CN211837257U

CN211837257U - System for handle high concentration VOCs waste gas

Info

Publication number: CN211837257U
Application number: CN201922144481.4U
Authority: CN
Inventors: 韩全; 张恒
Original assignee: Guangdong Yeanovo Environmental Protection Co ltd
Current assignee: Guangdong Shangchen Environmental Technology Co ltd
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2020-11-03
Anticipated expiration: 2029-12-03

Abstract

The utility model discloses a system for handle high concentration VOCs waste gas, include the dissolubility organic matter absorption system, Fenton sludge circulation system and MBR membrane sewage treatment system that connect gradually through the pipeline. The utility model firstly leads most of the high-concentration VOCs waste gas into the soluble organic matter absorption system, so that most of the soluble VOCs waste gas is dissolved in water, high-concentration organic waste gas which is difficult to treat is converted into organic waste water which is easy to treat, and then Fenton oxidation and MBR membrane separation treatment are carried out, so that the treatment difficulty is reduced, and the effluent reaches the discharge standard; and the other part of organic components which are difficult to dissolve in water are treated by adopting photocatalysis degradation and activated carbon adsorption, so that the discharged gas reaches the emission standard. The system realizes complete treatment of the high-concentration VOCs waste gas, and greatly reduces the treatment difficulty and the treatment cost.

Description

System for handle high concentration VOCs waste gas

Technical Field

The utility model belongs to the technical field of the pollutant is handled, concretely relates to system for handle high concentration VOCs waste gas.

Background

The Volatile Organic Compounds (VOCs) mainly comprise fluorine-containing aromatic hydrocarbon, alcohol, ether and ester, and also comprise partial HCl and H₂S and other inorganic substances have the characteristics of large concentration, complex components and strong toxicity.

At present, the treatment of VOCs mainly comprises combustion treatment, adsorption treatment and catalytic treatment, wherein the combustion treatment is to directly introduce VOCs into an incinerator for combustion and convert the VOCs into CO₂And H₂And O. The treatment is simple in operation and high in treatment efficiency. But the equipment investment is high, and when other inorganic pollutants such as sulfide, nitrogen oxide and the like exist in VOCs, SO is generated after combustion₂、NO_XAnd the like, leading to secondary pollution of air. The adsorption treatment is to pass VOCs through adsorbing materials such as active carbon, resin and the like, and adsorb pollutants in the VOCs into pores of the adsorbing materials, so that the aim of purifying air is fulfilled. The method has the advantages of low investment and simple operation, and can remove inorganic pollutants, but the adsorption capacity and the adsorption efficiency of the resin are limited, so the method is not suitable for treating high-concentration VOCs. The catalytic treatment is to pass VOCs through a catalyst and simultaneously cooperate with an ultraviolet lamp to degrade pollutants into CO₂And H₂And compared with combustion and adsorption, the treatment efficiency is high, and the tail gas can be efficiently degraded aiming at VOCs with high concentration and complex components, including various inorganic pollutants, so that the tail gas can reach the emission standard. However, the process equipment investment is large and the catalyst needs to be replaced frequently, making its operation more costly.

In view of the above-mentioned drawbacks, a technology for treating VOCs by using a Fenton oxidation circulation system has been developed, which can effectively oxidize organic substances in wastewater, but can only oxidize substances completely dissolved in water, but high-concentration VOCs usually contain a large amount of water-soluble VOCs and a small amount of insoluble organic components, and the treatment by using the Fenton oxidation circulation system alone still does not meet the discharge requirements.

SUMMERY OF THE UTILITY MODEL

Based on this, to above-mentioned technical problem, the utility model aims at providing a system of handling high concentration VOCs waste gas.

In order to realize the purpose of the utility model, the utility model discloses take following technical scheme: a system for treating high-concentration VOCs waste gas comprises a soluble organic matter absorption system, a Fenton sludge circulation system and an MBR membrane sewage treatment system which are sequentially connected through pipelines.

Furthermore, the soluble organic matter absorption system is a water tank or a water tank, and the high-concentration VOCs waste gas is introduced into the soluble organic matter absorption system firstly, so that most of soluble organic matters in the VOCs waste gas are dissolved in water, the high-concentration organic waste gas which is difficult to treat can be converted into the organic waste water which is easy to treat, and the treatment difficulty of the waste water can be reduced.

Furthermore, a sealed gas-collecting hood is arranged above the water tank or the water tank and is used for collecting part of insoluble VOCs in the high-concentration VOCs waste gas.

Furthermore, the gas-collecting hood is connected with a photocatalytic system through a pipeline. The gas collecting hood can continuously extract gas, so that organic components which come out from the water tank and are insoluble in water can enter the photocatalytic system through the pipeline to degrade insoluble VOCs gas, and in order to improve the catalytic efficiency, the system is additionally provided with a plate type catalyst, wherein the main component of the plate type catalyst is TiO₂. And the material of a connecting pipeline between the gas collecting hood and the photocatalytic system is U-PVC.

Further, in order to meet the emission requirement, the photocatalytic system is connected with an active carbon adsorption system through a connecting pipe of U-PVC; and the gas treated by the photocatalytic system enters an activated carbon adsorption system through a pipeline for further adsorption treatment. Furthermore, the activated carbon adsorption system is filled with 80-100 meshes of activated carbon, and residual tail gas is removed through the adsorption effect of the activated carbon, so that the discharged gas can be directly discharged up to the standard.

Further, the Fenton sludge circulating system is a conventional system and generally comprises a Fenton oxidation tower, a neutralization tank, a degassing tank, a coagulation reaction tank and a final sedimentation tank which are sequentially connected through pipelines.

Further, an electrolysis system is arranged at the bottom of the Fenton sludge circulation system. When the Fenton reaction begins to proceed, the electrolytic system is synchronously started, and Fe (OH) is generated₃By the action of an electric current, converted into Fe²⁺Due to H₂O₂The addition amount of the catalyst is far larger than the reaction amount, so that the circulating Fenton reaction can be realized through electrolysis, and the addition amount of the reagent and the generation amount of sludge are greatly reduced.

Compared with the prior art, the utility model discloses following beneficial effect has:

1) the utility model firstly leads most of the high-concentration VOCs waste gas into the soluble organic matter absorption system, so that most of the soluble VOCs waste gas is dissolved in water, high-concentration organic waste gas which is difficult to treat is converted into organic waste water which is easy to treat, and then Fenton oxidation and MBR membrane separation treatment are carried out, so that the treatment difficulty is reduced, and the effluent reaches the discharge standard; and the other part of organic components which are difficult to dissolve in water are treated by adopting photocatalytic degradation and activated carbon adsorption, so that the discharged gas reaches the emission standard, the system realizes the complete treatment of the high-concentration VOCs waste gas, and the treatment difficulty and the treatment cost are greatly reduced.

2) Fenton sludge circulating system's bottom is provided with electrolysis system, opens electrolysis system when Fenton oxidation reaction goes on, not only can promote the organic matter degradation, still can be with the Fe that generates simultaneously³⁺Reduction to Fe by electrolysis²⁺Thereby reducing the dosage of the ferric salt, ensuring that the subsequent sludge yield can be obviously reduced, and the reduction rate of the ferric salt is more than 98 percent.

Drawings

FIG. 1 is a schematic diagram of a processing system architecture;

FIG. 2 is a schematic view of a process for treating waste gas containing high concentrations of VOCs.

In fig. 1, a dissolved organic matter absorption system 1; a Fenton sludge circulating system 2; an MBR membrane sewage treatment system 3; a photocatalytic system 4; an activated carbon adsorption system 5.

Detailed Description

The above-described aspects of the present invention will be described in further detail below with reference to specific embodiments of the present invention. It should not be understood that the scope of the above-described subject matter of the present invention is limited to the following examples.

In the examples, the experimental methods used were all conventional methods unless otherwise specified, and the materials, reagents and the like used were commercially available without otherwise specified.

Embodiment 1 System for treating waste gas containing high-concentration VOCs

As shown in figure 1, the system for treating high-concentration VOCs waste gas of the utility model comprises a soluble organic matter absorption system, a Fenton sludge circulation system and an MBR membrane sewage treatment system which are connected in sequence through pipelines.

In this embodiment, the soluble organic matter absorption system is a water tank 1, a water outlet of the water tank is communicated with a Fenton sludge circulation system 2 through a U-PVC pipeline, and the Fenton sludge circulation system is communicated with a conventional MBR membrane sewage treatment system 3 through a U-PVC pipeline.

A sealed gas-collecting hood (not shown in the figure) is arranged above the water pool, the gas-collecting hood is connected with a photocatalytic system 4 through a pipeline, and insoluble VOCs gas which is one of products from the water pool can be sent into the photocatalytic system through the pipeline by continuously pumping; the connecting pipeline between the gas-collecting hood and the photocatalytic system is made of U-PVC.

The photocatalytic system is connected with an activated carbon adsorption system 5. Wherein the photocatalytic system is a transverse cylindrical reactor, 6-9 high-power ultraviolet lamps are fixed in the reactor, and gas enters from the front end of the reactor and is converted into CO through the irradiation of the ultraviolet lamps₂And discharged from the rear end. In order to increase the catalytic efficiency, the system is provided with a plate catalyst, the main component of which is TiO₂. Gas treated by a photocatalytic system through a U-PVC connecting pipeAnd (2) entering an activated carbon adsorption system, wherein 80-100 meshes of activated carbon is filled in the system, and residual tail gas is removed through the adsorption effect of the activated carbon, so that the discharged gas can be directly discharged up to the standard.

The Fenton sludge circulating system is a conventional Fenton sludge circulating system and generally comprises a Fenton oxidation tower, a neutralization tank, a degassing tank, a coagulation reaction tank and a final sedimentation tank (not shown in the figure) which are sequentially connected through pipelines. Wherein the bottom of the reaction tank of the oxidation tower is provided with an electrolysis system, when the Fenton reaction starts to be carried out, the electrolysis system is synchronously started, and the generated Fe (OH) is generated under the action of electrolysis₃By the action of an electric current, converted into Fe²⁺Due to H₂O₂The addition amount of the catalyst is far larger than the reaction amount, so that the circulating Fenton reaction can be realized through electrolysis, and the addition amount of the reagent and the generation amount of the sewage and sludge are greatly reduced.

Example 2 method for treating high-concentration VOCs waste gas by using the treatment system

In this embodiment, the concentration of the high-concentration VOCs waste gas is about 4000mg/L, and the specific treatment process is shown in fig. 2.

Step 1, absorbing water-soluble VOCs: firstly, introducing high-concentration VOCs waste gas into a water tank, dissolving most soluble organic matters into water, after absorption is completed, collecting insoluble VOCs gas with COD concentration of about 3000mg/L, wherein the COD concentration of the gas is about 12000 mg/L;

step 2, Fenton oxidation: introducing the wastewater absorbed with soluble VOCs into a Fenton sludge circulation system for degradation, wherein the pH value is approximately equal to 2.6-2.9, n (Fe) in the system²⁺)：n(H₂O₂) The reaction temperature T is approximately equal to 2.15 ℃, the reaction time T is approximately equal to 40 min; after the reaction is finished, the COD value in the wastewater is reduced from 4000mg/L to 720 mg/L; the electrolysis system is synchronously started to carry out electrolysis when the oxidation reaction starts, the voltage U is 24V, the current I is 4A, the reaction temperature T is approximately equal to 40 ℃, the reaction time T is 30min, and in order to ensure Fe (OH)₃Can be reduced to Fe²⁺Adding a proper amount of 1.5mol/L sulfuric acid, and adjusting the pH value to 0.7-0.8; after the electrolysis is finished, the COD value in the wastewater is further reduced from 720mg/L to 180mg/L, and simultaneously, the iron saltThe reduced rate of the catalyst is more than 98 percent, and the requirement of subsequent recycling can be basically met;

step 3, MBR treatment: in order to ensure that the effluent reaches the standard, a membrane bioreactor is adopted for treatment for 3 hours, and the COD of the effluent can reach 25-32mg/L after the treatment is finished, so that the effluent reaches the discharge standard.

Step 4, photocatalytic degradation: insoluble VOCs gas collected by the gas collecting hood is input into a photocatalytic system for degradation treatment through a pipeline, the power of an ultraviolet lamp used by the system is 12W, the illumination time is 40min, meanwhile, in order to improve the catalytic efficiency, a plate type catalyst is added to the system, and the main component of the plate type catalyst is TiO₂. After the treatment by the method, the concentration of the VOCs is reduced to 30mg/L from 1200 mg/L;

and 5, activated carbon adsorption treatment: and introducing the gas treated by the photocatalytic system into an activated carbon adsorption system through a pipeline to further adsorb residual VOCs, wherein the particle size of the activated carbon in the system is about 80 meshes, the adsorption time is 30min, and the concentration of the VOCs is further reduced to 0.2-0.4mg/L, so that the emission standard is reached.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A system for treating high-concentration VOCs waste gas is characterized by comprising a soluble organic matter absorption system, a Fenton sludge circulation system and an MBR membrane sewage treatment system which are sequentially connected through pipelines; the dissolved organic matter absorption system is a water tank or a water tank, a sealed gas-collecting hood is arranged above the water tank or the water tank, and the gas-collecting hood is connected with a photocatalytic system through a pipeline.

2. The system for treating high concentration VOCs exhaust of claim 1, wherein the photocatalytic system is a horizontal cylindrical reactor having 6 to 9 high power uv lamps fixed therein.

3. The system for treating exhaust gas containing high concentrations of VOCs of claim 1, wherein a plate catalyst is disposed within said photocatalytic system.

4. The system of claim 1, wherein the photocatalytic system is coupled to an activated carbon adsorption system via piping.

5. The system for treating waste gas containing high concentrations of VOCs as claimed in claim 4, wherein said activated carbon adsorption system is packed with activated carbon granules having a mesh size of 80-100 mesh.

6. The system for treating waste gas containing high-concentration VOCs according to claim 1, wherein the Fenton sludge circulating system comprises a Fenton oxidation tower, a neutralization tank, a degassing tank, a coagulation reaction tank and a final sedimentation tank which are sequentially connected through pipelines.

7. The system for treating waste gas containing high concentration of VOCs according to claim 1 or 6, wherein the bottom of the Fenton sludge recycling system is provided with an electrolysis system.