Integrated elution-reflux external circulation mixed filler biofilter column reactor and its application

Abstract

The present invention discloses an integrated elution-reflux external circulation mixed filler biofilter column reactor and its application. The reactor comprises a reaction column and a circulation component; the reaction column is provided with a defoaming gas distributor, a liquid distributor, a biofilm reaction chamber, a grid plate, a redistributor, an elution chamber, a filter material layer and a supporting layer in sequence from top to bottom; an air outlet is provided on the top of the reaction column, an air inlet is provided in the elution chamber, and a liquid outlet is provided at the bottom of the supporting layer; the circulation component comprises a connecting pipe and a lifting pump, and the connecting pipe is connected to the liquid distributor via the lifting pump from the liquid outlet. The present invention realizes the purification of waste gas by the biofilm method, and the discharge liquid is recycled for secondary use, and the process is simple, the device occupies a small area, the cost is low, and the purification efficiency of organic waste gas is high.

Description

Technical Field

[0001] The invention belongs to the technical field of organic waste gas purification, and specifically relates to an integrated elution-reflux external circulation mixed filler biological filter column reactor and application thereof. Background Art

[0002] At present, industries such as cosmetics workshops, spice workshops and food workshops are prone to produce volatile organic waste gases such as ethyl acetate, toluene, benzene and n-hexane during operation.

[0003] The traditional catalytic co-combustion technology has problems such as reduced adsorption saturation efficiency, difficulty in adsorbent regeneration and high catalyst cost.

[0004] The biological method for treating VOCs has the advantages of high safety, no secondary pollution, low cost and high treatment efficiency. It uses microorganisms to grow partially on the filter material to form a biofilm, and partially grow in suspension between the gaps in the filter material. When sewage flows through the filter material with biofilm, the organic matter in the water diffuses to the surface of the biofilm and is degraded by the microorganisms in the biofilm. The purified water is discharged outside the pool through drainage equipment.

[0005] Traditional biofilter adsorption fillers use a single filler, which is usually flat and requires drainage equipment, so the water cannot circulate. Some require additional regulating tanks, clear water tanks and backwash systems to achieve reasonable sewage treatment, resulting in large floor space and low removal rate. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an integrated elution-reflux external circulation mixed filler biofilter column reactor and its application. A vertical biofilter column is adopted, which has the advantages of a large aspect ratio, a small footprint, and a more significant removal rate. A mixed filler is adopted to enhance the treatment effect of a variety of fillers, and the reflux system promotes secondary utilization and resource circulation, thereby solving the problems in the above-mentioned background technology.

[0007] One of the technical solutions adopted by the present invention to solve the technical problem is: providing an integrated elution-reflux external circulation mixed filler biofilter column reactor, including a reaction column and a circulation component;

[0008] The reaction column is provided with a defoaming gas distributor, a liquid distributor, a biofilm reaction chamber, a grid plate, a redistributor, an elution chamber, a filter material layer and a supporting layer in sequence from top to bottom; an air outlet is provided on the top of the reaction column, an air inlet is provided in the elution chamber, and a liquid outlet is provided at the bottom of the supporting layer;

[0009] The circulation component comprises a connecting pipe and a lifting pump, and the connecting pipe is connected to the liquid distributor from the liquid outlet via the lifting pump.

[0010] In a preferred embodiment of the present invention, the defoaming gas distributor is a baffle defoaming gas distributor.

[0011] In a preferred embodiment of the present invention, the liquid distributor is composed of a plurality of atomized liquid distributors connected in series.

[0012] In a preferred embodiment of the present invention, a packing partition is provided between the biofilm reaction chamber and the liquid distributor.

[0013] In a preferred embodiment of the present invention, the biofilm reaction chamber is filled with at least two fillers selected from the group consisting of activated carbon, quartz sand, oyster shells, expanded clay, zeolite, and volcanic rock. The particle size of the filler is 3 to 10 mm, and the filler stacking height accounts for 1 / 2 to 3 / 4 of the total height of the reaction column.

[0014] In a preferred embodiment of the present invention, the filler is a mixed filler of ceramsite and quartz sand, the inner diameter of the ceramsite filler is 3-5 mm, and the inner diameter of the quartz sand filler is 1-3 mm. The filler is filled in a ratio of ceramsite to quartz sand of 4:1.

[0015] In a preferred embodiment of the present invention, a biofilm is arranged in the biofilm reaction chamber, and the biofilm is formed by adding biological strains and sludge to the filler while the organic waste gas eluent is passed through the filler and then the biofilm is formed.

[0016] In a preferred embodiment of the present invention, an aeration device is provided in the leaching chamber, and the aeration device is used to maintain the dissolved oxygen concentration in the reaction column at 5-7 mg / L.

[0017] In a preferred embodiment of the present invention, the supporting layer is a gravel supporting layer, and the height thereof is 1 / 20 to 1 / 30 of the total height of the reaction column.

[0018] In a preferred embodiment of the present invention, the outer periphery of the reaction column is a cylindrical or cubic shell, the height-to-diameter ratio of the cylinder is 10:1 to 25:1, and a skirt is further provided at the bottom of the shell.

[0019] The second technical solution adopted by the present invention to solve the technical problem is: to provide an organic waste gas treatment process, using the above-mentioned integrated elution-reflux external circulation mixed filler biofilter column reactor, comprising the following steps:

[0020] 1) Build a biofilter reaction column;

[0021] The organic waste gas enters the reaction column through the air inlet, and the liquid distributor sprays water to wash the organic waste gas, while the aeration device is turned on to stir the mixed liquid in the washing chamber;

[0022] The organic waste gas is discharged from the liquid outlet after being eluted, and introduced into the reaction column by the lifting pump through the connecting pipe, and the water inlet flow rate of the lifting pump is controlled to ensure that the hydraulic retention time is 4h to 12h;

[0023] The reaction column is first started by forming a biofilm, and biological strains and sewage are introduced to perform sludge acclimation while filling the filler. The biofilm formation and sludge acclimation are completed within 14 to 16 days, and the effluent operation process does not discharge sludge;

[0024] 2) Elution-reflux external circulation:

[0025] The eluent is introduced into the reaction column, and the eluent purifies the pollutants from top to bottom through the aeration condition of 5-7 mg / L dissolved oxygen in the reaction column through the aerobic decomposition of the biofilm attached to the filler. The clean effluent after the reaction is refluxed to the liquid distributor through the connecting pipe under the action of the lifting pump, and the new organic waste gas is eluted for the second time by the liquid distributor, thereby realizing the elution-reflux external circulation.

[0026] Compared with the background technology, this technical solution has the following advantages:

[0027] 1. The present invention introduces small-particle mixed fillers into the reaction column. The small-particle mixed fillers have a large specific surface area, which is conducive to the attachment of microorganisms, and are stable in nature, which is conducive to the growth of biofilms, so that a large number of microorganisms can promote the removal of pollutants. Due to the different properties of the mixed fillers, it is conducive to the pretreatment of one filler and the subsequent deep treatment of other fillers. There are certain gaps between the fillers, which can enhance the oxygen transmission effect and promote the microbial reaction. Compared with traditional single fillers, mixed fillers have obvious advantages.

[0028] 2. The filter column style of the present invention has a larger height-to-diameter ratio than the biological filter tank, occupies a small area, and can promote the sewage to slowly pass through the biofilm from top to bottom for full reaction.

[0029] 3. The reaction column of the present invention is beneficial to the aerobic decomposition and nitrification of microorganisms under strong aeration.

[0030] 4. The present invention recycles the effluent through the reflux effect, and the secondary treatment can further improve the removal rate, and the pollutant removal rate reaches more than 95%, which is also beneficial to resource circulation.

[0031] 5. The reaction column of the present invention adopts a baffled defoaming plate gas distributor to enhance the effect of recovering liquid foam and droplets entrained by the gas, so that the organic waste gas can be removed more efficiently.

[0032] 6. The process of the present invention is simple, the device occupies a small area, and the cost is low. The reflux external circulation mixed filler biofilter column reactor can effectively purify organic waste gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1This is a structural diagram of the integrated elution-reflux external circulation mixed filler biofilter column reactor of Example 1.

[0034] Among them, 1- defoaming gas distributor, 2- liquid distributor, 3- packing partition, 4- grid plate, 5- redistributor, 6- filter material layer, 7- supporting layer, 8- skirt, 9- lifting pump, 10- biofilm reaction chamber, 11- elution chamber, 12- aeration device, A- air inlet, B- air outlet, C- liquid outlet, D- reflux outlet. DETAILED DESCRIPTION

[0035] It should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “top”, “bottom”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0036] Example 1

[0037] This embodiment is an integrated elution-reflux external circulation mixed filler (ceramsite + quartz sand) biofilter column reactor, which is designed as a shell and a skirt 8, a reaction column is arranged inside the shell, and a circulation component is arranged outside;

[0038] The reaction column is provided with a defoaming gas distributor 1, a liquid distributor 2, a biofilm reaction chamber 10, a grid plate 4, a redistributor 5, an elution chamber 11, a filter material layer 6 and a support layer 7 in order from top to bottom; an air outlet B is provided on the top of the shell, an air inlet A is provided on the left side of the elution chamber 11, a liquid outlet C is provided at the bottom of the support layer 7, and a reflux port D is connected to the liquid distributor 2. The circulation component includes a connecting pipe and a lifting pump 9, and the connecting pipe is connected from the liquid outlet C to the reflux port D via the lifting pump 9, and then enters the reaction column from the liquid distributor 2.

[0039] Specifically, the defoaming gas distributor 1 is a baffle defoaming gas distributor. The liquid distributor 2 is a high-pressure atomizing liquid distributor 2, and 3 to 4 series-connected liquid distributors 2 are provided. The reaction column shell is a cylindrical PVC pipe with a size of φ70mm*1700mm.

[0040] A filler partition 3 is provided between the biofilm reaction chamber 10 and the liquid distributor 2 to prevent the filler from escaping. The biofilm reaction chamber 10 is filled with at least two fillers selected from activated carbon, quartz sand, oyster shells, ceramsite, zeolite, and volcanic rock. The filler particle size is 3 to 10 mm, and the filler stacking height accounts for 1 / 2 to 3 / 4 of the total height of the reaction column. When the biofilm is started, a biofilm is formed in the biofilm reaction chamber 10. The biofilm is formed by adding biological strains and sludge taming while the organic waste gas elution liquid is passed into the filler.

[0041] The elution chamber 11 is provided with an aeration device 12, and the aeration device 12 includes an impeller, etc., which fully stirs the elution liquid to maintain the dissolved oxygen concentration in the reaction column at 5-7 mg / L.

[0042] The supporting layer 7 is a gravel supporting layer 7, and its height is 1 / 20 to 1 / 30 of the total height of the reaction column.

[0043] The organic waste gas treatment process using the reactor of this embodiment includes the following steps:

[0044] 1) Build a biofilter column reaction column. The organic waste gas enters the reaction column through the reaction column air inlet A, and the liquid distributor 2 sprays water to wash the organic waste gas, and builds a biofilter column reaction column. The organic waste gas enters the reaction column through the reaction column air inlet A, and the liquid distributor 2 sprays water to wash the organic waste gas, forming a wash liquid from top to bottom, and at the same time, the aeration device 12 is turned on to fully stir the mixed liquid in the entire wash tower.

[0045] The bottom layer of the reaction column is provided with a gravel support layer 7, and on the support layer 7 is a quartz sand filter material layer 6, and the inner diameter of the quartz sand filler is 3mm. Above the leaching chamber 11 is a ceramsite filler chamber, and the inner diameter of the ceramsite filler is 5mm. Ceramsite and quartz sand are introduced into the reaction column at a ratio of 4:1, and the total height of the filler is 3 / 4 of the height of the filter column. The eluted organic waste gas elution liquid passes through the quartz sand filter material layer 6 and the liquid outlet C and flows back into the biological filter column through the lifting pump 9, and the hydraulic retention time is 12h.

[0046] The organic waste gas leachate has sufficient dissolved oxygen under full aeration, and the dissolved oxygen concentration is 7 mg / L. The microorganisms on the expanded clay filler carry out aerobic decomposition under aeration conditions. The leachate passes through the biofilm from top to bottom and is fully decomposed on the biofilm.

[0047] 2) The treated effluent is discharged through the grid plate 4 and the redistributor 5, and re-enters the elution chamber 11 for reaction, while the lifting pump 9 can lift the elution liquid to the liquid distributor 2 for secondary elution and repeated use, thereby realizing reflux external circulation.

[0048] The ceramsite and quartz sand mixed filler added to the reaction column has good adsorption performance and stable properties, which is conducive to the attachment of microorganisms and the removal of pollutants. And because the aeration device 12 operates for 24 hours, it provides sufficient dissolved oxygen, which is conducive to biochemical reactions. The eluent after the reaction flows back to the reaction column for secondary elution, which is conducive to resource circulation and secondary utilization. In the reflux state, the water flow has a strong shear force, which can promote the flushing in the reaction column, thereby removing the aged biofilm.

[0049] The reaction column uses PVC pipes, which are low in cost and durable, while the biological filler has high stability, excellent adsorption performance, and a developed pore structure, which can reduce resistance. During the operation, the process has a short sludge acclimation cycle in the early stage, a fast stabilization speed, stable process operation in the formal operation stage, and a long service life during the entire operation process, and a high pollutant removal rate in the reflux state.

[0050] The reactor of this embodiment is replaced and supplemented with eluent after running for one month. The process is simple and the device occupies a small area. The integrated reflux external circulation external circulation mixed filler biofilter column reactor in the reaction column can effectively purify organic waste gas and realize the recycling of discharged water.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated elution-reflux external circulation mixed filler biofilter column reactor, characterized in that: Includes reaction column and circulation assembly; The reaction column is provided with a defoaming gas distributor, a liquid distributor, a biofilm reaction chamber, a grid plate, a redistributor, a leaching chamber, a filter material layer and a supporting layer in order from top to bottom; an air outlet is provided on the top of the reaction column, an air inlet is provided in the leaching chamber, and a liquid outlet is provided at the bottom of the supporting layer; the biofilm reaction chamber is filled with at least two fillers selected from activated carbon, quartz sand, oyster shell, ceramsite, zeolite and volcanic rock, the filler particle size is 3 to 10 mm, and the filler stacking height accounts for 1 / 2 to 3 / 4 of the total height of the reaction column; The circulation component comprises a connecting pipe and a lifting pump, and the connecting pipe is connected to the liquid distributor from the liquid outlet via the lifting pump.

2. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: The defoaming gas distributor is a baffle defoaming gas distributor.

3. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: The liquid distributor is composed of a plurality of atomized liquid distributors connected in series.

4. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: A filler partition is arranged between the biofilm reaction chamber and the liquid distributor.

5. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: The biofilm is arranged in the biofilm reaction chamber, and the biofilm is formed by adding biological bacteria and sludge to the filler while the organic waste gas washing liquid is passed through the filler, and then the biofilm is formed.

6. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: The leaching chamber is provided with an aeration device, and the aeration device is used to maintain the dissolved oxygen concentration in the reaction column at 5-7 mg / L.

7. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: The supporting layer is a gravel supporting layer, and the height thereof is 1 / 20 to 1 / 30 of the total height of the reaction column.

8. The integrated elution-reflux external circulation mixed filler biofilter column reactor according to claim 1, characterized in that: The outer periphery of the reaction column is a cylindrical or cubic shell, the height-to-diameter ratio of the cylinder is 10:1-25:1, and a skirt is further provided at the bottom of the shell.

9. An organic waste gas treatment process, characterized in that: The integrated elution-reflux external circulation mixed filler biofilter column reactor according to any one of claims 1 to 8 comprises the following steps: 1) Build a biofilter reaction column; The organic waste gas enters the reaction column through the air inlet, and the liquid distributor sprays water to wash the organic waste gas, while the aeration device is turned on to stir the mixed liquid in the washing chamber; The organic waste gas is discharged from the liquid outlet after being eluted, and introduced into the reaction column by the lifting pump through the connecting pipe, and the water inlet flow rate of the lifting pump is controlled to ensure that the hydraulic retention time is 4h to 12h; The reaction column is first started by forming a biofilm, and biological strains and sewage are introduced to perform sludge acclimation while filling the filler. The biofilm formation and sludge acclimation are completed within 14 to 16 days, and the effluent operation process does not discharge sludge; 2) Elution-reflux external circulation: The eluent is introduced into the reaction column, and the eluent purifies the pollutants from top to bottom through the aeration condition of 5-7 mg / L dissolved oxygen in the reaction column through the aerobic decomposition of the biofilm attached to the filler. The clean effluent after the reaction is refluxed to the liquid distributor through the connecting pipe under the action of the lifting pump, and the new organic waste gas is eluted for the second time by the liquid distributor, thereby realizing the elution-reflux external circulation.

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