A catalytic reduction filler and a catalytic reduction reactor

Abstract

The present invention discloses a catalytic reduction filler and a catalytic reduction reactor, wherein the catalytic reduction filler comprises a filler shell, a metal catalyst, an electrode foil, and a floating member, wherein the filler shell is a porous structure, the metal catalyst, the electrode foil, and the floating member are placed in the filler shell, and the floating member is used to provide buoyancy for the filler. The filler provided by the present invention can solve the problems of the existing iron-carbon filler being easy to harden during use, the processing efficiency decreasing quickly, being difficult to replace, having large loss, and producing large amount of mud.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic reduction in sewage treatment, and in particular relates to a catalytic reduction filler and a catalytic reduction reactor. Background Art

[0002] As a traditional process of micro-electrolysis technology, the iron-carbon method is mostly used in the pretreatment process of high-concentration, highly toxic, and difficult-to-degrade organic wastewater (such as printing and dyeing wastewater). As the reaction proceeds, the iron as the anode is continuously consumed to generate ferrous ions. Under the condition of oxygen, it further generates colloidal flocculants with strong adsorption capacity such as ferrous hydroxide and ferric hydroxide. The [H] and [O] produced by the cathode can undergo redox reactions with pollutants in the wastewater, causing macromolecular organic matter to break and degrade, such as reducing nitrobenzene in printing and dyeing wastewater to aniline, which reduces the color of the wastewater and improves its biodegradability. The traditional iron-carbon process also has problems such as large filler loss, easy compaction, and large sludge production, which affects the efficiency of micro-electrolysis, and the replacement of fillers is time-consuming and labor-intensive. Therefore, it is necessary to develop a new type of catalytic reducing filler to replace the iron-carbon system, improve the treatment efficiency, prevent compaction, and solve the problem of troublesome filler replacement. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a catalytic reduction filler and a catalytic reduction reactor, which solves the problems of the existing filler being easy to compact during use, rapid decrease in treatment efficiency, difficult to replace, large loss, and large sludge production.

[0004] To solve the above problems, the technical solution of the present invention is:

[0005] A catalytic reduction filler comprises a filler shell, a metal catalyst, an electrode foil and a floating member. The filler shell is a porous structure. The metal catalyst, the electrode foil and the floating member are placed in the filler shell. The floating member is used to provide rising buoyancy for the filler.

[0006] Preferably, the floating member is a hollow ball.

[0007] Preferably, the mass ratio of the metal catalyst to the electrode foil filled in the filler shell is no more than 1:10.

[0008] Preferably, the metal catalyst is in the shape of a sheet, a ring, or a hollow sphere.

[0009] Preferably, the metal catalyst is one or more of copper, zinc and palladium.

[0010] Preferably, the electrode foil is in the shape of a paper ball.

[0011] Preferably, the filler shell is spherical.

[0012] Preferably, the diameter of the filler shell is 5-10 cm.

[0013] The present invention also provides a catalytic reduction reactor, which contains a plurality of catalytic reduction fillers described in the above embodiments.

[0014] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0015] (1) The catalytic reduction filler provided by the present invention loads the metal catalyst and the electrode foil into a filler shell with a porous structure, so that the entire filler area is divided into a large number of relatively independent micro-electrolysis systems that do not affect each other. Therefore, the reactor using the filler of the present invention does not require an additional frame and will not become hardened. It is superior to traditional iron-carbon micro-electrolysis fillers in both early production and later maintenance and operation.

[0016] (2) The catalytic reduction packing provided by the present invention is also filled with a floating member. The function of the floating member is to provide buoyancy to the packing. When the electrode foil is consumed, the density of the packing decreases. With the help of the floating member, the packing floats up. The operator can observe it very conveniently above the reactor. It only needs to fish out the failed packing and add new packing to complete the packing replacement, which saves time and effort and reduces operating costs.

[0017] (3) The present invention designs the filler to have a porous filler shell structure. This structure has a large specific surface area, which can ensure that the filler is in full contact with the wastewater. The filler is appropriately filled in the reactor and is not prone to clogging under the action of intermittent air purge, thereby maintaining a high treatment efficiency for a long time.

[0018] (4) The existing iron-carbon filler needs to adjust the pH to about 3 when used, which consumes a lot of acid and produces a lot of sludge. The catalytic reduction filler of the present invention can not only be used under pH=4-6 conditions, which greatly reduces the amount of sludge, but also achieves a good treatment effect under alkaline conditions (pH: 8-11). If the treated wastewater itself is alkaline, the pH value of the influent can be adjusted without adjusting or to a slightly adjusted pH value, so the dosage is greatly reduced, and the physical and chemical sludge produced by the reaction is also much smaller than that of the traditional iron-carbon method.

[0019] (5) The filler shell is a porous structure, preferably spherical, and can be made into two hemispheres connected on one side, and a simple detachable connection, such as a snap, is made on the other side. The structure is simple and reliable, and the electrode foil and the metal catalyst can be directly mixed and placed in the filler shell without special processing. Compared with the existing iron-carbon filler, the processing and manufacturing cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the catalytic reduction filler in Example 1 of the present invention;

[0021] Figure 2 Schematic diagram of the cross-sectional structure of the catalytic reduction filler in Example 1 of the present invention;

[0022] Figure 3 Schematic diagram of the structure of the catalytic reduction reactor in Example 2 of the present invention.

[0023] Explanation of the reference numerals: 1-packing shell; 2-metal catalyst; 3-electrode foil; 4-floating member; 5-reactor body; 6-water inlet; 7-water outlet; 8-mud outlet; 9-air inlet; 10-air purge device; 11-packing area. DETAILED DESCRIPTION

[0024] The catalytic reduction filler and catalytic reduction reactor proposed by the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0025] Example 1

[0026] It should be noted that the first generation of iron-carbon fillers is to directly mix iron filings and carbon powder and pile them in the iron-carbon bed reactor. The initial treatment effect is good, but it will soon become hardened and the treatment efficiency will decrease. When it is replaced later, the entire pool needs to be cleaned, which is labor-intensive and costly. The second generation of iron-carbon fillers is to mix iron filings and carbon powder into block fillers, which are piled in the reactor when used. Although the hardening problem is solved well, the surface area of ​​the filler in contact with the wastewater is reduced, which affects the treatment effect. In addition, the filler has a high stacking density and low porosity. It is very easy to get blocked during operation, and channeling occurs, which further affects the treatment effect.

[0027] Therefore, this embodiment proposes a catalytic reduction filler, see Figure 1 and Figure 2 The catalytic reduction filler includes a filler shell 1, a metal catalyst 2, an electrode foil 3, and a floating member 4. The filler shell 1 is a porous structure. The metal catalyst 2, the electrode foil 3 and the floating member 44 are placed in the filler shell 1. The floating member 44 is used to provide buoyancy for the filler. When the electrode foil 3 is consumed, the density of the filler decreases. With the help of the floating member 4, the filler floats up. The operator can observe it very conveniently above the reactor. It only needs to salvage the failed filler and add new filler to complete the replacement of the filler, which saves labor and operating costs. The floating member 44 can be a hollow material of various shapes, or it can be an acid- and alkali-resistant plastic or foam material with a density less than water, preferably a hollow ball.

[0028] The specific surface area of ​​the catalytic reduction filler in this embodiment is very large, especially when the filler shell 1 is preferably spherical, 1m 3 The specific surface area of ​​the filler is greater than 700m 2When the specific surface area is large, it can ensure that the filler is in full contact with the wastewater, and when the filler has a suitable filling rate in the reactor (the diameter of the spherical filler shell 1 is preferably 5-10 cm, and the filling rate is preferably 45%-55%), it is not easy to be blocked under the action of intermittent air blowing, so the expected high treatment efficiency can be maintained for a long time.

[0029] Preferably, the metal catalyst 2 is in the shape of a sheet, a ring, or a hollow sphere.

[0030] Preferably, the metal catalyst 2 is one or more of copper, zinc, and palladium. However, due to cost considerations, copper is generally selected as the catalyst, or a catalyst mainly composed of copper.

[0031] Preferably, the electrode foil 3 is in the shape of a paper ball.

[0032] The catalytic reduction filler provided in this embodiment loads the metal catalyst 2 and the electrode foil 3 in a filler shell 1 with a porous structure, so that the entire filler area is divided into a large number of relatively independent micro-electrolysis systems that do not affect each other. Therefore, the reactor using the filler of the present invention does not require an additional frame and will not become hardened. The shape of the metal catalyst 2 is preferably sheet-shaped or ring-shaped, and the shape of the electrode foil 3 is preferably paper ball-shaped or round. Therefore, the possibility of hardening of the electrode foil 3 or the metal catalyst 2 in the filler shell 1 is also very low. Therefore, the filler of this embodiment is superior to the traditional iron-carbon micro-electrolysis filler in both early production and later maintenance and operation.

[0033] In this embodiment, the filler shell 1 is spherical, including two hemispheres, one side of which is movably connected, such as hinged, and the other side is detachably connected, such as snap-on connection, so that the two hemispheres can be opened and locked conveniently. When opened, the metal catalyst 2 and the electrode foil 3 can be directly mixed and placed in the spherical shell without special processing. Compared with the second generation iron-carbon filler, the processing and manufacturing cost is low. Of course, the filler shell 1 can also be other shapes, or made into a cuboid or a cube, with a feeding port on the surface for loading the electrode foil 3, the metal catalyst 2 and the floating member 4.

[0034] Preferably, the mass ratio of the metal catalyst 2 to the electrode foil 3 filled in the filler shell 1 is not greater than 1:10.

[0035] The existing iron-carbon filler needs to adjust the pH to about 3 when used, which consumes a large amount of acid and produces a large amount of sludge. The catalytic reduction filler of the present invention uses an electrode foil 3 as the anode. The electrode foil is made of refined aluminum (also called high-purity aluminum) through a series of processes such as rolling, corrosion, and energization. Since aluminum has strong reduction activity and electron transfer ability, it can still achieve very good treatment effects (the decolorization rate is increased by more than 80% compared with the iron-copper method) when used under pH=4-6. Therefore, the amount of acid required to be added and the amount of alkali added during coagulation and precipitation after the reaction are greatly reduced, greatly reducing the amount of sludge; at the same time, a good treatment effect can also be achieved under alkaline conditions (pH=8-11). The electrode foil loses electrons as the anode and is oxidized, and the catalyst acts as the cathode. The organic matter in the wastewater obtains electrons at the cathode and is reduced. Moreover, under alkaline conditions, aluminum itself can react with hydroxide and dissolve. If the treated wastewater itself is alkaline, the pH value of the influent can be adjusted without or to a slightly adjusted pH value, so the amount of drug added is greatly reduced, and the physical and chemical sludge produced by the reaction is also much smaller than that of the traditional iron-carbon method.

[0036] Example 2

[0037] See also Figure 3 The present embodiment provides a catalytic reduction reactor for pretreatment of printing and dyeing wastewater, comprising a reactor body 5, an air purge device 10 and a filling area 11. The reactor body 5 is provided with a water inlet 6 at the bottom, a water outlet 7 at the top, and a mud discharge port 8 at the bottom. The air purge device 10 is arranged in the reactor body 5. The air inlet 9 of the air purge device 10 is connected to an external air supply device. The air purge device 10 can select a perforated pipe or a rotary mixed flow aerator or an ejector. The space above the air purge device 10 and below the water outlet 7 is the filling area 11, and the filling area 11 is filled with the catalytic reduction filler described in Example 1.

[0038] After the printing and dyeing wastewater enters the reactor body 5 from the water inlet 6, through the catalytic reduction reaction, the macromolecular refractory organic matter is decomposed into easily degradable small molecular substances, and the highly toxic substances are converted into low-toxic or non-toxic substances, which is conducive to improving the removal effect of the subsequent aerobic biological treatment system on pollutants. When the bottom aeration is turned on, the filler can continuously roll inside the reactor, fully contact and mix with the wastewater, strengthen the mass transfer between the gas, liquid and solid phases, and improve the removal effect of pollutants in the wastewater. As the catalytic reduction reaction proceeds, the electrode foil 3 is continuously consumed, the weight of the filler is reduced, and due to the action of the floating part 4, the filler will float up. When the filler floats on the water surface, it can be directly salvaged, and new filler can be added at the same time to complete the replacement of the filler. The consumed electrode foil 3 becomes sludge and is discharged from the reactor body 5 through the mud discharge port 8 for further treatment, and the treated wastewater is discharged from the reactor body 5 from the water outlet 7.

[0039] The hydrolysis acidification process is a commonly used pretreatment process for printing and dyeing wastewater. The corresponding hydrolysis acidification tank generally occupies a large area. The reactor equipped with catalytic reduction filler can completely replace the hydrolysis acidification tank. It can reduce the floor space of the tank while ensuring the pretreatment effect. It is especially suitable for renovation projects with limited land.

[0040] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A catalytic reduction filler used in the micro-electrolysis treatment process of high-concentration, highly toxic, and difficult-to-degrade organic wastewater, characterized in that: It includes a packing shell, a metal catalyst, an electrode foil, and a floating member. The packing shell is a porous structure. The metal catalyst, the electrode foil, and the floating member are placed in the packing shell. The floating member is used to provide buoyancy for the packing. The electrode foil is made of refined aluminum. The catalytic reduction filler uses the electrode foil as the anode and the metal catalyst as the cathode to form a micro-electrolysis system.

2. The catalytic reduction filler according to claim 1, characterized in that: The floating member is a hollow ball.

3. The catalytic reduction filler according to claim 1, characterized in that: The mass ratio of the metal catalyst filled in the filler shell to the electrode foil is no more than 1:

10.

4. The catalytic reduction filler according to claim 1, characterized in that: The metal catalyst is in the shape of a sheet, a ring or a hollow sphere.

5. The catalytic reduction filler according to claim 1 or 4, characterized in that: The metal catalyst is one or more of copper, zinc and palladium.

6. The catalytic reduction filler according to claim 1, characterized in that: The electrode foil is in the shape of a paper ball.

7. The catalytic reduction filler according to claim 1, characterized in that: The filler shell is spherical.

8. The catalytic reduction filler according to claim 7, characterized in that: The diameter of the filler shell is 5-10 cm.

9. A catalytic reduction reactor, characterized in that: Contains the catalytic reduction fillers described in any one of claims 1 to 8.

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