TWI738985B - Apparatus and method for wastewater treatment - Google Patents

Abstract

The subject of the present invention is to provide a waste water treatment device that can prevent the precipitation of scale components on the surface of the catalyst, and thereby can maintain the treatment performance of the catalyst to a high degree. 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 sequence from the waste water supply side. When the distance between the dispersion plate 2 and the dispersion plate 1 is H1, the dispersion plate 1 and When the distance between the interface on the waste water supply side of the filling layer is H2, the layer length of the filling layer is H3, and the sum of the above H2 and the above H3 is H6, the above H6 exceeds 100mm, and relative to the above H1, the above The ratio of H6 (H6/H1) is 0.1 or more (including 0.1) and 100 or less (including 100).

Description

Waste water treatment device and waste water treatment method

The invention relates to a waste water treatment device and waste water treatment method.

Wastewater discharged from various industrial plants such as chemical factories, food processing equipment, metal processing equipment, metal plating equipment, printing and plate making equipment, photographic processing equipment, etc., can be treated by wet oxidation, wet decomposition, and ozone oxidation. Purification treatment is carried out by various methods such as hydrogen peroxide method.

For example, in the wet oxidation method in which the solid catalyst is filled in the reaction tower, the wastewater and oxygen-containing gas are usually introduced from the lower part of the solid catalyst packing layer (catalyst layer) to purify the wastewater. Therefore, due to 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, and the loss of the solid catalyst or the water-containing scale component in the wastewater (Heavy metals such as copper and iron, calcium, aluminum, etc.) are deposited on the surface of the catalyst, so it is unavoidable to cause problems such as a reduction in the handling performance of the catalyst.

Patent Document 1 discloses a waste water treatment device, which relates to the loss of solid catalyst caused by waste water introduced from the lower part of the reaction tower. Layer), in addition to preventing the loss of solid catalysts, the waste water can also be uniformly It is supplied to the catalyst layer, so the reduction in the processing efficiency of the catalyst can be suppressed.

Patent Document 2 discloses that by disposing a catalyst-free wet oxidation reaction layer before the solid catalyst layer, the treatment efficiency in the solid catalyst layer is improved. Furthermore, Patent Document 3 discloses that the treatment efficiency is improved by providing a gas-liquid dispersion member on the upper portion of the solid catalyst layer.

(Prior technical literature) (Patent Document)

[Patent Document 1] Japanese Patent No. 5330751

[Patent Document 2] Japanese Patent Application Publication No. 2001-276855

[Patent Document 3] JP 2004-098023 A

Indeed, Patent Document 1 shows that by providing a lower filling layer, the loss of the catalyst can be prevented and the reduction in the treatment efficiency of the catalyst can be suppressed.

However, in the wastewater treatment device disclosed in Patent Document 1, when the wastewater contains scale components (heavy metals such as copper and iron, calcium, aluminum, etc.), the scale components reach the catalyst layer in an ionic state and deposit on the surface of the catalyst. , There will be a problem of hindering the activity of the catalyst.

On the other hand, in Patent Document 2, although the durability of the solid catalyst layer is improved by the installation of the catalyst-free wet oxidation reaction layer, the wastewater treatment capacity is insufficient, and the first treatment step and the second treatment step are required. The reaction tower, and these need to be further controlled, so it is not conducive to the cost.

On the other hand, in Patent Document 3, although the treatment efficiency of the solid catalyst layer is improved by the provision of a gas-liquid dispersion member, it is the same as the invention described in Patent Document 1, but has insufficient durability due to scale components.

Therefore, the object of the present invention is to provide a method that can prevent the scale components from reaching the catalyst layer in an ionic state, that is, prevent the precipitation of scale components on the surface of the catalyst, and can maintain the processing performance of the catalyst at a high level, and then can be constructed simply Provide low-cost wastewater treatment equipment and wastewater treatment methods.

In order to solve the above-mentioned problems, the inventors devoted themselves to the review. First, regarding the combination of the technology disclosed in Patent Document 1 and the technology disclosed in Patent Document 2, specifically, the combination of the lower part of the reaction tower of Patent Document 1 and the catalyst-free wet oxidation reaction layer of Patent Document 2 However, it is not possible to obtain sufficient results. Therefore, considering whether the gas-liquid dispersibility is poor, referring to Patent Document 3, a dispersion plate is provided in the catalyst-free wet oxidation reaction layer, but a sufficient effect is still not obtained. Furthermore, as a result of various reviews of the dispersing plate arrangement, it was found that having at least 2 dispersing plates and setting the arrangement in a specific range can solve the above-mentioned problems, and thus the present invention is 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 from the waste water supply side in this order, when the dispersing plate 2 and The distance between the dispersion plate 1 is H1, the distance 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 and the upper When the total of the 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).

The second aspect of the present invention relates to a treatment method, which uses a device having at least a gas-liquid diffuser 1, a gas-liquid diffuser 2, a gas-liquid diffuser 3, and a catalyst layer in sequence from the waste water supply side In the wastewater treatment method, the above-mentioned wastewater has gas dispersion and meets the following (1)~(3): (1) The above-mentioned wastewater retention time in the above-mentioned gas-liquid diffusion part 1~3 is 0.5 seconds or more (including 0.5 seconds); (2) The total of the waste water retention time in the gas-liquid diffusion portion 3 and the gas-liquid diffusion portion 2 is 5 seconds or more (including 5 seconds); and (3) relative to the gas-liquid diffusion The wastewater retention time in Part 1, the total of the wastewater retention time in (2) above is 0.1 to 100 times.

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

1: reaction tower

2: heat exchanger

3: Wastewater supply pump

4: Compressor

5: Gas-liquid separator

6: Liquid level control valve

7: Pressure control valve

8: Heating means (heater or heating medium)

9: Cooler

10: Wastewater supply pipeline

11: Oxygen-containing gas supply line

12: Treatment liquid pipeline

13: Gas discharge line

14: Treatment liquid discharge pipeline

15: Dispersion plate

16: Lower filling layer

17: Catalyst layer

18: Upper filling layer

19: The second filling layer

Figure 1 is a schematic diagram showing a waste water treatment method in one embodiment of the present invention.

Figure 2 is a schematic diagram showing the wastewater treatment equipment used in the Examples and Comparative Examples.

Figure 3-1 shows the outline of the wastewater treatment equipment used in the examples picture.

Figure 3-2 is a schematic diagram showing the wastewater treatment equipment used in the examples.

Figure 3-3 is a schematic diagram showing the wastewater treatment equipment used in the examples.

Figures 3-4 are schematic diagrams showing the wastewater treatment equipment used in the examples.

Figures 3-5 are schematic diagrams showing the wastewater treatment equipment used in the comparative example.

Fig. 4 is a schematic diagram showing the wastewater treatment equipment used in the examples.

Fig. 5 is a schematic diagram showing an example of the dispersion plate of the present invention.

(The 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.

<Type 1: Wastewater treatment plant>

According to one aspect of the present invention, a treatment device is provided, which is a wastewater treatment device having a dispersing plate 2, a dispersing plate 1, a filling layer, and a catalyst layer in sequence from the waste water supply side, when the dispersing plate 2 and the dispersing plate When the distance of 1 is H1, the distance of 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 sum of the above H2 and the above H3 is H6, the above H6 exceeds 100mm, and the ratio of the above H6 to the above 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 dispersion plate 1 and the wastewater supply side of the filling layer is H2, the layer length of the filling layer is H3, and the contact The layer length of the media layer is H4 (unit: mm). When a filling layer is also arranged on the waste water discharge side of the catalyst layer, the layer length of the filling layer is H5. Moreover, 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 of the dispersion plate 2 on the waste water discharge side to the surface of the dispersion plate 1 on the waste water supply side.

In the dispersion plate, the surface systems on the waste water supply side and the discharge side are defined as follows. The wastewater treatment device is installed perpendicular to the ground. When the wastewater is supplied from the lower part of the wastewater treatment device and discharged from the upper part of the wastewater treatment device, the waste water discharge side surface (upper surface) of the dispersion plate and the waste water supply side surface (lower surface) , Is the plane based on the middle position of the highest part and the lowest part among all the faces. 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 Figure 2 has a collision plate, the middle position between the highest part and the lowest part other than the collision plate is used as the 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 waste water supply side and the waste water 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 surface of the dispersion plate 1 on the waste water discharge side to the interface between the waste water supply side of the filling layer.

The interface between the wastewater supply side and the discharge side of the filling layer is defined as follows. Since the filling material layer is filled with filling material, the surface exposed to the waste water supply side and the discharge side may not be completely flat. Wastewater treatment equipment When the installation is perpendicular to the ground, 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 middle position between the lowest part and the highest part of the filling exposed on the upper or lower surface of the material layer is the reference surface. This system is the same even when the exposed surface of the filling layer is inclined. Generally, the interface on the waste water discharge side and the interface 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 interface on the waste water discharge side and the interface on the waste water supply side are parallel.

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

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

The catalyst layer is filled with a catalyst (for example, solid catalyst). The definition of the interface between the wastewater supply side 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, by having the above-mentioned structure, can prevent the precipitation of scale components on the surface of the catalyst. Thereby, the processing performance of the catalyst can be maintained at a high level.

Historically, it has been known that multiple dispersing plates can effectively improve the gas-liquid mixing efficiency. However, in the case of wastewater containing scale components (heavy metals such as copper and iron, and calcium, aluminum, etc.), a high degree of dispersion technology is further required. As the characteristic system of the scale component, for example, by wet oxidation In the treatment of wastewater, before heating, the scale components dissolved in the form of ions are heated and pressurized in the presence of oxygen to partially analyze solids such as oxides or hydroxides. Therefore, depending on the conditions, the scale components dissolved in the wastewater may reach the catalyst layer in an ionic state, and precipitate on the surface of the catalyst, which may hinder the activity of the catalyst. Therefore, in the present invention, by setting the ratio of H6 to H1 (H6/H1) in an appropriate range, and setting H6 to 100mm or more (including 100mm), it is possible to precipitate solid scale components before reaching the catalyst layer. , Can prevent the precipitation of scale components on the surface of the catalyst in advance.

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

In the wastewater treatment device of the present invention, H6 exceeds 100mm. When H6 is below 100mm (including 100mm), the scale components will not be uniformly dispersed, and the scale components will reach the catalyst layer in an ionic state, so there is a concern that the surface of the catalyst layer will be poisoned by the scale components. From the viewpoint of further suppressing the precipitation of scale components in the catalyst, H6 is preferably more than 150mm, more preferably more than 250mm. 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 reduction in gas-liquid contact efficiency due to the re-aggregation of fine air bubbles through the mixing of the dispersion plate can be suppressed.

In the wastewater treatment device 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). H6/H1 not reached When 0.1 or more than 100, between the dispersing plate 2 and the dispersing plate 1, an unbalanced flow of scale components will occur due to the insufficient gas-liquid mixing effect, which will cause the scale components to accumulate locally and reduce the treatment efficiency. H6/H1 is preferably 0.2 or more (including 0.2), more preferably 0.3 or more (including 0.3). H6/H1 is preferably less than 80 (including 80), and more preferably less than 50 (including 50). Within these ranges, the above-mentioned effects can be further exerted.

There is no particular limitation as long as H1 satisfies the above-mentioned ratio (H6/H1). For example, it is 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). Moreover, H1 is 1000 mm or less (including 1000 mm), preferably 900 mm or less (including 900 mm), and more preferably 750 mm or less (including 750 mm). Since H1 of 10mm or more (including 10mm) and 1000mm or less (including 1000mm) will fully carry out the gas-liquid dispersion and mixing, the reduction of catalyst treatment efficiency can be suppressed, and the scale component 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 satisfies the aforementioned H6 and H6/H1, and can be the size of a reaction tower or a reaction vessel 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 vessel generally used in wastewater treatment. For reaction towers or reaction vessels, cylindrical ones with a diameter of 200~3000mm and a length of 1000~20000mm can be used.

The wastewater treatment device of the present invention can apply various methods of wastewater treatment. In terms of wastewater treatment methods, for example, wet oxidation method, wet decomposition method, ozone oxidation method, hydrogen peroxide oxidation method, etc. can be cited. In terms of waste water treatment methods, high-level treated water quality can be obtained, which has excellent From an economic point of view, the wet oxidation method is preferred. Therefore, one embodiment of the present invention provides a wastewater treatment device used in wastewater treatment by a wet oxidation method.

[Wastewater]

There is no particular limitation on the type of waste water treated by the waste water treatment device of the present invention. If it is the wastewater treatment device of the present invention, it can effectively treat wastewater containing any one or more of organic compounds, nitrogen compounds, and sulfur compounds.

The above-mentioned organic compounds can be exemplified: epoxy compounds such as ethylene oxide and propylene oxide; alcohol compounds such as methanol, ethanol, and ethylene glycol;-acrylic acid, methacrylic acid, terephthalic acid, etc., and these The esters of carboxylic acids and/or their derivatives, etc. The above-mentioned nitrogen compounds can be exemplified by organic nitrogen compounds such as amines and imines; inorganic nitrogen compounds having nitrogen-hydrogen bonds such as ammonia and hydrazine. Examples of the above-mentioned sulfur compounds include inorganic sulfur compounds such as hydrogen sulfide, sodium sulfide, potassium sulfide, sodium hydrosulfide, thiosulfate, and sulfite, and organic sulfur compounds such as mercaptans and sulfonic acids. Moreover, it is not limited to waste water containing only the above-mentioned compounds, and may contain organic halogen compounds such as dioxane, dioxin, chlorofluoroalkane, diethylhexyl phthalate, nonylphenol, and environmental hormone compounds, etc. Of harmful substances.

Examples of wastewater containing such compounds include: wastewater discharged from various industrial plants such as chemical factories, electronic parts manufacturing equipment, food processing equipment, metal processing equipment, metal plating equipment, printing plate making equipment, photographic equipment, etc.; 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 its ester production equipment, aromatic carboxylic acid or aromatic carboxylic acid ester production equipment, paper/pulp, fiber Wastewater discharged from factories in various industrial fields such as iron and steel, ethylene/BXT, coal gasification, edible meat processing, and pharmaceutical processing.

Moreover, it is not limited to industrial waste water, but also exemplifies domestic waste water such as sewage and excrement.

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

(Scale ingredient)

Furthermore, 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 the wastewater (heavy metals such as copper and iron, calcium, aluminum, etc.) contains scale components, the scale components reach the catalyst layer in an ionic state and precipitate the catalyst. On the surface of the catalyst, there may be situations that hinder the activity of the catalyst. 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 maintained at a high level.

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

The concentration of the scale component contained in the waste water is not particularly limited. The wastewater treatment device of the present invention is different from the conventional ones, and can exhibit an effect in wastewater treatment containing a scale component of 0.1 mg/L or more (including 0.1 mg/L). The concentration of the scale component 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 effect of the present invention can be fully exerted.

[Dispersion board]

The wastewater treatment device of the present invention has a dispersing plate 2, a dispersing plate 1, a filling layer, and a catalyst layer in order from the waste water supply side. That is, the wastewater treatment device of the present invention has at least two dispersion plates. As for the dispersion plate, the single-well plate, single-well plate with collision plate, perforated plate or perforated plate with collision plate as illustrated in Figure 5 can be used. Regarding the dispersion plate, the same type of dispersion plate can be configured, or different dispersion plates can be configured. In the wastewater treatment device of the present invention, when the dispersing plate 2 and the dispersing plate 1 are arranged at a predetermined distance (H1), the present invention can be realized. Furthermore, if necessary, an additional dispersing plate may be arranged closer to the waste water supply side (upstream side) than the dispersing plate 2. In addition, the dispersion plate can be composed of one plate, but from the viewpoint of the workability of installation and removal, it is preferably composed of a shape that can be divided into two or more (including two).

The open porosity of single-well plates and multi-well plates (including those with collision plates) is generally above 0.005% (including 0.005%) and below 30% (including 30%). The above-mentioned open 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 more than 1% (including 1%). ) Is particularly good. Moreover, the above-mentioned open porosity is preferably 10% or less (including 10%), and more preferably 5% or less (including 5%). By being in such a range Inside, the unbalanced flow caused by the stirring effect can be prevented, and the gas contained in the waste water can be evenly distributed. Therefore, the gas-liquid is improved and the processing performance of the catalyst can be improved.

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

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

The number of holes in the perforated plate (including those with collision plates) is generally 5 or more (including 5) and 200 or less (including 200) ^{per 1 m 2.} From the viewpoint of obtaining a sufficient dispersion effect, the number of holes per 1 m ² is preferably 10 or more (including 10), and more preferably ^{25 or more per 1 m 2} (including 25). 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.

There are no special restrictions on the shape of the hole, but cylindrical or conical ones are preferred because they are easy to manufacture. Moreover, 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, and in the case of a porous plate, it is preferable to arrange it as uniformly as possible.

Patterns for the preferred embodiment of the present invention, the dispersion plate 2 of the plate 1 and the dispersion of at least one of a perforated plate, the hole of the perforated plate ² 1M coefficients every 5 or more (including 5) 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 maintained at a higher level.

The distance H2 between the interface between the dispersion plate 1 and the waste water supply side of the filling layer, such as the sum of H2 and the layer length H3 of the following filling layer (H6) exceeds When it is 100mm, there is no particular limitation, but from the viewpoint of the dispersion effect of waste water, it is better to be 10mm or more (including 10mm).

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

[Filling layer]

The waste water treatment device of the present invention has a filling layer on the waste water discharge side of the dispersion plate 1. With such a structure, the loss of the catalyst can be prevented, and the waste water will not flow unbalanced, and it can flow evenly in the catalyst layer as much as possible. Moreover, it can prevent the precipitation of scale components on the surface of the catalyst.

The filler layer is filled with a metal or ceramic filler. The filler system includes at least one selected from the group consisting of iron, copper, stainless steel (SUS), Hester alloy, Inconel, titanium, zirconium, titanium oxide, zirconium oxide, silicon nitride, or carbon nitride . The filler may be one type alone, two or more types (including two types), or an alloy. When treating waste water by wet oxidation method, the filling material is preferably stainless steel (SUS), zirconium, Hester alloy, Inconel or titanium from the viewpoint of abrasion resistance, corrosion resistance and strength. It is better to use stainless steel (SUS) or zirconia.

The shape of the filling is not particularly limited, and examples include pellets, spheres, blocks, rings, saddles, polyhedrons, etc. Shape; fiber-like, chain-like, bead-like and other continuum shapes. From the viewpoint that it can be easily filled in the reaction tower, the shape of the filler is preferably granular, and more preferably pellets, spheres or rings.

The size of the filling material is not particularly limited as long as the above-mentioned effects can be obtained. For example, in the case of a granular filling, the average particle size 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). Moreover, the average particle size 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 this specification, the average particle size of the granular filler and the solid catalyst described later is the arithmetic average of the particle size. Moreover, the particle size refers to the largest diameter of the filler or solid catalyst. For example, the particle size of a spherical filler or solid catalyst is the diameter, and the particle size of a pelletized filler or solid catalyst refers to the length of its diagonal.

The average particle size d1 of the filler and the average particle size d0 of the catalyst contained in the following catalyst layer are preferably d1>d2 from the viewpoint of the dispersion effect of waste water.

The specific gravity of the filling (meaning the true specific gravity, which is different from the volume specific gravity, filling specific gravity, and apparent specific gravity used in general) is not particularly limited, and can be selected appropriately. In terms of specific gravity, it is generally 2.5 or more (including 2.5), preferably 4~12.

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

The filling material filled by the filling material layer does not need to have the same If the material, shape, size, specific gravity, etc. can exhibit the effects of the present invention, two or more types (including two types) of fillers can be used. Moreover, according to the usage type and usage conditions, a suitable filling material can be appropriately selected.

The filling generally adopts a method in which metal meshes, grids, etc., alone or in combination, are set in the reaction tower and filled on the support base.

The layer length (H3) of the filling layer is not particularly limited if the sum of H2 (H6) exceeds 100mm. Generally, it is 10mm or more (including 10mm). From the viewpoint of preventing the scale component from directly accumulating in the catalyst layer , Preferably 50mm or more (including 50mm), more preferably 80mm or more (including 80mm), and more preferably 100mm or more (including 100mm). The upper limit of H3 is not particularly limited, but 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, from the viewpoint of further improving the dispersion effect of waste water, the filling layer has a two-layer structure. That is, the wastewater treatment device of the present invention preferably further has a filler layer between the filler layer and the catalyst layer. Since the filling layer has a two-layer structure, the processing performance of the catalyst can be further maintained at a high level.

When the filling layer on the supply side of wastewater is filling layer 1, when the filling layer on the catalyst layer side is filling layer 2, the average particle size d1 of the filling contained in filling layer 1 and the filling layer 2 contain The relationship between the average particle size d2 of the filler can be d1>d2, or d1<d2. For d1 and d2, from the viewpoint of the dispersion effect of waste water, d1>d2 is better. If d1>d2, the ratio of d2 to d1 (d2/d1) is preferably 0.2 or more (including 0.2), and 0.3 or more (including 0.3) More preferably, it is more preferably 0.4 or more (including 0.4). Moreover, 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 size d1 of the filler 1 contained in the filler layer 1 and the average particle size d2 of the filler 2 contained in the filler layer 2 and the following catalyst layer The average particle size d2 of the catalyst satisfies the relationship of d1>d2>d0. From the wastewater supply side to the filling layer 1, the filling layer 2 and the catalyst layer, the average particle size of the filling 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. Moreover, 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). Moreover, d0/d2 is preferably less than 1.00, and more preferably less than 0.95.

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

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

From the viewpoint of the dispersion effect of waste water, 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) . Moreover, the H7 series is preferably 500mm or less (including 500mm), more preferably 400mm or less (including 400mm), and more preferably 300mm or less (including 300mm). 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 above-mentioned filling The layer length of layer 2 is 30 mm or more (including 30 mm) and 500 mm or less (including 500 mm).

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

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

[Catalyst layer]

The catalyst processing device of the present invention has a dispersing plate 2, a dispersing plate 1, a filling layer, and a catalyst layer in order from the discharge side of the waste water. The catalyst contained in the catalyst layer is a general solid catalyst. If the solid catalyst is used in general wastewater treatment, it can be used without any special restrictions. As for the solid catalyst, for example, at least one metal selected from 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, zirconium oxide, iron oxide, titanium-zirconium composite oxide, and titanium-iron composite oxide are suitable.

The solid catalyst system may contain other components (second component) in addition to the above-mentioned components (first component). For solid catalysts containing two components, examples include: containing selected from iron, titanium, silicon, aluminum, zirconium and cerium At least one metal; oxides or composite oxides of these, or activated carbon (the first component), and selected from manganese, cobalt, nickel, tungsten, copper, silver, platinum, palladium, rhodium, gold, indium, ruthenium At least one metal in the metal; or a catalyst of these metal compounds (the second component). A preferred solid catalyst is that the first component is titanium oxide, zirconium oxide, iron oxide, titanium-zirconium composite oxide, or titanium-iron composite oxide; and the second component is platinum. Among the solid catalysts containing two components, it is preferable to contain 75 to 99.95% by weight of the first component and 0.05 to 25% by weight of the second component. In addition, the total of the first component and the second component is preferably 100% by weight. However, the third component such as a non-catalyst active carrier, inorganic catalyst, and binder component can be appropriately contained. At this time, the weight ratio of the first component and the second component is the weight of the first component and the second component The weight is determined without considering the third component.

The above-mentioned solid catalyst is suitable for the oxidation treatment using the wet oxidation method. From the viewpoint of high-grade treated water quality and economic efficiency, the wastewater treatment device of the present invention is suitable for 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 if it is a shape commonly used in wastewater treatment. The shape of the solid catalyst can include pellets, spheres, rings, etc.; honeycombs, etc.

The size of the solid catalyst is not particularly limited as long as the above-mentioned effects can be obtained. For example, in the case of a granular solid catalyst, the average particle size is, for example, 1~30mm, preferably 1.5~20mm, and more preferably 2~15mm. Moreover, from the viewpoint of the dispersion effect of waste water, the average particle size of the solid catalyst is the average of the filler contained in the filler layer closer to the waste water supply side than the catalyst layer The smaller particle size is better.

The solid catalyst system may be used singly or in combination of two or more types (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 0.1hr ^-1 ~10hr ^-1 , preferably 0.2hr ^-1 ~5hr ^-1, preferably 0.3hr ^-1 ~3hr ^-1 . When the space velocity is above 0.1hr ^-1 (including 0.1hr ^-1 ), the filling amount of the catalyst can be ensured and the expansion of equipment can be avoided. Moreover, when the space velocity is 10hr ^-1 or less (including 10hr ^-1 ), the oxidation/decomposition treatment of wastewater in the reaction tower can be sufficiently performed.

<Type 2: Wastewater treatment method>

According to another aspect of the present invention, a waste water treatment method is provided, which uses at least a gas-liquid diffuser 1, a gas-liquid diffuser 2, a gas-liquid diffuser 3, and a catalyst in order from the waste water supply side The wastewater treatment method of the device of the layer, the above-mentioned wastewater has gas dispersion, and meets the following (1)~(3): (1) The above-mentioned wastewater retention time in the above-mentioned gas-liquid diffusion section 1~3 is 0.5 seconds Above (including 0.5 seconds); (2) the total of the waste water retention time in the gas-liquid diffuser 3 and the gas-liquid diffuser 2 is 5 seconds or more (including 5 seconds); and (3) relative to the gas -The waste water retention time in the liquid diffuser 1, the total of the waste water retention time in (2) above is 0.1 to 100 times.

In this type of device, the catalyst layer is the same as the above-mentioned wastewater treatment device (No. 1 The catalyst layer of the type) is the same, so the description is omitted.

This type of device has gas-liquid diffusers 1 to 3 as a means for uniformly dispersing scale components and gas (especially oxygen).

The gas-liquid diffuser 1 (also referred to as "diffuser 1" in this specification) is from the waste water supply side, the space between the gas-liquid dispersion and the gas-liquid dispersion, or the dispersion plate and the filling layer The space between the sides of the waste water supply side; or the filling layer. The diffuser 1 corresponds to, for example, the range shown by H1 in FIG. 2.

The gas-liquid diffuser 2 (also referred to as the "diffuser 2" in this specification) is from the waste water supply side, the space between the gas-liquid dispersion and the gas-liquid dispersion, 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 diffuser 2 corresponds to, for example, the range indicated by H2 in FIG. 2.

The gas-liquid diffuser 3 (also referred to as "diffuser 3" in this specification) is from the waste water supply side, the space between the gas-liquid dispersion and the surface of the catalyst layer on the waste water supply side or the filling layer The space between the waste water discharge side surface and the waste water supply side surface of the catalyst layer; or the filling layer. The diffuser 3 corresponds to, for example, the range indicated by H3 in FIG. 2. When the filler layer has a two-layer structure, the total of the two layers corresponds to the diffuser 3, which corresponds to, for example, the range indicated by H3+H7 in Figure 4.

In this type of processing method, at least one of the gas-liquid dispersion parts 1 to 3 is a filling layer. The filler layer may be one layer or two or more layers (including two layers). Moreover, the filling layer of this type of device is the same as the above-mentioned wastewater treatment device. The filling material layer of the device (the first type) is the same, so the description is omitted.

The gas-liquid dispersing part is a member that can uniformly distribute the gas contained in the waste water by preventing unbalanced flow due to the stirring effect, and an example of a dispersing plate can be cited. The dispersing plate of the device of this type is the same as the dispersing 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 waste water. This type of device improves the gas-liquid contact by having at least three gas-liquid diffusers, which can improve the processing performance of the catalyst.

In this type of treatment method, the retention time of wastewater in the gas-liquid diffusion section meets the conditions (1) to (3) above.

Hereinafter, (1) to (3) will be described.

(1) The retention time of wastewater in the gas-liquid diffuser 1~3 is all 0.5 seconds or more (including 0.5 seconds). When the wastewater retention time is less than 0.5 seconds, the gas-liquid mixing effect is insufficient, and the effect of the present invention cannot be exhibited. The wastewater retention time is preferably 2~300 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 (including 5 seconds). When the total retention time of the waste water is less than 5 seconds, the scale components are unevenly dispersed, and the scale components reach the catalyst layer in an ion state, and there is a concern that the surface of the catalyst layer will be poisoned by the scale components. The total lower limit of the above-mentioned wastewater retention time is preferably 10 seconds or more (including 10 seconds), more preferably 35 seconds or more (including 35 seconds), and more preferably 60 seconds or more (including 60 seconds). The upper limit of the total waste water retention time mentioned above is not particularly limited, but the total waste water retention time in the diffuser 2 and the diffuser 3 is preferably 2500 seconds or less (including 2500 seconds), preferably 1500 seconds or less (including 1500 seconds) Better, It is more preferably less than 750 (including 750 seconds), and more preferably less than 300 seconds (including 300 seconds).

(3) With respect to the wastewater retention time in the gas-liquid diffusion section 1, the total wastewater retention time in (2) above is 0.1 to 100 times. Compared with the wastewater retention time in the gas-liquid diffusion section 1, if the total wastewater retention time in (2) is less than 0.1 times or more than 100 times, the gas-liquid mixing effect is insufficient, and it is easy to cause unbalanced flow of scale components. , So it will locally accumulate scale components and reduce the treatment efficiency. With respect to the wastewater retention time in the gas-liquid diffusion section 1, the total wastewater retention time of (2) above is preferably 0.2 times or more (including 0.2 times), and 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 diffuser is a filling layer, and 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 filler layer is generally 20~90% by volume (based on the total volume of the filler layer), preferably 30~70% by volume, and more preferably 35-60% by volume. When the porosity is reduced, the degree of turbulence in the filling layer increases, and the same effect as extending the retention time of wastewater can be obtained. Moreover, even if the gas-liquid diffusion part is composed of two or more filling layers (including two layers), the waste water retention time in the gas-liquid diffusion part meets the above-mentioned conditions (1) to (3).

The waste water retention time in the gas-liquid diffuser can be appropriately controlled by the flow rate of the waste water supplied and the size of the device. In addition, the wastewater retention time can be calculated by the method described in the examples.

In a preferred embodiment, the diffusion portion 3 is a filler layer with a porosity of 20 to 90% by volume (based on the total volume of the filler layer). The above porosity system 30~70 volume% is preferred, 35~60 volume% is more preferred, and 35~55 volume% is particularly preferred. Furthermore, when the diffusion portion 3 is a filler layer, the better of the diffusion portion 2 and the diffusion portion 1 is not a type of a filler layer.

In a preferred embodiment, the diffuser 3 is a two-layered filling layer. Since the filling layer has a two-layer structure, the processing performance of the catalyst can be maintained at a high level.

The indwelling time of wastewater in the above-mentioned diffuser 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 seconds, the effects of the present invention cannot be sufficiently obtained. The upper limit of the waste water retention time is not particularly limited, but if the retention time is too long, the dispersibility of the gas and liquid of the waste water reaching the catalyst layer is reduced, and when the diffuser 3 is a filling layer, the pressure loss increases and energy is generated Loss, its effect has not improved. Therefore, the wastewater retention time in the diffuser 3 is preferably 1800 seconds or less (including 1800 seconds), more preferably 500 seconds or less (including 500 seconds), more preferably 100 seconds or less (including 100 seconds), and 50 seconds or less. Less than seconds (including 50 seconds) is particularly preferred.

The waste water retention time in the diffusion section 2 is 0.5 second or more (including 0.5 second), and the total waste water retention time in the diffusion section 2 and the diffusion section 3 is 5 seconds or more (including 5 seconds). The upper limit of the waste water retention time in the diffuser 2 is not particularly limited. However, if the waste water retention time is too long, the dispersibility of gas and liquid in the waste water supplied to the diffuser 3 may decrease. The amount of waste water to be treated is too large, and it is economically disadvantageous. Therefore, the retention time of wastewater in the diffuser 2 is preferably 700 seconds or less (including 700 seconds).

The indwelling time of waste water in the above-mentioned diffuser 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 waste water retention time is not particularly limited. If the retention time is too long, the dispersibility of gas and liquid in the waste water supplied to the diffuser 2 may be reduced. Moreover, the equipment is less expensive than the amount of waste water to be treated. Excessive remarks are also unfavorable economically. Therefore, the upper limit of the wastewater retention time in the diffuser 1 is preferably 2500 seconds or less (including 2500 seconds), preferably 1000 seconds or less (including 1000 seconds), and even more preferably 600 seconds or less (including 600 seconds). 300 seconds or less (including 300 seconds) is particularly preferred.

In one embodiment, the processing method of this type is that the gas-liquid diffuser 1 has a dispersion plate 1 at the interface of the waste water supply side, and the gas-liquid diffuser 2 is in contact with the gas-liquid diffuser 1 The interface has a dispersion plate 2. In this case, 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 aperture ratio of 0.005 %~30% perforated plate structure.

The porosity of the above-mentioned 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 more than 1% (Including 1%) is particularly good. Moreover, the above-mentioned open porosity is preferably 10% or less (including 10%), and more preferably 5% or less (including 5%). Within this range, the unbalanced flow caused by the stirring effect can be prevented and the gas contained in the waste water can be evenly distributed. Therefore, the gas-liquid contact can be improved and the processing performance of the catalyst can be improved.

The method of calculating the open porosity of the dispersing plate, the number of holes in the perforated plate, and the shape of the holes are the same as those of the dispersing plate in the above-mentioned wastewater treatment device (the first type), so The description is omitted.

Other reaction conditions of the present invention can be exemplified by the following (i) to (iv).

The preferred treatment method of the present invention further satisfies the following (i)~(iv): (i) the LHSV in the above-mentioned catalyst layer is 0.1hr ^-1 ~10hr ^-1 ; (ii) the above-mentioned catalyst layer The temperature of the wastewater in the gas is 80℃~370℃; (iii) the pressure in the above catalyst layer maintains at least a part of the wastewater in the liquid phase; and (v) the amount of oxygen contained in the gas is the pressure The theoretical oxygen demand of oxide is 0.5 to 5.0 times.

Hereinafter, (i) to (iv) will be described.

(i) LHSV (Liquid Hourly Space Velocity) in the catalyst layer

The LHSV is 0.1hr ^-1 ~10hr ^-1 , preferably 0.2hr ^-1 ~5hr ^{-1, and more} preferably 0.3hr ^-1 ~3hr ^-1 . When the LHSV is 0.1hr ^-1 or more (including 0.1hr ^-1 ), it can be implemented with cost-effective equipment. Moreover, when the LHSV is 10hr ^-1 or less (including 10hr ^-1 ), the oxidation/decomposition treatment of wastewater in the reaction tower can be sufficiently performed.

(ii) Wastewater temperature in the catalyst layer

The temperature of wastewater in the catalyst layer is 80℃~370℃, preferably 100℃~270℃, more preferably 110℃~270℃, especially 200℃~270℃. When the wastewater temperature exceeds 370°C, high pressure has to be applied in order to maintain the liquid state of the wastewater. In this case, the equipment may become larger, which may increase the operating cost. When the temperature of the wastewater does not reach 80°C, the oxidation/decomposition treatment of the oxides in the wastewater may be difficult to effectively proceed.

(iii) Pressure in the catalyst layer

In this type of device, the pressure in the catalyst layer is the pressure that at least a part of the waste water maintains the liquid phase. Since at least a part of the wastewater remains in the liquid phase, it is better to adjust the pressure appropriately in response to the treatment temperature of the wastewater.

Specifically, it is as illustrated below.

‧When the processing temperature is above 80°C (including 80°C) and does not reach 95°C

If it is above atmospheric pressure (including atmospheric pressure), it can be atmospheric pressure from an economic point of view, but in order to improve the processing efficiency, it is better to pressurize.

‧When the processing temperature is above 95℃ (including 95℃) and does not reach 170℃

The pressure is about 0.2~1MPa (Gauge)

‧When the processing temperature is above 170°C (including 170°C) and does not reach 230°C

Pressure of about 1~5MPa (Gauge)

‧When the processing temperature is above 230℃ (including 230℃)

The pressure exceeds about 5MPa (Gauge)

In addition, the upper limit of the pressure in the above processing temperature range is only a rough standard and 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). Moreover, the upper limit of the pressure is 2 times or less (including 2 times) of the saturated vapor pressure of the wastewater temperature in the catalyst layer, preferably 1.5 times or less (including 1.5 times).

(iv) The amount of oxygen contained in the gas

According to the definition of "theoretical oxygen demand" described later, the oxygen contained in the gas is 0.5 to 5.0 times the theoretical oxygen demand of the oxidized waste water. The amount of oxygen It is preferable that the theoretical oxygen demand of oxidized in the wastewater is 0.7 times or more (including 0.7 times), and 5.0 times or less (including 5.0 times) is preferable, and 3.0 times or less (including 3.0 times) is more preferable.

In the treatment method of this type, the wastewater treatment device is preferably the treatment device of the above-mentioned first type.

<Description of specific aspects of the present invention>

Hereinafter, the waste water treatment method using the waste water treatment device of the first aspect of the present invention (this specification, also referred to as the "waste water treatment device of the present invention") will be specifically described. Fig. 1 is a schematic diagram showing an embodiment of a waste water treatment method when wet oxidation treatment is used as one of the oxidation treatment steps, but the treatment method used in a type of waste water treatment device of the present invention is not limited Here.

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 according to the processing capacity of the catalyst.

In the wastewater treatment device of the present invention, the wet oxidation treatment can be carried out under any conditions in the presence or absence of oxygen-containing gas. However, 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 oxygen-containing gas into wastewater.

When the wet oxidation treatment is performed in the presence of oxygen-containing gas, for example, the oxygen-containing gas is introduced from the oxygen-containing gas supply line 11, and the pressure is increased by the compressor 4, and the wastewater is mixed with the wastewater before being supplied to the heat exchanger 2. In the present invention, "oxygen-containing gas" is a gas containing molecular oxygen and/or ozone, For this gas, it can be pure oxygen, oxygen-enriched gas, air, hydrogen peroxide aqueous solution, and other oxygen-containing gas produced in factories. The type of oxygen-containing gas is not particularly limited. From an economic point of view, the While waiting, it is recommended to use air.

The supply amount of the oxygen-containing gas when 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 oxides in the wastewater. The supply amount of oxygen-containing gas can be appropriately adjusted by providing an oxygen-containing gas flow control valve (not shown) or the like on the oxygen-containing gas supply line 11, for example. The preferred supply of oxygen-containing gas is recommended to be more than 0.5 times (including 0.5 times) of the theoretical oxygen demand of the oxidized gas in the recommended wastewater, preferably at least 0.7 times (including 0.7 times), and preferably at least 5.0 times (including 5.0) Times) is better, and 3.0 times or less (including 3.0 times) is more preferred.

In addition, in the present invention, "theoretical oxygen demand" refers to 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 theoretical oxygen demand is represented by the chemical oxygen demand (COD(Cr)).

The wastewater sent to the heat exchanger 2 is preheated. However, under the condition that more than 1/2 of the waste water evaporates inside the heat exchanger 2, the organic matter and scale components in the waste water accumulate in the heat exchanger 2, resulting in reduced heat exchange efficiency, clogged pipes, and rapid expansion of the volume. This leads to problems such as the load on the outlet side of the pipe and the gas hammer phenomenon caused by liquefaction in the reaction tower. Therefore, it is better to have a structure that can withstand the pressure corresponding to the heating temperature.

The wastewater preheated in the heat exchanger 2 is supplied to the reaction tower 1 (the wastewater treatment device of the present invention) provided with the heating means 8 (heater or heat medium). add The thermal means 8 is that the temperature of the wastewater in the reaction tower is preferably capable of being heated to the range described in the above "(ii) Wastewater temperature in the catalyst layer".

Furthermore, the heat exchanger 2 and the reaction tower 1 are preferably constructed to withstand the pressure described in the above-mentioned "(iii) Pressure in the catalyst layer".

Moreover, the heating order of the waste water is not particularly limited. As described above, it may be further heated in the reaction tower after preheating outside the reaction tower, or it may be heated only in the reaction tower. Moreover, there is no particular limitation on the method of heating wastewater, and heaters and heat exchangers can be used, and a heater can be installed in the reaction tower to heat the wastewater. It is also possible to further supply a heat source such as steam in the waste water.

When processing under pressure, a pressure adjustment mechanism can be installed downstream of the reaction tower. For example, as shown in Figure 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 above "(iii) the pressure in the catalyst layer" in the reaction tower can be maintained.

Furthermore, in the wet oxidation treatment used in the present invention, the number, type, shape, etc. of the reaction towers are not particularly limited, and a singular or a combination of plural kinds of reaction towers can be used. The reaction tower can be a single-tube type or a multi-tube type. When a plurality of reaction towers are installed, the reaction towers in series or parallel can be arranged arbitrarily according to the purpose.

In terms of the method of supplying wastewater to the reaction tower, various types such as gas-liquid upward cocurrent flow, gas-liquid downward cocurrent flow, gas-liquid convection, etc. can be used. Moreover, when multiple reaction towers are installed, two or more types (including two Kinds) of these supply methods.

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

When multiple reaction towers are used, different catalysts can be used respectively. Moreover, it is also possible to combine a reaction tower filled with a catalyst (the waste water treatment device of the present invention) and a reaction tower that does not use a catalyst.

The oxides in the wastewater undergo oxidation/decomposition treatment in the reaction tower, but the "oxidation/decomposition treatment" in the present invention exemplifies the oxidative decomposition treatment of converting acetic acid into carbon dioxide and water; converting acetic acid into carbon dioxide and methane Decarboxylation treatment; oxidation treatment to convert sulfide, hydrosulfide, sulfite, thiosulfate into sulfate; oxidation and oxidation of dimethyl sulfite into carbon dioxide, water, sulfate ion, etc. Oxidative decomposition treatment; hydrolysis treatment that converts urea into ammonia and carbon dioxide; oxidative decomposition treatment that converts ammonia or hydrazine into nitrogen and water; oxidation treatment that converts dimethyl sulfite into dimethyl sulfide or methanesulfonic acid, etc., That is, it includes decomposition treatment to decompose easily decomposable oxides into nitrogen, carbon dioxide, water, ash, etc., decomposition treatment to reduce the molecular weight of difficult-to-decompose organic compounds and nitrogen compounds, or oxidation for oxidation Various oxidation and/or decomposition meanings such as treatment.

In addition, in the treatment liquid obtained by wet oxidation treatment without using a catalyst, many of the hardly decomposable organic compounds in the oxide remain low molecular weight, and low molecular weight organic compounds have many residues and low scores. Organic acids, especially acetic acid. However, in the method of using the catalyst of the present invention, the residual amount can be reduced by increasing the reaction temperature and increasing the amount of the catalyst.

Figure 1 shows a concrete example of the treatment. After the wastewater is oxidized/decomposed in the reaction tower 1, the treatment liquid is taken out from the treatment liquid line 12, appropriately cooled by the cooler 9 as necessary, and then separated by the gas-liquid separator 5. Into gas and liquid. At this time, the liquid level controller LC is used to detect the liquid level state, and the liquid level in the gas-liquid separator is controlled to be constant by the liquid level control valve 6. Furthermore, it is better to use the pressure controller PC to detect the pressure state, and to 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 range of the processing conditions in the reaction tower such as the installation before the gas-liquid separator.

Here, the temperature in the gas-liquid separator is not particularly limited. However, the treated liquid obtained by oxidizing/decomposing wastewater in the reaction tower contains carbon dioxide. Therefore, for example, the temperature in the gas-liquid separator is increased. It is better to release the carbon dioxide in the waste water, or the liquid separated by the gas-liquid separator is bubbled with air and other gases to release the carbon dioxide in the liquid.

In the temperature control of the processing liquid, the processing liquid can be cooled by cooling means such as heat exchanger 2, cooler 9, etc. before the processing liquid is supplied to the gas-liquid separator 5. It is also possible to install a heat exchanger after the gas-liquid separation (not shown) ) Or cooler (not shown) and other cooling means to cool the processing liquid.

The liquid (treatment liquid) obtained by separation in the gas-liquid separator 5 is It is discharged from the processing 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 treated liquid obtained by the wet oxidation treatment is directly returned to the waste water before the wet oxidation treatment is performed, or is supplied to the waste water from any position of the waste water supply line, or is subjected to the wet oxidation treatment. For example, the treated liquid obtained by wet oxidation treatment can also be used as the dilution water of wastewater to reduce the TOD concentration or COD concentration of the wastewater. Furthermore, 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 may be further subjected to other steps. Furthermore, when performing the wet oxidation treatment used in the present invention, the heat exchanger can also be used for a heater and a cooler, and these heat exchangers can be used in combination as appropriate.

Example

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these.

[Example 1]

The details of the reaction tower of Example 1 are shown in Figure 2. Installed on the support base of the grid and metal mesh of the cylindrical reaction tower 1 with a diameter of 600mm and a length of 9000mm, and pellets the cylindrical SUS with a diameter of 600mm and a length of 5-8mm (average length of 6.5mm) The material (average particle size 8.5 mm) is filled with 100 mm (H3) in the height direction (lower filling material layer 16; diffuser 3). The specific gravity of the pellets is about 7.9, and the porosity is 43%.

Next, the lower filler layer 16 is filled with a solid catalyst 2000L (catalyst layer 17) in the height direction of 7074 mm (H4). The solid catalyst used is a catalyst composed of titanium oxide and platinum as main components, and the weight ratio of each is 99.0:1.0 _{in terms of TiO 2 :Pt.} In addition, the shape of the solid catalyst is a pellet with a diameter of 4 mm φ × a length of 6 mm (average particle diameter 7.2 mm). Then, the catalyst layer 17 is filled with SUS pellets (upper filler layer 18) in the height direction of 300 mm (H5) in the same manner as described above.

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

(Waste water physical test)

In the wastewater treatment method shown in Figure 1, the reaction tower 1 uses the reaction tower of Example 1, and performs wastewater treatment for a total of 1000 hours under the following conditions. The waste water transported from the waste water supply pipeline 10 is ^{pressurized and fed by the waste water supply pump 3 at a flow rate of 4 m 3} /hr, and the maximum temperature of the reaction tower is 250 ℃ by heat exchanger 2 and electric heater (heating means 8 ) 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 after the compressor 4 is pressurized, the air is supplied _{from the heat exchanger at a ratio of O 2} /COD (Cr) (oxygen content in the air/chemical oxygen demand) = 1.5 The front part of 2 is supplied, mixed with the waste water. The LHSV in the catalyst layer is 2.0hr ^-1 . After the treatment liquid after wet oxidation treatment is cooled in the cooler 9 through the treatment liquid line 12, the gas-liquid separation treatment is performed through the gas-liquid separator 5. In the gas-liquid separator 5, the liquid level is detected by the liquid level controller (LC), and the liquid level control valve 6 is operated to maintain a constant liquid level. At the same time, the pressure is detected by the pressure controller (PC), and the pressure control valve 7 It operates to maintain a pressure of 7MPaG. Then, the treatment liquid treated in this manner is discharged from the treatment 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 calcium and 1mg/L iron.

(COD(Cr) processing rate)

The COD (Cr) treatment rate after 1000 hours of reaction is 85%. The COD (Cr) treatment rate is calculated using the following formula.

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

(Attachment of scale ingredients)

Take out the catalyst and visually confirm the adhesion state of the scale components, and evaluate it as B according to the following criteria.

A: Hardly any adhesion is seen.

B: Slightly attached.

C: Obvious adhesion (brown) is seen.

(Retention time of wastewater)

The waste water retention time in the diffuser 1~3 is calculated using the following formula. The retention time of wastewater in the diffusion section 1~3 is shown in Table 1-2.

Wastewater retention time (seconds) = layer length of diffusion part (mm) ÷ wastewater flow rate (mm/ Second)

[Examples 2~7]

In Examples 2-7, in the reaction tower of Example 1, the distance H1 between the perforated plate 15-1 and the single-hole plate 15-2 with the collision plate and the distance from the perforated plate 15-1 to the lower filling layer 16 In the reaction tower where the distance H2 from the inlet was changed to the value shown in Table 1-1, the above wastewater treatment test was performed. The treatment rate after 1000 hours and the adhesion state of scale components on the catalyst are shown in Table 1, and the wastewater retention time is shown in Table 1-2.

[Examples 8~9]

In Examples 8-9, in the reaction tower of Example 4, the reaction tower whose value of H1 was changed to the 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 retention time is shown in Table 2-2.

[Comparative Example 1]

In Comparative Example 1, in the reaction tower of Example 1, a reaction tower whose value of H1 was changed to 1200 mm was used to conduct 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 3-1, and the wastewater retention time is shown in Table 3-2.

[Comparative Example 2]

In Comparative Example 2, in the reaction tower of Example 1, the reaction tower in which the values of H1 and H2 were changed to the values shown in Table 3-1 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 3-1, and the wastewater retention time is shown in Table 3-2.

[Comparative Example 3]

In Comparative Example 3, in the reaction tower of Example 1, the reaction tower in which the values of H1 and H2 were changed to the values shown in Table 3-1 and was not filled with the lower filling layer 16 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 3-1, and the wastewater retention time is shown in Table 3-2.

As shown in Tables 1-1 and 2-1, it can be seen that in Examples 1-9, by setting H6 and H6/H1 within a predetermined range, the scale composition in the catalyst can be suppressed and the catalyst can be maintained at a high level. Media processing performance. On the other hand, as shown in Table 3-1, it can be seen that in Comparative Examples 1 to 3, the value of H6/H1 or H6 is not within the scope of the present invention, the scale component is obviously attached to the catalyst, and the catalyst performance is reduced .

Moreover, as shown in Tables 1-2 and 2-2, it can be seen that in Examples 1-9, (1) the waste water retention time in the diffusion part 1~3, (1) the waste water in the diffusion part 3 and the diffusion part 2 The total retention time and (3) the total retention time of the wastewater in the diffusion section 1 (2) The total retention time of the wastewater in the above-mentioned (2) wastewater retention time is within a predetermined range, and the scale components in the catalyst can be inhibited from being analyzed, thereby achieving a high degree of maintenance. Catalyst treatment performance. On the other hand, as shown in Table 3-2, it can be seen that in Comparative Examples 1 to 3, none of the above (1) to (3) is satisfied, the scale component is obviously attached to the catalyst, and the catalyst performance reduce.

[Example 10-14]

In Examples 10-14, in the reaction tower of Example 4, the opening ratio of the perforated plate provided as the dispersion plate 15-1 and the number of holes per 1 m ² of the perforated plate were changed to the values shown in Table 4 In the reaction tower, the above-mentioned wastewater treatment test was carried out.

The open porosity of the perforated plate is the value calculated by the following formula.

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

The results are shown in Table 4.

As shown in Table 4, it can be seen that the treatment 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 15-1~15-4]

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

Figure 3-1 (Example 15-1): Dispersion plate 15-1 is arranged as a single-hole plate with collision plate, and dispersion plate 15-2 is arranged as a perforated plate

Figure 3-2 (Embodiment 15-2): Dispersion plates 15-1 and 15-2 are made into perforated plates

Figure 3-3 (Embodiment 15-3): Dispersing plates 15-1 and 15-2 are made into single-hole plates with collision plates

Figure 3-4 (Embodiment 15-4): The single-well plate (15-4) and the perforated plate (15-3) with the collision plate are additionally equipped with another device. The distance between the dispersion plate 15-3 and the dispersion plate 15-4 was set to 150 mm, and the distance between the dispersion plate 15-2 and the dispersion plate 15-3 was set to 300 mm.

[Comparative Example 4]

The reaction of Comparative Example 4, as shown in Figs. 3-5, was a device in which only one perforated plate was arranged as a dispersing plate. The values of H2~H6 are shown in Table 5-1, which 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]

As shown in Tables 5-1 and 5-2, with respect to the flow of waste water in the lower filling layer, by installing two dispersing plates on the upstream side (waste water supply side), the scale components in the catalyst can be suppressed. Thereby, the processing performance of the catalyst can be maintained at a high level. Furthermore, in Example 4, by setting a perforated plate (dispersion plate 15-2) as the dispersion plate 2, a single-hole plate with collision plate (dispersion plate 15-1) was provided as the dispersion plate 1, compared to Example 15. -1~15-3, can inhibit the scale composition in the catalyst, so as to maintain the catalyst's processing performance to a high degree. 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 a dispersion plate.

[Example 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 conduct 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 filler layer 16 (H3: 170 mm; filler layer 1), a spherical SUS ball with a diameter of 8.0 mm is filled with 30 mm (H7) in the height direction as the second filler layer 19 (filler layer 2). ). The specific gravity of the SUS ball is about 8.2, and the porosity of the second filling layer 19 is 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 18-20]

In Examples 18 to 20, in the reaction tower of Example 17, a reaction tower in which the value of H7 was changed to the 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]

In Example 21, in the second filling layer 19 (filling layer 2) of the reaction tower of Example 18, spherical zirconium balls with a diameter of 7.5 mm were used to fill 100 mm (H7) in the height direction instead of SUS balls For the reaction tower, the above-mentioned wastewater treatment test was carried out. The specific gravity of the zirconium balls is about 5.3, and the porosity of the second filling layer 19 (filling layer 2) is 41%. The results are shown in Tables 6-1 and 6-2.

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

1‧‧‧Reaction Tower

2‧‧‧Heat exchanger

3‧‧‧Waste water supply pump

4‧‧‧Compressor

5‧‧‧Gas-liquid separator

6‧‧‧Liquid level control valve

7‧‧‧Pressure control valve

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

9‧‧‧Cooler

10‧‧‧Wastewater supply pipeline

11‧‧‧Oxygen-containing gas supply pipeline

12‧‧‧Treatment liquid pipeline

13‧‧‧Gas discharge pipeline

14‧‧‧Processing liquid discharge pipeline

Claims (10)

A treatment device comprising a reaction vessel. The reaction vessel has a dispersing plate 2, a dispersing plate 1, a filling layer, and a catalyst layer in sequence from the waste water supply side of the reaction vessel. When the dispersing plate 2 and the dispersing plate 1 When the distance is H1, the distance 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 sum of the above H2 and the above H3 is H6, the above H6 Exceeding 100mm, and the ratio of the above H6 to the above H1 (H6/H1) is 0.1 or more (including 0.1) and 100 or less (including 100), where the above H1 is 10mm or more (including 10mm) and 1000mm or less (including 1000mm), H1, and The distance of H2 corresponds to a space of the gas-liquid diffusion portion 1 and a space of the gas-liquid diffusion portion 2 in the reaction vessel, and the reaction vessel has an oxygen-containing gas supply line. For example, the processing device of claim 1, wherein at least one of the dispersing plate 1 and the dispersing plate 2 is a perforated plate, and the number of holes of the perforated plate is 5 or more (including 5) and 200 or less (including 5) ^{per 1 m 2} 200). Such as the processing device of claim 1, wherein the above-mentioned filling layer has a two-layer structure. Such as the treatment device of claim 3, wherein in the above-mentioned two-layer structure of the filling layer, when the filling layer on the waste water supply side is the filling layer 1, and the filling layer on the catalyst layer side is the filling layer 2, the above The layer length of the filling layer 2 is 30 mm or more (including 30 mm) and 500 mm or less (including 500 mm). Such as the treatment device of claim 3 or 4, wherein in the above-mentioned two-layer structure of the filling layer, when the filling layer on the waste water supply side is the filling layer 1, and the filling layer on the catalyst layer side is the filling layer 2. , The average particle size d1 of the filler 1 contained in the filler layer 1, the average particle size d2 of the filler 2 contained in the filler layer 2, and the average particle size d0 of the catalyst contained in the catalyst layer satisfy The relationship of d1>d2>d0. The processing device of claim 1, wherein the catalyst contained in the above-mentioned catalyst layer is a wet oxidation catalyst. A waste water treatment method, which is a waste water treatment method using the treatment device of claim 1, wherein the layer length H3 of the filling layer corresponds to a space of the gas-liquid diffusion part 3 in the reaction vessel, and the waste water is It has gas dispersion and satisfies the following (1)~(3): (1) The above-mentioned wastewater retention time in the above-mentioned gas-liquid diffusion section 1~3 is 0.5 seconds or more (including 0.5 seconds); (2) The above gas -The total of the waste water retention time in the liquid diffusion part 3 and the gas-liquid diffusion part 2 is 5 seconds or more (including 5 seconds); and (3) with respect to the waste water retention time in the gas-liquid diffusion part 1, the above (2) The total retention time of wastewater is 0.1-100 times. The processing method of claim 7, wherein the gas-liquid diffusion part 3 is a filling layer with a porosity of 20 to 90% by volume. Such as the processing method of claim 7, wherein the dispersing plate 1 and the dispersing plate 2 each have more than one (including one) hole, and the At least one of the bulk plate 1 and the aforementioned dispersion plate 2 has a porous plate structure with an opening ratio of 0.005% to 30%. Such as the processing method of any one of Claims 7 to 9, which further meets the following (i) to (iv): (i) The LHSV in the above-mentioned catalyst layer is 0.1hr ^-1 ~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 being oxidized is 0.5 to 5.0 times.

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