TW201834974A - Apparatus and method for wastewater treatment capable of reducing the consumption of catalyst and preventing scaling deposits on the surface of catalyst - Google Patents

Abstract

The present invention provides a wastewater treatment apparatus which can keep scaling deposits from a catalyst surface, thereby highly maintaining the processing performance of the catalyst. The wastewater treatment device of the present invention has a dispersion plate 2, a dispersion plate 1, a filling layer and a catalyst layer disposed in this order from the wastewater supply side. When the distance between the dispersion plate 2 and the dispersion plate 1 is H1, the distance between the dispersion plate 1 and the interface on the wastewater supply side of the aforementioned filling layer is H2, the layer length of the filling layer is H3, and when the total of H2 and H3 is H6, then the H6 exceeds 100mm, and the ratio of H6 with respect to the above H1(H6/H1) is 0.1 or more (including 0.1) and 100 or less (including 100).

Description

Wastewater treatment device and method

The invention relates to a wastewater treatment device and a wastewater treatment method.

Wastewater discharged from various industrial plants such as chemical plants, food processing equipment, metal processing equipment, metal plating equipment, printing platemaking equipment, and photographic processing equipment can be processed by wet oxidation, wet decomposition, and ozone oxidation. Purification treatment is performed by various methods such as a hydrogen peroxide method.

For example, in the wet oxidation method in which a solid catalyst is charged into a reaction tower, usually, a wastewater is mainly introduced from a lower portion of a solid catalyst filling layer (catalyst layer) to purify the wastewater. Therefore, by the action of the introduced wastewater and oxygen-containing gas, it is easy to cause the movement and vibration of the solid catalyst in the catalyst layer, the loss of the solid catalyst, or the scale components in the wastewater. (Heavy metals such as copper, iron, and calcium, aluminum, etc.) are precipitated on the surface of the catalyst, so problems such as a decrease in the processing performance of the catalyst cannot be avoided.

Patent Document 1 discloses a waste water treatment device for the loss of solid catalyst caused by waste water or the like introduced from the lower part of a reaction tower. A layer of filler such as metal (lower filler) is provided below the catalyst layer. Layer), in addition to preventing the loss of solid catalyst, waste water and the like can also be uniformly supplied to the catalyst layer, so that the reduction in catalyst treatment efficiency can be suppressed. Patent Document 2 discloses that a catalyst-free wet oxidation reaction layer is provided in front of a solid catalyst layer to improve the processing efficiency in the solid catalyst layer. Furthermore, Patent Document 3 discloses that a gas-liquid dispersion member is provided on the upper portion of the solid catalyst layer to improve the processing efficiency. (Prior Art Literature) (Patent Literature)

[Patent Document 1] Japanese Patent No. 5330751 [Patent Document 2] Japanese Patent Laid-Open No. 2001-276855 [Patent Document 3] Japanese Patent Laid-Open No. 2004-098023

(Problems to be solved by the invention)

Indeed, Patent Document 1 shows that by providing a lower filler layer, the catalyst can be prevented from being consumed and the reduction in the efficiency of the catalyst can be suppressed.

However, in the wastewater treatment device disclosed in Patent Document 1, when scale components (heavy metals such as copper, iron, and calcium, aluminum, etc.) are contained in the wastewater, the scale components reach the catalyst layer in an ionic state and precipitate on the catalyst surface. , There will be problems hindering catalyst activity. On the other hand, in Patent Document 2, although the durability of the solid catalyst layer is improved by the installation of a catalyst-free wet oxidation reaction layer, the first treatment step and the second treatment step are not sufficient in terms of wastewater treatment capacity. Reaction tower, and these need further control, which is not conducive to cost. On the other hand, in Patent Document 3, although the treatment efficiency of the solid catalyst layer is improved by the installation of a gas-liquid dispersion member, it is the same as the invention described in Patent Document 1, and it has a lack of durability due to scale components.

Therefore, an object of the present invention is to provide a person who can prevent scale components from reaching the catalyst layer in an ionic state, that is, can prevent the precipitation of scale components on the catalyst surface and can maintain the catalyst processing performance to a high degree, and then can be structured in a simple manner. Provide a low-cost wastewater treatment device and a wastewater treatment method. (Means to solve problems)

In order to solve the above problems, the present inventors devoted themselves to conducting a review. First, regarding the type of combination of the technology disclosed in Patent Document 1 and the technology disclosed in Patent Document 2, specifically, the type in which the lower part of the reaction tower of Patent Document 1 is combined with the catalyst-free wet oxidation reaction layer of Patent Document 2 Review of the state, but it is not sufficient. Therefore, considering whether the gas-liquid dispersibility is poor, referring to Patent Document 3, a dispersing plate is provided in the catalyst-free wet oxidation reaction layer, but a sufficient effect cannot be obtained. Furthermore, as a result of various reviews of the configuration of the dispersion plate, it was found that the above problem can be solved by having at least two dispersion plates and setting the configuration in a specific range, and the present invention was completed. That is, the first aspect of the present invention relates to a treatment device, which is a wastewater treatment device having a dispersing plate 2, a dispersing plate 1, a filling layer, and a catalyst layer in this order from a wastewater supply side. The distance between the dispersion plate 1 is H1, the distance between the interface between the dispersion plate 1 and the waste water supply side of the filling layer is H2, the layer length of the filling layer is H3, and the total of the H2 and the H3 is H6 At this time, the H6 exceeds 100 mm, and the ratio (H6 / H1) of the H6 to the H1 is 0.1 or more (including 0.1) and 100 or less (including 100). The second aspect of the present invention relates to a treatment method using a device having at least a gas-liquid diffusion portion 1, a gas-liquid diffusion portion 2, a gas-liquid diffusion portion 3, and a catalyst layer in order from a wastewater supply side. The method for treating wastewater includes gas dispersion in the wastewater and satisfies the following (1) to (3): (1) The wastewater indwell time in the gas-liquid diffusion sections 1 to 3 are all 0.5 seconds or more (including 0.5 seconds); (2) the total of the waste water retention time in the gas-liquid diffusion section 3 and the gas-liquid diffusion section 2 is 5 seconds or more (inclusive); and (3) relative to the gas-liquid diffusion The wastewater indwelling time in Part 1 is 0.1 to 100 times the total of the wastewater indwelling time in (2) above. (Effect of the invention)

According to the present invention, scale components can be prevented from precipitating on the surface of the catalyst, so that the catalyst's treatment performance can be maintained at a high level, and a low-cost wastewater treatment device and a wastewater treatment method can be provided with a simple structure.

(Best embodiment of the invention)

Hereinafter, specific forms for implementing the present invention will be described in detail, but the technical scope of the present invention should be determined based on the description of the scope of the patent claims, and is not limited to the following forms.

<1st form: waste water treatment device> According to one aspect of the present invention, a treatment device is provided, which is a waste water treatment device having a dispersing plate 2, a dispersing plate 1, a filling layer and a catalyst layer in order from a waste water supply side When the distance between the dispersion plate 2 and the dispersion plate 1 is H1, the distance between the interface between the dispersion plate 1 and the waste water supply side of the filling layer is H2, the layer length of the filling layer is H3, and the H2 When the total with H3 is H6, the H6 exceeds 100 mm, and the ratio of the H6 to the H1 (H6 / H1) is 0.1 or more (including 0.1) and 100 or less (including 100).

In the wastewater treatment device of the present invention, the distance between the dispersion plate 2 and the dispersion plate 1 is H1, the distance between the interface between the dispersion plate 1 and the waste water supply side of the filling layer is H2, the layer length of the filling layer is H3, and The layer length of the media layer is H4 (unit: mm). When a filler layer is also arranged on the waste water discharge side of the catalyst layer, the layer length of the filler layer is H5. The sum of H2 and H3 is H6.

The distance (H1) between the dispersion plate 2 and the dispersion plate 1 is the distance from the surface on the waste water discharge side of the dispersion plate 2 to the surface on the waste water supply side of the dispersion plate 1.

In the dispersion plate, the surfaces of the wastewater supply side and the discharge side are defined as follows. The waste water treatment device is installed perpendicular to the ground, and when waste water is supplied from the lower part of the waste water treatment device, and the waste water is discharged from the upper part of the waste water treatment device, the waste water discharge side surface (upper surface) and the waste water supply side surface (lower surface) , It is the surface in which the middle position between the highest part and the lowest part is used as a reference. This system is the same even when the surface of the dispersion plate is uneven or inclined. However, when the dispersion plate 15-2 in FIG. 2 has a collision plate, the intermediate position between the highest portion and the lowest portion other than the collision plate is used as a reference. Generally, the surface on the waste water discharge side and the surface on the waste water supply side are parallel to the surface (ground) perpendicular to the direction of the waste water supply. At this time, the surfaces of the wastewater supply side and the wastewater discharge side are parallel.

The distance (H2) of the interface between the dispersion plate 1 and the waste water supply side of the filling layer is the distance from the interface of the waste water discharge side of the dispersion plate 1 to the waste water supply side of the filler layer.

The interface between the waste water supply side and the discharge side of the filling layer is defined as follows. Since the filler is filled in the filler layer, the surfaces exposed on the waste water supply side and the discharge side may not be completely flat. The waste water treatment device is installed perpendicular to the ground. When the waste water is supplied from the lower part of the waste water treatment device and the waste water is discharged from the upper part of the waste water treatment device, the interface (upper surface) of the waste water supply side and the interface (lower surface) on the discharge side are The middle position between the lowest part and the highest part of the filler exposed on the upper or lower surface of the filler layer is the reference surface. This system is the same even when the exposed surface of the filler layer is inclined. Generally, the interface between the wastewater discharge side and the wastewater supply side is parallel to the surface (ground) perpendicular to the direction of wastewater supply. At this time, the interface on the wastewater discharge side and the interface on the wastewater supply side are parallel.

The layer length (H3) of the filling layer is the distance from the interface on the wastewater supply side to the interface on the wastewater discharge side. When a filler layer is arranged on the waste water discharge side of the catalyst layer, the layer length (H5) of the filler layer is also the same as H3.

The layer length (H4) of the catalyst layer is the distance from the interface of the wastewater supply side to the interface of the wastewater discharge side of the catalyst layer.

The catalyst layer is filled with a catalyst (for example, a solid catalyst). The definition of the interface between the wastewater supply side interface and the wastewater discharge side of the catalyst layer is the same as that of the filler layer.

The wastewater treatment device of the present invention has the structure described above, and can prevent the scale component from being deposited on the catalyst surface. Thereby, the processing performance of the catalyst can be highly maintained.

Historically, it has been known that disposing a plurality of dispersion plates can effectively improve gas-liquid mixing efficiency. However, in the case of wastewater containing scale components (heavy metals such as copper, iron, and calcium, aluminum, and the like), a high degree of dispersion technology is further required. The characteristic system of the scale component includes, for example, when the wastewater is treated by wet oxidation treatment, the scale component dissolved in ionic form before heating is heated and pressurized in the presence of oxygen, and the oxide or hydrogen is partially analyzed. Solids such as oxides. Therefore, depending on the conditions, the scale component dissolved in the wastewater may reach the catalyst layer in an ionic state and precipitate on the catalyst surface, which may hinder the catalyst activity. Therefore, in the present invention, by setting the ratio of H 6 to H 1 (H6 / H1) within an appropriate range and setting H6 to 100 mm or more (including 100 mm), it is possible to make the solids precipitate before reaching the catalyst layer. Scale components can prevent precipitation of scale components on the catalyst surface in advance.

In addition, in order to prevent scale components from directly accumulating on the catalyst layer, the filler layer also needs to be a dispersion and relaxation layer. The presence of the lower filler layer accelerates the precipitation of scale components in the filler layer, so that the precipitation on the catalyst surface can be prevented in advance. At the same time, compared with the past, the dispersion effect is improved, which can prevent local precipitation and accumulation of scale components, and enable the catalyst to exhibit high processing performance for a long time.

In the wastewater treatment apparatus of the present invention, the H6 series exceeds 100 mm. When H6 is less than 100mm (including 100mm), the scale components will not be uniformly dispersed, and the scale components will reach the catalyst layer in an ionic state. Therefore, the surface of the catalyst layer may be poisoned by the scale components. From the viewpoint of further suppressing the precipitation of scale components in the catalyst, the H6 series is preferably more than 150 mm, and more preferably more than 250 mm. The upper limit of H6 is not particularly limited, for example, it is less than 2000 mm. When H6 is less than 2000 mm, the decrease in gas-liquid contact efficiency caused by the re-aggregation of the finer bubbles through the dispersion plate mixing can be suppressed.

In the wastewater treatment apparatus of the present invention, the ratio of H6 to H1 (H6 / H1) is 0.1 or more (including 0.1) and 100 or less (including 100). When H6 / H1 is less than 0.1 or more than 100, an unbalanced flow of scale components will occur between the dispersion plate 2 and the dispersion plate 1 due to insufficient gas-liquid mixing effect, which will cause local accumulation of scale components and reduce processing efficiency. H6 / H1 is preferably 0.2 or more (including 0.2), and more preferably 0.3 or more (including 0.3). H6 / H1 is preferably 80 or less (including 80), and more preferably 50 or less (including 50). If it is in these ranges, the above effects can be further exerted.

There is no particular limitation as long as H1 satisfies the above-mentioned ratio (H6 / H1), and is, for example, 10 mm or more (including 10 mm), preferably 20 mm or more (including 20 mm), and more preferably 30 mm or more (including 30 mm). In addition, H1 is preferably 1,000 mm or less (including 1000 mm), more preferably 900 mm or less (including 900 mm), and even more preferably 750 mm or less (including 750 mm). Since H1 is more than 10mm (including 10mm) and less than 1000mm (including 1000mm), the gas-liquid dispersion and mixing can be sufficiently performed, so that the reduction in catalyst treatment efficiency can be suppressed, and scale components can be prevented from directly reaching the catalyst layer in an ionic state.

The size of the wastewater treatment device of the present invention is not particularly limited as long as it meets the above-mentioned H6 and H6 / H1, and may be the size of a reaction tower or a reaction container generally used in wastewater treatment. The shape of the wastewater treatment device of the present invention is also not particularly limited, and may be the shape of a reaction tower or a reaction container generally used in wastewater treatment. As for the reaction tower or the reaction vessel, a cylindrical shape having a diameter of 200 to 3000 mm and a length of 1,000 to 20,000 mm can be used.

The wastewater treatment apparatus of the present invention is applicable to various methods for wastewater treatment. Examples of the method for treating wastewater include wet oxidation, wet decomposition, ozone oxidation, and hydrogen peroxide oxidation. In terms of wastewater treatment methods, high-grade treated water quality can be obtained. From the viewpoint of excellent economical efficiency, a wet oxidation method is preferred. Therefore, one embodiment of the present invention provides a wastewater treatment device for wastewater treatment by a wet oxidation method.

[Wastewater] There is no particular limitation on the kind of wastewater treated by the wastewater treatment apparatus of the present invention. According to the wastewater treatment device of the present invention, wastewater containing any one or more of organic compounds, nitrogen compounds, and sulfur compounds can be effectively treated. Examples of the above organic compounds include epoxy compounds such as ethylene oxide and propylene oxide; alcohol compounds such as methanol, ethanol, and ethylene glycol; acrylic acid and methacrylic acid, terephthalic acid, and the like; Carboxylic acids such as esters and / or derivatives thereof. Examples of the nitrogen compound include organic nitrogen compounds such as amines and imines, and inorganic nitrogen compounds having nitrogen-hydrogen bonds such as ammonia and hydrazine. Examples of the sulfur compounds include inorganic sulfur compounds such as hydrogen sulfide, sodium sulfide, potassium sulfide, sodium sulfide, thiosulfate, and sulfite, and organic sulfur compounds such as thiols and sulfonic acids. Moreover, it is not limited to wastewater containing only the above compounds, and may include organic halogen compounds such as dioxane, dioxin and chlorochloroethane, diethylhexyl phthalate, nonylphenol, and environmental hormone compounds. Of harmful substances. Examples of wastewater containing such compounds include wastewater discharged from various industrial plants such as chemical plants, electronic component manufacturing equipment, food processing equipment, metal processing equipment, metal plating equipment, printing platemaking equipment, and photographic equipment; and thermal power generation. And waste water discharged from power generation equipment such as atomic power generation. Specific examples of industrial wastewater include: EOG production equipment, alcohol production equipment, aliphatic carboxylic acid and ester production equipment, aromatic carboxylic acid or aromatic carboxylic acid ester production equipment, and paper / pulp, fiber , Steel, ethylene / BXT, coal gasification, edible meat processing, pharmaceutical processing, etc. Furthermore, it is not limited to industrial wastewater, but also exemplifies domestic wastewater such as sewage and feces.

That is, the "wastewater" of the present invention is not limited to the so-called industrial wastewater discharged from the industrial plant as described above, but any liquid containing any one or more (including one) of organic compounds, nitrogen compounds, and sulfur compounds, The supply source (generation source) of such a liquid is not particularly limited.

(Scale component) Further, the wastewater treatment device of the present invention is suitable for wastewater treatment containing scale components. As described above, in the wastewater treatment device disclosed in Patent Document 1, when scale components are contained in waste water (heavy metals such as copper and iron, and calcium, aluminum, etc.), the scale components reach the catalyst layer in an ionic state and precipitate the catalyst. The surface of the catalyst may hinder the catalyst activity. On the other hand, in the wastewater treatment device of the present invention, the precipitation of scale components on the surface of the catalyst can be suppressed, and the treatment efficiency of the catalyst can be highly maintained.

The scale component is at least one element selected from the group consisting of heavy metals, aluminum, phosphorus, silicon, calcium, and magnesium. The heavy metals are not particularly limited, and examples thereof include cadmium (Cd), nickel (Ni), cobalt (Co), manganese (Mn), copper (Cu), zinc (Zn), silver (Ag), and iron (Fe). , Tin (Sn), antimony (Sb), lead (Pb), thorium (Tl), mercury (Hg), arsenic (As), chromium (Cr), bismuth (Bi), and the like.

There is no particular limitation on the concentration of scale components contained in the wastewater. The wastewater treatment device of the present invention is different from the conventional one, and can exhibit an effect in wastewater treatment containing scale components of 0.1 mg / L or more (including 0.1 mg / L). The concentration of scale components can be 0.5 mg / L or more (including 0.5 mg / L). If the concentration of the scale component is 1 g / L or less (including 1 g / L), the effects of the present invention can be fully exerted.

[Dispersion plate] The wastewater treatment device of the present invention has a dispersion plate 2, a dispersion plate 1, a filling layer, and a catalyst layer in this order from the supply side of the wastewater. That is, the wastewater treatment apparatus of the present invention has at least two dispersion plates. As for the dispersion plate, a single-well plate, a single-well plate with a collision plate, a perforated plate, or a perforated plate with a collision plate as shown in FIG. 5 can be used. As for the dispersing plate, the same type of dispersing plate can be arranged, and different dispersing plates can also be arranged. In the wastewater treatment apparatus of the present invention, the present invention can be manifested when the dispersion plate 2 and the dispersion plate 1 are arranged at a predetermined distance (H1). Further, if necessary, an additional dispersion plate may be disposed closer to the wastewater supply side (upstream side) than the dispersion plate 2. In addition, the dispersion plate may be constituted by one sheet, but it is preferable that it is constituted by a shape that can be divided into two or more pieces (including two pieces) from the viewpoint of workability of installation and removal.

The aperture ratio of single-well plates and multi-well plates (including those with collision plates) is generally 0.005% or more (including 0.005%) and 30% or less (including 30%). The above porosity is preferably 0.05% or more (including 0.05%), more preferably 0.1% or more (including 0.1%), more preferably 0.5% or more (including 0.5%) and even more preferably, 1% or more (including 1%) ) Is particularly good. The above-mentioned porosity is preferably 10% or less (including 10%), and more preferably 5% or less (including 5%). By being in such a range, an unbalanced flow caused by the stirring effect can be prevented, and the gas contained in the wastewater can be evenly distributed. Therefore, the improvement of the gas-liquid can improve the processing performance of the catalyst.

The porosity of the dispersion plate is calculated by the following formula.

Opening rate [%] = cross-sectional area of the entire hole / cross-sectional area of the entire dispersion plate × 100

The number of holes in perforated plates (including those with collision plates) is generally 5 or more (including 5) and 200 or less (including 200) per 1 m ² . Effect can be obtained sufficiently from the viewpoint of the dispersion, based in the number of holes per 1m ² of 10 or more (including 10) preferably, less than 1m ² per 25 (including 25) better. Further, the strength of the porous plate can be maintained in view of the number of holes per 1m ² in a line of 150 or less (including 150) preferably, per 1m ² of 120 or less (including 120) the better.

The shape of the hole is not particularly limited, but a cylindrical or conical shape is preferable because it is easy to manufacture. In addition, the arrangement of the holes is not particularly limited. In the case of a single-well plate, it is preferable to arrange it in the center. In the case of a multi-well plate, it is preferable to arrange it uniformly as much as possible.

In a preferred embodiment of the present invention, at least one of the dispersing plate 1 and the dispersing plate 2 is a porous plate, and the number of holes of the porous plate is 5 or more (including 5) per 1 m ^{2 and} 200 or less (including 200). With such a configuration, the precipitation of scale components on the catalyst can be further suppressed, and the processing performance of the catalyst can be further maintained.

The distance H2 between the interface between the dispersing plate 1 and the waste water supply side of the filling layer, such as the sum of H2 and the layer length H3 (H6) of the filling layer described below exceeds 100mm, there is no particular limitation, but the dispersion effect of the wastewater From the viewpoint, it is preferably 10 mm or more (including 10 mm).

The diameter of the collision plate provided in the single-well plate with collision plate and the porous plate with collision plate is preferably 0.5 to 10.0 times, more preferably 1.0 to 5.0 times, and even more preferably 1.5 to 3.0 times. Moreover, the distance between the collision plate and the single-well plate or perforated plate is preferably 0.05 to 5.0 times, more preferably 0.1 to 3.0 times, and even more preferably 0.2 to 1.0 times. By setting in such a range, the waste water and gas can effectively collide on the collision plate, and can be evenly dispersed in the circumferential direction of the collision plate.

[Filling material layer] (1) The waste water treatment device of the present invention has a filling material layer on the waste water discharge side of the dispersion plate 1. With this structure, the catalyst can be prevented from being consumed, and the wastewater does not flow unbalanced, and can flow as evenly as possible in the catalyst layer. Furthermore, it is possible to prevent scale components from precipitating on the catalyst surface.

The filler layer is filled with a metal or ceramic filler. The filler system contains at least one member selected from the group consisting of iron, copper, stainless steel (SUS), Herstoy, Inconel, titanium, zirconium, titanium oxide, zirconia, silicon nitride, or carbon nitride. . The filler may be a single kind, or two or more kinds (including two kinds) or an alloy. When the wastewater is treated by wet oxidation, the filler is preferably stainless steel (SUS), zirconium, Herst alloy, Inconel or titanium from the viewpoint of wear resistance, corrosion resistance and strength. It is better to use stainless steel (SUS) or zirconia.

The shape of the filler is not particularly limited, and examples thereof include pellets such as pellets, spheres, blocks, rings, saddles, and polyhedrons; shapes of fibrous, chain, and bead-like continuum Wait. From the viewpoint that the reaction tower can be easily filled, the shape of the filling is preferably granular, and more preferably pellets, spheres, or rings.

The size of the filler is not particularly limited as long as the above-mentioned effects can be obtained. For example, when it is a granular filling, the average particle diameter is 3 mm or more (including 3 mm), preferably 4 mm or more (including 4 mm), and more preferably 5 mm or more (including 5 mm). The average particle diameter is 30 mm or less (including 30 mm), preferably 20 mm or less (including 20 mm), and more preferably 15 mm or less (including 15 mm).

In addition, in this specification, the average particle diameter of a granular filler and the solid catalyst mentioned later are the arithmetic mean of a particle diameter. The particle diameter refers to the maximum diameter of the filler or solid catalyst. For example, the particle diameter of a spherical filler or solid catalyst is the diameter, and the particle diameter of a pellet-shaped filler or solid catalyst refers to the length of its diagonal.

The average particle diameter d1 of the filler and the average particle diameter d0 of the catalyst contained in the catalyst layer described below are preferably d1> d2 from the viewpoint of the dispersion effect of the wastewater.

The specific gravity of the filling material (meaning the true specific gravity, which is different from the volume specific gravity, filling specific gravity, and apparent specific gravity generally used) is not particularly limited, and may be appropriately selected. The specific gravity is generally 2.5 or more (including 2.5), and preferably 4 to 12.

The porosity of the filling layer is not particularly limited, and is generally 20 to 90% by volume (based on the total volume of the filling layer), preferably 30 to 70% by volume, more preferably 35 to 60% by volume, and 35 to 55 Capacity% is even better.

The filling material to be filled by the filling material layer does not need to have the same material, shape, size, specific gravity, etc. If the effects of the present invention can be exhibited, two or more types (including two types) of filling materials can be used. In addition, a suitable filler can be appropriately selected according to a use type and a use situation.

The filling is generally a method in which a support base made of a metal net, a grille, etc., alone or in combination, is set in a reaction tower and filled thereon.

The layer length (H3) of the filling layer is not particularly limited if the sum of the H2 (H6) and the above H2 exceeds 100mm, and is generally 10mm or more (including 10mm). From the viewpoint of preventing scale components from directly accumulating in the catalyst layer It is more preferably 50mm or more (including 50mm), more preferably 80mm or more (including 80mm), and even more preferably 100mm or more (including 100mm). The upper limit of H3 is not particularly limited, and is 300 mm or less (including 300 mm), and from the viewpoint of cost, it is preferably 250 mm or less (including 250 mm).

In a preferred embodiment of the present invention, the filler layer has a two-layer structure from the viewpoint of further improving the dispersion effect of wastewater. That is, the wastewater treatment device of the present invention preferably has a filler layer between the filler layer and the catalyst layer. Since the filler layer has a two-layer structure, it is possible to further maintain the catalyst processing performance to a high degree.

When the filler layer on the supply side of the waste water is the filler layer 1, and the filler layer on the catalyst layer side is the filler layer 2, the average particle diameter d1 of the filler contained in the filler layer 1 and the filler particle layer 2 are included. The relationship between the average particle diameter d2 of the filler can be d1> d2, or d1 <d2. d1 and d2 are preferably d1> d2 from the viewpoint of the dispersion effect of the wastewater. When d1> d2, the ratio of d2 to d1 (d2 / d1) is preferably 0.2 or more (including 0.2), more preferably 0.3 or more (including 0.3), and even more preferably 0.4 or more (including 0.4). The d2 / d1 is preferably less than 1.00, and more preferably less than 0.95.

In a preferred embodiment of the present invention, the average particle diameter d1 of the filler 1 contained in the filler layer 1 and the average particle diameter d2 of the filler 2 contained in the filler layer 2 and the following catalyst layer The average particle diameter d2 of the catalyst satisfies the relationship of d1> d2> d0. From the supply side of the wastewater to the filler layer 1, the filler layer 2 and the catalyst layer, the average particle diameter of the filler or catalyst is gradually reduced, thereby further improving the dispersion effect of the wastewater. The ratio of d2 to d1 (d2 / d1) is as described above. The ratio of d0 to d2 (d0 / d2) is preferably 0.2 or more (including 0.2), more preferably 0.3 or more (including 0.3), and even more preferably 0.4 or more (including 0.4). In addition, d0 / d2 is preferably less than 1.00, and more preferably less than 0.95.

The material, shape, and specific gravity of the fillers contained in the filler layer 1 and the filler layer 2 may be the same or different.

The layer length of the filler layer is set as the layer length of the filler layer 1 as H3 and the layer length of the filler layer 2 as H7. The definition of the layer length is as described above. Moreover, H6 is the sum of H2, H3, and H7. The filling layer may have a two-layer structure, and the preferred range of the above H6 is the same.

From the viewpoint of the dispersion effect of the wastewater, the layer length (H7) of the filling layer 2 is preferably 30mm or more (including 30mm), more preferably 50mm or more (including 50mm), and more preferably 100mm or more (including 100mm). . The H7 series is preferably 500 mm or less (including 500 mm), more preferably 400 mm or less (including 400 mm), and even more preferably 300 mm or less (including 300 mm). However, H7 is set so that H6 and H6 / H1 do not deviate from the above range.

Therefore, in a preferred form of the present invention, the layer length of the filler layer 2 is 30 mm or more (including 30 mm) and 500 mm or less (including 500 mm).

The wastewater treatment device of the present invention may further have a filling layer on the wastewater discharge side of the catalyst layer.

For example: As shown in Figure 2, when the wastewater treatment device is a cylindrical device that flows upward, in order to apply a load from above to press the catalyst, a filler layer (the upper filler layer) is further provided on the wastewater discharge side of the catalyst layer. ). The setting of the upper filling layer can suppress catalyst loss. The layer length (H5) of the upper filling layer is not particularly limited, and can be appropriately selected from a range of 30 to 1000 mm. As for the filler contained in the upper filler layer, the above-mentioned filler can be used. However, the size of the filler contained in the upper filler layer is preferably larger than the size of the catalyst in order to prevent the filler from entering the catalyst layer.

[Catalyst layer] 之 The catalyst treatment device of the present invention has a dispersion plate 2, a dispersion plate 1, a filler layer, and a catalyst layer in this order from the discharge side of the wastewater. The catalyst contained in the catalyst layer is a general solid catalyst. If the solid catalyst is a user in general wastewater treatment, it can be used without special restrictions. In terms of solid catalysts, at least one metal selected from the group consisting of titanium, iron, aluminum, silicon, zirconium, and cerium; oxides or composite oxides thereof; or catalysts containing activated carbon or the like. Among these, oxides such as titanium oxide, zirconia, iron oxide, titanium-zirconium composite oxide, and titanium-iron composite oxide are applicable.

The solid catalyst system may contain other components (second component) in addition to the above-mentioned component (first component). For solid catalysts containing two types of components, examples include: at least one metal selected from the group consisting of iron, titanium, silicon, aluminum, zirconium, and cerium; oxides or composite oxides thereof; or activated carbon (No. 1 component), contact with at least one metal selected from the group consisting of manganese, cobalt, nickel, tungsten, copper, silver, platinum, palladium, rhodium, gold, indium, and ruthenium; or a metal compound (second component) of these Media. The preferred solid catalyst is that the first component is titanium oxide, zirconia, iron oxide, titanium-zirconium composite oxide, or titanium-iron composite oxide; and the second component is platinum. Among solid catalysts containing two types of components, it is preferable that the first component contains 75 to 99.95% by weight and the second component contains 0.05 to 25% by weight. The total of the first component and the second component is preferably 100% by weight. However, the third component, such as a catalyst-free carrier, an inorganic catalyst, and an adhesive component, may be appropriately contained. In this case, the weight ratio of the first component and the second component is determined by the weight of the first component and the weight of the second component. Weight is determined without considering the third component.

The solid catalyst is suitable for an oxidation treatment using a wet oxidation method. From the viewpoint of high-grade treated water quality and economy, the wastewater treatment apparatus of the present invention is applicable to wastewater treatment using a wet oxidation method. Therefore, in a preferred embodiment of the present invention, the catalyst contained in the catalyst layer is a wet oxidation catalyst.

The shape of the solid catalyst is not particularly limited as long as it is generally used in wastewater treatment. Examples of the shape of the solid catalyst include pellets, pellets, rings, and the like; honeycomb shapes, and the like.

The size of the solid catalyst is not particularly limited as long as the above effects can be obtained. For example, when it is a granular solid catalyst, the average particle diameter is, for example, 1 to 30 mm, preferably 1.5 to 20 mm, and more preferably 2 to 15 mm. Furthermore, from the viewpoint of the dispersion effect of the wastewater, the average particle diameter of the solid catalyst is preferably the smaller the average particle diameter of the filler contained in the filler layer closer to the wastewater supply side than the catalyst layer.

The solid catalyst system may be used singly or in combination of two or more kinds (including two types).

The layer length H4 of the catalyst layer is determined by the filling amount of the catalyst. The filling amount of the catalyst is not particularly limited, and can be appropriately determined according to the purpose. Generally, it is recommended to adjust the filling amount of the catalyst so that the space velocity of the catalyst layer becomes 0.1 hr ^-1 to 10 hr ^-1 , preferably 0.2hr ^-1 to 5hr ^-1 , and more preferably 0.3hr ^-1 to 3hr ^-1 good. When the space velocity is 0.1 hr ^-1 or more (including 0.1 hr ^-1 ), the processing capacity of the catalyst can be ensured, and the expansion of the equipment can be avoided. In addition, when the space velocity is 10 hr ^-1 or less (including 10 hr ^-1 ), the oxidation / decomposition treatment of the wastewater in the reaction tower can be sufficiently performed.

<Second aspect: Treatment method of waste water> According to another aspect of the present invention, there is provided a treatment method of waste water, which uses at least a gas-liquid diffusion section 1 and a gas-liquid diffusion section in order from a supply side of the wastewater. 2. Wastewater treatment method for the gas-liquid diffusion section 3 and the device of the catalyst layer, the above-mentioned wastewater has a gas dispersion and satisfies the following (1) to (3): (1) the above-mentioned gas-liquid diffusion section 1 to The above-mentioned wastewater indwelling time in 3 are all 0.5 seconds or more (including 0.5 seconds); (2) The total indwelling time of the wastewater in the gas-liquid diffusion unit 3 and the gas-liquid diffusion unit 2 is 5 seconds or more (including 5 Seconds); and (3) The total of the wastewater indwelling time in (2) above is 0.1 to 100 times the wastewater indwelling time in the gas-liquid diffusion section 1 described above. In the device of this type, the catalyst layer is the same as the catalyst layer of the above-mentioned wastewater treatment device (the first type), so the description is omitted. This type of device has gas-liquid diffusion sections 1 to 3 as a means for uniformly dispersing scale components and a gas (especially oxygen). The gas-liquid diffusion unit 1 (also referred to as "diffusion unit 1" in this specification) refers to the space between the gas-liquid dispersion unit and the gas-liquid dispersion unit from the supply side of the wastewater, or the dispersion plate and the filling layer. The space between the surfaces of the wastewater supply side; or the filling layer. The diffusion portion 1 corresponds to, for example, a range indicated by H1 in the second figure. The gas-liquid diffusion section 2 (also referred to as "diffusion section 2" in this specification) refers to the space between the gas-liquid dispersion section and the gas-liquid dispersion section from the supply side of the wastewater, or the dispersion plate and the filling layer. The space between the waste water supply side or the space between the waste water discharge side of the filling layer and the waste water supply side of the filling layer; or the filling layer. The diffusion portion 2 corresponds to, for example, a range indicated by H2 in the second figure. The gas-liquid diffusion portion 3 (also referred to as "diffusion portion 3" in this specification) refers to the space or filling layer between the gas-liquid dispersion portion and the surface of the catalyst layer on the wastewater supply side from the wastewater supply side. The space between the surface on the waste water discharge side and the surface on the waste water supply side of the catalyst layer; or a filling layer. The diffusion portion 3 corresponds to, for example, a range indicated by H3 in the second figure. When the filler layer has a two-layer structure, the total of the two layers corresponds to the diffusion portion 3, for example, it corresponds to the range shown by H3 + H7 in FIG. 4. In this type of processing method, at least one of the gas-liquid dispersion sections 1 to 3 is a filling layer. The filling layer may be one layer or two or more layers (including two layers). In addition, the filling layer of the device of this type is the same as the filling layer of the above-mentioned waste water treatment device (the first type), so the description is omitted. The gas-liquid dispersion unit is a member that can prevent the unbalanced flow by the stirring effect and can evenly distribute the gas contained in the waste water, and examples include a dispersion plate. The dispersion plate of the device of this type is the same as the dispersion plate of the above-mentioned wastewater treatment device (the first type), so the description is omitted. In this type of treatment method, gas is dispersed in the wastewater. This type of device improves gas-liquid contact by having at least three gas-liquid diffusion sections, which can improve the processing performance of the catalyst. In the treatment method of this type, the wastewater indwelling time in the gas-liquid diffusion section satisfies the conditions (1) to (3) above. Hereinafter, (1) to (3) will be described. (1) The wastewater indwell time in the gas-liquid diffusion sections 1 to 3 are all 0.5 seconds or more (including 0.5 seconds). When the wastewater indwelling time is less than 0.5 seconds, the gas-liquid mixing effect is insufficient, and the effects of the present invention cannot be exhibited. The wastewater indwelling time is preferably 2 to 300 seconds. (2) The total of the wastewater indwell time in the gas-liquid diffusion section 3 and the gas-liquid diffusion section 2 is 5 seconds or more (including 5 seconds). When the total indwelling time of the wastewater is less than 5 seconds, the scale components are unevenly distributed, and the scale components may reach the catalyst layer in an ionic state. Therefore, the surface of the catalyst layer may be poisoned by the scale components. The lower limit of the total waste water retention time is preferably 10 seconds or more (including 10 seconds), more preferably 35 seconds or more (including 35 seconds), and even more preferably 60 seconds or more (including 60 seconds). There is no particular limitation on the total upper limit of the waste water retention time, but the total waste water retention time in the diffusion unit 2 and the diffusion unit 3 is preferably 2500 seconds or less (including 2500 seconds), and 1500 seconds or less (including 1500 seconds). More preferably, it is more preferably 750 or less (including 750 seconds), and particularly preferably 300 or less (including 300 seconds). (3) The total of the wastewater indwelling time in (2) above is 0.1 to 100 times the wastewater indwelling time in the gas-liquid diffusion section 1 described above. Compared with the waste water retention time in the gas-liquid diffusion unit 1, when the total waste water retention time in (2) is less than 0.1 times or exceeds 100 times, the gas-liquid mixing effect is insufficient, and an unbalanced flow of scale components is likely to occur. Therefore, scale components will be locally accumulated, which will reduce the processing efficiency. Compared to the wastewater indwelling time in the gas-liquid diffusion section 1 described above, the total of the wastewater indwelling time in (2) above is preferably 0.2 times or more (including 0.2 times), more preferably 0.3 times or more (including 0.3 times), It is preferably 80 times or less (including 80 times), and more preferably 50 times or less (including 50 times). When the gas-liquid diffusion part is a filling layer, when the waste water retention time is 0.5 seconds or more (including 0.5 seconds), it is not necessary to consider the porosity of the filling layer. The porosity of the filling layer is generally 20 to 90% by volume (based on the total volume of the filling layer), preferably 30 to 70% by volume, and more preferably 35 to 60% by volume. When the porosity decreases, the degree of turbulence in the filling layer increases, and the same effect as that of extending the residence time of the wastewater can be obtained. In addition, even if the gas-liquid diffusion section is composed of two or more (including two) filling layers, the wastewater indwelling time in the gas-liquid diffusion section satisfies the conditions (1) to (3) described above. The residence time of the waste water in the gas-liquid diffusion section can be appropriately controlled by the supplied waste water flow rate and the size of the device. The wastewater indwelling time can be calculated by the method described in the examples. In a preferred embodiment, the diffusion portion 3 is a filling layer having a porosity of 20 to 90% by volume (based on the total volume of the filling layer). The porosity is preferably 30 to 70% by volume, more preferably 35 to 60% by volume, and particularly preferably 35 to 55% by volume. In addition, when the diffusion portion 3 is a filler layer, the more preferable one of the diffusion portion 2 and the diffusion portion 1 is not a type of a filler layer. In a preferred embodiment, the diffusion portion 3 is a two-layered filling layer. Since the filler layer has a two-layer structure, the catalyst processing performance can be maintained to a high degree. The wastewater indwelling time in the diffusion part 3 is 0.5 seconds or more (including 0.5 seconds), preferably 5 seconds or more (including 5 seconds), more preferably 8 seconds or more (including 8 seconds), and 10 seconds or more (including 10 seconds). Seconds) is particularly good. When it is less than 0.5 second, the effect of the present invention cannot be sufficiently obtained. The upper limit of the wastewater indwelling time is not particularly limited, but when the indwelling time is too long, the dispersion of the gas and the liquid in the wastewater reaching the catalyst layer decreases, and when the diffusion portion 3 is a filling layer, the pressure loss increases and energy is generated Loss, its effect has not improved. Therefore, the wastewater indwelling time in the diffusion section 3 is preferably 1800 seconds or less (including 1800 seconds), more preferably 500 seconds or less (including 500 seconds), and even more preferably 100 seconds or less (including 100 seconds), and more preferably 50 seconds. It is particularly good if it is less than or equal to 50 seconds. The wastewater indwelling time in the diffusion unit 2 is 0.5 seconds or more (inclusive), and the total wastewater indwelling time in the diffusion unit 2 and the diffusion unit 3 is 5 seconds or more (inclusive). The upper limit of the wastewater indwelling time in the diffusion section 2 is not particularly limited, but when the wastewater indwelling time is too long, the dispersibility of the gas and liquid in the wastewater supplied to the diffusion section 3 may decrease, and the equipment is relatively The amount of wastewater to be treated is too large and it is also economically disadvantageous. Therefore, the wastewater indwelling time in the diffusion section 2 is preferably 700 seconds or less (including 700 seconds). The wastewater indwelling time in the diffusion unit 1 is 0.5 seconds or more (including 0.5 seconds), preferably 1 second or more (including 1 second), and more preferably 2 seconds or more (including 2 seconds). The upper limit of the wastewater indwelling time is not particularly limited. When the indwelling time is too long, the dispersibility of the gas and liquid in the wastewater supplied to the diffusion section 2 may be reduced. In addition, the equipment is relatively small relative to the amount of wastewater to be treated. Excessive words are also economically disadvantageous. Therefore, the upper limit of the wastewater indwelling time in the diffusion section 1 is preferably 2500 seconds or less (including 2500 seconds), more preferably 1000 seconds or less (including 1000 seconds), and even more preferably 600 seconds or less (including 600 seconds), Particularly preferred is 300 seconds or less. In an implementation form, the processing method of this form is such that the gas-liquid diffusion part 1 has a dispersion plate 1 at the interface of the wastewater supply side, and the gas-liquid diffusion part 2 is disposed between the gas-liquid diffusion part 2 and the gas-liquid diffusion part 1. The interface has a dispersion plate 2. At this time, each of the dispersion plate 1 and the dispersion plate 2 has one or more holes, and at least one of the dispersion plate 1 and the dispersion plate 2 has an opening ratio of 0.005. % ～ 30% porous plate structure. The porosity of the above porous plate structure is preferably 0.05% or more (including 0.05%), more preferably 0.1% or more (including 0.1%), more preferably 0.5% or more (including 0.5%) and even more preferably, 1% or more (Including 1%) is particularly good. The above-mentioned porosity is preferably 10% or less (including 10%), and more preferably 5% or less (including 5%). Within such a range, an unbalanced flow due to the stirring effect can be prevented and the gas distribution in the wastewater can be made uniform. Therefore, the gas-liquid contact can be improved to improve the processing performance of the catalyst. The method for calculating the open porosity of the dispersion plate, the number of holes in the porous plate, and the shape of the holes are the same as those of the dispersion plate in the above-mentioned waste water treatment apparatus (the first type), so descriptions are omitted. Other reaction conditions of the present invention include the following (i) to (iv). The treatment method of the present invention is preferably to further satisfy the following (i) to (iv): (i) the LHSV in the catalyst layer is 0.1 hr ^-1 to 10 hr ^-1 ; (ii) the catalyst The temperature of the wastewater in the layer is 80 ° C to 370 ° C; (iii) the pressure in the catalyst layer is the pressure to maintain at least a part of the wastewater in the liquid phase; and (v) the amount of oxygen contained in the gas is The theoretical oxygen demand of the oxide is 0.5 to 5.0 times. Hereinafter, (i) to (iv) will be described. (i) The LHSV (Liquid Hourly Space Velocity) in the catalyst layer is 0.1 hr ^-1 to 10 hr ^-1 , preferably 0.2 hr ^-1 to 5 hr ^-1 , and 0.3 hr ^-1 to 3 hr ^{-1 is} better. When LHSV is 0.1 hr ^-1 or more (including 0.1 hr ^-1 ), it can be implemented with cost-effective equipment. When the LHSV is 10 hr ^-1 or less (including 10 hr ^-1 ), the oxidation / decomposition treatment of the wastewater in the reaction tower can be sufficiently performed. (ii) Temperature of wastewater in the catalyst layer The temperature of the wastewater in the catalyst layer is 80 ° C to 370 ° C, preferably 100 ° C to 270 ° C, more preferably 110 ° C to 270 ° C, and 200 ° C to 270 ° C. good. When the temperature of the wastewater exceeds 370 ° C, high pressure has to be applied in order to maintain the liquid phase state of the wastewater. In this case, the equipment may become larger and the operating cost may increase. When the temperature of the wastewater is less than 80 ° C, it may be difficult to effectively perform oxidation / decomposition treatment of oxides in the wastewater. (iii) Pressure in the catalyst layer In this type of device, the pressure in the catalyst layer is the pressure at which at least a part of the wastewater is maintained in the liquid phase. Since at least a part of the wastewater remains in the liquid phase, it is preferable to appropriately adjust the pressure in accordance with the temperature of the wastewater treatment. Specific examples are as follows. • When the processing temperature is 80 ° C or higher (including 80 ° C) and less than 95 ° C, it is sufficient to be atmospheric pressure or higher (including atmospheric pressure). From the economic point of view, it can be atmospheric pressure. However, in order to improve the processing efficiency, It is better to pressurize. • When the processing temperature is above 95 ° C (including 95 ° C) and below 170 ° C, the pressure is about 0.2 to 1 MPa (Gauge). • When the processing temperature is above 170 ° C (including 170 ° C) and below 230 ° C: A pressure of about 1 to 5 MPa (Gauge) • A pressure exceeding 5 MPa (Gauge) when the processing temperature is above 230 ° C (inclusive). In addition, the upper limit of the pressure in the above processing temperature range is only a rough standard. It can be determined by the balance between the processing efficiency and the pressure resistance of the device. The specific upper limit is 21 MPa or less (including 21 MPa), preferably 10 MPa or less (including 10 MPa), and particularly preferably 8 MPa or less (including 8 MPa). In addition, the upper limit of the pressure is preferably 2 times or less (including 2 times) the saturated vapor pressure of the temperature of the wastewater in the catalyst layer, and preferably 1.5 times or less (including 1.5 times). (iv) According to the definition of "theoretical oxygen demand" described later, the oxygen content in the gas is 0.5 to 5.0 times the theoretical oxygen demand of the oxide in the wastewater. The oxygen amount is preferably 0.7 times or more (including 0.7 times) the theoretical oxygen demand of the oxides in the wastewater, and preferably 5.0 times or less (including 5.0 times), and 3.0 times or less (including 3.0 times). Better. In this type of treatment method, the waste water treatment device is preferably a treatment device of the first type described above. <Description of Specific Aspects of the Present Invention> Hereinafter, a waste water treatment method using a waste water treatment apparatus of the first type of the present invention (this specification, also referred to as "a waste water treatment apparatus of the present invention") will be specifically described. FIG. 1 is a schematic diagram showing an embodiment of a wastewater treatment method when a wet oxidation treatment is used as one of the oxidation treatment steps, but the treatment method used by a type of wastewater treatment device of the present invention is not limited herein.

The waste water supplied from the waste water supply source is supplied to the waste water supply pump 3 through the waste water supply line 10, and is further sent to the heat exchanger 2. The space velocity at this time is not particularly limited, and can be appropriately determined depending on the processing capacity of the catalyst.

In the wastewater treatment device of the present invention, the wet oxidation treatment can be carried out in the presence or absence of oxygen-containing gas, but increasing the oxygen concentration in the wastewater can improve the oxidation / decomposition efficiency of the oxides contained in the wastewater. Therefore, it is better to mix the oxygen-containing gas into the wastewater.

When performing wet oxidation treatment in the presence of an oxygen-containing gas, for example, it is preferable to introduce the oxygen-containing gas from the oxygen-containing gas supply line 11 and pressurize it with the compressor 4 before mixing the waste water into the waste water before supplying it to the heat exchanger 2. In the present invention, the "oxygen-containing gas" refers to a gas containing molecular oxygen and / or ozone. If this gas is used, it may be pure oxygen, an oxygen-enriched gas, air, an aqueous hydrogen peroxide solution, and other oxygen-containing gases produced in factories. There is no particular limitation on the type of the gas such as the oxygen-containing gas, and from the viewpoint of economy, it is recommended to use air.

The supply amount of the oxygen-containing gas when it is supplied to the wastewater is not particularly limited as long as it is supplied in an effective amount that can increase the oxidation / decomposition ability of the oxide in the wastewater. The supply amount of the oxygen-containing gas is, for example, an oxygen-containing gas flow regulating valve (not shown) provided in the oxygen-containing gas supply line 11 to appropriately adjust the supply amount of wastewater. The preferred supply of oxygen-containing gas is 0.5 times or more (including 0.5 times) the theoretical oxygen demand of the oxides in the recommended wastewater, more preferably 0.7 times or more (including 0.7 times), and 5.0 times or less (including 5.0 times). Times), more preferably 3.0 times or less (including 3.0 times).

In addition, in the present invention, "theoretical oxygen demand" means the amount of oxygen required to oxidize and / or decompose organic compounds and nitrogen compounds in wastewater into nitrogen, carbon dioxide, water, and ash in the present invention. In theory, the theoretical oxygen demand is expressed by chemical oxygen demand (COD (Cr)).

The waste water sent to the heat exchanger 2 is preheated. However, under the condition that more than 1/2 of the waste water in the heat exchanger 2 is evaporated, the organic matter and scale components in the waste water are accumulated in the heat exchanger 2, which results in a decrease in heat exchange efficiency, clogging of pipes, and rapid expansion of volume. This causes problems such as the load on the outlet side pipe section, the gas hammer phenomenon caused by the liquefaction in the reaction tower, and the like. Therefore, a structure capable of withstanding the pressure corresponding to the heating temperature is preferred.预 The waste water preheated in the heat exchanger 2 is supplied to a reaction tower 1 (a waste water treatment device of the present invention) provided with a heating means 8 (a heater or a heat medium). It is preferable that the temperature of the waste water in the heating means 8 system reaction tower is capable of heating to the range described in "(ii) Wastewater temperature of the catalyst layer" described above. The heat exchanger 2 and the reaction tower 1 preferably have a structure capable of withstanding the pressure described in the "(iii) Pressure in the catalyst layer" described above.

In addition, the heating sequence of the waste water is not particularly limited. As described above, it may be further heated in the reaction tower after being preheated outside the reaction tower, or may be heated only in the reaction tower. In addition, there is no particular limitation on the method of heating wastewater. A heater or heat exchanger can be used, and a heater can be installed in the reaction tower to heat the wastewater. A heat source such as steam may be further supplied to the wastewater.

When processing under pressure, a pressure adjustment mechanism can be installed downstream of the reaction tower. For example, as shown in FIG. 1, it can be controlled by conventional means such as installing a pressure control valve 7 on the exhaust outlet side of the gas-liquid separator. What is necessary is just to control the control range of the pressure so that the conditions described in the "(iii) pressure in a catalyst layer" in the reaction tower can be maintained.

Further, in the wet oxidation treatment used in the present invention, the number, type, shape, and the like of the reaction towers are not particularly limited, and a single or plural reaction towers may be used. The reaction tower may be a single-tube type or a multi-tube type. When a plurality of reaction towers are installed, in-line or side-by-side reaction towers can be arbitrarily arranged according to the purpose.

As for the method of supplying wastewater to the reaction tower, various types of gas-liquid co-current, gas-liquid co-current, and gas-liquid convection can be used. In addition, when multiple reaction towers are installed, two or more types can be combined (including 2 Types) of these supply methods.

When using the above-mentioned wet oxidation catalyst in a reaction tower, in addition to improving the oxidation / decomposition treatment efficiency of any one or more (including one) organic compounds, nitrogen compounds, and sulfur compounds contained in the wastewater At the same time, it maintains excellent catalyst activity and catalyst durability for a long period of time, and can obtain treated water with high-level purification of wastewater.

When using a plurality of reaction towers, different catalysts can be used respectively. Moreover, a catalyst-filled reaction tower (the wastewater treatment apparatus of the present invention) and a reaction tower not using a catalyst may be combined.

The oxides in the wastewater are subjected to oxidation / decomposition treatment in the reaction tower, but the "oxidation / decomposition treatment" in the present invention is exemplified as: oxidative decomposition treatment for converting acetic acid into carbon dioxide and water; Decarboxylation decomposition treatment; oxidation treatment to convert sulfide, hydrosulfide, sulfite, thiosulfate to sulfate; oxidation of ash to convert dimethylsulfine to carbon dioxide, water, sulfate ion, etc. Oxidative decomposition treatment; hydrolysis treatment that converts urea to ammonia and carbon dioxide; oxidative decomposition treatment that converts ammonia or hydrazine to nitrogen and water; oxidative treatment that converts dimethylsulfine to dimethylphosphonium or methanesulfonic acid, etc. In other words, the decomposition treatment includes decomposition treatment until the easily decomposable oxide is decomposed into nitrogen, carbon dioxide, water, ash, etc., decomposition treatment for reducing the molecular weight of the hardly decomposable organic compound and nitrogen compound, or oxidation oxidation. Various treatments such as oxidation and / or decomposition.

In addition, in the treatment liquid obtained by wet oxidation treatment without using a catalyst, low-molecular-weight, low-molecular-weight organic compounds are often left in organic compounds that are difficult to decompose in the oxide, and low-molecular-weight organic acids are left in , Especially acetic acid. However, in the method using the catalyst of the present invention, the residual amount of these can be reduced by increasing the reaction temperature and increasing the amount of the catalyst.

FIG. 1 shows a specific example of the treatment. The wastewater is taken out from the treatment liquid line 12 after the reaction tower 1 is subjected to oxidation / decomposition treatment. If necessary, it is cooled by the cooler 9 and then separated by the gas-liquid separator 5. Into gas and liquid. At this time, it is better to use the liquid level controller LC to detect the liquid level state, and to control the liquid level in the gas-liquid separator to be constant by the liquid level control valve 6. Furthermore, it is preferable to use a pressure controller PC to detect the pressure state, and control the pressure in the gas-liquid separator to be constant through the pressure control valve 7.

The position of the pressure control valve can be appropriately changed as long as it can maintain / control the processing conditions in the reaction tower installed before the gas-liquid separator.

Here, the temperature in the gas-liquid separator is not particularly limited. However, since the treatment liquid obtained by subjecting the wastewater to oxidation / decomposition treatment contains carbon dioxide, the temperature in the gas-liquid separator may be increased by, for example, increasing the temperature in the gas-liquid separator. Carbon dioxide in the wastewater is released, or the liquid separated by the gas-liquid separator is bubbled with air and other gas to release carbon dioxide in the liquid.

In the temperature control of the processing liquid, the processing liquid can be cooled by cooling means such as the heat exchanger 2 and the cooler 9 before being supplied to the gas-liquid separator 5, or a heat exchanger (not shown) can be installed after the gas-liquid separation. ) Or a cooling means (not shown) to cool the processing liquid.

The liquid (treatment liquid) separated in the gas-liquid separator 5 is discharged from the treatment liquid discharge line 14. The discharged liquid can be further purified by various conventional steps such as biological treatment or membrane separation treatment. Furthermore, a part of the treatment liquid obtained by the wet oxidation treatment is directly returned to the wastewater before being subjected to the wet oxidation treatment, or is supplied to the wastewater from an arbitrary position of the wastewater supply line, or the wet oxidation treatment is performed. For example, the treatment liquid obtained by the wet oxidation treatment can also be used as dilution water of wastewater to reduce the TOD concentration or COD concentration of wastewater. Moreover, the gas system separated in the gas-liquid separator 5 is discharged to the outside through the gas discharge line 13. In addition, the exhaust gas can be further subjected to other steps. In addition, when performing the wet oxidation treatment used in the present invention, a heat exchanger may be used for a heater and a cooler, and these heat exchangers may be used in appropriate combinations. Examples

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto.

[Example 1] The details of the reaction tower of Example 1 are shown in FIG. 2. It is installed on a support base made of a grid and a metal net of a cylindrical reaction tower 1 with a diameter of 600 mm and a length of 9000 mm, and a cylindrical SUS pellet shape with a diameter of 600 mm and a length of 5 to 8 mm (average length 6.5 mm). An object (average particle diameter: 8.5 mm) was filled with 100 mm (H3) in the height direction (lower filler layer 16; diffusion portion 3). The pellet had a specific gravity of about 7.9 and a porosity of 43%.

Next, a solid catalyst 2000L (catalyst layer 17) was filled on the lower filler layer 16 in a height direction of 7074 mm (H4). The solid catalyst used was a catalyst composed of titanium oxide and platinum as main components, and the weight ratio of each was 99.0: 1.0 in terms of TiO ₂ : Pt. The shape of the solid catalyst is a pellet (diameter: 7.2 mm) with a diameter of 4 mmφ and a length of 6 mm. Then, similar to the above, the catalyst layer 17 is filled with SUS pellets (upper filling layer 18) in a height direction of 300 mm (H5).

A lower plate (upstream side) of the lower filling layer 16 is provided with a porous plate 15-1 (gas-liquid dispersion portion) and a single-well plate 15-2 (gas-liquid dispersion portion) with a collision plate. The distance between the spaces (diffusion section 1) is 950 mm (H1), and the distance between the single-hole plate 15-2 with collision plate and the surface on the waste water supply side of the lower filling layer 16 (diffusion section 2) is 10 mm (H2), and the distance from the perforated plate 15-1 to the entrance (interface) of the catalyst layer 17 is 110 mm (H6). The opening ratio of the perforated plate 2.2% based porous plate ² uniformly arranged holes 53 of each of 1m.

(Wastewater physical test) In the waste water treatment method shown in FIG. 1, the reaction tower 1 uses the reaction tower of Example 1 and performs a total of 1,000 hours of waste water treatment under the following conditions. The waste water delivered from the waste water supply line 10 is pressurized and fed at a flow rate of 4 m ³ / hr by the waste water supply pump 3, and the heat exchanger 2 and electric heater (heating means 8) are used so that the maximum temperature of the reaction tower becomes 250 ° C. ) Is adjusted and supplied from the bottom of the reaction tower 1. In addition, air is supplied from the oxygen-containing gas supply line 11 and is boosted by the compressor 4 from the heat exchanger such that O ₂ / COD (Cr) (the amount of oxygen in the air / chemical oxygen demand) = 1.5. The front part of 2 is supplied, and this waste water is mixed. The LHSV in the catalyst layer was 2.0hr ^-1 . The treatment liquid after the wet oxidation treatment is cooled by the treatment liquid line 12 in the cooler 9, and then subjected to a gas-liquid separation treatment through a gas-liquid separator 5. In the gas-liquid separator 5, the liquid level is detected by a liquid level controller (LC), and the liquid level control valve 6 is operated to maintain a constant liquid level, while the pressure is detected by a pressure controller (PC), and the pressure control valve 7 Operate to maintain a pressure of 7 MPaG. Then, the processing liquid processed in this way is discharged from the processing liquid discharge line 14. The inlet pressure (PI) of the reaction tower at the beginning of the treatment was 7.2 MPaG.

The wastewater used for treatment is COD (Cr) = 43g / L, pH = 11, and the scale component contains 25mg / L of calcium and 1 mg / L of iron.

(COD (Cr) treatment rate) The COD (Cr) treatment rate after 8 hours of reaction is 85%. The COD (Cr) treatment rate is calculated using the following formula.

COD (Cr) treatment rate [%] = [COD (Cr) of wastewater-COD (Cr) of treatment liquid] / COD (Cr) of wastewater × 100

(Adhesion of scale components) Remove the catalyst and confirm the adhesion state of scale components with the naked eye, and evaluate it as B according to the following criteria.

A: Hardly any adhesion was seen. B: I saw a little adhesion. C: Obvious adhesion (brown) was seen. (Wastewater indwelling time) Wastewater indwelling time in diffusion unit 1 to 3 is calculated using the following formula. The wastewater indwelling time in the diffusion sections 1 to 3 is shown in Table 1-2. Wastewater indwelling time (seconds) = layer length of the diffuser (mm) ÷ wastewater flow rate (mm / second)

[Examples 2 to 7] In Examples 2 to 7, in the reaction tower of Example 1, the distance H1 between the perforated plate 15-1 and the single-well plate 15-2 with the collision plate and the self-perforated plate 15 were used. -1 The reaction tower whose distance H2 from the inlet of the lower filling layer 16 was changed to the value shown in Table 1-1 was subjected to the above-mentioned wastewater treatment test. The treatment rate after 1000 hours and the adhesion state of scale components on the catalyst are shown in Table 1, and the wastewater indwelling time is shown in Table 1-2.

[Examples 8 to 9] In Examples 8 to 9, in the reaction tower of Example 4, a reaction tower whose value of H1 was changed to a value shown in Table 2-1 was used to perform the above-mentioned wastewater treatment test. The treatment rate after 1000 hours and the adhesion state of scale components on the catalyst are shown in Table 2-1, and the wastewater indwelling time is shown in Table 2-2.

[Comparative Example 1] In Comparative Example 1, in the reaction tower of Example 1, the above-mentioned wastewater treatment test was performed using a reaction tower whose value of H1 was changed to 1200 mm. The treatment rate after 1000 hours and the adhesion state of scale components on the catalyst are shown in Table 3-1, and the wastewater indwelling time is shown in Table 3-2.

[Comparative Example 2] In Comparative Example 2, in the reaction tower of Example 1, the above-mentioned wastewater treatment test was performed using a reaction tower whose values of H1 and H2 were changed to the values shown in Table 3-1. The treatment rate after 1000 hours and the adhesion state of scale components on the catalyst are shown in Table 3-1, and the wastewater indwelling time is shown in Table 3-2.

[Comparative Example 3] In Comparative Example 3, in the reaction tower of Example 1, the above-mentioned wastewater was carried out by using a reaction tower in which the values of H1 and H2 were changed to the values shown in Table 3-1 without filling the lower filling layer 16 Processing test. The treatment rate after 1000 hours and the adhesion state of scale components on the catalyst are shown in Table 3-1, and the wastewater indwelling time is shown in Table 3-2.

[Table 1-1] ※ COD (Cr) treatment rate after 1000 hours [Table 1-2]

[table 2-1] ※ COD (Cr) treatment rate after 1000 hours [Table 2-2]

[Table 3-1] ※ COD (Cr) treatment rate after 1000 hours [Table 3-2]

As shown in Tables 1-1 and 2-1, it can be seen that in Examples 1 to 9, by setting H6 and H6 / H1 within a predetermined range, scale formation in the catalyst can be suppressed, and the contact can be highly maintained. Media processing performance. On the other hand, as shown in Table 3-1, in Comparative Examples 1 to 3, it can be seen that the values of H6 / H1 or H6 are not within the scope of the present invention, scale components are significantly attached to the catalyst, and the catalyst performance is reduced. . In addition, as shown in Tables 1-2 and 2-2, it can be seen that in Examples 1 to 9, (1) the wastewater indwelling time in the diffusion sections 1 to 3, (1) the wastewater in the diffusion sections 3 and 2, and The total indwell time and (3) the total of the above (2) the total indwelling time of waste water with respect to the indwelling time of waste water in the diffusion section 1 are within a predetermined range, which can inhibit the scale formation in the catalyst from being analyzed, and can be highly maintained Catalyst processing performance. On the other hand, as shown in Table 3-2, in Comparative Examples 1 to 3, none of the above (1) to (3) was satisfied, scale components were obviously attached to the catalyst, and the catalyst performance reduce.

[Example 10-14] In Example 10-14, in the reaction tower of Example 4, the aperture ratio of the porous plate provided as the dispersion plate 15-1 and the number of holes per 1 m ² of the porous plate were changed to The reaction tower having the values shown in Table 4 was subjected to the above-mentioned wastewater treatment test.

The porosity of the perforated plate is a value calculated from the following formula.

Opening rate [%] = cross-sectional area of the entire hole / cross-sectional area of the entire dispersion plate × 100

The results are shown in Table 4.

[Table 4] ※ COD (Cr) treatment rate after 1000 hours

As shown in Table 4, it can be seen that the processing performance of the catalyst and the precipitation of scale components in the catalyst can be controlled by the opening rate of the porous plate and the number of holes per 1 m ² .

[Examples 15-1 to 15-4] The details of the reaction towers of Examples 15-1 to 15-4 are shown in Figs. 3-1 to 3-4. The values of H1 to H6 are shown in Table 5-1, and are the same values as the reaction tower of Example 4. For the dispersion plates 15-1 to 15-4, the above-mentioned wastewater treatment test was performed using a reaction tower modified as described below. The results are shown in Tables 5-1 and 5-2.

Figure 3-1 (Example 15-1): Dispersion plate 15-1 is configured as a single-well plate with collision plate, and dispersion plate 15-2 is configured as a perforated plate Figure 3-2 (Example 15-2) ): Device for making perforated plates 15-1 and 15-2 into a perforated plate Fig. 3-3 (Example 15-3): Device for making perforated plates with a collision plate for a diffuser 15-1 and 15-2. Figure -4 (Example 15-4): A device in which a single-well plate (15-4) with a collision plate and a porous plate (15-3) are additionally arranged. The distance between the dispersion plate 15-3 and the dispersion plate 15-4 is 150 mm, and the distance between the dispersion plate 15-2 and the dispersion plate 15-3 is 300 mm.

[Comparative Example 4] 反应 The reaction of Comparative Example 4 is an apparatus in which only one perforated plate is arranged as a dispersion plate, as shown in Figs. 3-5. The values of H2 to H6 are shown in Table 5-1, and are the same values as the reaction tower of Example 4. Using this reaction tower, the above-mentioned wastewater treatment test was performed. The results are shown in Tables 5-1 and 5-2.

[Table 5-1] ※ COD (Cr) treatment rate after 1000 hours [Table 5-2]

As shown in Tables 5-1 and 5-2, with respect to the flow of wastewater in the lower filling layer, by setting two dispersion plates on the upstream side (wastewater supply side), the scale formation in the catalyst can be suppressed. Thereby, the processing performance of the catalyst can be highly maintained. Furthermore, in Example 4, a perforated plate (dispersion plate 15-2) was provided as the dispersion plate 2, and a single-well plate (dispersion plate 15-1) with a collision plate was provided as the dispersion plate 1, compared with Example 15 -1 ～ 15-3, can inhibit the formation of scale in the catalyst, so that the catalyst's processing performance can be highly maintained. Furthermore, when Example 4 is compared with Example 15-4, it can be seen that the effect of the present invention can be improved by adding the dispersion plate.

[Example 16] 16 In Example 16, in the reaction tower of Example 4, a reaction tower whose value of H3 was changed to 200 mm was used to perform the above-mentioned wastewater treatment test. The results are shown in Tables 6-1 and 6-2.

[Example 17] The details of the reaction tower of Example 17 are shown in FIG. 4. On the lower filling layer 16 (H3: 170mm; filling layer 1), a spherical SUS ball with a diameter of 8.0mm is filled with 30mm (H7) in the height direction as a second filling layer 19 (filling layer 2 ). The SUS ball had a specific gravity of about 8.2, and the porosity of the second filler layer 19 was 41%. Using this reaction tower, the above-mentioned wastewater treatment test was performed. The results are shown in Tables 6-1 and 6-2.

[Examples 18 to 20] In Examples 18 to 20, in the reaction tower of Example 17, a reaction tower in which the value of H7 was changed to a value shown in Table 6-1 was used to perform the above-mentioned wastewater treatment test. The results are shown in Tables 6-1 and 6-2.

[Example 21] (1) In Example 21, in the second filling layer 19 (filling layer 2) of the reaction tower of Example 18, a zirconium ball with a diameter of 7.5 mm was used to fill 100 mm (H7) in the height direction. ) To replace the SUS ball reaction tower, the above wastewater treatment test was performed. The specific gravity of the zirconium ball was about 5.3, and the porosity of the second filler layer 19 (filler layer 2) was 41%. The results are shown in Tables 6-1 and 6-2.

[Table 6-1] ※ COD (Cr) treatment rate after 1000 hours [Table 6-2]

As shown in Tables 6-1 and 6-2, it can be seen that the two-layer structure of the lower filler layer (diffusion section 3) can maintain the catalyst processing performance to a higher degree. Furthermore, in Example 21, compared to Example 18, by using a ceramic filler in the second filler layer 19, it is considered that the catalyst processing performance can be maintained more highly, and the precipitation of scale components in the catalyst can be further suppressed. .

1‧‧‧ reaction tower

2‧‧‧ heat exchanger

3‧‧‧ wastewater supply pump

4‧‧‧compressor

5‧‧‧Gas-liquid separator

6‧‧‧ level control valve

7‧‧‧Pressure Control Valve

8‧‧‧ heating means (heater or heat medium)

9‧‧‧ cooler

10‧‧‧ wastewater supply pipeline

11‧‧‧Oxygen-containing gas supply line

12‧‧‧ treatment liquid pipeline

13‧‧‧Gas exhaust line

14‧‧‧ treatment liquid discharge line

15‧‧‧dispersion plate

16‧‧‧ lower filling layer

17‧‧‧ catalyst layer

18‧‧‧ Upper filling layer

19‧‧‧ 2nd filling layer

FIG. 1 is a schematic diagram showing a wastewater treatment method according to an embodiment of the present invention. (2) FIG. 2 is a schematic diagram showing a wastewater treatment device used in Examples and Comparative Examples. FIG. 3-1 is a schematic diagram showing a wastewater treatment apparatus used in the embodiment. Figure 3-2 is a schematic view showing a wastewater treatment device used in the embodiment. Figures 3-3 are schematic views showing a wastewater treatment device used in the examples. Figures 3-4 are schematic views showing a wastewater treatment device used in the embodiment. Figures 3-5 are schematic diagrams showing a wastewater treatment apparatus used in a comparative example. FIG. 4 is a schematic diagram showing a wastewater treatment device used in the embodiment. Fig. 5 is a schematic diagram showing an example of the dispersion plate of the present invention.

Claims (11)

A treatment device is a wastewater treatment device having a dispersion plate 2, a dispersion plate 1, a filling layer, and a catalyst layer in this order from a wastewater supply side. When the distance between the dispersion plate 2 and the dispersion plate 1 is H1, the dispersion plate 1 When the distance between the interface with the waste water supply side of the filling layer is H2, when the layer length of the filling layer is H3, and when the total of the H2 and the H3 is H6, the H6 exceeds 100 mm, and the H6 and the above The H1 ratio (H6 / H1) is 0.1 or more (inclusive) and 100 or less (inclusive). For example, the processing device of claim 1, wherein the H1 is more than 10mm (including 10mm) and less than 1000mm (including 1000mm). The processing apparatus 1 or 2 of the requested item, wherein said dispersion plate 1 and said dispersion plate 2 is at least one of a perforated plate, holes of the porous plate of the coefficient ² per 1m 5 or more (including 5) below 200 (Including 200). The processing device according to any one of claims 1 to 3, wherein the filler layer has a two-layer structure. For example, in the processing device of claim 4, in the above-mentioned two-layered filling layer, when the filling layer on the wastewater supply side is the filling layer 1 and the filling layer on the catalyst layer side is the filling layer 2, The layer length of the filler layer 2 is 30 mm or more (including 30 mm) and 500 mm or less (including 500 mm). For example, the processing device of claim 4 or 5, wherein among the filling layers of the two-layer structure described above, when the filling layer on the wastewater supply side is filling layer 1 and the filling layer on the catalyst layer side is filling layer 2 The average particle diameter d1 of the filler 1 contained in the filler layer 1 and the average particle diameter d2 of the filler 2 contained in the filler layer 2 and the average particle diameter d0 of the catalyst contained in the catalyst layer satisfy The relationship of d1> d2> d0. The processing device according to any one of claims 1 to 6, wherein the catalyst contained in the catalyst layer is a wet oxidation catalyst. A wastewater treatment method is a wastewater treatment method using a device having at least a gas-liquid diffusion portion 1, a gas-liquid diffusion portion 2, a gas-liquid diffusion portion 3, and a catalyst layer in order from a wastewater supply side. It has a gas dispersion and satisfies the following (1) to (3):) (1) The above-mentioned wastewater indwell time in the gas-liquid diffusion sections 1 to 3 are all 0.5 seconds or more (including 0.5 seconds); (2) the above The total waste water indwell time in the gas-liquid diffusion unit 3 and the gas-liquid diffusion unit 2 is 5 seconds or more (inclusive); and (3) compared to the waste water indwell time in the gas-liquid diffusion unit 1, The total waste water indwelling time of (2) above is 0.1 to 100 times. The processing method according to claim 8, wherein the gas-liquid diffusion part is a filling layer having a porosity of 20 to 90% by volume. The processing method according to claim 8 or 9, wherein the gas-liquid diffusion unit 1 has a dispersion plate 1 at the interface of the wastewater supply side, and the gas-liquid diffusion unit 2 has the interface with the gas-liquid diffusion unit 1 In the dispersion plate 2, the dispersion plate 1 and the dispersion plate 2 each have one or more (including one) holes, and at least one of the dispersion plate 1 and the dispersion plate 2 has an opening ratio of 0.005% to 30%. The perforated plate structure. The processing method of any one of claims 8 to 10, further satisfying the following (i) to (iv): (i) the LHSV in the catalyst layer is 0.1hr ^-1 to 10hr ^-1 ; (ii) The temperature of the wastewater in the catalyst layer is 80 ° C to 370 ° C; (iii) the pressure in the catalyst layer is the pressure at which at least a part of the wastewater maintains the liquid phase; and (iv) the amount of oxygen contained in the gas is in the wastewater The theoretical oxygen demand of the oxide is 0.5 to 5.0 times.