KR20180105588A - Waste water processing apparatus and Waste water processing method - Google Patents

Abstract

The present invention provides a waste water treating device capable of preventing a scale component from being precipitated on a surface of a catalyst and can highly maintain treating performance of the catalyst. The waste water treating device sequentially provides a distribution plate 2, a distribution plate 1, a filling material layer and a catalyst layer from a supply side of waste water. When a distance between the distribution plate 2 and the distribution plate 1 is H1, a distance of a boundary surface of the distribution plate 1 and the supply side of the waste water of the filling material layer is H2, a layer length of the filling material layer is H3 and a sum of the H2 and H3 is H6, the H6 is more than 100 mm and a ratio (H6/H1) of the H6 with respect to the H1 is 0.1 or more and 100 or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus and a wastewater treatment method,

The present invention relates to an apparatus for treating wastewater and a method for treating wastewater.

Wastewater discharged from various industrial plants such as chemical plants, food processing facilities, metal processing facilities, metal plating facilities, printing plate making facilities and photographic processing facilities is purified according to various methods such as wet oxidation, wet decomposition, ozone oxidation and hydrogen peroxide oxidation Are being processed.

For example, in the case of a wet oxidation method in which a solid catalyst is packed in a reaction tower, it is common to purify wastewater by introducing drainage and an oxygen-containing gas mainly from a lower portion of the solid catalyst packed bed (catalyst bed). Therefore, movement of the solid catalyst, vibration, and the like are likely to occur in the catalyst layer due to the action of the introduced wastewater and the oxygen-containing gas, so that the solid catalyst is worn out or the scale component (heavy metals such as Cu and Fe and Ca , Al, etc.) precipitate on the surface of the catalyst, thereby causing problems such as deterioration of the treatment performance of the catalyst.

In Patent Document 1, a layer of a filler such as a metal (a lower packing layer) is provided under the catalyst layer with respect to abrasion of the solid catalyst by drain water introduced from the lower portion of the reaction column to prevent abrasion of the solid catalyst, The catalyst can be supplied to the catalyst layer so that the deterioration of the treatment efficiency of the catalyst can be suppressed.

Patent Document 2 discloses that the treatment efficiency in the solid catalyst layer is improved by providing the non-catalytic wet oxidation reaction layer in front of the solid catalyst layer. In Patent Document 3, it is disclosed that the treatment efficiency is improved by providing a gas-liquid dispersion member on the solid catalyst layer.

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

In Patent Document 1, it is clear that provision of the lower packing layer can prevent the wear of the catalyst and suppress the deterioration of the treatment efficiency of the catalyst.

However, in the waste water treatment apparatus disclosed in Patent Document 1, when scale components (heavy metals such as Cu and Fe, etc.) are contained in the waste water, the scale components reach the catalyst layer in the ion state and precipitate on the surface of the catalyst There is a problem that the activity of the catalyst is inhibited.

On the other hand, in Patent Document 2, although the durability of the solid catalyst layer is improved by providing the non-catalytic wet oxidation reaction layer, the treatment capacity of the wastewater is insufficient, and the reaction tower of the first treatment step and the second treatment step is required, And it was disadvantageous in cost.

In Patent Document 3, the treatment efficiency of the solid catalyst layer is improved by the provision of the gas-liquid dispersing member, but the durability by the scale component is insufficient as in the invention disclosed in Patent Document 1.

Therefore, the present invention can prevent the scale component from reaching the catalyst layer in the ion state, that is, preventing the scale component from precipitating on the catalyst surface, thereby keeping the treatment performance of the catalyst high, And a method for treating wastewater.

Means for Solving the Problems The present inventors have conducted close examination to solve the above problems. First, a combination of the technique disclosed in Patent Document 1 and the technique disclosed in Patent Document 2-specifically, the case where the non-catalytic wet oxidation reaction layer of Patent Document 2 is combined with the lower portion of the reaction column of Patent Document 1 has been studied The effect could not be obtained. Thus, considering that the dispersibility of vapor-liquid is bad, the dispersing plate is provided in the non-catalytic wet oxidation reaction layer with reference to Patent Document 3, but sufficient effect can not be obtained. Further, as a result of various studies on the arrangement of the dispersion plates, it has been found that the above problems can be solved by having at least two dispersion plates and arranging them in a specific range, and accomplished the present invention.

That is, a first embodiment of the present invention is a waste water treatment apparatus having a dispersion plate 2, a dispersion plate 1, a packing layer and a catalyst layer in this order from the supply side of waste water, wherein a distance between the dispersion plate 2 and the dispersion plate 1 is H1, The distance H 2 between the interface between the dispersion plate 1 and the supply side of the drainage of the packing layer is H 2, the length of the layer (layer) of the packing layer is H 3 and the total of H 2 and H 3 is H 6, And the ratio (H6 / H1) of H6 to H1 is not less than 0.1 and not more than 100. [

A second mode of the present invention is a method of treating wastewater using an apparatus having at least a gas-liquid diffusing portion 1, a gas-liquid diffusing portion 2, a gas-liquid diffusing portion 3 and a catalyst layer in this order from the supply side of waste water,

The wastewater is dispersed in the gas,

(1) to (3) below:

(1) the residence times of the wastewater in the gas-liquid diffusion units 1 to 3 are all at least 0.5 second;

(2) the sum of the residence times of the wastewater in the gas-liquid diffusion section 3 and the gas-liquid diffusion section 2 is 5 seconds or more; And

(3) The treatment method satisfies that the sum of the residence times of the waste water in (2) above is 0.1 to 100 times the residence time of the waste water in the gas-liquid diffusion unit 1. [

According to the present invention, it is possible to prevent the scale component from being deposited on the surface of the catalyst, thereby maintaining the treatment performance of the catalyst at a high level, and to provide a treatment device of waste water having a low cost with a simple structure and a treatment method of waste water have.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a method of treating wastewater in an embodiment of the present invention. Fig.
Fig. 2 is a schematic view showing a treatment apparatus for wastewater used in Examples and Comparative Examples. Fig.
3 is a schematic view showing a processing apparatus for waste water used in the embodiment.
4 is a schematic view showing a processing apparatus for waste water used in the embodiment.
5 is a schematic view showing a processing apparatus for waste water used in the embodiment.
6 is a schematic view showing a processing apparatus for waste water used in the embodiment.
Fig. 7 is a schematic view showing a waste water treatment apparatus used in a comparative example. Fig.
8 is a schematic view showing a processing apparatus for waste water used in the embodiment.
9 is a schematic view showing an example of a dispersion plate according to the present invention.

Hereinafter, specific modes for carrying out 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 claims, and is not limited to the following embodiments.

≪ First Embodiment: Apparatus for treating waste water &

According to one aspect of the present invention, there is provided a waste water treatment apparatus having a dispersion plate 2, a dispersion plate 1, a packing layer and a catalyst layer in this order from a supply side of waste water, wherein a 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 supply side of the drainage of the packing layer is H2, the layer length of the packing layer is H3, and the sum of H2 and H3 is H6, the H6 is more than 100 mm, And a ratio H6 / H1 of H6 is 0.1 or more and 100 or less.

In the apparatus for treating wastewater according to 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 supply side of the waste water of the packing layer is H2, the layer length of the packing layer is H3, The length is H4 (unit: mm). In the case where the filling layer is also disposed on the drainage side of the catalyst layer, the length of the filling 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 a distance from a surface on the discharge side of the dispersion plate 2 to a surface on the supply side of the discharge water of the dispersion plate 1.

In the distributor plate, the supply side and discharge side of the waste water are defined as follows. When the waste water treatment apparatus is installed vertically to the ground and waste water is supplied from the lower portion of the waste water treatment apparatus and waste water is discharged from the upper portion of the waste water treatment apparatus, (Lower surface) on the supply side of the drainage are surfaces based on the intermediate position between the highest portion and the lowest portion on each surface. This is also the case when the surface of the dispersing plate is not flat or inclined. However, in the case of having the impingement plate like the dispersion plate 15-2 in FIG. 2, the middle position between the highest part and the lowest part except for the impingement plate is referred to. Further, the surface on the drainage discharge side and the surface on the supply side of the drainage are generally parallel to the plane (ground) perpendicular to the supply direction of the drainage. At this time, the supply side and discharge side of the drainage water are parallel.

The distance H2 between the dispersion plate 1 and the interface of the supply side of the drainage of the packing layer is the distance from the drainage discharge side of the dispersion plate 1 to the interface of the supply side of the packing layer.

The interface between the supply side and the discharge side of the drainage of the packing layer is defined as follows. Since the filler layer is filled with the filler, the surface exposed to the supply side and the discharge side of the drainage may not be perfectly flat. When the waste water treatment apparatus is installed vertically to the ground and drainage is supplied from the lower part of the waste water treatment apparatus and waste water is discharged from the upper part of the waste water treatment apparatus, the boundary surface (upper surface) Is a surface based on an intermediate position between the lowest part and the highest part of the filler exposed on the upper surface or lower surface of the packing layer. This is also the case when the exposed surface of the filling layer is inclined. In general, the interface on the drainage discharge side and the interface on the supply side of the drainage are parallel to the plane (ground) perpendicular to the supply direction of the drainage. At this time, the interface on the drainage discharge side and the interface on the supply side of drainage are parallel.

The layer length (H3) of the filling layer is a distance from the interface on the supply side of the drainage of the packing layer to the interface on the drainage side. When the filler layer is disposed on the drainage side of the catalyst layer, the layer length H5 of the filler layer is the same as H3.

The layer length (H4) of the catalyst layer is a distance from the interface on the supply side of the drainage of the catalyst layer to the interface on the drainage side.

The catalyst layer is filled with a catalyst (for example, a solid catalyst) as a filling material, and the definition of the boundary surface on the supply side and the boundary surface on the drainage side of the drainage of the catalyst layer is the same as that of the packing layer.

The apparatus for treating wastewater according to the present invention has such a constitution as described above, the scale component can be prevented from precipitating on the surface of the catalyst, and thus the treatment performance of the catalyst can be kept high.

It has been known that the disposition of a plurality of conventional dispersion plates is effective for improving the mixing efficiency of vapor-liquid. However, in the case of wastewater containing scale components (heavy metals such as Cu and Fe and Ca, Al, etc.), a more highly dispersed technique is required. As a characteristic of the scale component, when the wastewater is treated by the wet oxidation treatment, a scale component dissolved as an ion before heating is partially precipitated as a solid such as an oxide or a hydroxide by heating under pressure in the presence of oxygen. Therefore, depending on the conditions, the scale components dissolved in the wastewater may reach the catalyst layer in the ion state and precipitate on the catalyst surface, which may hinder the activity of the catalyst. Therefore, in the present invention, by setting the ratio of H6 to H1 (H6 / H1) to an appropriate range and setting H6 to 100 mm or more, it becomes possible to precipitate the scale component as a solid before reaching the catalyst layer, It is possible to prevent the occurrence of the trouble.

The filler layer is also required as a dispersion-reducing layer to prevent the scale component from being directly accumulated in the catalyst layer. The presence of the lower filler layer promotes the precipitation of the scale component in the filler layer and prevents it from precipitating on the surface of the catalyst. At the same time, the dispersing effect can be enhanced more than in the past, and the scale component can be prevented from local precipitation and deposition, and the catalyst can exhibit high treatment performance over a long period of time.

In the waste water treatment apparatus of the present invention, H6 is more than 100 mm. When H6 is 100 mm or less, the scale component is not uniformly dispersed and the scale component reaches the catalyst layer while remaining in the ion state, so that the surface of the catalyst may be poisoned by the scale component. H6 is preferably more than 150 mm, more preferably more than 250 mm from the viewpoint of being able to further inhibit precipitation of scale components in the catalyst. The upper limit of H6 is not particularly limited, but is, for example, less than 2000 mm. When H6 is less than 2000 mm, it is possible to suppress the deterioration of the contact efficiency of the vapor-liquid due to the agglomeration of the fine bubbles mixed by the dispersion plate.

In the waste water treatment apparatus of the present invention, the ratio (H6 / H1) of H6 to H1 is 0.1 or more and 100 or less. If H6 / H1 is less than 0.1 or more than 100, the mixing effect of the gas mixture between the dispersing plate 2 and the dispersing plate 1 becomes insufficient and the scale component drifts, so that the scale component locally accumulates and the treatment efficiency is lowered. H6 / H1 is preferably 0.2 or more, and more preferably 0.3 or more. H6 / H1 is preferably 80 or less, more preferably 50 or less. Such a range can exert the above-described effect.

H1 is not particularly limited as long as the above ratio (H6 / H1) is satisfied, but is, for example, 10 mm or more, preferably 20 mm or more, and more preferably 30 mm or more. Further, H1 is 1000 mm or less, preferably 900 mm or less, and more preferably 750 mm or less. Since H1 is 10 mm or more and 1000 mm or less, sufficient dispersion and mixing of vapor-liquid can be achieved, so that deterioration of treatment efficiency of the catalyst can be suppressed and the scale component can be prevented from reaching the catalyst layer while remaining in the ion state.

The size of the waste water treatment apparatus of the present invention is not particularly limited as long as it satisfies the above-mentioned H6 and H6 / H1, and is the size of the reaction tower or the reaction vessel usually used for the wastewater treatment. The shape of the waste water treatment apparatus of the present invention is not particularly limited, and the shape of the reaction tower or the reaction vessel usually used for wastewater treatment is obtained. As the reaction tower or reaction vessel, a cylindrical vessel having a diameter of 200 to 3000 mm and a length of 1000 to 20000 mm can be used.

The apparatus for treating wastewater of the present invention can be applied to various methods for treating wastewater. Wastewater treatment methods include wet oxidation, wet decomposition, ozone oxidation, hydrogen peroxide oxidation, and the like. As a treatment method of wastewater, wet oxidation is preferable from the viewpoint of obtaining a high level of treated water quality and having excellent economical efficiency. Therefore, an embodiment of the present invention provides an apparatus for treating wastewater used in the treatment of wastewater according to the wet oxidation method.

[Drainage]

The kind of the wastewater to be treated by the wastewater treatment apparatus of the present invention is not particularly limited. The wastewater treatment apparatus of the present invention can effectively treat wastewater containing any one or more of organic compounds, nitrogen compounds and sulfur compounds.

Examples of the organic compound include epoxy compounds such as ethylene oxide and propylene oxide, alcohol compounds such as methanol, ethanol and ethylene glycol, and carboxylic acids and / or derivatives thereof such as acrylic acid, methacrylic acid, terephthalic acid and their esters . Examples of the nitrogen compound include organic nitrogen compounds such as amine and imine, and inorganic nitrogen compounds having nitrogen-hydrogen bond 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 mercaptans and sulfonic acids. Furthermore, the present invention is not limited to the wastewater containing only the above-mentioned compounds, but may contain harmful substances such as dioxane, dioxins, fluorocarbons, dihalohexyl phthalate, nonylphenol and the like, and environmental hormone compounds.

Waste water containing such compounds may be discharged from various industrial plants such as chemical plants, electronic parts manufacturing facilities, food processing facilities, metal processing facilities, metal plating facilities, printing plate making facilities and photographic facilities, And drainage discharged from power generation facilities and the like.

Specific examples of industrial wastewater include paper, pulp, fiber, steel, ethylene · BTX, coal gasification, food processing, etc., in addition to EOG manufacturing facilities, alcohol production facilities, aliphatic carboxylic acid and ester production facilities, aromatic carboxylic acid or aromatic carboxylic acid ester production facilities , Chemical treatment, and the like.

In addition, not only industrial drainage but also life drainage such as sewage or excrement are exemplified.

That is, the term " drainage " in the present invention is not limited to so-called industrial drainage discharged from an industrial plant as described above, and may be any liquid containing at least one of organic compounds, nitrogen compounds and sulfur compounds And the source (source) of such liquid is not particularly limited.

[Scale component]

Further, the apparatus for treating wastewater of the present invention is suitable for the treatment of wastewater containing scale components. As described above, in the waste water treatment apparatus disclosed in Patent Document 1, when a scale component (heavy metals such as Cu and Fe) and Ca and Al are contained in the waste water, the scale component reaches the catalyst layer in the ion state, And there are cases where the activity of the catalyst is inhibited. On the other hand, in the wastewater treatment apparatus of the present invention, since the scale component can be suppressed from precipitating on the surface of the catalyst, the treatment efficiency of the catalyst can be kept high.

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

The concentration of the scale component contained in the drainage is not particularly limited. The waste water treatment apparatus of the present invention can exhibit an effect in the treatment of wastewater containing a scale component of 0.1 mg / L or more, unlike the prior art. The concentration of the scale component may be 0.5 mg / L or more. When the concentration of the scale component is 1 g / L or less, the effect of the present invention can be sufficiently exhibited.

[Distributed edition]

The apparatus for treating wastewater according to the present invention has a dispersion plate 2, a dispersion plate 1, a packing layer and a catalyst layer in this order from the supply side of waste water. That is, the waste water treatment apparatus of the present invention has at least two dispersion plates. As the dispersion plate, a single plate, a plate with an impingement plate, a perforated plate, or a perforated plate with an impingement plate as illustrated in FIG. 9 can be used. As the dispersion plate, a dispersion plate of the same kind may be disposed, or another dispersion plate may be disposed. In the waste water treatment apparatus of the present invention, since the dispersion plate 2 and the dispersion plate 1 are arranged at a predetermined distance H1, the effect of the present invention can be exhibited. Further, an additional dispersing plate may be disposed on the supply side (upstream side) of the waste water than the dispersing plate 2 if necessary. The dispersion plate may be composed of a single plate, but it is preferable that the dispersion plate is formed in a shape divisible into two or more sheets from the standpoint of installation and separation workability.

The aperture ratio of the perforated plate and the perforated plate (including those with the impingement plate) is usually not less than 0.005% and not more than 30%. The hole area ratio is preferably 0.05% or more, more preferably 0.1% or more, still more preferably 0.5% or more, particularly preferably 1% or more. Further, the hole area ratio is preferably 10% or less, and more preferably 5% or less. By such a range, it is possible to prevent the drift due to the stirring effect and uniform the distribution of the gas contained in the waste water. Therefore, the gas-liquid contact can be improved and the treatment performance of the catalyst can be enhanced.

The aperture ratio of the dispersion plate is calculated by the following equation.

[Equation 1]

The number of holes of the perforated plate (including those with the impingement plate) is usually not less than 5 but not more than 200 per m < 2 > The number of holes is preferably 10 or more per 1 m 2, more preferably 25 or more per 1 m 2 from the viewpoint of obtaining a sufficient dispersion effect. The number of holes is preferably 150 or less per 1 m 2, more preferably 120 or less per 1 m 2 from the viewpoint of maintaining the strength of the perforated plate.

The shape of the hole is not particularly limited, but a cylindrical shape or a truncated cone shape is preferable because it is easy to manufacture. The arrangement of the holes is not particularly limited. However, in the case of the single plate, it is preferable to arrange the holes at the center, and in the case of the perforated plate, it is preferable to arrange the holes uniformly as a whole.

In a preferred embodiment of the present invention, at least one of the dispersion plate 1 and the dispersion plate 2 is a porous plate, and the number of holes of the porous plate is 5 or more and 200 or less per 1 m2. By such a constitution, precipitation of the scale component can be further suppressed to the catalyst, and thus the treatment performance of the catalyst can be maintained to be higher.

The distance H2 between the interface between the dispersion plate 1 and the supply side of the drainage of the packing material layer is not particularly limited as long as the sum H6 of H2 and the layer length H3 of the filling material layer is more than 100 mm, Preferably 10 mm or more.

The diameter of the impingement plate provided on the impingement plate and the impingement plate with the impingement plate is preferably 0.5 to 10.0 times, more preferably 1.0 to 5.0 times, and still more preferably 1.5 to 3.0 times the pore diameter. The distance between the impingement plate and the perforated plate or perforated plate is preferably 0.05 to 5.0 times, more preferably 0.1 to 3.0 times, and still more preferably 0.2 to 1.0 times, the hole diameter. With this range, the drainage and the gas can efficiently collide with the impingement plate, and can be evenly distributed in the circumferential direction of the impingement plate.

[Filling layer]

The apparatus for treating wastewater of the present invention has a filling layer on the discharge side of the wastewater of the dispersion plate 1. With this configuration, wear of the catalyst can be prevented, and the drainage can be made to flow as uniformly as possible into the catalyst layer without drifting. Further, it is possible to prevent the scale component from being precipitated on the surface of the catalyst.

The filler layer is filled with a metal or ceramic filler. The filling material is made of at least one material selected from the group consisting of iron, copper, stainless steel (SUS), Hastelloy, inconel, titanium, zirconium, titania, zirconia, silicon nitride or carbon nitride. The filler may be one type alone, or two or more types or alloys. When the wastewater is treated by wet oxidation, stainless steel (SUS), zirconium, Hastelloy, inconel or titanium is preferable as the filler from the viewpoints of abrasion resistance, corrosion resistance and strength, more preferably stainless steel (SUS) or zirconia .

The shape of the packing is not particularly limited and may be a granular shape such as a pellet shape, a sphere shape, a lump shape, a ring shape, a saddle shape, or a polyhedral shape; A shape of a continuum such as a fibrous shape, a chain shape, and a salt cast shape. The shape of the packing is preferably a granular shape, more preferably a pellet shape, a spherical shape, or a ring shape, from the viewpoint of facilitating filling into the reaction tower.

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 granular fillers, the average particle diameter is at least 3 mm, preferably at least 4 mm, and more preferably at least 5 mm. The average particle diameter is 30 mm or less, preferably 20 mm or less, and more preferably 15 mm or less.

In the present specification, the average particle diameter of the particulate filler and the solid catalyst to be described later is an arithmetic average value of the particle diameters. The particle diameter means the maximum diameter of the filler or solid catalyst. For example, the particle diameter of a spherical packing or solid catalyst is a diameter, and the particle diameter of a pellet-shaped packing or solid catalyst means the length of the diagonal line.

It is preferable that the average particle diameter d1 of the packing and the average particle diameter d0 of the catalyst contained in the following catalyst layer satisfy d1 >

The specific gravity of the packing (true specific gravity, generally used volume fraction, charging specific gravity, apparent specific gravity) is not particularly limited and can be appropriately selected. The specific gravity is usually 2.5 or more, preferably 4 to 12.

The porosity of the packing layer is not particularly limited and is usually 20 to 90% by volume (based on the total volume of the packing layer), preferably 30 to 70% by volume, more preferably 35 to 60% Is 35 to 55% by volume.

The filler to be filled in the filler layer need not have the same material, shape, size and specific gravity, and two or more fillers can be used provided that the effect of the present invention is exhibited. In addition, an appropriate filler can be appropriately selected depending on the use form and the use situation.

The filling is usually carried out by providing a supporting base made of a metal mesh, a grid or the like alone or in combination in a reaction tower and filling the supporting base.

The layer length (H3) of the filler layer is not particularly limited as long as the sum (H6) with respect to H2 is 100 mm or more, but is usually 10 mm or more, preferably 50 mm or more from the viewpoint of preventing the scale component from being directly accumulated in the catalyst layer, More preferably not less than 80 mm, and still more preferably not less than 100 mm. The upper limit of H3 is not particularly limited, but is 300 mm or less, and preferably 250 mm or less from the viewpoint of cost.

In a preferred embodiment of the present invention, the filling layer is a two-layer structure from the viewpoint of further enhancing the dispersing effect of the drainage. That is, it is preferable that the waste water treatment apparatus of the present invention further has a packing layer between the packing layer and the catalyst layer. Since the packing layer has a two-layer structure, the treatment performance of the catalyst can be maintained higher.

(D1) of the filler contained in the filler layer 1 and the average particle diameter (d2) of the filler contained in the filler layer 2 when the filler layer on the supply side of the waste water is used as the filler layer 1 and the filler layer on the catalyst layer side is the filler layer 2, ) May be d1 > d2 and d1 < d2. d1 and d2 are preferably d1 > d2 from the viewpoint of the dispersion effect of the multiple. When d1 > d2, the ratio (d2 / d1) of d2 to d1 is preferably 0.2 or more, more preferably 0.3 or more, and further preferably 0.4 or more. Further, d2 / d1 is preferably less than 1.00, and more preferably less than 0.95.

In the preferred embodiment of the present invention, the average particle diameter (d1) of the packing 1 contained in the packing layer 1, the average particle size (d2) of the packing 2 contained in the packing layer 2, and the average particle diameter d0 d1 > d2 > d0. The effect of dispersing the waste water can be further improved by gradually reducing the average particle diameter of the filler or the catalyst from the supply side of the waste water to the filler layer 1, the filler layer 2 and the catalyst layer. The ratio (d2 / d1) of d2 to d1 is as described above. The ratio d0 / d2 of d0 to d2 is preferably 0.2 or more, more preferably 0.3 or more, and further preferably 0.4 or more. Also, d0 / d2 is preferably less than 1.00, and more preferably less than 0.95.

The material, shape, and specific gravity of the filler contained in the filler layer 1 and filler 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 the layer length is as described above. H6 is the sum of H2, H3 and H7. Although the filler layer has a two-layer structure, the preferable range of H6 is the same.

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

Accordingly, in the preferred embodiment of the present invention, the layer length of the filling layer 2 is 30 mm or more and 500 mm or less.

The waste water treatment apparatus of the present invention may further have a filler layer on the drainage side of the catalyst layer.

For example, as shown in FIG. 2, when the waste water treatment apparatus is an upflow type cylindrical apparatus, a filling material layer (upper packing layer) is further installed on the drainage side of the catalyst layer for pressing the catalyst by applying a load from above. By setting the upper filler layer, wear of the catalyst can be suppressed. The layer length (H5) of the upper filler layer is not particularly limited and may be suitably selected in the range of 30 to 1000 mm. As the filler contained in the upper filler layer, the filler described above may be used. However, it is preferable that the size of the packing included in the upper packing layer is larger than the size of the catalyst in order to prevent the filling material from entering the catalyst layer.

[Catalyst layer]

The waste water treatment apparatus of the present invention has a dispersion plate 2, a dispersion plate 1, a packing layer and a catalyst layer in this order from the discharge side of waste water. The catalyst contained in the catalyst layer is usually a solid catalyst. The solid catalyst is not particularly limited as long as it is generally used for the wastewater treatment. Examples of the solid catalyst include catalysts containing at least one metal selected from the group consisting of titanium, iron, aluminum, silicon, zirconium and cerium, oxides or complex oxides thereof, activated carbon and the like. Of these, oxides such as titanium oxide, zirconium oxide, iron oxide, titanium-zirconium composite oxide, and titanium-iron composite oxide are suitably used.

The solid catalyst may contain another component (second component) in addition to the above components (first component). Examples of the solid catalyst containing two components include at least one metal selected from the group consisting of iron, titanium, silicon, aluminum, zirconium and cerium, oxides or complex oxides thereof or activated carbon (first component), manganese, cobalt, nickel, A catalyst containing at least one metal selected from tungsten, copper, silver, platinum, palladium, rhodium, gold, indium and ruthenium or a metal compound thereof (second component). The solid catalyst is preferably 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. In the case of a solid catalyst containing two components, it is preferable to contain 75 to 99.95 wt% of the first component and 0.05 to 25 wt% of the second component. The total of the first component and the second component is preferably 100% by weight. In this case, the weight ratio of the first component and the second component may be appropriately selected in consideration of the weight ratio of the first component and the second component without considering the third component. And the weight of the second component.

The above-mentioned solid catalyst is suitably used in the oxidation treatment using the wet oxidation method. The apparatus for treating wastewater of the present invention is suitable for the treatment of wastewater by wet oxidation in view of high level of treated water quality and economy. Accordingly, 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 a shape commonly used for wastewater treatment. Examples of the shape of the solid catalyst include granular particles such as pellets, spheres, and rings; A honeycomb shape, and the like.

The size of the solid catalyst is not particularly limited as long as the above effect can be obtained. For example, in the case of a solid catalyst in a granular state, the average particle diameter is, for example, 1 to 30 mm, preferably 1.5 to 20 mm, and more preferably 2 to 15 mm. The average particle diameter of the solid catalyst is preferably smaller than the average particle diameter of the filler contained in the filler layer on the supply side of the drainage water from the viewpoint of the dispersing effect of the drainage water.

The solid catalysts may be used alone or in combination of two or more.

The layer length (H4) of the catalyst layer is determined according to the charged amount of the catalyst. The charged amount of the catalyst is not particularly limited and may be suitably determined according to the purpose. Normally to adjust the charge amount of the catalyst to be 0.1hr ^-1 ~ 10hr ^-1, more preferably from 0.2hr ^-1 ~ 5hr ^-1, more preferably from 0.3hr ^-1 ~ 3hr ^-1 at a space velocity per catalyst Recommended. If the space velocity is 0.1 ^{hr &lt;}&quot; ¹ &gt; or greater, the throughput of the catalyst can be ensured and the size of the facility can be avoided. Further, when the space velocity is 10 ^{hr -1} or less, it is possible to sufficiently perform the oxidation / decomposition treatment of the waste water in the reaction tower.

&Lt; Second embodiment: Method of treating drainage >

According to another aspect of the present invention, there is provided a method of treating wastewater using an apparatus having at least a gas-liquid diffusion unit 1, a gas-liquid diffusion unit 2, a gas-liquid diffusion unit 3,

The wastewater is dispersed in the gas,

(1) to (3) below:

(1) the residence times of the wastewater in the gas-liquid diffusion units 1 to 3 are all at least 0.5 second;

(2) the sum of the residence times of the wastewater in the gas-liquid diffusion section 3 and the gas-liquid diffusion section 2 is 5 seconds or more; And

(3) A treatment method is provided in which the sum of the residence times of the waste water in (2) above is 0.1 to 100 times the residence time of the waste water in the gas-liquid diffusion unit 1. [

In the apparatus according to this embodiment, since the catalyst layer is the same as the catalyst layer relating to the above-described waste water treatment apparatus (first embodiment), a description thereof will be omitted.

The apparatus according to this embodiment has gas-liquid diffusions 1 to 3 as a means for uniformly dispersing a scale component and a gas (particularly oxygen).

The gas-liquid diffusing portion 1 (also referred to as &quot; diffusing portion 1 &quot; in this specification) is a space between the gas-liquid dispersing portion and the gas-liquid dispersing portion from the supply side of the waste water, The space between them; Or filler layer. The diffusion section 1 corresponds to, for example, the range indicated by H1 in FIG.

The gas-liquid diffusion portion 2 (also referred to as &quot; diffusion portion 2 &quot; in this specification) has a space between the gas-liquid dispersion portion and the gas-liquid dispersion portion from the supply side of the waste water, A space between the surface on the drainage discharge side of the packing layer and the supply side of the drainage of the packing layer; Or filler layer. The diffusing portion 2 corresponds to, for example, the range indicated by H2 in Fig.

The gas-liquid diffusing portion 3 (also referred to as &quot; diffusing portion 3 &quot; in this specification) is a space between the gas-liquid dispersing portion and the supply side of the drainage of the catalyst layer from the supply side of the waste water, A space between the surfaces on the supply side of the waste water of the catalyst layer; Or filler layer. The diffusion portion 3 corresponds to, for example, the range indicated by H3 in Fig. When the filler layer has a two-layer structure, the total of the two layers corresponds to the diffusing portion 3, for example, the range represented by H3 + H7 in Fig.

In the treatment method of this embodiment, at least one of the gas-liquid dispersing units 1 to 3 is a packing layer. The filler layer may be a single layer or two or more layers. Since the filling layer of the apparatus according to this embodiment is the same as the filling layer of the above-described waste water treatment apparatus (first embodiment), the description is omitted.

The gas-liquid dispersion part is a member capable of preventing the drift by the stirring effect and making the distribution of the gas included in the drainage water uniform, for example, a dispersion plate. The diffusing plate of the apparatus according to this embodiment is the same as the diffusing plate relating to the above-described apparatus for treating wastewater (first embodiment), and a description thereof will be omitted.

In the treatment method of this embodiment, the gas is dispersed in the waste water. The apparatus according to this embodiment has at least three gas-liquid diffusing portions, so that gas-liquid contact can be improved and the treatment performance of the catalyst can be enhanced.

In the treatment method of this embodiment, the residence time of the wastewater in the gas-liquid diffusion portion satisfies the above conditions (1) to (3).

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

(1) The residence time of the drainage in the gas-liquid diffusing parts 1 to 3 is at least 0.5 second. If the residence time of the waste water is less than 0.5 sec, the mixing effect of the gas liquid becomes insufficient and the effect of the present invention can not be exhibited. The residence time of the waste water is preferably 2 to 300 seconds.

(2) The sum of the residence times of the wastewater in the gas-liquid diffusing portion 3 and the gas-liquid diffusing portion 2 is 5 seconds or more. If the sum of the residence times of such waste water is less than 5 seconds, the scale component is not uniformly dispersed and the scale component reaches the catalyst layer while remaining in the ion state, so that the surface of the catalyst may be poisoned with the scale component. The total lower limit of the residence time of the waste water is preferably 10 seconds or more, more preferably 35 seconds or more, and still more preferably 60 seconds or more. Although the total upper limit of the residence time of the drain water is not particularly limited, the sum of the residence times of the drain water in the diffusion section 2 and the diffusion section 3 is preferably 2500 seconds or less, more preferably 1500 seconds or less, Is not more than 750 seconds, particularly preferably not more than 300 seconds.

(3) The sum of the residence times of the waste water in the above (2) is 0.1 to 100 times the residence time of the waste water in the gas-liquid diffusing portion 1. If the sum of the residence times of the waste water in the above (2) is less than 0.1 times or more than 100 times the residence time of the waste water in the gas-liquid diffusing portion 1, the mixing effect of the gas liquid becomes insufficient and drifting of the scale component occurs The scale component is deposited locally and the treatment efficiency is lowered. The total of the residence times of the waste water in the above (2) is preferably 0.2 or more, more preferably 0.3 or more, and preferably 80 or more times the residence time of the waste water in the gas- Or less, and more preferably 50 times or less.

When the gas-liquid diffusion portion is a filler layer, it is not necessary to consider the porosity of the filler layer when the retention time of the wastewater is 0.5 seconds or more. The porosity of the packing layer is usually 20 to 90% by volume (based on the total volume of the packing layer), preferably 30 to 70% by volume, and more preferably 35 to 60% by volume. If the porosity is lowered, the degree of turbulence in the filling layer becomes higher, so that an effect similar to that obtained by increasing the residence time of the waste water can be obtained. Also, even if the gas-liquid diffusion portion is composed of two or more filler layers, the residence time of the wastewater in the gas-liquid diffusion portion satisfies the conditions (1) to (3).

The residence time of the wastewater in the gas-liquid diffusion portion can be appropriately controlled in accordance with the flow rate of the supplied wastewater and the size of the apparatus. Further, the residence time of the drainage water can be calculated by the method described in the embodiment.

In a preferred embodiment, the diffusing portion 3 is a filler layer having a porosity of 20 to 90% by volume (based on the total volume of the filler layer). The porosity is preferably 30 to 70% by volume, more preferably 35 to 60% by volume, particularly preferably 35 to 55% by volume. When the diffusion section 3 is a filler layer, the diffusion section 2 and the diffusion section 1 are preferably not filler layers.

In a preferred embodiment, the diffusion portion 3 is a filler layer having a two-layer structure. Since the packing layer has a two-layer structure, the treatment performance of the catalyst can be maintained higher.

The residence time of the waste water in the diffusion section 3 is 0.5 seconds or more, preferably 5 seconds or more, more preferably 8 seconds or more, and particularly preferably 10 seconds or more. The effect of the present invention can not be sufficiently obtained in less than 0.5 seconds. Although the upper limit of the residence time of the waste water is not particularly limited, if the residence time is too long, the dispersibility of the gas and the liquid in the waste water reaching the catalyst layer is lowered. The effect is not enhanced. Therefore, the residence time of the waste water in the diffusion part 3 is preferably 1800 seconds or less, more preferably 500 seconds or less, further preferably 100 seconds or less, particularly preferably 50 seconds or less.

The residence time of the drainage in the diffusion section 2 is 0.5 seconds or more, and the sum of the residence times of the drainage in the diffusion section 2 and the diffusion section 3 is 5 seconds or more. The upper limit of the residence time of the waste water in the diffusion section 2 is not particularly limited. However, if the residence time of the waste water is too long, the dispersibility of the gas and the liquid in the waste water supplied to the diffusion section 3 may decrease. The device is too large for economical reasons. Therefore, the residence time of the waste water in the diffusion portion 2 is preferably 700 seconds or less.

The residence time of the waste water in the diffusion portion 1 is 0.5 seconds or more, preferably 1 second or more, and more preferably 2 seconds or more. The upper limit of the residence time of the waste water is not particularly limited. However, if the residence time is too long, the dispersibility of the gas and the liquid in the waste water supplied to the diffusion part 2 may be lowered. In addition, Which is economically disadvantageous. Therefore, the upper limit of the residence time of the waste water in the diffusion section 1 is preferably 2500 seconds or less, more preferably 1000 seconds or less, still more preferably 600 seconds or less, particularly preferably 300 seconds or less.

In one embodiment, the treatment method of this embodiment is characterized in that the gas-liquid diffusion portion 1 has a dispersion plate 1 at the interface of the supply side of the waste water, and the gas-liquid diffusion portion 2 has an interface Wherein at least one of the dispersion plate 1 and the dispersion plate 2 has at least one hole, and at least one of the dispersion plate 1 and the dispersion plate 2 has a porous plate structure with an aperture ratio of 0.005% to 30% .

The porosity of the porous plate structure is preferably 0.05% or more, more preferably 0.1% or more, still more preferably 0.5% or more, particularly preferably 1% or more. Further, the hole area ratio is preferably 10% or less, and more preferably 5% or less. By such a range, it is possible to prevent the drift by the stirring effect and uniform the distribution of the gas contained in the drainage. As a result, the gas-liquid contact can be improved and the treatment performance of the catalyst can be enhanced.

The method of calculating the aperture ratio of the dispersing plate, the number of holes of the perforated plate, and the shape of the holes are the same as those of the dispersing plate relating to the above-mentioned waste water treatment apparatus (first embodiment), and the description thereof is omitted.

Other reaction conditions in the present invention include the following (i) to (iv).

The processing method of this embodiment is preferably further satisfied with the following (i) to (iv):

(i) an LHSV of 0.1hr ^-1 ~ 10hr ^-1 at the catalyst layer being;

(ii) the temperature of the wastewater in the catalyst layer is 80 ° C to 370 ° C;

(iii) the pressure in the catalyst bed is such that at least a portion of the drainage water maintains a liquid phase; And

(iv) the amount of oxygen contained in the gas is 0.5 to 5.0 times the theoretical oxygen demand of the oxide in the wastewater.

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

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

LHSV is 0.1hr ^-1 ~ 10hr ^-1, preferably from 0.2hr ^-1 ~ 5hr ^-1, and more preferably from 0.3hr ^-1 ~ 3hr ^-1. When the LHSV is 0.1 ^hr &lt;&quot; ¹ &gt; or more, it can be carried out with an economically efficient facility. When the LHSV is 10 ^hr &lt; -1 &gt; or less, the waste water can be sufficiently oxidized and decomposed in the reaction tower.

(ii) the temperature of the drainage in the catalyst bed

The temperature of the waste water in the catalyst layer is 80 ° C to 370 ° C, preferably 100 ° C to 270 ° C, more preferably 110 ° C to 270 ° C, and particularly preferably 200 ° C to 270 ° C. When the temperature of the drainage water exceeds 370 ° C, high pressure must be applied in order to maintain the liquid state of the drainage water. In such a case, the facility may be enlarged and the operation cost may increase. When the temperature of the drainage is less than 80 캜, oxidation and decomposition treatment of the oxides in the wastewater may be difficult to efficiently perform.

(iii) the pressure in the catalyst bed

In the apparatus according to this embodiment, the pressure in the catalyst layer is a pressure at least a part of the drainage water retaining the liquid phase. It is preferable that the pressure is suitably adjusted according to the treatment temperature of the waste water to maintain at least a part of the waste water in the liquid phase.

Specifically, it is exemplified as follows.

· When the treatment temperature is 80 ° C or more and less than 95 ° C

It may be atmospheric pressure or higher, and it may be performed under atmospheric pressure from the viewpoint of economy, but it is preferable to pressurize to improve the treatment efficiency.

· When the treatment temperature is 95 ° C or more and less than 170 ° C

Pressure of about 0.2 to 1 MPa (Gauge)

· When the treatment temperature is higher than or equal to 170 ° C and lower than 230 ° C

Pressure of about 1 to 5 MPa (Gauge)

· When the treatment temperature is 230 ° C or higher

Pressure above 5 MPa (Gauge).

The upper limit of the pressure in the range of the above-mentioned treatment temperature is a guess, and it may be determined by a balance between the treatment efficiency and the pressure resistance of the apparatus. The specific upper limit value is 21 MPa or less, preferably 10 MPa or less, particularly preferably 8 MPa or less. Or the upper limit of the pressure is not more than twice the saturation vapor pressure at the temperature of the drainage in the catalyst layer, and preferably not more than 1.5 times.

(iv) the amount of oxygen contained in the gas

The amount of oxygen contained in the gas is 0.5 to 5.0 times the theoretical oxygen demand of the oxide in the wastewater based on the definition of &quot; theoretical oxygen demand &quot; The amount of oxygen is preferably 0.7 times or more, more preferably 5.0 times or less, and still more preferably 3.0 times or less the theoretical oxygen demand of the oxide in the wastewater.

In the treatment method of this embodiment, it is preferable to use the treatment device of the first type as a treatment device for wastewater.

<Description of Specific Embodiments of the Present Invention>

Hereinafter, a method of treating wastewater using a wastewater treatment apparatus (also referred to as &quot; wastewater treatment apparatus of the present invention &quot; in the present specification) as a first aspect of the present invention will be described in detail. FIG. 1 is a schematic diagram showing an embodiment of a method for treating wastewater when a wet oxidation treatment is employed as one oxidation treatment process. However, the treatment method used in the wastewater treatment apparatus, which is one embodiment of the present invention, no.

The drain water supplied from the drainage source is supplied to the drainage pump 3 through the drainage supply line 10 and further to the heat exchanger 2. The space velocity at this time is not particularly limited and may be suitably determined according to the treatment capacity of the catalyst.

In the waste water treatment apparatus of the present invention, the wet oxidation treatment can be carried out under any condition in the presence or absence of the oxygen-containing gas. However, if the oxygen concentration in the waste water is increased, the oxidation and decomposition efficiency of the oxides contained in the waste water can be improved It is preferable to incorporate an oxygen-containing gas into the waste water.

In the case of carrying out the wet oxidation treatment in the presence of the oxygen-containing gas, for example, an oxygen-containing gas is introduced from the oxygen-containing gas supply line 11 and the pressure is increased to the compressor 4, It is preferable to incorporate into the drainage. In the present invention, the term "oxygen-containing gas" means a gas containing molecular oxygen and / or ozone, and may be pure oxygen, oxygen-enriched gas, air, hydrogen peroxide, oxygen- The kind of oxygen-containing gas is not particularly limited, but from the viewpoint of economy, it is recommended to use air among these.

The amount of the oxygen-containing gas to be supplied to the waste water is not particularly limited and may be an amount effective to enhance the ability to oxidize and decompose the oxidized substance in the waste water. The supply amount of the oxygen-containing gas can be appropriately adjusted by providing, for example, an oxygen-containing gas flow rate control valve (not shown) on the oxygen-containing gas supply line 11. Preferably, the supply amount of the oxygen-containing gas is 0.5 times or more, more preferably 0.7 times or more, preferably 5.0 times or less, more preferably 3.0 times or less of the theoretical oxygen demand amount of the oxide in the wastewater.

In the present invention, the "theoretical oxygen demand amount" is the amount of oxygen necessary for oxidizing and / or decomposing the oxidized substances such as organic compounds and nitrogen compounds in the waste water to nitrogen, carbon dioxide, water and ash. In the present invention, Demand theoretical oxygen demand by demand (COD (Cr)).

The waste water sent to the heat exchanger 2 is preheated. However, under the condition that 1/2 or more of the waste water is vaporized in the heat exchanger 2, organic matter and scale components in the waste water are accumulated in the heat exchanger 2, resulting in reduction of heat exchange efficiency, clogging of the pipe and rapid volume expansion A load on the outlet-side piping portion, and a steam hammer phenomenon caused by liquefaction in the reaction tower may occur. Therefore, it is preferable that the structure can withstand the pressure according to the heating temperature.

The waste water preliminarily heated in the heat exchanger 2 is supplied to a reaction tower 1 (treatment apparatus of waste water of the present invention) provided with a heating means 8 (a heater or a heating medium). The heating means 8 preferably has an ability to heat the drainage temperature in the reaction tower to the range described in the above-mentioned &quot; (ii) Temperature of drainage in the catalyst layer &quot;.

It is also preferable that the heat exchanger 2 and the reaction tower 1 have a structure capable of withstanding the pressure described in the above "(iii) Pressure in the catalyst layer".

The order of heating the waste water is not particularly limited, and may be further heated in the reaction tower after preliminary heating at the outside of the reaction tower as described above, or may be heated only in the reaction tower. The method of heating the waste water is not particularly limited, and a heater or a heat exchanger may be used, or a heater may be provided in the reaction tower to heat the waste water. Further, a heat source such as steam may be supplied to the drainage.

When the treatment is carried out under pressure, a pressure adjusting mechanism may be provided downstream of the reaction tower. For example, as shown in Fig. 1, the pressure control valve 7 may be provided on the exhaust gas outlet side of the gas-liquid separator by a known means. The control range of the pressure may be controlled so as to maintain the conditions described in "(iii) Pressure in the catalyst layer" in the reaction column.

In the wet oxidation treatment used in the present invention, the number, type, shape and the like of the reaction tower are not particularly limited, and the reaction tower may be used singly or in combination. The reaction tower may be a single-tube type or a multi-tube type. When a plurality of reaction columns are provided, any arrangement such as a series or parallel arrangement of reaction columns may be used depending on the purpose.

As the method of supplying the waste water to the reaction tower, various forms such as gas-liquid upward flow, gas-liquid downstream flow, and vapor-liquid flow can be used, and when a plurality of reaction columns are provided, two or more of these supply methods may be combined.

When the wet oxidation catalyst described above is used in the reaction tower, the oxidation and decomposition treatment efficiency of the at least one of the organic compounds, the nitrogen compounds and the sulfur compounds contained in the wastewater is improved, and the long-term excellent catalytic activity, And the drainage can be obtained as treated water purified at a high level.

When a plurality of reaction columns are used, different catalysts may be used. Alternatively, a reaction tower packed with a catalyst (a treatment apparatus for waste water of the present invention) and a reaction tower not using a catalyst may be combined.

The "oxidation and decomposition treatment" in the present invention refers to an oxidative decomposition treatment using acetic acid as carbon dioxide and water, a decarboxylic acid decomposition treatment using acetic acid as carbon dioxide and methane, Oxidation treatment in which dimethyl sulfoxide is used as a batch of carbon dioxide, water, and sulfate ions, hydrolysis treatment of urea with ammonia and carbon dioxide, treatment of ammonia or hydrazine with ammonia or carbon dioxide, An oxidative decomposition treatment using nitrogen gas and water, and an oxidation treatment using dimethylsulfone as dimethylsulfone or methanesulfonic acid. In other words, the treatment for decomposing easily decomposable oxides into nitrogen gas, carbon dioxide, water, Decomposition treatment for decomposing decomposable organic compounds or nitrogen compounds into low molecular weight It is meant to include a number of oxidation and / or decomposition process of oxide.

In addition, in the treatment liquid obtained through the wet oxidation treatment without using a catalyst, the refractory organic compound in the oxidized product often becomes low in molecular weight and remains, and a low molecular weight organic acid, particularly acetic acid, remains as the low molecular weight organic compound There are many cases. However, in the method using the catalyst according to the present invention, the residual amount of the catalyst can be reduced by increasing the reaction temperature and increasing the catalyst amount.

The waste water is oxidized and decomposed in the reaction tower 1, taken out from the treatment liquid line 12 as a treatment liquid, cooled as necessary in the cooler 9 Liquid separator 5 into gas and liquid. At this time, it is preferable to detect the liquid level state by using the liquid level controller LC and to control the liquid level in the gas-liquid separator to be constant by the liquid level control valve 6. It is also preferable that the pressure state is detected by using the pressure controller PC and the pressure in the gas-liquid separator is controlled by the pressure control valve 7 to be constant.

The position of the pressure control valve can be appropriately changed within a range in which the processing conditions in the reaction tower can be maintained and controlled such as by being 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 oxidizing and decomposing the wastewater in the reaction tower contains carbon dioxide, for example, the temperature in the gas-liquid separator is raised to release carbon dioxide It is preferable that the liquid after being separated from the gas-liquid separator is bubbled into a gas such as air to release carbon dioxide in the liquid.

The temperature of the treatment liquid may be controlled by cooling means such as a heat exchanger 2 and a cooler 9 before the treatment liquid is supplied to the gas-liquid separator 5 or may be cooled by a heat exchanger (not shown) (Not shown) may be provided to cool the treatment liquid.

The liquid (treatment liquid) obtained by separation in the gas-liquid separator 5 is discharged from the treatment liquid discharge line 14. The discharged liquid may be subjected to various known processes such as biological treatment and membrane separation treatment to further perform purification treatment. Furthermore, a part of the treatment liquid obtained through the wet oxidation treatment may be directly returned to the wastewater before the wet oxidation treatment, or may be supplied to the wastewater from an arbitrary position of the wastewater supply line to be subjected to the wet oxidation treatment. For example, the treatment liquid obtained through the wet oxidation treatment may be used as dilution water of drainage to lower the TOD concentration or the COD concentration of the wastewater. Further, the gas obtained by separation in the gas-liquid separator 5 is discharged from the gas discharge line 13 to the outside. The discharged exhaust gas may be given to another process. In the wet oxidation treatment used in the present invention, a heat exchanger may be used as the heater and the cooler, and these may be used in appropriate combination.

Example

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Example 1]

Details of the reaction column of Example 1 are shown in Fig. Cylindrical SUS product pellets (average particle diameter: 8.5 mm) having a diameter of 6 mm and a length of 5 to 8 mm (average length of 6.5 mm) were placed on a support base made of a grid and a metal net provided in a reaction column 1 having a cylindrical shape with a diameter of 600 mm and a length of 9000 mm mm) was filled 100 mm (H3) in the height direction (bottom filler layer 16; diffuser 3). The pellet had a specific gravity of about 7.9 and a porosity of 43%.

Next, a solid catalyst was packed on the lower packing layer 16 in a 2000 liter height direction at 7074 mm (H4) (catalyst layer 17). The solid catalyst used was a catalyst composed of titania and platinum as main components, and each weight ratio was 99.0: 1.0 in terms of TiO ₂ : Pt. The shape of the solid catalyst was a pellet shape having a diameter of 4 mm and a length of 6 mm (average particle diameter: 7.2 mm). The above-described SUS product pellets were packed on the catalyst layer 17 in a height direction of 300 mm (H5) (upper packing layer 18).

A porous plate 15-1 (gas-liquid dispersing portion) and a plate with an impingement plate 15-2 (gas-liquid dispersing portion) are disposed on the lower side (upstream side) of the lower packing layer 16, The distance between these diffuser plates (diffuser 1) is 950 mm (H1), and the space between the impingement plate (15-2) and the surface of the lower filler layer (16) And the distance from the perforated plate 15-1 to the inlet (interface) of the catalyst layer 17 was 110 mm (H6). The perforation ratio of the perforated plate was 2.2%, and 53 holes per 1 m 2 were uniformly arranged in the perforated plate.

(Drainage treatment test)

In the waste water treatment method shown in Fig. 1, the reaction tower of Example 1 was used as the reaction tower 1, and the waste water treatment was carried out for a total of 1000 hours under the following conditions. The waste water sent from the drainage supply line 10 is supplied to the drainage pump 3 at a flow rate of 4 m3 / hr and fed to the heat exchanger 2 and the electric heater (heating means 8) The maximum temperature was adjusted to 250 DEG C and fed from the bottom of the reaction tower (1). After the air is supplied from the oxygen-containing gas supply line 11 and the pressure is increased to the compressor 4, the heat exchanger 2 (CO 2) is supplied so that the ratio of O ₂ / COD (Cr) ) And mixed in the drainage. The LHSV in the catalyst layer was 2.0 ^hr &lt; ^{-1 &} gt ;. The treatment liquid after the wet oxidation treatment was cooled in the cooler 9 through the treatment liquid line 12 and then subjected to gas-liquid separation treatment by the gas-liquid separator 5. In the gas-liquid separator 5, the liquid level is detected by the liquid level controller LC, the liquid level control valve 6 is operated to maintain a constant liquid level, the pressure is detected by the pressure controller PC, And operated to maintain a pressure of 7 MPaG. Then, the treatment liquid thus treated was discharged from the treatment liquid discharge line 14. The reaction inlet pressure (PI) at the start of the treatment was 7.2 MPaG.

The wastewater supplied to the treatment contained COD (Cr) = 43 g / L, pH 11, containing 25 mg / L of Ca and 1 mg / L of Fe as scale components.

(COD (Cr) throughput)

The COD (Cr) treatment rate after 1000 hours of reaction was 85%. The COD (Cr) throughput was calculated using the following equation.

&Quot; (2) &quot;

(Attachment of scale component)

The catalyst was pulled out and visually confirmed with respect to the scale component attachment condition and evaluated according to the following criteria.

A: Almost no adhesion

B: Some attachment is visible

C: Obviously the attachment (brown) is visible

(Residence time of drainage)

The residence time of the drainage in the diffusion parts 1 to 3 was calculated using the following equation. Table 2 shows the residence times of the drains in the diffusing portions 1 to 3.

&Quot; (3) &quot;

Dwell time of drainage (sec) = Length of diffusion layer (mm) ÷ Flow rate of drainage (mm / sec)

[Examples 2 to 7]

In Examples 2 to 7, the distance H1 between the perforated plate 15-1 and the impinged plate 15-2 in the reaction column of Example 1 and the distance H1 between the perforated plate 15-1 and the lower filling layer And the value of the distance H2 from the inlet to the inlet (16) was changed to the values shown in Table 1, the above-mentioned drainage treatment test was carried out. The treatment rate after 1000 hours and the scale component attachment state to the catalyst are shown in Table 1, and the retention time of the waste water is shown in Table 2.

[Examples 8 to 9]

In Examples 8 to 9, the above-mentioned wastewater treatment test was carried out using the reaction tower in which the value of H1 in the reaction column of Example 4 was changed as shown in Table 3. [ The treatment rate after 1000 hours and the scale component attachment state to the catalyst are shown in Table 3, and the retention time of the waste water is shown in Table 4.

[Comparative Example 1]

In Comparative Example 1, the above-mentioned wastewater treatment test was carried out using a reaction tower in which the value of H1 was changed to 1200 mm in the reaction column of Example 1. [ The treatment rates after 1000 hours and the scale component attachment state to the catalyst are shown in Table 5, and the retention time of the waste water is shown in Table 6.

[Comparative Example 2]

In Comparative Example 2, the above-mentioned wastewater treatment test was carried out using the reaction tower in which the values of H1 and H2 in the reaction column of Example 1 were changed to the values shown in Table 5. [ The treatment rates after 1000 hours and the scale component attachment state to the catalyst are shown in Table 5, and the retention time of the waste water is shown in Table 6.

[Comparative Example 3]

In Comparative Example 3, the values of H1 and H2 in the reaction column of Example 1 were changed to the values shown in Table 5, and the above-mentioned drainage treatment test was carried out using a reaction tower in which the lower filling layer 16 was not filled. The treatment rates after 1000 hours and the scale component attachment state to the catalyst are shown in Table 5, and the retention time of the waste water is shown in Table 6.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 H1 [mm] 950 700 750 150 10 10 10 H2 [mm] 10 60 160 240 390 690 840 H3 [mm] 100 ← ← ← ← ← ← H4 [mm] 7074 ← ← ← ← ← ← H5 [mm] 300 ← ← ← ← ← ← H6 [mm] 110 160 260 340 490 790 940 H6 / H1 0.12 0.23 0.35 2.3 49 79 94 Throughput [%] ※ 85 87 89 92 89 86 85 Catalyst
Precipitation of scale components B B A A A B B

※ COD (Cr) treatment rate after 1000 hours

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 (a) In the diffuser 1
Retention time of drainage [sec] 242 178 191 38.2 2.5 2.5 2.5 (b) in diffusion section 2
Retention time of drainage [sec] 2.5 15.3 40.7 61.1 99.2 175.6 213.8 (c) In the diffuser 3
Retention time of drainage [sec] 25.4 25.4 25.4 25.4 25.4 25.4 25.4 (b) + (c) [sec] 27.9 40.7 66.1 86.5 124.6 201.0 239.2 {(b) + (c)} / (a) 0.12 0.23 0.35 2.3 49.8 80.4 95.7

Example 4 Example 8 Example 9 H1 [mm] 150 900 25 H2 [mm] 240 ← ← H3 [mm] 100 ← ← H4 [mm] 7074 ← ← H5 [mm] 300 ← ← H6 [mm] 340 340 340 H6 / H1 2.3 0.38 14 Throughput [%] ※ 92 89 91 Catalyst
Precipitation of scale components A B A

※ COD (Cr) treatment rate after 1000 hours

Example 4 Example 8 Example 9 (a) In the diffuser 1
Retention time of drainage [sec] 38.2 229 6.4 (b) in diffusion section 2
Retention time of drainage [sec] 61.1 ← ← (c) In the diffuser 3
Retention time of drainage [sec] 25.4 ← ← (b) + (c) [sec] 86.5 86.5 86.5 {(b) + (c)} / (a) 2.3 0.38 14

Comparative Example 1 Comparative Example 2 Comparative Example 3 H1 [mm] 1200 5 100 H2 [mm] 10 500 100 H3 [mm] 100 ← H4 [mm] 7074 ← ← H5 [mm] 300 ← ← H6 [mm] 110 600 100 H6 / H1 0.09 120 1.00 Throughput [%] ※ 56 65 45 Catalyst
Precipitation of scale components C C C

※ COD (Cr) treatment rate after 1000 hours

Comparative Example 1 Comparative Example 2 Comparative Example 3 (a) In the diffuser 1
Retention time of drainage [sec] 305 1.3 25.4 (b) in diffusion section 2
Retention time of drainage [sec] 2.5 127.2 25.4 (c) In the diffuser 3
Retention time of drainage [sec] 25.4 25.4 0.0 (b) + (c) [sec] 27.9 152.6 25.4 {(b) + (c)} / (a) 0.09 117.4 1.00

As shown in Tables 1 and 3, in Examples 1 to 9, the precipitation of scale components into the catalyst can be suppressed by setting H6 and H6 / H1 within a predetermined range, and accordingly, . On the other hand, as shown in Table 5, in Comparative Examples 1 to 3, any one of the values of H6 / H1 or H6 was not included in the scope of the present invention, so that the scale component clearly adhered to the catalyst, .

As shown in Tables 2 and 4, in Examples 1 to 9, (1) the retention times of the wastewater in the diffusion portions 1 to 3, (2) the retention times of the wastewater in the diffusion portion 3 and the diffusion portion 2 And (3) the residence time of the drain water of (2) relative to the residence time of the drainage in the diffusion part 1 is set to a predetermined range, scale component precipitation to the catalyst can be suppressed, It can be seen that the performance can be kept high. On the other hand, as shown in Table 6, in Comparative Examples 1 to 3, any one of the above-mentioned (1) to (3) was not satisfied, so that the scale component clearly adhered to the catalyst and the catalyst performance was deteriorated.

[Examples 10 to 14]

In Examples 10 to 14, the reaction tower obtained by changing the hole area ratio of the perforated plate provided as the dispersion plate (15-1) and the number of perforated plate per square meter in the reaction column of Example 4 to the value shown in Table 7 The above-mentioned drainage treatment test was carried out.

The aperture ratio of the perforated plate is a value calculated by the following equation.

&Quot; (4) &quot;

The results are shown in Table 7.

Example 4 Example 10 Example 11 Example 12 Example 13 Example 14 Opening Rate [%] 2.2 0.30 0.35 10.4 2.2 2.2 Number of holes per 1m2
[Dog / ㎡] 53 53 53 53 21 106 Throughput [%] ※ 92 85 88 87 88 90 Catalyst
Precipitation of scale components A B B B A A

※ COD (Cr) treatment rate after 1000 hours

As shown in Table 7, it can be seen that the treatment performance of the catalyst and the precipitation of scale components on the catalyst can be controlled by the hole area ratio of the perforated plate and the number of holes per 1 m 2.

[Examples 15-1 to 15-4]

Details of the reaction columns of Examples 15-1 to 15-4 are shown in Figs. The values of H1 to H6 are the same as those of the reaction column of Example 4 as shown in Table 8. The above-mentioned drainage treatment test was carried out using the reaction tower modified as follows for the dispersion plates 15-1 and 15-2. The results are shown in Tables 8 and 9.

3 (Example 15-1): A device in which a dispersing plate 15-1 is a plate having an impingement plate and a dispersing plate 15-2 is arranged as a porous plate

4 (Example 15-2): A device in which the dispersing plates 15-1 and 15-2 were formed as a porous plate

5 (Example 15-3): A device in which the dispersion plates 15-1 and 15-2 were made into plates

6 (Example 15-4): An apparatus in which a single plate (15-4) with an impact plate and a perforated plate (15-3) are arranged one by one. The distance between the dispersion plate 15-3 and the dispersion plate 15-4 was 150 mm and the distance between the dispersion plate 15-2 and the dispersion plate 15-3 was 300 mm.

[Comparative Example 4]

The reaction tower of Comparative Example 4 is an apparatus in which only one perforated plate is disposed as a dispersing plate as shown in Fig. The values of H2 to H6 are the same values as those of the reaction column of Example 4 as shown in Table 8. The wastewater treatment test was carried out using this reaction tower. The results are shown in Tables 8 and 9.

Example 4 Example 15-1 Example 15-2 Example 15-3 Example 15-4 Comparative Example 4 H1 [mm] 150 ← ← ← ← H2 [mm] 240 ← ← ← ← ← H3 [mm] 100 ← ← ← ← ← H4 [mm] 7074 ← ← ← ← ← H5 [mm] 300 ← ← ← ← ← H6 [mm] 340 ← ← ← ← ← H6 / H1 2.3 ← ← ← ← Throughput [%] ※ 92 90 88 87 93 50 Catalyst
Precipitation of scale components A B B B A C

※ COD (Cr) treatment rate after 1000 hours

Example 4 Example 15-1 Example 15-2 Example 15-3 Example 15-4 Comparative Example 4 (a) In the diffuser 1
Retention time of drainage [sec] 38.2 ← ← ← ← (b) in diffusion section 2
Retention time of drainage [sec] 61.1 ← ← ← ← ← (c) In the diffuser 3
Retention time of drainage [sec] 25.4 ← ← ← ← ← (b) + (c) [sec] 86.5 ← ← ← ← ← {(b) + (c)} / (a) 2.3 ← ← ← ←

As shown in Tables 8 and 9, it is possible to suppress the precipitation of scale components in the catalyst by providing two dispersion plates on the upstream side (the supply side of the drainage) with respect to the drainage of the lower packing material layer, The processing performance can be maintained at a high level. In Example 4, by providing a porous plate (dispersing plate 15-2) as a dispersing plate 2 and a single-plate (scattering plate 15-1) with an impingement plate as a dispersing plate 1, -3, it is possible to further suppress the precipitation of the scale component into the catalyst, and thus the treatment performance of the catalyst can be maintained to be higher. Furthermore, it can be understood that the effect of the present invention can be enhanced by adding a dispersion plate to the fourth and the fifth embodiments.

[Example 16]

In Example 16, the above-mentioned wastewater treatment test was carried out using a reaction tower in which the value of H3 in the reaction column of Example 4 was changed to 200 mm. The results are shown in Tables 10 and 11.

[Example 17]

The details of the reaction column of Example 17 are shown in Fig. A spherical SUS ball having a diameter of 8.0 mm was filled as a second filling material layer 19 (filling material layer 2) 30 mm (H7) in the height direction on the lower filling material layer 16 (H3: 170 mm; Filler layer 1). The specific gravity of the SUS ball was about 8.2, and the porosity of the second packing layer 19 was 41%. The wastewater treatment test was carried out using this reaction tower. The results are shown in Tables 10 and 11.

[Examples 18 to 20]

In Examples 18 to 20, the above-mentioned wastewater treatment test was carried out using the reaction tower in which the value of H7 in the reaction column of Example 17 was changed to the values shown in Table 10. [ The results are shown in Tables 10 and 11.

[Example 21]

In Example 21, a reaction tower in which spherical zirconia balls having a diameter of 7.5 mm were packed in a height direction of 100 mm (H7) in the second packing layer 19 (packing layer 2) of the reaction column of Example 18 The above-mentioned drainage treatment test was carried out. The specific gravity of the zirconia balls was about 5.3, and the porosity of the second packing layer 19 (packing layer 2) was 41%. The results are shown in Tables 10 and 11.

Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 H1 [mm] 150 ← ← ← ← ← H2 [mm] 240 ← ← ← ← ← H3 [mm] 200 170 100 100 100 100 H4 [mm] 7074 ← ← ← ← ← H5 [mm] 300 ← ← ← ← ← H6 [mm] 440 440 440 640 840 440 H7 [mm] 0 30 100 300 500 100 Ball material SUS SUS SUS SUS SUS Zirconia H6 / H1 2.9 2.9 2.9 4.3 5.6 2.9 Throughput [%] ※ 92 93 95 94 92 96 Catalyst
Precipitation of scale components A A A A A A

※ COD (Cr) treatment rate after 1000 hours

Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 (a) In the diffuser 1
Retention time of drainage [sec] 38.2 ← ← ← ← ← (b) in diffusion section 2
Retention time of drainage [sec] 61.1 ← ← ← ← ← (c) In the diffuser 3
Retention time of drainage [sec] 50.9 50.9 50.9 101.8 152.7 50.9 (b) + (c) [sec] 112.0 112.0 112.0 162.9 213.8 112.0 {(b) + (c)} / (a) 2.9 2.9 2.9 4.3 5.6 2.9

As shown in Tables 10 and 11, it can be seen that the processing performance of the catalyst can be maintained higher by making the lower filling layer (diffusing portion 3) have a two-layer structure. Further, in Example 21, since the treatment performance of the catalyst can be maintained higher by using the ceramic filler for the second packing layer 19 as compared with Example 18, precipitation of the scale component into the catalyst can be further suppressed I think.

1 reaction tower
2 heat exchanger
3 drainage 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 drainage supply lines
11 oxygen-containing gas supply line
12 processing solution line
13 gas discharge line
14 Treatment liquid discharge line
15 diffuser plate
16 bottom filling layer
17 catalyst layer
18 top packing layer
19 second filling layer

Claims (11)

As a waste water treatment apparatus having a dispersion plate 2, a dispersion plate 1, a packing layer and a catalyst layer in this order from the supply side of waste water,
The distance between the dispersion plate 2 and the dispersion plate 1 is H1, the distance between the dispersion plate 1 and the interface of the supply side of the discharge water of the packing layer is H2, the layer length of the packing layer is H3 and the sum of H2 and H3 H6,
Wherein the H6 is more than 100 mm and the ratio (H6 / H1) of the H6 to the H1 is 0.1 or more and 100 or less. The method according to claim 1,
And the H1 is 10 mm or more and 1000 mm or less. The method according to claim 1 or 2,
Wherein at least one of the dispersion plate 1 and the dispersion plate 2 is a porous plate and the number of holes of the porous plate is 5 or more and 200 or less per 1 m2. The method according to any one of claims 1 to 3,
Wherein the filling layer has a two-layer structure. The method of claim 4,
Wherein the filler layer (1) and the catalyst layer side filler layer (2) have a layer length of 30 mm or more and 500 mm or less when the two-layer filler layer has a filler layer on the supply side of waste water. The method according to claim 4 or 5,
(D1) of the filling material 1 contained in the filling material layer 1, and the average particle diameter d1 of the filling material layer 2 in the filling material layer 2 as the filling material layer 1 and the catalyst layer- The average particle diameter (d2) of the filler (2) contained in the packing layer (2) and the average particle diameter (d0) of the catalyst contained in the catalyst layer satisfy a relationship d1>d2> d0. The method according to any one of claims 1 to 6,
Wherein the catalyst contained in the catalyst layer is a wet oxidation catalyst. A method of treating wastewater using a device having at least a gas-liquid diffusion portion (1), a gas-liquid diffusion portion (2), a gas-liquid diffusion portion (3)
The wastewater is dispersed in the gas,
(1) to (3) below:
(1) the residence times of the wastewater in the gas-liquid diffusion units 1 to 3 are all at least 0.5 second;
(2) the sum of the residence times of the wastewater in the gas-liquid diffusion section 3 and the gas-liquid diffusion section 2 is 5 seconds or more; And
(3) The treatment method according to (1), wherein the sum of the residence times of the waste water in (2) above is 0.1 to 100 times the residence time of the waste water in the gas- The method of claim 8,
Wherein the gas-liquid diffusion portion 3 is a filler layer having a porosity of 20 to 90% by volume. The method according to claim 8 or 9,
The gas-liquid diffusion portion 1 has a dispersion plate 1 at the interface between the supply side of the waste water and the gas-liquid diffusion portion 2 has a dispersion plate 2 at the interface with the gas-liquid diffusion portion 1,
At this time, the dispersion plate 1 and the dispersion plate 2 each have at least one hole, and at least one of the dispersion plate 1 and the dispersion plate 2 has a perforated plate structure with an aperture ratio of 0.005% to 30%. The method according to any one of claims 8 to 10,
(I) to (iv) below:
(i) an LHSV of 0.1hr ^-1 ~ 10hr ^-1 at the catalyst layer being;
(ii) the drainage temperature in the catalyst layer is 80 ° C to 370 ° C;
(iii) the pressure in the catalyst bed is such that at least a portion of the drainage water maintains a liquid phase; And
(iv) the oxygen content contained in the gas is 0.5 to 5.0 times the theoretical oxygen demand of the oxidized substance in the wastewater.

Images