Thiol wastewater treatment system

Abstract

The utility model relates to a mercaptan wastewater treatment system, which comprises a raw water tank, a coagulation reactor A, a precipitation tank A, a micro-electrolysis reaction tank, a Fenton catalytic oxidation tank, a coagulation reactor B, a precipitation tank B, a biochemical treatment unit and a discharge water tank, the precipitation tank A, the micro-electrolysis reaction tank, the precipitation tank B and the biochemical treatment unit are respectively communicated with the sludge treatment unit. The organic wastewater treatment system treats organic wastewater containing mercaptan through a Fenton catalytic oxidation method, mercaptan macromolecular organic matters can be effectively decomposed and degraded into micromolecular organic matters, the subsequent treatment effect is ensured, meanwhile, the whole system adopts double coagulating sedimentation systems, organic matters insoluble in water are effectively removed, and the treatment effect is improved. And by adopting a process of combining coagulating sedimentation, Fenton catalytic oxidation and biochemical treatment, the effluent of the system is ensured to reach the discharge standard, and the system has relatively high application and popularization values.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a thiol wastewater treatment system. Background Art

[0002] Thiol has a foul smell and potential toxic effects on the human body. The petroleum refining industry produces a large amount of thiol-containing wastewater. It can not only cause nausea and vomiting, but also cause extremely serious harm to the human body after long-term contact, so it must be properly treated. At present, the main treatment methods for this type of wastewater at home and abroad include adsorption method, chemical oxidation method, direct combustion, biological decomposition, etc. Among them, the adsorption method is widely used, but there are troubles in regeneration and secondary pollution. Although the direct combustion method has a simple process, it has high energy consumption and is prone to cause secondary pollution. Although the biological deodorization technology has good treatment effects in foreign applications, the screening and domestication of microbial strains are still relatively difficult. Most of the chemical oxidation methods use chlorine oxidation method, but it may cause secondary pollution problems brought by chlorine. Content of the Utility Model

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies in the prior art and provide a thiol wastewater treatment system.

[0004] The utility model is realized by the following technical solutions:

[0005] A thiol wastewater treatment system includes a raw water tank, a coagulation reactor A, a sedimentation tank A, a micro-electrolysis reaction tank, a Fenton catalytic oxidation tank, a coagulation reactor B, a sedimentation tank B, a biochemical treatment unit and a discharge water tank. The micro-electrolysis reaction tank is provided with sulfuric acid dosing, and iron-carbon fillers are arranged in the micro-electrolysis reaction tank. The sedimentation tank A, the micro-electrolysis reaction tank, the sedimentation tank B and the biochemical treatment unit are respectively connected to a sludge treatment unit.

[0006] According to the above technical solution, preferably, the micro-electrolysis reaction tank is provided with sulfuric acid dosing for controlling the pH of the wastewater at 2-3, and iron-carbon fillers are arranged in the micro-electrolysis reaction tank for carrying out electrochemical reactions with the wastewater to form Fe 2+ .

[0007] According to the above technical solution, preferably, an aeration device is further arranged in the micro-electrolysis reaction tank.

[0008] According to the above technical solution, preferably, the Fenton catalytic oxidation tank is used for oxidizing the wastewater by hydroxyl radicals to form sulfides, and the sulfides form insoluble precipitates with iron salts.

[0009] According to the above technical solution, preferably, the biochemical treatment unit is used for removing nitrogen, phosphorus and organic matters in the wastewater.

[0010] According to the above technical solution, preferably, an intermediate water tank is connected between the sedimentation tank A and the micro-electrolysis reaction tank.

[0011] According to the above technical solution, preferably, a backwashing water tank is connected between the sedimentation tank B and the biochemical treatment unit, and the backwashing water tank is connected to the Fenton catalytic oxidation tank, and the Fenton catalytic oxidation tank can be backwashed by a water pump.

[0012] According to the above technical solution, preferably, the coagulation reactor A includes a coagulant and a flocculant aid, and the coagulation reactor B includes slaked lime, a coagulant and a flocculant aid.

[0013] According to the above technical solution, preferably, the coagulant is PAC (poly aluminum chloride), and the flocculant aid is PAM (polyacrylamide).

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

[0015] The present utility model treats the organic wastewater containing mercaptan by the Fenton catalytic oxidation method, which can effectively decompose the macromolecular organic matter of mercaptan and degrade it into small molecular organic matter, ensuring the subsequent treatment effect. At the same time, the whole system adopts a double-set coagulation and sedimentation system to effectively remove the organic matter insoluble in water. The process of coagulation and sedimentation + Fenton catalytic oxidation + biochemical treatment is adopted to ensure that the effluent of the system reaches the discharge standard, and it has high application and popularization value. Description of the Drawings

[0016] Figure 1 is a schematic diagram of the system connection of the present utility model.

[0017] In the figure: 1, raw water tank; 2, coagulation reactor A; 3, sedimentation tank A; 4, intermediate water tank; 5, micro-electrolysis reaction tank; 6, Fenton catalytic oxidation tank; 7, coagulation reactor B; 8, sedimentation tank B; 9, backwashing water tank; 10, biochemical treatment unit; 11, discharge water tank; 12, sludge treatment unit. Detailed Embodiments

[0018] In order to enable those skilled in the art of the present technology to better understand the technical solution of the present utility model, the present utility model will be further described in detail below with reference to the drawings and the best embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present utility model.

[0019] In the description of the utility model, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the utility model.

[0020] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "setting", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] As shown in the figure, the present utility model includes an original water tank 1, a coagulation reactor A 2, a sedimentation tank A 3, a micro-electrolysis reaction tank 5, a Fenton catalytic oxidation tank 6, a coagulation reactor B 7, a sedimentation tank B 8, a biochemical treatment unit 10, and a treated water tank 11. Preferably, an intermediate water tank 4 is additionally provided between the sedimentation tank A 3 and the micro-electrolysis reaction tank 5. The micro-electrolysis reaction tank 5 is provided with sulfuric acid dosing, and iron-carbon fillers are provided in the micro-electrolysis reaction tank 5. The sedimentation tank A 3, the micro-electrolysis reaction tank 5, the sedimentation tank B 8, and the biochemical treatment unit 10 are respectively connected and communicated with a sludge treatment unit 12.

[0022] The water outlet of the original water tank 1 is connected and communicated with the water inlet of the coagulation reactor A 2. The original water tank 1 is connected and communicated with the coagulation reactor A 2 through a pipeline and a lifting water pump. Among them, the coagulation reactor A 2 includes a coagulant PAC (poly aluminum chloride) and a coagulant aid PAM (polyacrylamide), which cause the wastewater to undergo a flocculation reaction to form larger flocs. The wastewater after the flocculation reaction in the coagulation reactor A 2 overflows into the sedimentation tank A 3 for solid-liquid separation. The supernatant of the sedimentation tank overflows into the intermediate water tank 4, and the bottom sludge is discharged into the sludge treatment unit 12 through a sludge pump.

[0023] The water outlet of the intermediate water tank 4 is connected and communicated with the micro-electrolysis reaction tank 5. The intermediate water tank 4 is connected and communicated with the micro-electrolysis reaction tank 5 through a pipeline and an intermediate water pump. Among them, sulfuric acid dosing is provided in the micro-electrolysis reaction tank 5 to ensure that the inlet water pH is between 2 and 3. Iron-carbon fillers are arranged in the micro-electrolysis reaction tank 5 to carry out an electrochemical reaction with the wastewater to form Fe 2+ , and at the same time, the micro-electrolysis reaction tank 5 is provided with an aeration device. The aeration reaction consumes a large amount of hydrogen ions in the water, increasing the pH value of the wastewater and creating conditions for subsequent catalytic oxidation treatment.

[0024] The water outlet of the micro-electrolysis reaction tank 5 is connected to the inlet of the Fenton catalytic oxidation tank 6. The water from the micro-electrolysis reaction tank 5 overflows into the Fenton catalytic oxidation tank 6. Hydrogen peroxide is dosed at the inlet of the Fenton catalytic oxidation tank 6, and Fe 2+ and H 2 O 2 constitute the Fenton reagent. The chain reaction between Fe 2+ and hydrogen peroxide catalyzes the generation of hydroxyl radicals, which have strong oxidation ability. Its oxidation potential is second only to fluorine, up to 2.80V. In addition, the hydroxyl radical has a high electronegativity or electrophilicity, and its electron affinity is as high as 569.3 kJ, with strong addition reaction characteristics. Therefore, it can oxidize large molecular organics such as mercaptans in water. At the same time, a Fenton reaction catalyst is installed in the tank to accelerate the reaction rate and improve the treatment effect. The mercaptan wastewater enters the Fenton oxidation tank and is oxidized by hydroxyl radicals to form sulfides. The sulfides form insoluble precipitates with iron salts and are thus removed.

[0025] The water outlet of the Fenton catalytic oxidation tank 6 is connected to the inlet of the coagulation reactor B7. The water outlet of the Fenton catalytic oxidation tank 6 is connected to the coagulation reactor B7 through a pipeline and a lift pump. The coagulation reactor B7 includes slaked lime, a coagulant, and a flocculant, and the wastewater is coagulated in the coagulation reactor B7. The water outlet of the coagulation reactor B7 is connected to the sedimentation tank B8. The water from the coagulation reactor B7 overflows into the sedimentation tank B8, and solid-liquid separation is carried out in the sedimentation tank B8. The bottom sludge is discharged into the sludge treatment system through a sludge pump.

[0026] In addition, a backwash water tank 9 can be additionally installed between the sedimentation tank B8 and the biochemical treatment unit 10. The water outlet of the sedimentation tank B8 is connected to the inlet of the backwash water tank 9. The bottom water outlet of the backwash water tank 9 is connected to the backwash inlet of the Fenton catalytic oxidation tank 6. Regular backwashing is carried out through a backwash water pump to prevent short-circuiting and blockage of the catalyst in the tank. The backwash water outlet of the Fenton catalytic oxidation tank 6 is discharged into the raw water tank 1, and the upper water outlet of the backwash water tank 9 overflows into the subsequent biochemical treatment unit 10.

[0027] The biochemical treatment unit 10 adopts the traditional AO process or MBR process. Taking the AO process as an example, the AO process method is also called the anaerobic-aerobic process method. A (Anaerobic) is the anaerobic section, which is used for denitrification and phosphorus removal. O (Oxic) is the aerobic section, which is used for removing organic matter in water. The wastewater first enters the anaerobic tank. Under the action of anaerobic bacteria, the organic matter in the water is decomposed. Part of the organic matter is decomposed into methane, and the rest is discharged into the subsequent aerobic tank. Under the action of aerobic bacteria in the aerobic tank, the organic matter in the water is decomposed into carbon dioxide and water, removing most of the organic matter in the water. In addition, the ammonia nitrogen in the sewage is nitrified into nitrate nitrogen by nitrifying bacteria in the aerobic tank and flows back to section A. Under anoxic conditions, through the action of facultative anaerobic denitrifying bacteria, the nitrate nitrogen is reduced to pollution-free nitrogen gas, which escapes into the atmosphere, thus achieving the final purpose of denitrification. The water outlet of the biochemical treatment unit 10 is communicated with the effluent tank 11. At the same time, the sludge of the biochemical treatment unit 10 is discharged into the sludge treatment unit 12 for subsequent treatment such as sludge dewatering.

[0028] The preferred process flow of this application is as follows: The wastewater first enters the raw water tank 1, and then is pumped into the coagulation reactor A2. The wastewater after coagulation reaction enters the sedimentation tank A3. The supernatant of the sedimentation tank overflows into the intermediate water tank 4, and the sludge is discharged into the sludge treatment unit 12. The water outlet of the intermediate water tank 4 is pumped into the micro-electrolysis reaction tank 5 by a water pump. The bottom sludge is regularly discharged into the sludge treatment unit 12. The effluent of the micro-electrolysis enters the Fenton catalytic oxidation tank 6 for Fenton oxidation treatment. After the wastewater is oxidized, it enters the coagulation reactor B7 for secondary coagulation treatment. The coagulated wastewater enters the sedimentation tank B8 for sedimentation separation. The supernatant after sedimentation enters the backwashing water tank 9, and the sludge is discharged into the sludge treatment unit 12. The backwashing water tank 9 regularly backwashes the Fenton catalytic oxidation tank 6 through a water pump. The water outlet of the backwashing water tank 9 overflows and is discharged into the biochemical treatment unit 10 for biochemical treatment. The effluent enters the effluent tank 11 and then is discharged up to standard. The biochemical sludge is discharged into the sludge treatment unit 12.

[0029] The utility model treats the organic wastewater containing mercaptan by the Fenton catalytic oxidation method, which can effectively decompose the macromolecular organic matter of mercaptan and degrade it into small molecular organic matter, ensuring the subsequent treatment effect. At the same time, the whole system adopts a double-set coagulation sedimentation system to effectively remove the organic matter insoluble in water. The process of coagulation sedimentation + Fenton catalytic oxidation + biochemical treatment is adopted to ensure that the effluent of the system meets the discharge standard, and it has high application and popularization value.

[0030] The above are only the preferred embodiments of the utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the utility model, several improvements and retouches can still be made, and these improvements and retouches should also be regarded as the protection scope of the utility model.

Claims

1. A mercaptan wastewater treatment system, characterized in that: The invention comprises a raw water tank (1), a coagulation reactor A (2), a sedimentation tank A (3), a micro-electrolysis reaction tank (5), a Fenton catalytic oxidation tank (6), a coagulation reactor B (7), a sedimentation tank B (8), a biochemical treatment unit (10) and a discharge water tank (11); the micro-electrolysis reaction tank (5) is provided with a sulfuric acid dosing device, and an iron-carbon filler is provided in the micro-electrolysis reaction tank (5); the sedimentation tank A (3), the micro-electrolysis reaction tank (5), the sedimentation tank B (8) and the biochemical treatment unit (10) are respectively connected to a sludge treatment unit (12).

2. A mercaptan wastewater treatment system according to claim 1, characterized in that: The micro-electrolysis reaction tank (5) is provided with sulfuric acid dosing device for controlling the pH value of the wastewater to be between 2 and 3. An iron-carbon filler is arranged in the micro-electrolysis reaction tank (5) for reacting electrochemically with the wastewater to form Fe2+.

3. A mercaptan wastewater treatment system according to claim 2, characterized in that: An aeration device is also provided in the micro-electrolysis reaction tank (5).

4. A mercaptan wastewater treatment system according to claim 1, characterized in that: The Fenton catalytic oxidation tank (6) is used to oxidize the wastewater by hydroxyl radicals to form sulfides, and the sulfides have iron salts to form insoluble precipitates.

5. A mercaptan wastewater treatment system according to claim 1 or 4, characterized in that: The biochemical treatment unit (10) is used to remove nitrogen, phosphorus and organic matter from wastewater.

6. A mercaptan wastewater treatment system according to claim 1, characterized in that: An intermediate water tank (4) is connected between the precipitation tank A (3) and the micro-electrolysis reaction tank (5).

7. A mercaptan wastewater treatment system according to claim 1 or 6, characterized in that: A backwash water tank (9) is connected between the sedimentation tank B (8) and the biochemical treatment unit (10), and the backwash water tank (9) is connected to the Fenton catalytic oxidation tank (6), and the Fenton catalytic oxidation tank (6) can be backwashed by a water pump.

8. A mercaptan wastewater treatment system according to claim 1, characterized in that: The coagulation reactor A (2) comprises a coagulant and a coagulant aid, The coagulation reactor B (7) comprises slaked lime, a coagulant and a coagulant aid.

9. A mercaptan wastewater treatment system according to claim 8, characterized in that: The coagulant is PAC polyaluminium chloride, and the coagulant aid is PAM polyacrylamide.

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