JP5779408B2 - Method and apparatus for treating peroxide-containing water - Google Patents

Description

  The present invention relates to a treatment method and a treatment apparatus for water containing a peroxide (hereinafter also referred to as “peroxide-containing water”).

Peroxides typified by hydrogen peroxide are not only excellent in cleaning and sterilizing effects, but are also environmentally friendly chemicals that decompose into harmless oxygen and water. For example, bleaching agents for paper pulp and fibers, chemicals, etc. It is widely used in industries such as oxidizing agents, cleaning agents in semiconductor manufacturing plants, and bactericides in food factories.
For example, in a factory for manufacturing a semiconductor, a processing solution containing hydrogen peroxide is used for polishing or etching a silicon wafer. In food factories, containers and caps are sterilized using water containing hydrogen peroxide or other peroxides as a disinfectant when aseptically filling various beverages into Tetra Pak or PET containers. .

  Since such a peroxide itself becomes a COD source, the peroxide-containing water after use cannot be discharged directly into public water areas, and activated sludge also when discharged into a wastewater treatment facility. Therefore, it is necessary to decompose the peroxide when discharging.

  Methods for decomposing peroxide-containing water include 1) a method of adding a reducing agent such as hydrazine and sodium bisulfite, 2) a method of contacting with activated carbon, 3) a method of contacting with an enzyme such as catalase, 4) platinum There are known a method of decomposing using a metal catalyst such as palladium, manganese and the like, and 5) a method of decomposing using a photocatalyst.

Specifically, regarding a method of bringing peroxide-containing water into contact with activated carbon, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 63-39695), an iron salt is added to hydrogen peroxide-containing water, and the pH is 2 to 3. A treatment method of adjusting to .5 and contacting with activated carbon has been proposed.
In Patent Document 2 (Japanese Utility Model Publication No. 2-43515), an aqueous solution containing hydrogen peroxide adjusted to a pH of 10 or more is directly sprayed on the upper surface of a fixed granular activated carbon packed bed, and hydrogen peroxide that is catalytically decomposed by the activated carbon layer A removal device is disclosed.
In Patent Document 3 (Utility Model Registration No. 2560167), the waste liquid containing hydrogen peroxide stored in the treated water tank is circulated and passed through a granular activated carbon filter through a circulation line system to generate hydrogen peroxide. An apparatus for decomposing hydrogen peroxide water to be decomposed is disclosed.

Patent Document 4 (JP-A-8-39078) discloses a method for efficiently decomposing hydrogen peroxide by passing an alkaline compound through an activated carbon tower and then passing hydrogen peroxide-containing waste water. Has been.
In Patent Document 5 (Japanese Patent Laid-Open No. 2000-135492), raw water is diluted and mixed with circulating water and then supplied to a fluidized bed activated carbon tower, and the upward flow velocity in the fluidized bed activated carbon tower is set to 40 m. A method is disclosed in which the hydrogen peroxide load is 50 kgH ₂ O ₂ / m ³ activated carbon · h or less.

  Regarding the method of contacting with hydrogen peroxide enzyme, for example, in Patent Document 6 (Japanese Patent Application Laid-Open No. Hei 6-170355), the pH of semiconductor manufacturing wastewater containing hydrogen peroxide is adjusted to pH 8 to 11, and then contacted with catalase. A method of treating semiconductor manufacturing wastewater containing hydrogen peroxide that decomposes hydrogen oxide is disclosed.

Regarding a method of decomposing using a metal catalyst, for example, Patent Document 7 (Japanese Patent Laid-Open No. 11-290870) uses a hydrogen peroxide decomposition catalyst having a manganese compound as an active component as a catalyst component. By passing waste water through a hydrogen peroxide decomposition tower packed with a decomposition catalyst, primary treated water having a reduced concentration of hydrogen peroxide is obtained. Subsequently, hydrogen peroxide is further passed through the primary treated water into a tower packed with activated carbon. A treatment method is disclosed in which reduced secondary treated water is obtained, and then this secondary treated water is passed through an ammonia concentration and purification tower to concentrate and recover ammonia.
In Patent Document 8 (Japanese Patent Laid-Open No. 2010-240557), treated water is brought into contact with a hydrogen peroxide decomposition catalyst, and hydrogen peroxide in the treated water is decomposed into oxygen and water to obtain treated water. In a hydrogen peroxide treatment apparatus, a hydrogen peroxide decomposition reactor having an inlet for treated water and a discharge outlet for treated water and filled with a hydrogen peroxide decomposition catalyst, and the hydrogen peroxide decomposition reaction A gas-liquid separator into which the outflow water of the vessel is introduced, the gas-liquid separator comprising a cylindrical container having an exhaust pipe connected to the upper part and a drain pipe connected to the lower part. A hydrogen peroxide solution treatment apparatus is disclosed in which the effluent water is introduced into the side portion.

Regarding a method using a photocatalyst, for example, in Patent Document 9 (Japanese Patent Laid-Open No. 10-151451), hydrogen peroxide-containing wastewater is added with titanium oxide (TiO ₂ ), strontium titanate (SrTiO ₂ ), cadmium oxide (CdS) and A method of decomposing hydrogen peroxide by adding a photocatalyst such as zinc oxide (ZnO) and irradiating with ultraviolet rays is disclosed.

  By the way, when the peroxide is decomposed as described above, oxygen gas is generated along with this decomposition reaction. If the bubbles of oxygen gas remain in the system, the catalyst and hydrogen peroxide are generated. Therefore, it is necessary to release oxygen gas bubbles generated during decomposition out of the system.

Therefore, conventionally, as a method for solving the above problem, for example, in Patent Document 10 (Japanese Patent Publication No. 1-203094), an upward flow is used as a water flow method, and the activated carbon layer is caused to flow, whereby oxygen in the activated carbon layer is obtained. A method for preventing gas accumulation has been proposed.
Further, in Patent Document 11 (Japanese Patent Publication No. 6-61541), by adjusting the raw water pH to 10 or more and passing it in a downward flow from the upper part of the activated carbon catalyst, most of the peroxidation at the upper part of the catalyst. Since hydrogen is decomposed, it is described that the generation of gas inside the catalyst can be suppressed as a result.

In Patent Document 12 (Japanese Patent Laid-Open No. 2003-190972), as a method for preventing bubbles of oxygen gas generated by decomposition of hydrogen peroxide from inhibiting the contact between the catalyst and hydrogen peroxide, hydrogen peroxide containing In a reaction tower that treats wastewater in an upward flow, the catalyst is divided into a plurality of layers in the vertical direction in the reaction tower, and an oxygen gas discharge pipe is installed in the reaction tower, so that the lower catalyst A method is disclosed in which bubbles of oxygen gas generated in the bed are discharged out of the reaction tower without contacting the upper catalyst layer.
In Patent Document 13 (Japanese Patent Application Laid-Open No. 2006-000827), spherical activated carbon having a uniform particle diameter is used as a catalyst when hydrogen peroxide containing wastewater and a catalyst are brought into contact with each other to decompose hydrogen peroxide in the wastewater. Thus, a method for preventing the accumulation of oxygen gas in the catalyst layer is disclosed.
Furthermore, in Patent Document 14 (Japanese Patent Laid-Open No. 2007-185587), hydrogen peroxide-containing water is preferably flowed downward in a column packed with a hydrogen peroxide decomposition catalyst, and then the column effluent is directly subjected to membrane deaeration. A method for removing oxygen produced by decomposition of hydrogen peroxide by passing water through a dissolved oxygen removing apparatus such as an apparatus is disclosed.

JP 63-39695 A Japanese Utility Model Publication No. 2-34351 Utility Model Registration No. 2560167 JP-A-8-39078 JP 2000-135492 A JP-A-6-170355 JP 11-290870 A JP 2010-240557 A JP-A-10-151451 Japanese Patent Publication No. 1-203094 Japanese Examined Patent Publication No. 6-61541 JP 2003-190972 A JP 2006-000827 A JP 2007-185587 A

  The inventor, for example, as shown in FIG. 7, the first reaction tank 52 filled with the peroxide decomposition material 51, and the second reaction tank 53 filled with the peroxide decomposition material 51, And a processing device 50 having a communication opening portion 54 communicating with the upper end openings of the first reaction tank 52 and the second reaction tank 53, and a peroxide from the bottom to the top of the first reaction tank 52. After the contained water (treated water) is circulated upward, the treated water is circulated downward from the upper end opening of the second reaction tank 53 toward the bottom via the communication opening portion 54, thereby forming a peroxide. I came up with a way to break down.

According to such a method for treating peroxide-containing water, oxygen bubbles generated by the decomposition of hydrogen peroxide in the first reaction tank 52 rise to the upper end opening of the first reaction tank 52 by the upward flow. It was expected that most of the bubbles could escape outside the communication opening 54.
However, when the processing apparatus as described above was actually manufactured and processed, the oxygen bubbles generated in the first reaction tank 52, together with the peroxide decomposition material developed by the upward flow, were second. It was found that the reaction tank 53 overflowed, bubbles entered the second reaction tank, and the decomposition efficiency could not be increased as expected.

  Therefore, in the present invention, after the water to be treated flows upward in the first reaction tank filled with the peroxide decomposition material, the second reaction tank filled with the peroxide decomposition material faces downward. In the method and apparatus for treating peroxide-containing water that circulates, the bubbles generated in the first reaction tank, which is the upward water-flowing reaction tank, are effectively released outside the system, and the second water-flowing reaction tank is the second water-flowing reaction tank. It is an object of the present invention to provide a new peroxide-containing water treatment method and apparatus capable of further improving the decomposition efficiency of peroxide without being allowed to flow through a reaction vessel.

The present invention includes a first reaction tank in which a peroxide decomposition material is filled, a peroxide-containing water serving as water to be treated flows upward, and bubbles generated are floated in an upward flow; decomposed material is filled therein, and a second reaction vessel that peroxide-containing water flows downward, and communicating an upper portion of the first reaction vessel and the second reaction vessel, upwardly said first reaction vessel a communicating opening which causes inflow distribution was peroxide-containing water to the second reaction vessel, wherein the first provided on the upper portion of the reaction vessel, for discharging bubbles generated in the first reaction vessel from the system And a widening opening that spreads upward in the upward flow direction, and proposes a peroxide-containing water treatment apparatus that decomposes peroxide in the peroxide-containing water. .

In the present invention, the peroxide-containing water as the water to be treated is faced upward in the first reaction tank filled with the peroxide decomposition material and having the upper portion spread upward. The peroxide-containing water flowing out from the upper end of the first reaction tank was allowed to flow into the second reaction tank filled with the peroxide decomposition material through the communication opening part, in a second reaction vessel, by passing water down the peroxide-containing water, to decompose a peroxide-containing water of the peroxide, the first reaction vessel, in the second reaction vessel and the communicating opening switches the water flow direction alternately, said upward and passed through a peroxide-containing water to the second reaction vessel, via the communicating opening, when passed through downwards the first reaction vessel is the upper portion of the first reaction vessel, instead of the open mouth spreader unit spread upward, before The upper portion of the second reaction vessel, proposes a processing method of a peroxide-containing water, characterized in that the open mouth spreader portion spreads upward.

According to such a peroxide-containing water treatment apparatus and treatment method, in the first reaction tank, the peroxide decomposition material is developed and fluidized by the upward flow, and thus is generated by the decomposition of the peroxide. Oxygen bubbles to be discharged are effectively discharged to the upper portion, the contact between the peroxide decomposition material and the water to be treated is promoted, and the peroxide can be efficiently decomposed. Since the peroxide concentration in the water to be treated after passing through the first reaction tank is very low, the amount of bubbles generated in the second reaction tank is clearly less than that in the first reaction tank. For this reason, the second reaction tank is preferably directed downward for the following reasons.
Since the peroxide decomposition material is densely packed by the downward flow, the fixed bed made of the densely packed peroxide decomposition material and the water to be treated are in close contact with each other in the first reaction tank. The slightly remaining peroxide that has not been decomposed can be more completely decomposed.
Since the decomposition efficiency of peroxide can be increased in this way, it is possible to treat waste water containing a higher concentration of peroxide and reduce the amount of peroxide decomposition material used.

  Furthermore, since the upward flow velocity of the water to be treated that has flowed into the widened opening is reduced by making the upper part of the first reaction tank an open widened part that spreads upward, a part of the upward flow is caused by the upward flow. While the hydrogen peroxide decomposition material that floats settles in the widened opening, oxygen bubbles generated in the first reaction tank float along with the upward flow, and water flows in the widened opening. Since it spreads upward, it becomes easy to escape from the water surface to the outside of the system, and oxygen bubbles generated in the first reaction tank can be effectively discharged out of the system. Thereby, since it is possible to prevent the bubbles of oxygen generated in the first reaction tank, which is an upward water flow reaction tank, from flowing into the second reaction tank, in the second reaction tank, which is a downward water flow reaction tank. The peroxide decomposition efficiency can be further increased.

It is sectional drawing which showed roughly an example of the processing apparatus of the peroxide containing water which concerns on the 1st Embodiment of this invention. It is sectional drawing which showed roughly an example at the time of implementing a peroxide containing water using the processing apparatus shown in FIG. FIG. 2 is a cross-sectional view schematically showing an example in which the water flow direction is switched as an example when the peroxide-containing water is treated using the treatment apparatus shown in FIG. 1. It is the perspective view which showed roughly an example of the processing apparatus of the peroxide containing water which concerns on the 2nd Embodiment of this invention. It is sectional drawing which showed roughly an example at the time of implementing a peroxide containing water using the processing apparatus shown in FIG. Similarly, FIG. 5 is a cross-sectional view schematically showing an example in which the water flow direction is switched as an example when the treatment of peroxide-containing water is performed using the treatment apparatus shown in FIG. 4. It is sectional drawing which showed roughly an example of the processing apparatus demonstrated in the column of the processing apparatus of the peroxide containing water which became the foundation when conceiving this invention, ie, the problem which this invention is going to solve. It is sectional drawing which showed roughly an example at the time of implementing the process of peroxide containing water in the modification of the processing apparatus shown in FIG. FIG. 9 is a cross-sectional view schematically showing an example in which the water flow direction is switched as an example when the treatment of peroxide-containing water is performed using the treatment apparatus shown in FIG. 8.

  Next, although the example for implementing this invention is demonstrated, this invention is not limited to embodiment described below.

<First Embodiment>
The peroxide-containing water treatment apparatus 1 according to the first embodiment, as shown in, for example, FIG. 1C, erects a partition plate 3 in a vertical direction in a bottomed outer cylinder 2 that is placed vertically, The partition plate 3 divides the inside of the outer cylinder 2 into a first water passage 4 and a second water passage 5, and the space above the partition plate 3 in the outer cylinder 2 is divided into the first water passage 4 and the second water passage 2. A communication opening 6 that communicates with the upper end opening of the water passage 5 is provided. The first water passage 4 is filled with the peroxide decomposition material 8 to form the first reaction tank 10, while the second water passage 5 is filled with the peroxide decomposition material 8 to perform the second reaction. A tank 11 is provided, and pipes 12 and 13 are connected to the bottom of the first reaction tank 10 and the bottom of the second reaction tank 11, respectively.

Here, the upper part of the partition plate 3 is formed as an opening / closing part 3A that can be rotated like a wiper. For example, the opening / closing part 3A is inclined obliquely as shown by a solid line in FIG. The upper part of the first reaction tank 10 can be an opening 15 that expands upward, and conversely, the opening / closing part 3A is inclined obliquely as shown by the dotted line in FIG. The upper part of the second reaction tank 10 may be an expanded opening 16 that expands upward.
At this time, as shown in FIGS. 8 and 9, the tip end portion of the rotatable opening / closing portion 3 </ b> A can be formed as a mesh-like mesh plate 3 </ b> B so that the outflow of fine activated carbon can be further suppressed. .
However, the upper part of the 1st reaction tank 10 is used as the widening opening part 15 which spreads upwards, and the upper part of the 2nd reaction tank 10 is the widening opening part 16 which spreads upwards. The method is not limited to such a method, and is arbitrary.

  Moreover, the said communication open part 6 should just be a non-sealed space part instead of piping. That is, the gas discharged into the space may be opened upward so that the gas can be released outside the system, or the gas discharge pipe may be communicated.

  In such a treatment apparatus 1, when water containing peroxide as water to be treated (referred to as “water to be treated”) is continuously supplied to the bottom of the first reaction tank 10 through the pipe 12, Flows upward in the first reaction tank 10, flows out from the upper end opening of the first reaction tank 10, flows into the communication opening 6, and then passes through the communication opening 6 to the second reaction tank 11. In the second reaction tank 11, it flows downward from the top toward the bottom, and can then be discharged as treated water through the pipe 13.

If treated in this way, in the first reaction tank 10, the peroxide decomposition material is developed and fluidized by the upward flow, so that the contact between the peroxide decomposition material and the water to be treated is promoted, The oxide can be decomposed efficiently.
Since the peroxide concentration in the water to be treated after passing through the first reaction tank is very low, the amount of bubbles generated in the second reaction tank 11 is clearly less than that in the first reaction tank. For this reason, the second reaction tank is preferably directed downward for the following reasons. Since the peroxide decomposition material is densely packed by the downward flow, the fixed bed made of the densely packed peroxide decomposition material and the water to be treated are in close contact with each other, so that the decomposition is performed in the first reaction tank 10. The slightly remaining peroxide that has not been made can be more completely decomposed.

Here, when water flows in the first reaction tank 10 in the upward flow in this way, as described above, the opening and closing part 3A is inclined obliquely as shown by the solid line in FIG. It is important to make the upper part of the tank 10 into the opening part 15 which spreads upwards (refer FIG. 2). If it does in this way, since the to-be-processed water which distribute | circulated upwards in the 1st reaction tank 10 will flow in into the spreading opening part 15, since the flow velocity will fall, it is a part of the excess water that floated with the upward flow. The oxide decomposition material settles here. On the other hand, the bubbles of oxygen generated in the first reaction tank 10 rise with the upward flow, and the flow of water spreads upward in the opening 15, so that the bubbles are separated from the water surface. It becomes easier to escape and oxygen bubbles generated in the first reaction tank 10 can be effectively discharged out of the system.
As a result, oxygen bubbles generated in the first reaction tank 10 can be prevented from flowing into the second reaction tank 11, so that the decomposition efficiency of the peroxide in the second reaction tank 11 is further increased. be able to.

  In addition, although the filling amount of the peroxide decomposition material 8 in the 1st reaction tank 10 and the 1st reaction tank 11 is arbitrary, when passing the to-be-processed water upward in the 1st reaction tank 10, It is preferable that the filling amount of the first reaction tank 10 is such that the upper surface of the peroxide decomposition material 8 is positioned lower than the lower end portion of the spread opening 15. By doing so, a layer in which the peroxide decomposition material expands and flows due to the upward flow can be formed in the first reaction tank 10 below the spread opening 15, and the upper opening thereof can be formed. In the widened opening 15, a layer in which a part of the peroxide decomposition material that has floated due to the upward flow settles can be formed. This is the same when the water flow direction is switched as described below.

As shown in FIG. 3, the treatment apparatus 1 can switch the water flow direction in the first reaction tank 10 and the second reaction tank 11. For example, water containing peroxide as water to be treated (referred to as “water to be treated”) is continuously supplied to the bottom of the second reaction tank 11 through the pipe 13, so that the water to be treated is contained in the second reaction tank 11. The treated water flows upward, flows into the first reaction tank 10 via the communication opening 6, and can be switched to flow downward in the first reaction tank 10.
However, when switching in this way, for example, as shown by a dotted line in FIG. 1, the partition plate 3 is set so that the upper end opening of the second reaction tank 11 spreads upward, and the second reaction tank 11 It is preferable that the upper part of the is an opening 16 that widens upward. As before the switching, oxygen bubbles generated in the second reaction tank 11 can be effectively discharged out of the system.

By switching the water flow direction in the first reaction tank 10 and the second reaction tank 11, it is possible to prevent the generation of viable bacteria and slime due to the bactericidal agent present in the water to be treated and other residual organic substances. That is, the water to be treated is circulated from the first reaction tank 10 to the second reaction tank 11 using the water flow method in the first reaction tank 10 as an upward flow and the water flow method in the second reaction tank 11 as a downward flow. In the first reaction tank 10, many peroxides in the water to be treated are decomposed, so that the concentration of peroxide having sterilizing power is reduced in the second reaction tank 11 and the operation is continued for a long time. In the meantime, viable bacteria and slime are generated by residual organic substances contained in the water to be treated. Therefore, by switching the water flow direction, the water flow method in the second reaction tank 11 is an upward flow, and the water flow method in the first reaction tank 10 is a downward flow. If the water to be treated is allowed to flow through, the water to be treated flowing into the second reaction tank 11 has a high peroxide concentration, so that the generation of viable bacteria and slime is prevented by the sterilizing power of the peroxide. be able to.
However, when the water flow direction in the first reaction tank 10 and the second reaction tank 11 is switched as described above, the flow rates of the first reaction tank 10 and the second reaction tank 11 are substantially the same. It is preferable to design the capacity.

In any of the water flow directions, an overflow layer 17 made of an overflow of the water to be treated is provided to some extent above the first reaction tank 10 and the second reaction tank 11 in the communication opening portion 6. It is preferable to distribute the water to be treated so that it can be formed smoothly. Specifically, for example, in the case where water to be treated is passed upward in the first reaction tank 10, as shown in FIGS. 2 and 3, an opening 15 in the upper part of the first reaction tank 10 is provided. It is preferable that an overflow layer 17 having a certain height is formed by the overflow flowing into the communication opening portion 6 through.
If the overflow layer 17 is formed in this manner, the flow of the water to be treated is turbulent in the overflow layer 17 and is in a turbulent state.

<Second Embodiment>
The peroxide-containing water treatment apparatus 21 according to the second embodiment includes, as shown in FIG. 4-6, for example, a vertically disposed bottomed outer cylinder 22 and the height of the upper end portion of the outer cylinder 22. The bottomed inner cylinder 23 is concentrically disposed in the outer cylinder, and the inner cylinder 23 is filled with a peroxide decomposition material 28 to form the first reaction tank 30, while the outer cylinder 22 The peroxide decomposition material 28 is also filled between the inner cylinders 23 to form the second reaction tank 31, and the upper space portion of the inner cylinder 23 in the outer cylinder 22 is formed between the first reaction tank 30 and the second reaction tank 31. The upper end opening is connected to a communication opening 26, and pipes 32 and 33 are connected to the bottom of the first reaction tank 30 and the bottom of the second reaction tank, respectively.

Further, the upper opening cylinder 24 that can be expanded upward and the lower end opening thereof can be connected to the upper end opening of the inner cylinder 23, and the upper opening narrowed upward. The upwardly narrowed cylindrical portion 25 that can be connected to the upper end opening of the tube 23 is configured to be alternately connected to the upper end opening of the inner tube 23, and can be moved up and down by, for example, a wire or the like. When the upwardly expanded cylindrical portion 24 that is suspended is lowered and connected to the upper end opening of the inner cylinder 23, the upper portion of the first reaction tank 30 is made an expanded opening 35 that expands upward. On the other hand, for example, instead of the upward expanding cylindrical portion 24, the upward constricting cylindrical portion 25 suspended by a wire or the like can be lowered and connected to the upper end opening of the inner cylinder 23. For example, the upper part of the second reaction tank 31 may be an expanded opening 36 that expands upward. Kill.
However, the upper part of the 1st reaction tank 30 is used as the widening opening part 35 which spreads upwards, and the upper part of the 2nd reaction tank 31 is the widening opening part 36 which spreads upwards. The method is not limited to such a method, and is arbitrary.

  Moreover, the said communication open part 26 should just be a non-sealed space part instead of piping. That is, the gas discharged into the space may be opened upward so that the gas can be released outside the system, or the gas discharge pipe may be communicated.

  In such a processing apparatus 21, if water containing peroxide as water to be treated (referred to as “water to be treated”) is continuously supplied to the bottom of the first reaction tank 30 through the pipe 32, the water to be treated Circulates upward in the first reaction tank 30, flows out from the upper end opening of the first reaction tank 30, flows into the communication opening part 26, and enters the second reaction tank 31 through the communication opening part 26. In the second reaction tank 31, it flows downward from the top toward the bottom, and can then be discharged as treated water through the pipe 33.

If treated in this way, in the first reaction tank 30, the peroxide decomposition material is developed and fluidized by the upward flow, so that the contact between the peroxide decomposition material and the water to be treated is promoted. The oxide can be decomposed efficiently.
Since the peroxide concentration in the water to be treated after passing through the first reaction tank is very low, the amount of bubbles generated in the second reaction tank 31 is clearly less than that in the first reaction tank. For this reason, the second reaction tank is preferably directed downward for the following reasons. Since the peroxide decomposition material is densely packed by the downward flow, the fixed bed made of the densely packed peroxide decomposition material and the water to be treated are in close contact with each other, so that the decomposition is performed in the first reaction tank 30. The slightly remaining peroxide that has not been made can be more completely decomposed.

Here, when water flows in the first reaction tank 30 in an upward flow, as shown in FIG. 5, for example, by connecting the upward expanding cylinder portion 24 to the upper end opening of the inner cylinder 23, It is important to set the upper part of one reaction tank 30 as an expanded opening 35. In this way,
Since the water to be treated that has circulated upward in the first reaction tank 30 flows into the widened opening 35, the flow velocity thereof decreases, so a part of the peroxide decomposition material that floats with the upward flow is here It will become settled at. On the other hand, the oxygen bubbles generated in the first reaction tank 30 rise with the upward flow, and the flow of water spreads upward in the opening 35, so that the bubbles easily escape from the water surface. The oxygen bubbles generated in the first reaction tank 30 can be effectively discharged out of the system.
Thereby, since it is possible to prevent oxygen bubbles generated in the first reaction tank 30 from flowing into the second reaction tank 31, the decomposition efficiency of peroxide in the second reaction tank 31 is further increased. be able to.

In addition, although the filling amount of the peroxide decomposition material 28 in the first reaction tank 30 and the first reaction tank 31 is arbitrary, in the case of passing the treated water upward in the first reaction tank 30, The filling amount of the first reaction tank 30 is preferably set so that the upper surface of the peroxide decomposition material 28 is lower than the lower end portion of the widening opening 35. By doing so, a layer in which the peroxide decomposition material floats and flows due to the upward flow can be formed in the first reaction tank 30 below the opening 35, and the upper opening is opened. In the widened opening 35, a layer can be formed in which the peroxide decomposition material that has been levitated by the upward flow settles.
Such a point is the same even if the water flow direction is switched as described below.

The processing device 21 can switch the water flow direction in the first reaction tank 30 and the second reaction tank 31. For example, as shown in FIG. 6, the peroxide-containing water as the water to be treated (referred to as “water to be treated”) is continuously supplied to the bottom of the second reaction tank 21 through the pipe 33, In the two reaction tanks 31, the water to be treated flows upward, flows into the first reaction tank 30 through the communication opening part 26, and can flow through the first reaction tank 30 downward.
However, in this case, the upper constricted cylinder part 25 is connected to the upper end opening part of the inner cylinder 23 so that the upper part of the second reaction tank 31 becomes the widened opening part 36 spreading upward. Is preferred. By doing so, as described above, oxygen bubbles generated in the second reaction tank 31 can be effectively discharged out of the system.

By switching the water flow direction in the first reaction tank 30 and the second reaction tank 31 in this way, it is possible to prevent the generation of viable bacteria and slime due to residual organic matter, as in the processing apparatus 1.
However, when switching the water flow direction in the first reaction tank 30 and the second reaction tank 31 in this way, the flow rates of the first reaction tank 30 and the second reaction tank 31 are substantially the same. It is preferable to design the capacity.

  In any of the water flow directions, an overflow layer 37 made of overflow of the water to be treated is provided to some extent above the first reaction tank 30 and the second reaction tank 31 in the communication opening portion 26. The point that it is preferable to distribute the water to be treated is the same as that of the treatment apparatus 1 so that it can be formed.

<Treatment water>
In the processing apparatus and the processing method according to the first embodiment and the second embodiment, the peroxide-containing water as the water to be treated may be water containing peroxide, and a plurality of peroxides may be used. The type may contain other components. Further, the peroxide concentration is not particularly limited.

<Peroxide decomposition material>
In the processing apparatus and the processing method according to the first embodiment and the second embodiment, the peroxide decomposing materials 8 and 28 are appropriately used as long as they are solid substances capable of decomposing peroxide. be able to.
Specifically, for example, an iron compound, activated carbon, or a metal catalyst such as platinum, palladium, manganese, or a supported catalyst in which a catalytically active component is supported on an inert carrier, specifically, for example, platinum, palladium, rhodium. Inactive carriers such as alumina, silica, titania, silica-alumina, zirconia, iron oxide, ceria, silicon carbide, or noble metal elements such as cobalt, manganese, iron, copper and nickel And a supported catalyst formed on the substrate.

<Treatment water>
The treated water treated by the treatment apparatus and treatment method according to the first embodiment and the second embodiment is brought into contact with an ion exchange resin or subjected to a reverse osmosis membrane treatment as necessary. It is preferable to further remove residual substances in the treated water.

<Explanation of words>
In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X is preferably greater than X” or “preferably Y”. It also includes the meaning of “smaller”.
In addition, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), it is “preferably greater than X” or “preferably less than Y”. Includes intentions.

  Hereinafter, the present invention will be further described in detail based on the following examples and comparative examples.

Example 1
Using the treatment apparatus 21 shown in FIG. 5, peroxide-containing water (hydrogen peroxide: 500 mg / L, peracetic acid: 120 mg / L, pH value: 3) as the water to be treated is first fed through the pipe 32. Continuously supplied to the bottom of the reaction tank 30, flows upward in the first reaction tank 30, flows into the second reaction tank 31 through the communication opening part 26, and in the second reaction tank 31, After flowing downward from the bottom toward the bottom, a treatment of discharging as treated water through the pipe 33 was performed. At this time, the flow rate of the water to be treated is set to a space velocity (linear velocity): 15 hr ⁻¹ (15 m / hr), and the height of the overflow layer 37, that is, from the upper end of the upwardly expanding cylindrical portion 24 to the water surface. The height up to 200 mm.
Further, the processing apparatus 21 includes a first reaction tank 30: capacity 10L, height 1300mm, inner diameter 100mm, second reaction tank 31: capacity 10L, height 1300mm, inner diameter 150mm, total height of reaction tank 2000mm, upward expansion. Open tube portion 24: upper end opening diameter 130 mm, peroxide decomposition material: activated carbon (“Evadaya: LG-10S” (crushed charcoal) manufactured by Mizu-ing Co., Ltd.), the filling amount of each layer was 8L.

(Comparative Example 1)
In the processing apparatus 50 shown in FIG. 7, that is, the processing apparatus 21 used in the first embodiment, the water to be treated similar to that in the first embodiment is implemented using a processing apparatus that does not have the upwardly-expanded cylindrical portion 24. The treatment was performed under the same conditions as in Example 1.

In Example 1, hydrogen peroxide and peracetic acid in the water to be treated were successfully treated to less than the lower limit of quantification of 0.1 mg / L as shown in Table 1 until at least 18 hours from the start of water flow. .
On the other hand, in Comparative Example 1, hydrogen peroxide and peracetic acid were detected 6 hours after the start of water flow, and apparently poor treatment occurred 18 hours later. In the second reaction tank at this time, accumulation of bubbles was observed inside the activated carbon layer, and it was confirmed that bubbles were brought in from the first reaction tank.

(Example 2)
Using the treatment apparatus 21 used in Example 1, treated water similar to that in Example 1 was treated under the same conditions as in Example 1 (see FIG. 5), and the number of viable bacteria in the treated water was examined. . Thereafter, the water flow direction was switched to perform the treatment (see FIG. 6), and the number of viable bacteria in the treated water was examined. The water flow rate after switching and the height of the overflow layer 37 were the same as before switching.

As a result, in the treatment in the first water flow direction (first reaction tank → second reaction tank), an increase in viable bacteria was observed after 24 hours of water flow and reached 180 CFU / mL after 72 hours.
Then, as a result of switching the direction of water flow, the number of viable bacteria decreased to 3 CFU / mL, that is, the initial value of water flow after 1 hour from switching.
By switching the water flow direction in this way, the concentration of peroxide in the water to be treated flowing through the second reaction tank becomes higher than before switching, so the number of viable bacteria is reduced by the sterilizing power of the peroxide. Can be thought of as having been made.

1: treatment device, 2: outer cylinder, 3: partition plate, 4: first water passage, 5: second water passage,
6: open communication part, 8: peroxide decomposition material, 10: first reaction tank, 11: second reaction tank,
12, 13: pipe, 15: widened opening, 16: widened opening, 17: overflow layer 21: treatment device, 22: outer cylinder, 23: inner cylinder,
24: upwardly expanded cylindrical part, 25: upwardly constricted cylindrical part, 26: communication open part,
28: peroxide decomposition material, 30: first reaction tank, 31: second reaction tank, 32, 33: pipe 35: widening opening, 36: widening opening, 37: overflow layer 50: treatment device , 51: peroxide decomposition material, 52: first reaction tank, 53: second reaction tank 54: communication open part

Claims (4)

A first reaction vessel in which a peroxide decomposition material is filled, a peroxide-containing water as the water to be treated flows upward, and the generated bubbles are floated upward ;
A second reactor in which the peroxide decomposition material is filled, and the peroxide-containing water flows downward;
Said first reaction tank and the upper portion of the second reaction vessel was communicated, the communicating opening for the peroxide-containing water that has circulated upwardly a first reaction vessel causes flow into the second reaction vessel,
The first provided on the upper portion of the reaction vessel, and a spread open mouth spreader portion upward by the upward flow direction for discharging the air bubbles generated in the first reaction vessel to the outside of the system,
An apparatus for treating peroxide-containing water, comprising decomposing peroxide in the peroxide-containing water. A first reactor in which a peroxide decomposition material is filled, and peroxide-containing water as treated water flows upward;
A second reactor in which the peroxide decomposition material is filled, and the peroxide-containing water flows downward;
A communication opening portion for communicating the upper part of the first reaction tank and the second reaction tank and allowing the peroxide-containing water flowing upward in the first reaction tank to flow into the second reaction tank;
An upper opening that extends upward at the top of the first reaction tank;
The first reaction vessel, it is possible to switch the water flow direction in the second reaction vessel and the communicating opening,
Peroxide-containing water flows upwardly the second reaction vessel, via the communicating opening, when flowing through the first reaction vessel to downwardly, the upper portion of the first reaction vessel, instead of an open mouth spreader unit spread upward, the top of the second reaction vessel, treatment of peroxide-containing water having a configuration which can be opened mouth spreader unit spread upward apparatus. 3. The peroxide-containing water treatment apparatus according to claim 1, wherein the widening opening has a shape that widens upward by tilting a rotatable opening / closing portion obliquely. 4. Into the first reaction tank filled with a peroxide decomposition material and having an open-opening opening that spreads upward at the top, the peroxide-containing water as the water to be treated is passed upward, The peroxide-containing water flowing out from the upper end of the first reaction tank is caused to flow into the second reaction tank filled with the peroxide decomposition material through the communication open part, , Decompose the peroxide in the peroxide-containing water by passing the peroxide-containing water downward,
The first reaction vessel, said switches the water flow direction alternately in the second reaction vessel and the communicating opening, the upward and passed through a peroxide-containing water to the second reaction vessel, the communicating opening through it, wherein when the water flow is downwards a first reaction vessel, wherein the upper portion of the first reaction vessel, instead of the open mouth spreader unit spread upward, an upper portion of the second reaction vessel A method for treating peroxide-containing water, characterized in that the opening is an opening that widens upward.

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