Mercury-containing waste gas treatment device in Tibetan medicine processing process

Abstract

The utility model provides a mercury-containing waste gas treatment device in a Tibetan medicine processing process, which can effectively remove mercury and VOCs (Volatile Organic Compounds). The device is characterized by comprising an advanced oxidation reactor, an oxidation-reduction electrode, a Venturi tube type micro-nano bubble generating device and a cleaning liquid adding device, wherein the advanced oxidation reactor is used for enabling waste gas to be in contact with cleaning liquid; the oxidation-reduction electrode intersects with the flowing direction of the waste gas when the waste gas is in contact with the cleaning liquid; the Venturi tube type micro-nano bubble generating device is used for enabling the cleaning liquid to flow through a pipeline. The device disclosed by the utility model has the characteristics of small occupied area, high treatment efficiency, simple process and recyclable cleaning liquid, can degrade VOCs (Volatile Organic Compounds) and mineralize the VOCs into carbon dioxide and water, simultaneously oxidizes and removes mercury in waste gas, and recycles the mercury to realize recycling.

Description

Technical Field

[0001] The utility model relates to a device and method for treating mercury-containing waste gas during the preparation of Tibetan medicine Zuotai using advanced oxidation technology, and in particular to a waste gas treatment device suitable for treating waste gas discharged from heating treatment of treated objects contaminated by mercury and VOCs, and materials containing plants, animals and mercury. Background Art

[0002] Zuotai is a Tibetan word, "Zuo" means refining, and "Tai" means ash or powder. Zuotai means calcined into ash. It is a preparation with unique curative effect obtained by Tibetan doctors of all dynasties through special processing of highly toxic mercury. Zuotai is regarded as the most precious Tibetan medicine. It is the main raw material of precious Tibetan medicines such as Seventy Flavors Pearl Pills, Renqing Changjue, Renqing Mangjue, and Zuzhu Daxi. It is also used in ordinary preparations to increase the efficacy. It is known as the "King of All Medicines" and is also called the "King of Nectar Essence". It has the functions of treating diseases, detoxification, health care, and enhancement. The precious Tibetan medicine compound with "Zuotai" as the core ingredient is widely used in clinical practice. The entire processing operation process requires the mixing of more than 50 kinds of drugs, so a large amount of high-concentration mercury-containing and VOC mixed waste gas will be generated during the heat treatment process such as boiling and refining. A composite treatment mode of organic agent absorption spraying and activated carbon adsorption is usually adopted. However, spraying organic absorption liquid will produce secondary polluted waste liquid, and the continuous consumption of absorbent will also increase the treatment cost. In addition, since activated carbon is only suitable for purifying low-concentration mercury-containing exhaust gas, even if an activated carbon adsorption device is installed, the gas organic agent absorption liquid spraying device cannot efficiently and significantly remove mercury, so there is a problem of increased frequency of activated carbon replacement and higher operating costs. Utility Model Content

[0003] In view of the above-mentioned problems of the prior art, the utility model provides a device for treating mercury-containing waste gas during the preparation of Tibetan medicine. When the waste gas contains mercury and VOCs, high-concentration mercury and VOCs can be effectively removed. The use of electrochemical advanced oxidation technology has the advantages of high efficiency, environmental protection, and low cost, and can achieve effective removal of mixed waste gas of mercury and VOCs. The strong oxidizing free radicals with high oxidation potential generated by electrocatalysis can perform open-loop chain breaking degradation on VOCs, and eventually mineralize into carbon dioxide and water. At the same time, the strong oxidizing free radicals with high oxidation potential can oxidize the elemental mercury in the waste gas and convert it into ionic mercury soluble in water, thereby achieving the purpose of purification. The ionic mercury in the water is reduced to elemental mercury at the cathode and precipitated at the bottom of the reactor, thereby realizing mercury resource recovery. In addition, the cleaning liquid only needs to be supplemented with a small amount of electrolyte that may be carried away by the gas, so the cleaning liquid can be recycled.

[0004] The technical solution of this utility model is as follows:

[0005] A device for treating mercury-containing waste gas during the preparation of Tibetan medicine comprises an advanced oxidation reactor, the lower part of which is connected to a waste gas inlet pipe, the top part is connected to an outlet pipe, the middle part is connected to a cleaning liquid adding device, and a redox electrode is arranged inside.

[0006] The bottom of the advanced oxidation reactor is connected to a venturi tube type micro-nano bubble generating device through a circulation pump, and then connected to a spraying device at the upper part of the advanced oxidation reactor.

[0007] The exhaust gas inlet pipe is connected to the aeration device at the lower part of the advanced oxidation reactor.

[0008] The redox electrode comprises a plurality of electrode layers, which are staggered electrode layers of anode and cathode from the inside to the outside.

[0009] Mercury-containing waste gas flows into the waste gas inlet pipe at the lower part of the advanced oxidation reactor, is aerated through the aeration device, and the waste gas flows from the lower end to the upper end; the cleaning liquid is added into the advanced oxidation reactor from the cleaning liquid adding device, and the waste gas contacts with the cleaning liquid; at the same time, the cleaning liquid is circulated from the venturi tube type micro-nano bubble generating device accumulated in the lower part of the advanced oxidation reactor through the piping to the spraying device at the upper part of the advanced oxidation reactor through the circulating pump, so that the spraying device evenly spreads the cleaning liquid, which contacts with the waste gas in the countercurrent upward direction, and the redox electrode is configured with an electric field that intersects with the flow direction of the cleaning liquid and the waste gas.

[0010] The advanced oxidation reactor is in the shape of a cylindrical container, and the redox electrodes are multiple cylindrical electrodes concentric with the advanced oxidation reactor, which are alternately arranged at equal intervals from the center to the outside. The anode and the cathode are arranged at intervals of 5 to 50 mm, and an electric field with an intensity of 1 to 500 kV / m is generated between the anode and the cathode.

[0011] In addition, a level gauge and a drain valve are provided at the bottom of the advanced oxidation reactor. The level gauge is used to detect the amount of accumulated cleaning liquid, and the drain valve facilitates the discharge of precipitated particles and mercury precipitates.

[0012] The redox electrode is any one of a metal oxide electrode, a metal carbide electrode, a carbon-based electrode, a titanium-based electrode, and a stainless steel electrode, or a mixture of two or more thereof.

[0013] The cleaning solution is any one of sodium sulfate solution, sodium chloride solution, sodium hypochlorite solution, potassium sulfate solution, potassium chloride solution, and potassium iodide solution, or a mixture of two or more thereof, and its mass concentration is 0.01-10%.

[0014] The beneficial effects of the utility model are:

[0015] 1. The utility model adopts an advanced oxidation technology combining electrochemical catalytic oxidation and micro-nano bubble technology to treat mixed waste gas polluted by mercury and VOCs. The microbubble technology has the characteristics of large specific surface area, high mass transfer efficiency, surface charge, and generation of a large number of hydroxyl free radicals, which can assist in strengthening the electrochemical catalytic oxidation to oxidize and remove mercury and VOCs in the waste gas.

[0016] 2. Electrochemical direct and indirect catalytic oxidation of water produces oxidants for the oxidation and removal of mercury and VOCs in exhaust gas. The cleaning liquid is only electrolyte without any other agents and avoids the generation of secondary polluted waste liquid. The electrolyte can be recycled, thus reducing the treatment cost.

[0017] 3. The elemental mercury in the exhaust gas is converted into soluble ionic mercury after oxidation, and the ionic mercury dissolved in the cleaning liquid can be reduced to elemental mercury at the cathode and adsorbed on the cathode surface or settled at the bottom of the advanced oxidation reactor, thus realizing mercury resource recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 . Schematic diagram of the partial cross-section structure of the utility model. DETAILED DESCRIPTION

[0019] like Figure 1 As shown, a device for treating mercury-containing waste gas during the preparation of Tibetan medicine includes an advanced oxidation reactor 1, the lower part of which is connected to a waste gas inlet pipe 5, the top is connected to an outlet pipe 6, the middle part is connected to a cleaning liquid adding device 4, and a redox electrode 2 is arranged inside.

[0020] The bottom of the advanced oxidation reactor 1 is connected to a venturi tube type micro-nano bubble generating device 3 through a circulation pump 7, and then connected to a spraying device 8 at the upper part of the advanced oxidation reactor 1.

[0021] The exhaust gas inlet pipe 5 is connected to the aeration device 9 at the lower part of the advanced oxidation reactor 1 .

[0022] The redox electrode 2 comprises a plurality of electrode layers, which are staggered electrode layers of anode and cathode from the inside to the outside.

[0023] Mercury-containing waste gas flows into the waste gas inlet pipe 5 at the lower part of the advanced oxidation reactor 1, and is aerated through the aeration device 9, and the waste gas flows from the lower end to the upper end; the cleaning liquid is added to the advanced oxidation reactor 1 from the cleaning liquid adding device 4, and the waste gas contacts the cleaning liquid; at the same time, the cleaning liquid is circulated from the venturi tube micro-nano bubble generating device 3 accumulated in the lower part of the advanced oxidation reactor 1 through the piping to the spray device 8 at the upper part of the advanced oxidation reactor 1 through the circulation pump 7, so that the spray device 8 evenly spreads the cleaning liquid, which is fully in gas-liquid contact with the waste gas flowing in the countercurrent direction, and the redox electrode 2 is configured with an electric field that intersects with the flow direction of the cleaning liquid and the waste gas.

[0024] The advanced oxidation reactor 1 is in the shape of a cylindrical container, and the redox electrodes 2 are multiple cylindrical electrodes concentric with the advanced oxidation reactor 1, which are alternately arranged at equal intervals from the center to the outside. The anode and the cathode are arranged at intervals of 5 to 50 mm, and an electric field with an intensity of 1 to 500 kV / m is generated between the anode and the cathode.

[0025] In addition, a liquid level meter 10 and a drain valve 11 are provided at the lower part of the advanced oxidation reactor 1. The liquid level meter 10 is used to detect the amount of accumulated cleaning liquid, and the drain valve 11 facilitates the discharge of precipitated particles and mercury precipitates.

[0026] The redox electrode 2 is any one of a metal oxide electrode, a metal carbide electrode, a carbon-based electrode, a titanium-based electrode, and a stainless steel electrode, or a mixture of two or more thereof.

[0027] The cleaning solution is any one of sodium sulfate solution, sodium chloride solution, sodium hypochlorite solution, potassium sulfate solution, potassium chloride solution, and potassium iodide solution, or a mixture of two or more thereof, and its mass concentration is 0.01-10%.

[0028] Example 1

[0029] The waste gas treatment device of the utility model is used to treat the mixed waste gas containing mercury and TVOC, wherein the initial concentration of TVOC is 300mg / m 3 , the initial concentrations of mercury were 1189 μg / m 3 , the gas processing capacity is 20000m 3 / h.

[0030] Mixed waste gas containing mercury and TVOC flows into the waste gas inlet pipe 5 at the lower part of the advanced oxidation reactor 1, and is aerated through the aeration device 9, and the waste gas flows from the lower end to the upper end; a sodium hypochlorite solution with a mass concentration of 1.5% is added to the advanced oxidation reactor 1 from the cleaning liquid adding device 4, and the mixed waste gas contacts the cleaning liquid; at the same time, through the circulation pump 7, the cleaning liquid of the sodium hypochlorite solution with a mass concentration of 1.5% is circulated from the venturi tube micro-nano bubble generating device 3 accumulated in the lower part of the advanced oxidation reactor 1 through the piping to the spray device 8 at the upper part of the advanced oxidation reactor 1, so that the spray device 8 evenly spreads the cleaning liquid and fully contacts the waste gas in the countercurrent upward direction, and the redox electrode 2 is configured with an electric field that intersects with the flow direction of the cleaning liquid and the waste gas. The redox electrode 2 adopts a plurality of cylindrical electrodes concentric with the advanced oxidation reactor 1, and is alternately arranged at equal intervals from the center to the outside. Both the anode and the cathode are lattice-shaped carbon-based BDD electrodes. The anode and cathode were arranged at a distance of 10 mm, and an electric field with a strength of 100 kV / m was generated between the anode and the cathode.

[0031] In this embodiment 1, after treating the mixed exhaust gas containing mercury and TVOC, the TVOC concentration was reduced to 7 mg / m3 , the mercury concentration dropped to 2 μg / m 3 .

[0032] Example 2

[0033] The waste gas treatment device of the utility model is used to treat waste gas containing mercury and TVOC, wherein the initial concentration of TVOC is 517mg / m 3 , the initial concentration of mercury was 812 μg / m 3 , the gas processing capacity is 5000m 3 / h.

[0034] Mixed waste gas containing mercury and TVOC flows into the waste gas inlet pipe 5 at the lower part of the advanced oxidation reactor 1, and is aerated through the aeration device 9, and the waste gas flows from the lower end to the upper end; a sodium sulfate solution with a mass concentration of 1% is added to the advanced oxidation reactor 1 from the cleaning liquid adding device 4, and the mixed waste gas contacts the cleaning liquid; at the same time, through the circulation pump 7, the cleaning liquid with a mass concentration of 1% sodium sulfate solution is circulated from the venturi tube micro-nano bubble generating device 3 accumulated in the lower part of the advanced oxidation reactor 1 through the piping to the spray device 8 at the upper part of the advanced oxidation reactor 1, so that the spray device 8 evenly spreads the cleaning liquid and fully contacts the waste gas in the countercurrent upward direction, and the redox electrode 2 is configured with an electric field that intersects with the flow direction of the cleaning liquid and the waste gas. The redox electrode 2 uses a plurality of cylindrical electrodes concentric with the advanced oxidation reactor 1, which are alternately arranged at equal intervals from the center to the outside. The anode is a lattice-shaped ruthenium oxide-iridium oxide DAS electrode, and the cathode is a lattice-shaped titanium-based electrode. The anode and cathode were arranged with a spacing of 15 mm, and an electric field with a strength of 200 kV / m was generated between the anode and the cathode.

[0035] In Example 2, after treating the mixed exhaust gas containing mercury and TVOC, the TVOC concentration was reduced to 13.7 mg / m 3 , the mercury concentration dropped to 1 μg / m 3 .

[0036] Example 3

[0037] The waste gas treatment device of the utility model is used to treat the waste gas containing mercury and TVOC, wherein the initial concentration of TVOC is 264mg / m 3 , the initial concentration of mercury was 653 μg / m 3 , the gas processing capacity is 9000m 3 / h.

[0038] The mixed waste gas containing mercury and TVOC flows into the waste gas inlet pipe 5 at the lower part of the advanced oxidation reactor 1, and is aerated by the aeration device 9, and the waste gas flows from the lower end to the upper end; the sodium chloride solution with a mass concentration of 2.0% is added to the advanced oxidation reactor 1 from the cleaning liquid adding device 4, and the mixed waste gas contacts the cleaning liquid; at the same time, the cleaning liquid with a mass concentration of 2.0% sodium chloride solution is circulated from the venturi tube micro-nano bubble generating device 3 accumulated in the lower part of the advanced oxidation reactor 1 through the pipe to the spray device 8 at the upper part of the advanced oxidation reactor through the circulation pump 7, so that the spray device 8 evenly spreads the cleaning liquid and fully contacts the waste gas in the countercurrent upward direction, and the redox electrode 2 is configured with an electric field that intersects with the flow direction of the cleaning liquid and the waste gas. The redox electrode 2 adopts a plurality of cylindrical electrodes concentric with the advanced oxidation reactor 1, and is alternately arranged at equal intervals from the center to the outside. The anode is a lattice-shaped ruthenium oxide-iridium oxide DAS electrode, and the cathode is a lattice-shaped titanium-based electrode. The anode and cathode were arranged with a spacing of 20 mm, and an electric field with a strength of 400 kV / m was generated between the anode and the cathode.

[0039] After treating the mixed exhaust gas containing mercury and TVOC in Example 3, the TVOC concentration was reduced to 24.32 mg / m 3 , the mercury concentration dropped to 2 μg / m 3 .

[0040] The above descriptions are only some of the preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A device for treating mercury-containing waste gas during the preparation of Tibetan medicine, characterized in that: It comprises an advanced oxidation reactor, the lower part of which is connected to an exhaust gas inlet pipe, the top part is connected to an exhaust pipe, the middle part is connected to a cleaning liquid adding device, and a redox electrode is arranged inside.

2. The device for treating mercury-containing waste gas in the Tibetan medicine preparation process according to claim 1 is characterized in that: The bottom of the advanced oxidation reactor is connected to a venturi tube type micro-nano bubble generating device through a circulation pump, and then connected to a spraying device at the upper part of the advanced oxidation reactor.

3. The device for treating mercury-containing waste gas in the Tibetan medicine preparation process according to claim 1 is characterized in that: The exhaust gas inlet pipe is connected to the aeration device at the lower part of the advanced oxidation reactor.

4. The device for treating mercury-containing waste gas in the Tibetan medicine preparation process according to claim 1 is characterized in that: The redox electrode comprises a plurality of electrode layers, which are staggered electrode layers of anode and cathode from the inside to the outside.

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