the present embodiment, a first mesh plate 26 that crosses the first region Z1 is provided downstream (upward) of the injection nozzle (blowing means 23). In this embodiment in which the blowing means 23 is an injection nozzle, the flow V1 of the liquid D to be treated in the first region Z1 is accelerated by the upward injection of carbon dioxide, and the reaction between calcium and carbon dioxide is sufficiently advanced. There is a risk of not. Therefore, by providing the first mesh plate 26, the flow V1 of the liquid D to be treated is prevented from becoming too fast, and the reaction is surely advanced. Moreover, since the 1st net-like board 26 is net-like, the rectification effect (especially turbulent flow prevention effect) can also be anticipated, and the uniformity of reaction can also be ensured. In addition, the flow of the to-be-processed liquid D can be designed so that it may be set to 0.1-0.2 m / s, for example. In addition, in the above case, in order to more surely prevent the flow of the liquid to be processed D from becoming too fast, a form in which the liquid to be processed D is supplied from the side of the partition member 22 as shown in the drawing is adopted. Is preferred.

  Various things can be adopted as the first mesh plate 26 in consideration of the above effects. Specifically, for example, a punching metal, a perforated plate in which a large number of holes are formed in a single plate, a wire mesh, a honeycomb structure member, or the like can be employed.

  The to-be-processed liquid D that has flowed upward in the first region Z1 along the partition material 22 changes direction beyond the partition material 22 at the upper end portion of the reaction tank 21, and flows into the second region Z2. Note that the flow of the liquid D to be treated is indicated by arrows.

  The liquid D to be processed that has flowed into the second region Z2 flows downward through the second region Z2 and is discharged from the discharge port 25. The discharge port 25 is formed in the side wall at the bottom of the reaction vessel 21.

  According to this embodiment, there is no possibility that carbon dioxide is blown into the liquid D to be processed flowing in the second region Z2. Therefore, there is no possibility that an overreaction to calcium bicarbonate occurs with respect to calcium that has finished the reaction to calcium carbonate.

Further, in this embodiment, the device is devised so that a part of the liquid D to be processed flowing through the second region Z2 does not flow backward and an overreaction or the like occurs.
That is, a second mesh plate 27 that crosses the second region Z2 is provided in the second region Z2 upstream (upward) of the discharge port 25. By providing the mesh plate 27 in the second region Z2, it is possible to expect a rectifying effect of the liquid D to be treated, and it is possible to avoid overreaction to calcium bicarbonate.

  Various positions for providing the second mesh plate 27 can be considered, but it is preferable that the second mesh plate 27 is provided at the upper end of the second region Z2 as in the illustrated example. This is because the flow of the liquid D to be processed changes direction at the upper end of the reaction tank 21, and therefore the flow of the liquid D to be processed is easily disturbed.

  As the second mesh plate 27, various types can be adopted in consideration of the above effects. Specifically, for example, a punching metal, a perforated plate in which a large number of holes are formed in a single plate, a wire mesh, a honeycomb structure member, or the like can be employed. Moreover, the 2nd net-like board 27 can also be provided with two or more two or more in a flow direction (this embodiment up-down direction) like the example of illustration. In the present embodiment in which the partition member 22 is cylindrical, the second mesh plate 27 has a donut shape.

  The liquid D to be processed that flows through the second region Z2 and is discharged from the discharge port 25 is sent to the subsequent filtration device 30 by the pump P2. The latter-stage filtration device 30 is a device that removes calcium carbonate contained in the liquid D to be treated. Since calcium carbonate is difficult to dissolve in water, it can be reliably removed by the post-filter unit 30, and therefore, according to the present processing apparatus X, calcium can be reliably removed from the liquid D to be treated.

  As the post-stage filtration apparatus 30, as with the pre-stage filtration apparatus 10, various filtration apparatuses provided with filtration membranes such as a UF membrane (ultrafiltration membrane), an MF membrane (microfiltration membrane), and an RO membrane (reverse osmosis membrane), for example. Can be used. However, it is preferable to use a filtration device capable of removing particles of 0.3 μm or more. Moreover, the same filtration apparatus can be used as the front | former stage filtration apparatus 10 and the back | latter stage filtration apparatus 30 as needed.

The liquid D to be treated that has been filtered by the post-stage filtration device 30 can be reused as it is in the water jet method or the like, or can be discharged into the sea or river. In this embodiment, for the sake of safety. Further facilities are provided.
That is, the to-be-processed liquid D filtered by the post-stage filtration apparatus 30 is discharged through the flow path 85, and the ion concentration meter 43 and the bypass valve 53 are provided in the flow path 85. The ion concentration meter 43 is a meter that measures the ion concentration of calcium contained in the liquid D to be processed flowing through the flow path 85. The bypass valve 53 is a valve that switches the flow of the liquid D to be processed to either the channel 86 or the channel 87. The liquid D to be treated sent to the flow path 86 is reused or discharged as the purified water C. The liquid D to be processed sent to the flow path 87 is sent again to the reaction tank 21 through the flow path 82.

  Switching of the bypass valve 53 is performed based on the measurement value of the ion concentration meter 43. That is, when the measured value of the ion concentration meter 43 is not less than a predetermined value, for example, 50 g / L or more, the measured value is sent to the bypass valve 53 as the switching signal S2, and switching by the bypass valve 53 is performed. D is returned to the reaction vessel 21.

  In the above, the form in which the reaction vessel 21 is partitioned into the first region Z1 and the second region Z2 by the partition member 22 is shown, but the second region Z2 does not need to be one region. For example, as shown in (2) of FIG. 2, a second partition member 29 can be provided outside the partition member 22, and the second region Z2 can be partitioned into two regions. The second partition member 29 is cylindrical and is provided coaxially with the first partition member 22, the lower end portion is not in contact with the floor surface 21 a of the reaction tank 21, and the upper end portion is the liquid D to be treated. It extends above the liquid level. In this embodiment, the liquid D to be treated flows upward in the first region Z1 along the partition material 22 and changes its direction beyond the partition material 22 at the upper end portion of the reaction tank 21, and the partition material 22 and the second material After flowing downward between the partition materials 29, the second partition material 29 is further submerged and added in the direction to flow upward between the second partition material 29 and the reaction tank 21, and the upper end side wall of the reaction tank 21. It will be discharged from the discharge port 25 provided in. The feature of this form is that the reaction time of calcium and carbon dioxide can be lengthened by the form described above. However, since this form takes time to completely remove the liquid D to be treated in the reaction tank 21 when the reaction tank 21 is maintained, the above-described form is preferable when the maintenance is important.

  The capacity of the liquid D to be treated in the reaction tank 21 is preferably determined based on the reaction time of calcium and carbon dioxide. In order to maintain this capacity, in this embodiment, a level meter 54 for detecting the liquid level of the liquid D to be processed is provided. Based on the signal S3 from the level meter 54, the pump P1 that sends the liquid D to be treated to the pre-stage filtration device 10 is controlled.

(Second form)
Next, based on FIG. 3, the processing apparatus X2 of a 2nd form is demonstrated. In this description, the description will focus on differences from the processing apparatus X of the first embodiment.

  The processing device X2 of this embodiment is also mainly composed of the reaction tank 21 and the filtration device. However, in this embodiment, only the pre-stage filtration device 10 located in the pre-stage (upstream) of the reaction vessel 21 is provided as the filtration apparatus. That is, in the present embodiment, unlike the first embodiment, the latter-stage filtration device 30 is not provided. Accordingly, the ion concentration is measured by the ion concentration meter 43 of the liquid D to be treated discharged from the reaction tank 21 without being filtered, that is, without removing calcium carbonate. Then, the bypass valve 53 is switched based on the measured value (S2) of the ion concentration meter 43. However, since the calcium carbonate is not removed at this time, it is assumed that the measured value (S2) of the ion concentration meter 43 is usually a predetermined value or more, and the liquid D to be processed passes through the flow path 88 to the pre-stage filtration device 10. Will be sent. At this point, the calcium carbonate contained in the liquid D to be treated is removed.

  The liquid D to be treated from which the calcium carbonate has been removed in the pre-stage filtration device 10 is sent to the reaction tank 21 through the flow path 82. And reaction with a carbon dioxide is advanced in this reaction tank 21. FIG. In this regard, the reaction with carbon dioxide at this point is a re-reaction, but there is no possibility of overreaction because calcium carbonate has been removed. At this point, only the reaction of calcium that has not been completed proceeds.

  The liquid D to be treated in which the reaction with carbon dioxide has proceeded in the reaction tank 21 is discharged from the reaction tank 21, and the ion concentration of the calcium is measured by the ion concentration meter 43. If the measured value (S2) at this time is less than the predetermined value, the bypass valve 53 is switched, and the purified water C is discharged out of the system through the flow path 86. On the other hand, if the measured value (S2) is equal to or greater than the predetermined value, the liquid D to be treated is sent again to the pre-stage filtration device 10 to remove calcium carbonate.

  As described above, in this embodiment, the reaction of calcium and carbon dioxide (reaction process) and the removal of calcium carbonate (removal process) are repeated, and when the calcium ion concentration finally becomes less than a predetermined value, the system is treated as purified water C. Discharged outside. In this reaction process and removal process, a new liquid D to be treated may or may not be poured into the reaction tank 21. When the liquid D to be treated is not added, the liquid D to be treated is discharged out of the system as purified water C and gradually decreases, so that the reaction tank 21 is finally emptied. When the reaction tank 21 becomes empty, the reaction tank 21 is filled again with the liquid D to be processed, and the same process is repeated. This process can be referred to as a batch type because the same process is repeated. On the other hand, when adding the liquid D to be treated, the calcium removal process is continuously performed, which can be referred to as a continuous type. The batch method has an advantage in terms of processing stability, and the continuous method has an advantage in terms of processing efficiency.

  The present invention relates to a treatment apparatus and treatment method for a treatment liquid, and in particular, a treatment apparatus for a treatment liquid that is suitable when the treatment liquid is drainage containing calcium, such as water jet drainage, road cutter drainage, and waste disposal site drainage. And can be used as a processing method.

DESCRIPTION OF SYMBOLS 10 Pre-stage filtration apparatus 21 Reaction tank 22 Partition material 23 Blowing means 24 Supply port 25 Discharge port 26 1st mesh board 27 2nd mesh board 29 2nd partition material 30 Later stage filtration apparatus 41 Flowmeter 42 pH meter 43 Ion Densitometer 50 Storage tank 51 Pressure regulating valve 52 Flow valve (control means)
53 Bypass valve 54 Level meter D Liquid to be treated C Clean water S1 to S3 Signal X, X1 Processing device Z1 First region Z2 Second region P1 to P3 Pump

  The present invention relates to a processing apparatus and processing method for a liquid to be processed. In particular, the present invention relates to a treatment apparatus and a treatment method for a treatment liquid suitable when the treatment liquid is wastewater containing calcium such as water jet drainage, road cutter drainage, and waste treatment plant drainage.

At present, the water jet method (WJ method) is widely used in cutting concrete structures, turning work, and the like. In this water jet method, waste water containing calcium is generated. This wastewater has SS of 1000 to 3000 mg / L, calcium of 1000 mg / L or more, and pH of 11 or more. Therefore, it cannot be discharged into the sea or river as it is. Moreover, since calcium in the waste water is precipitated and granulated, there is a possibility that the ultra-high pressure (for example, 300 MPa) pump may break down, so that it cannot be reused in the water jet method as it is. Therefore, in the water jet construction method, tap water is currently used, which causes the cost to increase due to water charges, transportation costs, and the like. In addition, it costs money to transport and purify wastewater. These costs are about 3000 yen / m ^{2 for} water supply treatment (water charges and transportation costs), and about 5000 yen / m ² for wastewater treatment (recovery / transport costs and purification costs), so 80 m ³ / day Then, it becomes 640000 yen / day. Therefore, for example, in the bridge concrete flooring work, the water usage fee during the construction period is 6000 m ³ , so the cost related to the use of water alone is 48000000 yen. Of course, if the water supply place or the drainage place becomes far away, the cost will increase accordingly.

  In addition, the quality standards of tap water are, for example, SS 2 mg / L or less, hardness 300 mg / L or less, and pH 5.8 to 8.6. On the other hand, the water quality standard used for the water jet method is SS 1 mg / L or less, calcium 50 mg / L or less (magnesium is about 10 mg / L although there are differences depending on the region), and pH around 7 is recommended. . Therefore, even tap water may not be used as it is for water jet construction.

  Then, the processing apparatus of the water jet waste water aiming at reusing water jet waste water by a water jet construction method is proposed (refer patent document 1). This treatment apparatus is characterized by including a water jet wastewater neutralizing device and a solid matter removing device. Moreover, in the neutralization apparatus with which this processing apparatus is provided, water jet waste water and sulfuric acid are mixed.

  However, according to the knowledge of the present inventors, there is a possibility that this treatment apparatus cannot sufficiently remove calcium. Moreover, since this processing apparatus uses sulfuric acid, there is room for improvement in terms of safety.

JP-A-11-33549

  The main problem to be solved by the present invention is to provide a treatment apparatus and a treatment method for a liquid to be treated that can sufficiently remove calcium.

  First, the present inventors examined a method for removing calcium in a liquid to be treated using sulfuric acid as in the prior art. By reacting calcium with sulfuric acid to form calcium sulfate, the calcium sulfate is removed by a filtration device to remove calcium. However, calcium sulfate has a high solubility in water (about 2.4 g / L). Therefore, it has been found that according to the method using sulfuric acid, the pH of the liquid to be treated becomes neutral, but calcium cannot be sufficiently removed.

  Then, the method of removing the calcium in a to-be-processed liquid using a carbon dioxide was examined. It is based on a trial calculation that calcium carbonate produced by the reaction between calcium and carbon dioxide has low solubility (0.015 g / L) and becomes a crystal of several μm, and can be sufficiently removed by a filtration device. However, calcium cannot be sufficiently removed by simply reacting calcium with carbon dioxide. As a result of investigating the cause, when carbon dioxide is used, as the reaction proceeds, calcium carbonate becomes calcium hydrogen carbonate, and this calcium hydrogen carbonate is dissolved in water (solubility 16.6 g / L). It was discovered.

Therefore, the present invention has been created based on these examinations and findings.
That is, the means for solving the above problems are as follows:
A reaction tank for the liquid to be treated, and a filtration device for the liquid to be treated discharged from the reaction tank;
The reaction tank includes a partition material for partitioning the inside of the reaction tank into a first region and a second region, a supply port for supplying a liquid to be processed to the first region, and carbon dioxide to the first region. And a discharge means for discharging the liquid to be processed from the second region,
Treated liquid supplied from the supply port is in contact with the carbon dioxide, after flowing through said first region along said partition member, flows into the second region, is discharged from the discharge port ,
The partition material is cylindrical and is provided on the center bottom surface of the reaction vessel,
The supply port and the blowing means are provided at the bottom of the first region.
This is an apparatus for processing a liquid to be processed.

In addition, using the treatment apparatus provided with an ion concentration meter that measures the calcium ion concentration of the liquid to be treated discharged from the latter-stage filtration device,
When the measured value of this ion concentration meter is a predetermined value or more, return the liquid to be treated to the reaction vessel,
It is the processing method of the to-be-processed liquid characterized by the above-mentioned.

  According to the present invention, a processing apparatus and a processing method for a liquid to be processed that can sufficiently remove calcium.

It is an equipment figure of the processing device of the liquid to be processed of the 1st form. It is a modification of a reaction tank. It is the equipment figure of the processing apparatus of the to-be-processed liquid of a 2nd form.

  Next, the form for implementing this invention is demonstrated. This form is an example of the present invention. The scope of the present invention is not limited to the scope of this embodiment.

(First form)
FIG. 1 shows a processing apparatus X of this embodiment. The processing apparatus X of this form is an apparatus for removing calcium from the waste water (treatment liquid D) containing calcium, such as water jet waste water, road cutter waste water, and waste disposal site waste water. Therefore, the purified water C processed by the processing apparatus X can be reused by the water jet method, for example, and can be discharged into the sea, rivers, or the like.

  The processing apparatus X of this embodiment is mainly composed of a reaction vessel 21 and a filtration device, and as a filtration device, it is provided with a pre-stage filtration device 10 provided in the front stage (upstream) of the reaction tank 21 and a rear stage (downstream) of the reaction tank 21. A post-stage filtration device 30 is provided. In addition, although mentioned later for details, the 2nd processing apparatus X2 mentioned later is provided with only the front | former stage filtration apparatus 10 as a filtration apparatus, and this point (1st form) has a big difference in this point.

  The liquid D to be treated is first sent to the pre-filtration device 10 by the pump P1. This pre-stage filtration apparatus 10 is an apparatus for removing foreign matters such as sand, cement, and dust contained in the liquid D to be treated. By removing the foreign matters in the previous stage of the reaction tank 21, the reaction tank 21 is less likely to become dirty, and maintenance is facilitated. Moreover, by removing the cement from the liquid D to be treated, the reaction between the cement and carbon dioxide in the reaction tank 21 can be avoided, and the consumption (administration) amount of carbon dioxide can be reduced. In this regard, when the dose of carbon dioxide increases, the problem of simply increasing costs does not arise. As the dose of carbon dioxide increases, the possibility that calcium carbonate will change to calcium bicarbonate increases accordingly. Therefore, the benefit of reducing the dose of carbon dioxide is great.

  As the pre-stage filtration device 10, various filtration devices equipped with a filtration membrane such as a UF membrane (ultrafiltration membrane), an MF membrane (microfiltration membrane), and an RO membrane (reverse osmosis membrane) can be used. However, it is preferable to use a filtration device capable of removing particles of 0.3 μm or more.

The liquid D to be treated filtered by the pre-stage filtration apparatus 10 is sent to the reaction tank 21 through the flow path 81 and the flow path 82. This reaction tank 21 is a tank for causing carbon dioxide to react with calcium contained in the liquid D to be treated. This reaction vessel 21 is characterized in that it is designed to prevent carbon dioxide overreaction. Specifically, the reaction tank 21 is provided with a partition member 22, a supply port 24 for the liquid D to be processed, a blowing means 23 for carbon dioxide CO ₂ , and a discharge port 25 for the liquid D to be processed.

  The partition member 22 is a member that partitions the inside of the reaction tank 21 into a first region Z1 and a second region Z2. For example, as shown in (1) of FIG. 2, the partition member 22 can have a flat plate shape extending upward from the bottom surface 21 a of the reaction vessel 21. However, the partition material 22 of the present embodiment is cylindrical and is provided on the bottom surface 21a of the central portion of the reaction vessel 21, and extends upward from the central bottom surface 21a. In this embodiment, the inner side (inner side) of the cylindrical partition member 22 corresponds to the first region Z1, and the outer side (outer side) corresponds to the second region Z2.

  In this embodiment, the upper end edge 22 b of the partition member 22 is designed to be positioned below the liquid surface of the liquid D to be processed in the reaction tank 21. On the other hand, although the lower end part 22a of the partition material 22 protrudes below the floor surface 21a of the reaction tank 21, the form which does not protrude can also be considered. Moreover, although the partition material 22 of this form is made into the cylindrical shape, it can also be considered as a rectangular tube shape. However, from the viewpoint of a uniform reaction (contact) between the liquid D to be treated and carbon dioxide, a cylindrical shape is preferable.

  The liquid D to be processed sent to the reaction tank 21 through the flow path 81 and the flow path 82 is supplied into the reaction tank 21 through the supply port 24. The supply port 24 of this embodiment is an opening and is formed on the side wall of the lower end portion 22 a of the partition member 22. Accordingly, the supply port 24 is positioned at the bottom of the first region Z1, and the liquid D to be treated is first supplied to the first region Z1 in the reaction vessel 21. Note that the supply port 24 may be formed in a member other than the partition member 22 as long as the liquid D to be treated can be supplied to the first region Z1 first.

  The carbon dioxide blowing means 23 is a means for blowing carbon dioxide into the first region Z1. The blowing means 23 is located at the bottom of the first region Z1. Accordingly, first, carbon dioxide is blown into the liquid D to be treated supplied to the first region Z1.

  Various forms can be considered as the blowing means 23. However, in this embodiment, the blowing means 23 is configured by an injection nozzle that injects carbon dioxide as fine bubbles such as microbubbles, micronanovalves, and nanovalves. By injecting carbon dioxide as fine bubbles, the reaction efficiency between calcium and carbon dioxide contained in the liquid D to be treated is improved. In this regard, when the reaction efficiency is poor, a part of calcium has been completely reacted to calcium carbonate, but the rest of calcium is not yet completely reacted to calcium carbonate. Therefore, it is necessary to proceed with the reaction of calcium that has not been completed, and when the reaction proceeds, the reaction of calcium that has completed the reaction further proceeds and changes from calcium carbonate to calcium hydrogen carbonate. It will dissolve. Therefore, improvement of reaction efficiency is extremely important.

As described above, it is extremely important to control the reaction between calcium and carbon dioxide. In this embodiment, the amount of carbon dioxide blown from the blowing means 23 is controlled as follows, and the accuracy (excess Prevention of administration).
That is, first, as equipment relating to the supply of carbon dioxide, a storage tank 50 filled with carbon dioxide, a pressure regulating valve 51 for adjusting the pressure of carbon dioxide, and a flow valve (control means) 52 for controlling the flow rate of carbon dioxide, Is provided. Further, a flow meter 41 for measuring the flow rate of the liquid D to be processed and a pH meter 42 for measuring the pH of the liquid D to be processed are provided between the pre-stage filtration device 10 and the supply port 24. Furthermore, the values (flow rate and pH) measured by the flow meter 41 and the pH meter 42 are configured to be sent to the flow valve 52 as a signal S1. The flow rate valve 52 is controlled to open and close (flow rate) in accordance with the value of the signal S1, thereby controlling the flow rate of carbon dioxide blown into the first region Z1. The carbon dioxide is mixed with the liquid D to be treated that is taken in through the flow path 83 prior to being blown into the first region Z1. The channel 83 is branched from the channel 81 and the channel 82, and includes, for example, a transport pipe, a duct, and the like. The flow of the liquid D to be processed in the flow paths 81 to 83 is performed by the pump P3.

  In the test conducted by the present inventors, the flow rate of carbon dioxide was 0.4 L / min, the mixing ratio of the liquid D to be treated and the carbon dioxide from the flow path 83 was 10: 1, and the treatment in the reaction tank 21 was performed. The test was performed by setting the volume of the liquid D to 16.3 L and the residence time of the liquid D to be treated in the reaction tank 21 to 5 minutes. As a result, it was found that the reaction to calcium carbonate can be sufficiently performed while avoiding overreaction (change to calcium bicarbonate).

  When carbon dioxide is blown in as described above, the liquid D to be treated supplied to the first region Z1 comes into contact with the carbon dioxide, and the first region Z1 is separated along the partition material 22 (in this embodiment). Flows in the partition 22. During this time, the reaction between calcium and carbon dioxide proceeds. In order to ensure this reaction, the following devices have been devised in this embodiment.

  First, in the present embodiment, a first mesh plate 26 that crosses the first region Z1 is provided downstream (upward) of the injection nozzle (blowing means 23). In this embodiment in which the blowing means 23 is an injection nozzle, the flow V1 of the liquid D to be treated in the first region Z1 is accelerated by the upward injection of carbon dioxide, and the reaction between calcium and carbon dioxide is sufficiently advanced. There is a risk of not. Therefore, by providing the first mesh plate 26, the flow V1 of the liquid D to be treated is prevented from becoming too fast, and the reaction is surely advanced. Moreover, since the 1st net-like board 26 is net-like, the rectification effect (especially turbulent flow prevention effect) can also be anticipated, and the uniformity of reaction can also be ensured. In addition, the flow of the to-be-processed liquid D can be designed so that it may be set to 0.1-0.2 m / s, for example. In addition, in the above case, in order to more surely prevent the flow of the liquid to be processed D from becoming too fast, a form in which the liquid to be processed D is supplied from the side of the partition member 22 as shown in the drawing is adopted. Is preferred.

  Various things can be adopted as the first mesh plate 26 in consideration of the above effects. Specifically, for example, a punching metal, a perforated plate in which a large number of holes are formed in a single plate, a wire mesh, a honeycomb structure member, or the like can be employed.

  The to-be-processed liquid D that has flowed upward in the first region Z1 along the partition material 22 changes direction beyond the partition material 22 at the upper end portion of the reaction tank 21, and flows into the second region Z2. Note that the flow of the liquid D to be treated is indicated by arrows.

  The liquid D to be processed that has flowed into the second region Z2 flows downward through the second region Z2 and is discharged from the discharge port 25. The discharge port 25 is formed in the side wall at the bottom of the reaction vessel 21.

  According to this embodiment, there is no possibility that carbon dioxide is blown into the liquid D to be processed flowing in the second region Z2. Therefore, there is no possibility that an overreaction to calcium bicarbonate occurs with respect to calcium that has finished the reaction to calcium carbonate.

Further, in this embodiment, the device is devised so that a part of the liquid D to be processed flowing through the second region Z2 does not flow backward and an overreaction or the like occurs.
That is, a second mesh plate 27 that crosses the second region Z2 is provided in the second region Z2 upstream (upward) of the discharge port 25. By providing the mesh plate 27 in the second region Z2, it is possible to expect a rectifying effect of the liquid D to be treated, and it is possible to avoid overreaction to calcium bicarbonate.

  Various positions for providing the second mesh plate 27 can be considered, but it is preferable that the second mesh plate 27 is provided at the upper end of the second region Z2 as in the illustrated example. This is because the flow of the liquid D to be processed changes direction at the upper end of the reaction tank 21, and therefore the flow of the liquid D to be processed is easily disturbed.

  As the second mesh plate 27, various types can be adopted in consideration of the above effects. Specifically, for example, a punching metal, a perforated plate in which a large number of holes are formed in a single plate, a wire mesh, a honeycomb structure member, or the like can be employed. Moreover, the 2nd net-like board 27 can also be provided with two or more two or more in a flow direction (this embodiment up-down direction) like the example of illustration. In the present embodiment in which the partition member 22 is cylindrical, the second mesh plate 27 has a donut shape.

  The liquid D to be processed that flows through the second region Z2 and is discharged from the discharge port 25 is sent to the subsequent filtration device 30 by the pump P2. The latter-stage filtration device 30 is a device that removes calcium carbonate contained in the liquid D to be treated. Since calcium carbonate is difficult to dissolve in water, it can be reliably removed by the post-filter unit 30, and therefore, according to the present processing apparatus X, calcium can be reliably removed from the liquid D to be treated.

  As the post-stage filtration apparatus 30, as with the pre-stage filtration apparatus 10, various filtration apparatuses provided with filtration membranes such as a UF membrane (ultrafiltration membrane), an MF membrane (microfiltration membrane), and an RO membrane (reverse osmosis membrane), for example. Can be used. However, it is preferable to use a filtration device capable of removing particles of 0.3 μm or more. Moreover, the same filtration apparatus can be used as the front | former stage filtration apparatus 10 and the back | latter stage filtration apparatus 30 as needed.

The liquid D to be treated that has been filtered by the post-stage filtration device 30 can be reused as it is in the water jet method or the like, or can be discharged into the sea or river. In this embodiment, for the sake of safety. Further facilities are provided.
That is, the to-be-processed liquid D filtered by the post-stage filtration apparatus 30 is discharged through the flow path 85, and the ion concentration meter 43 and the bypass valve 53 are provided in the flow path 85. The ion concentration meter 43 is a meter that measures the ion concentration of calcium contained in the liquid D to be processed flowing through the flow path 85. The bypass valve 53 is a valve that switches the flow of the liquid D to be processed to either the channel 86 or the channel 87. The liquid D to be treated sent to the flow path 86 is reused or discharged as the purified water C. The liquid D to be processed sent to the flow path 87 is sent again to the reaction tank 21 through the flow path 82.

  Switching of the bypass valve 53 is performed based on the measurement value of the ion concentration meter 43. That is, when the measured value of the ion concentration meter 43 is not less than a predetermined value, for example, 50 g / L or more, the measured value is sent to the bypass valve 53 as the switching signal S2, and switching by the bypass valve 53 is performed. D is returned to the reaction vessel 21.

In the above, the form in which the reaction vessel 21 is partitioned into the first region Z1 and the second region Z2 by the partition member 22 is shown, but the second region Z2 does not need to be one region. For example, as shown in (2) of FIG. 2, a second partition member 29 can be provided outside the partition member 22, and the second region Z2 can be partitioned into two regions. The second partition member 29 is cylindrical and is provided coaxially with the first partition member 22, the lower end portion is not in contact with the floor surface 21 a of the reaction tank 21, and the upper end portion is the liquid D to be treated. It extends above the liquid level. In this embodiment, the liquid D to be treated flows upward in the first region Z1 along the partition material 22 and changes its direction beyond the partition material 22 at the upper end portion of the reaction tank 21, and the partition material 22 and the second material After flowing downward between the partition members 29, the second partition member 29 is further diverted to change the direction, and flows upward between the second partition member 29 and the reaction tank 21, and the upper end side wall of the reaction tank 21. It will be discharged from the discharge port 25 provided in. The feature of this form is that the reaction time of calcium and carbon dioxide can be lengthened by the form described above. However, since this form takes time to completely remove the liquid D to be treated in the reaction tank 21 when the reaction tank 21 is maintained, the above-described form is preferable when the maintenance is important.

  The capacity of the liquid D to be treated in the reaction tank 21 is preferably determined based on the reaction time of calcium and carbon dioxide. In order to maintain this capacity, in this embodiment, a level meter 54 for detecting the liquid level of the liquid D to be processed is provided. Based on the signal S3 from the level meter 54, the pump P1 that sends the liquid D to be treated to the pre-stage filtration device 10 is controlled.

(Second form)
Next, based on FIG. 3, the processing apparatus X2 of a 2nd form is demonstrated. In this description, the description will focus on differences from the processing apparatus X of the first embodiment.

  The processing device X2 of this embodiment is also mainly composed of the reaction tank 21 and the filtration device. However, in this embodiment, only the pre-stage filtration device 10 located in the pre-stage (upstream) of the reaction vessel 21 is provided as the filtration apparatus. That is, in the present embodiment, unlike the first embodiment, the latter-stage filtration device 30 is not provided. Accordingly, the ion concentration is measured by the ion concentration meter 43 of the liquid D to be treated discharged from the reaction tank 21 without being filtered, that is, without removing calcium carbonate. Then, the bypass valve 53 is switched based on the measured value (S2) of the ion concentration meter 43. However, since the calcium carbonate is not removed at this time, it is assumed that the measured value (S2) of the ion concentration meter 43 is usually a predetermined value or more, and the liquid D to be processed passes through the flow path 88 to the pre-stage filtration device 10. Will be sent. At this point, the calcium carbonate contained in the liquid D to be treated is removed.

  The liquid D to be treated from which the calcium carbonate has been removed in the pre-stage filtration device 10 is sent to the reaction tank 21 through the flow path 82. And reaction with a carbon dioxide is advanced in this reaction tank 21. FIG. In this regard, the reaction with carbon dioxide at this point is a re-reaction, but there is no possibility of overreaction because calcium carbonate has been removed. At this point, only the reaction of calcium that has not been completed proceeds.

  The liquid D to be treated in which the reaction with carbon dioxide has proceeded in the reaction tank 21 is discharged from the reaction tank 21, and the ion concentration of the calcium is measured by the ion concentration meter 43. If the measured value (S2) at this time is less than the predetermined value, the bypass valve 53 is switched, and the purified water C is discharged out of the system through the flow path 86. On the other hand, if the measured value (S2) is equal to or greater than the predetermined value, the liquid D to be treated is sent again to the pre-stage filtration device 10 to remove calcium carbonate.

  As described above, in this embodiment, the reaction of calcium and carbon dioxide (reaction process) and the removal of calcium carbonate (removal process) are repeated, and when the calcium ion concentration finally becomes less than a predetermined value, the system is treated as purified water C. Discharged outside. In this reaction process and removal process, a new liquid D to be treated may or may not be poured into the reaction tank 21. When the liquid D to be treated is not added, the liquid D to be treated is discharged out of the system as purified water C and gradually decreases, so that the reaction tank 21 is finally emptied. When the reaction tank 21 becomes empty, the reaction tank 21 is filled again with the liquid D to be processed, and the same process is repeated. This process can be referred to as a batch type because the same process is repeated. On the other hand, when adding the liquid D to be treated, the calcium removal process is continuously performed, which can be referred to as a continuous type. The batch method has an advantage in terms of processing stability, and the continuous method has an advantage in terms of processing efficiency.

  The present invention relates to a treatment apparatus and treatment method for a treatment liquid, and in particular, a treatment apparatus for a treatment liquid that is suitable when the treatment liquid is drainage containing calcium, such as water jet drainage, road cutter drainage, and waste disposal site drainage. And can be used as a processing method.

DESCRIPTION OF SYMBOLS 10 Pre-stage filtration apparatus 21 Reaction tank 22 Partition material 23 Blowing means 24 Supply port 25 Discharge port 26 1st mesh board 27 2nd mesh board 29 2nd partition material 30 Later stage filtration apparatus 41 Flowmeter 42 pH meter 43 Ion Densitometer 50 Storage tank 51 Pressure regulating valve 52 Flow valve (control means)
53 Bypass valve 54 Level meter D Liquid to be treated C Clean water S1 to S3 Signal X, X1 Processing device Z1 First region Z2 Second region P1 to P3 Pump

Claims (8)

A reaction tank for the liquid to be treated, and a filtration device for the liquid to be treated discharged from the reaction tank;
The reaction tank includes a partition material for partitioning the inside of the reaction tank into a first region and a second region, a supply port for supplying a liquid to be processed to the first region, and carbon dioxide to the first region. And a discharge means for discharging the liquid to be processed from the second region,
The liquid to be treated supplied from the supply port comes into contact with the carbon dioxide, flows through the first region along the partition material, then flows into the second region, and is discharged from the discharge port. ,
An apparatus for processing a liquid to be processed. The partition material is cylindrical and is provided on the center bottom surface of the reaction vessel,
The supply port and the blowing means are provided at the bottom of the first region.
The processing apparatus of the to-be-processed liquid of Claim 1. As the blowing means, provided with an injection nozzle for injecting carbon dioxide as fine bubbles,
Provided downstream of the injection nozzle is a first mesh plate that traverses the first region,
The processing apparatus of the to-be-processed liquid of Claim 1 or Claim 2. A second reticulated plate traversing the second region,
The outlet is provided downstream of the second mesh plate,
The processing apparatus of the to-be-processed liquid of any one of Claims 1-3. As the filtration device, a pre-stage filtration device is provided in the front stage of the reaction tank, and a post-stage filtration device is provided in the rear stage of the reaction tank.
The processing apparatus of the to-be-processed liquid of any one of Claims 1-4. Between the pre-stage filtration device and the supply port, a flow meter and a pH meter for the liquid to be treated are provided,
Control means for controlling the flow rate of carbon dioxide blown into the first region based on the measurement values of the flow meter and the pH meter is provided.
The processing apparatus of the to-be-processed liquid of Claim 5. Using the processing apparatus according to claim 5, comprising an ion concentration meter for measuring the calcium ion concentration of the liquid to be processed discharged from the latter-stage filtration apparatus.
When the measured value of this ion concentration meter is a predetermined value or more, return the liquid to be treated to the reaction vessel,
A method for treating a liquid to be treated. Using the treatment apparatus according to claim 1, further comprising an ion concentration meter that measures a calcium ion concentration of a liquid to be treated discharged from the reaction tank between the reaction tank and the filtration device.
If the measured value of this ion concentration meter is a predetermined value or more, send the liquid to be treated to the filtration device,
A method for treating a liquid to be treated.

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