Anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater

Abstract

The utility model relates to the technical field of wastewater treatment, and discloses an anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater, which comprises an IC (internal circulation) anaerobic reactor, a gas-liquid separator, a biogas cabinet and a biogas boiler. According to the anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater, mixed anaerobic biological pretreatment is carried out on polyamide wastewater, pollutants such as COD, ammonia nitrogen and organic matter in the polyamide wastewater are greatly reduced, the removal rate of COD is 85%-90%, the removal rate of ammonia nitrogen is 35%-40%, biogas generated in the anaerobic reactor is utilized through the biogas boiler, and the utilization rate of the biogas is improved. The heat insulation layer is arranged on the outer side of the reaction chamber, the indoor temperature can be maintained at about 35 DEG C, heat circulation is achieved, heat loss is reduced, and the method is easy and feasible to operate, small in occupied area, low in cost and suitable for large-scale application and popularization.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to an anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater. Background Art

[0002] Polyamide, commonly known as nylon, is a general term for polymers containing amide groups in the repeating units of the macromolecular main chain. It is a common polymer compound that can be used in the production of fiber fabrics and other products. A certain amount of polyamide wastewater will be generated in the production process of polyamide chips. The main components of polyamide wastewater are caprolactam monomer, titanium dioxide and purified terephthalic acid, etc., which makes the COD (chemical oxygen demand), total nitrogen and ammonia nitrogen content in the wastewater relatively high. Direct discharge will cause serious pollution to the environment and needs to be treated to meet the standards set by the environmental protection department before it can be discharged.

[0003] With the increasing shortage of water resources and the strengthening of people's awareness of environmental protection, the treatment technology of polyamide wastewater has gradually become a research hotspot. At present, the main treatment method is upflow sludge bed treatment.

[0004] The Chinese patent "A polyamide production wastewater treatment system" (application number 202020751454.3) proposes a polyamide production wastewater treatment system including a filter tank, a sedimentation tank and an adsorption tank to treat polyamide wastewater. It treats production wastewater by filtering with a filter plate and precipitating with a flocculant. Although this method can prevent blockage of the liquid inlet and outlet, the pollutants that can be removed by the system in the wastewater are limited, and the removal rate of major substances such as COD is not high.

[0005] The Chinese patent "Polyamide Wastewater Treatment System and Treatment Process Thereof" (application number 201810667471.6) proposes a polyamide wastewater treatment process to treat polyamide wastewater. It ensures the treatment effect of polyamide wastewater through the upflow sludge bed treatment method, and can properly treat the screens and sludge pollutants generated during the polyamide wastewater treatment process to avoid secondary pollution. However, the process treats and discharges the generated biogas, which will cause heat loss and waste.

[0006] Therefore, an anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater is developed to overcome the shortcomings of the prior art, thereby improving the efficiency of polyamide wastewater treatment and reducing energy loss. Utility Model Content

[0007] The utility model aims to provide an anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater, so as to solve the problem of pretreating pollutants in polyamide wastewater and recycling heat energy to reduce energy loss proposed in the above background technology.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions: an anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater, comprising an IC anaerobic reactor, a gas-liquid separator, a biogas cabinet, and a biogas boiler, wherein the IC anaerobic reactor comprises a reaction chamber, a water distributor is arranged at the bottom of the reaction chamber, a water inlet pipe is arranged on the right side of the reaction chamber, the water inlet pipe penetrates into the reaction chamber and is connected with the water distributor, a primary three-phase separator is arranged above the water distributor, a first anaerobic treatment zone is formed between the water distributor and the primary three-phase separator, a mud distribution pipe is arranged on the left side of the reaction chamber, the mud distribution pipe is connected with the first anaerobic treatment zone, and the primary A secondary three-phase separator is arranged above the three-phase separator, and a second anaerobic treatment zone is formed between the primary three-phase separator and the secondary three-phase separator. A gas-liquid separator is installed on the top of the reaction chamber, and a sedimentation zone is formed between the secondary three-phase separator and the gas-liquid separator. A water outlet pipe is arranged on the left side of the sedimentation zone, and an exhaust pipe is arranged on the right side of the gas-liquid separator. The end of the exhaust pipe away from the gas-liquid separator is connected to a biogas cabinet, and the biogas cabinet is connected to a biogas boiler. A water inlet pump is arranged at one end of the biogas boiler, and a hot water pipe is arranged at one end of the water inlet pump away from the biogas boiler, and the end of the hot water pipe away from the water inlet pump is connected to the water inlet pipe.

[0009] Preferably, a heat insulation layer is provided outside the reaction chamber, and the material used in the heat insulation layer is rock wool.

[0010] A heat-insulating layer is arranged outside the reaction chamber, and the material of the heat-insulating layer is generally rock wool, and the heat-insulating layer is used to keep the reaction chamber warm.

[0011] Preferably, the temperature in the reaction chamber is generally 35 degrees, the pH is 7.3-7.5, and the reaction residence time is 5-6 hours.

[0012] Preferably, a reflux pipe is provided at the bottom of the gas-liquid separator, and the gas-liquid separator is connected with the first anaerobic treatment zone through the reflux pipe at the bottom.

[0013] The gas-liquid separator is connected to the first anaerobic treatment zone through a return pipe, and the return sludge can be returned to the first anaerobic treatment zone through the return pipe.

[0014] Preferably, a biogas lifting pipe is provided at the bottom of the gas-liquid separator, and two biogas lifting pipes are provided. One end of the two biogas lifting pipes away from the gas-liquid separator is respectively connected to the upper part of the first-stage three-phase separator and the upper part of the second-stage three-phase separator, and filters are placed at the top and bottom of the two biogas lifting pipes.

[0015] Two biogas lifting pipes are provided, and the bottoms of the two biogas lifting pipes at the other end are respectively connected to the upper part of the first-stage three-phase separator and the upper part of the second-stage three-phase separator, and filters are respectively provided at the inlets of the two biogas lifting pipes. The function of the filter is to cut larger biogas bubbles into smaller bubbles and intercept part of the sludge to reduce the amount of returned sludge.

[0016] Preferably, both the first anaerobic treatment zone and the second anaerobic treatment zone are filled with anaerobic activated sludge.

[0017] Preferably, the activated sludge is a mixture of anaerobic granular sludge and digested sludge in a mass ratio of 3:5.

[0018] Preferably, the mass ratio of granular sludge to digested sludge in the anaerobic activated sludge in the first anaerobic treatment zone is 1:1, and the mass ratio of granular sludge to digested sludge in the anaerobic activated sludge in the second anaerobic treatment zone is 1:5.

[0019] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0020] First, the utility model greatly reduces pollutants such as COD, ammonia nitrogen, and organic matter in polyamide wastewater by performing mixed anaerobic biological pretreatment on polyamide wastewater. The COD removal rate is 85%~90%, and the ammonia nitrogen removal rate is 35%~40%. The biogas generated in the anaerobic reactor is utilized by a biogas boiler, and the generated hot water is returned to the water inlet to mix with the raw water and flow in. An insulating layer is provided on the outside of the reaction chamber to maintain the indoor temperature at about 35 degrees, realize heat circulation, and reduce heat loss. The method is simple and feasible to operate, occupies a small area, has low cost, and is suitable for large-scale promotion and application.

[0021] Second, in the utility model, a filter is provided at the inlet of the biogas lifting pipe, which can cut larger biogas bubbles into smaller bubbles, and play a certain interception role on anaerobic sludge, reduce the sludge return ratio, and improve the stability of the anaerobic reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the utility model.

[0023] Among them: 1. reaction chamber; 2. water distributor; 3. water inlet pipe; 4. primary three-phase separator; 5. mud distribution pipe; 6. secondary three-phase separator; 7. gas-liquid separator; 8. water outlet pipe; 9. exhaust pipe; 10. biogas cabinet; 11. biogas boiler; 12. water inlet pump; 13. hot water pipe; 14. thermal insulation layer; 15. return pipe; 16. biogas lifting pipe. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] The utility model provides the following technical solutions: Embodiment 1

[0026] See also Figure 1 An anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater, comprising an IC anaerobic reactor, a gas-liquid separator 7, a biogas cabinet 10, and a biogas boiler 11. The IC anaerobic reactor comprises a reaction chamber 1, a water distributor 2 is arranged at the bottom of the reaction chamber 1, a water inlet pipe 3 is arranged on the right side of the reaction chamber 1, the water inlet pipe 3 penetrates into the reaction chamber 1 and is connected with the water distributor 2, a primary three-phase separator 4 is arranged above the water distributor 2, a first anaerobic treatment zone is formed between the water distributor 2 and the primary three-phase separator 4, a mud distribution pipe 5 is arranged on the left side of the reaction chamber 1, the mud distribution pipe 5 is connected with the first anaerobic treatment zone, and a secondary three-phase separator 6 is arranged above the primary three-phase separator 4 , and a second anaerobic treatment zone is formed between the primary three-phase separator 4 and the secondary three-phase separator 6, a gas-liquid separator 7 is installed on the top of the reaction chamber 1, and a sedimentation zone is formed between the secondary three-phase separator 6 and the gas-liquid separator 7, a water outlet pipe 8 is arranged on the left side of the sedimentation zone, and an exhaust pipe 9 is arranged on the right side of the gas-liquid separator 7, and the end of the exhaust pipe 9 away from the gas-liquid separator 7 is connected to a biogas cabinet 10, and the biogas cabinet 10 is connected to a biogas boiler 11, and a water inlet pump 12 is arranged at one end of the biogas boiler 11, and a hot water pipe 13 is arranged at one end of the water inlet pump 12 away from the biogas boiler 11, and the end of the hot water pipe 13 away from the water inlet pump 12 is connected to the water inlet pipe 3.

[0027] A heat insulation layer 14 is disposed outside the reaction chamber 1 , and the material used in the heat insulation layer 14 is rock wool.

[0028] The temperature in the reaction chamber 1 is generally 35 degrees, the pH is 7.3-7.5, and the reaction residence time is 5-6 hours.

[0029] A reflux pipe 15 is provided at the bottom of the gas-liquid separator 7 , and the gas-liquid separator 7 is connected to the first anaerobic treatment zone through the reflux pipe 15 at the bottom.

[0030] Through the above technical scheme, the polyamide wastewater is subjected to mixed anaerobic biological pretreatment, and the pollutants such as COD, ammonia nitrogen, and organic matter in the polyamide wastewater are greatly reduced. The COD removal rate is 85%~90%, and the ammonia nitrogen removal rate is 35%~40%. The biogas generated in the anaerobic reactor is utilized by the biogas boiler 11, and the generated hot water is returned to the water inlet to mix with the raw water. The outside of the reaction chamber 1 is provided with a heat insulation layer 14, which can maintain the indoor temperature at about 35 degrees, realize the circulation of heat, and reduce heat loss. The method is simple and feasible to operate, occupies a small area, and has low cost, and is suitable for large-scale promotion and application. Embodiment 2

[0031] See also Figure 1 , and on the basis of Example 1, it is further obtained that: a biogas lifting pipe 16 is arranged at the bottom of the gas-liquid separator 7, and two biogas lifting pipes 16 are arranged, and one end of the two biogas lifting pipes 16 away from the gas-liquid separator 7 is respectively connected to the upper part of the primary three-phase separator 4 and the upper part of the secondary three-phase separator 6, and a filter is arranged on the top of the two biogas lifting pipes 16.

[0032] The first anaerobic treatment zone and the second anaerobic treatment zone are both filled with anaerobic activated sludge.

[0033] The activated sludge is a mixture of anaerobic granular sludge and digested sludge in a mass ratio of 3:5.

[0034] The mass ratio of granular sludge to digested sludge in the anaerobic activated sludge in the first anaerobic treatment zone is 1:1, and the mass ratio of granular sludge to digested sludge in the anaerobic activated sludge in the second anaerobic treatment zone is 1:5.

[0035] Through the above technical solution, a filter is provided at the inlet of the biogas lifting pipe 16, which can cut larger biogas bubbles into smaller bubbles and play a certain interception role on the anaerobic sludge, reduce the sludge return ratio, and improve the stability of the anaerobic reactor.

[0036] In actual operation, when the device is in use, raw water is mixed with boiler hot water and enters the IC anaerobic reactor through the water inlet pipe 3, and the water distributor 2 realizes uniform water distribution, so that the raw water is evenly distributed in the first anaerobic reaction zone. The height of the first anaerobic reaction zone does not exceed one-third of the total height of the reaction chamber 1. The sewage treated in the first anaerobic reaction zone flows upward through the primary three-phase separator 4, and part of the biogas and sludge pass through the inlet filter of the biogas riser 16 and reach the gas-liquid separator 7 along the pipeline. The sludge flows back to the first anaerobic treatment zone through the reflux pipe 15 and passes through the first anaerobic treatment zone. The water treated in the treatment area enters the second anaerobic treatment area upward and undergoes secondary treatment. The sewage enters the sedimentation area for sedimentation after being treated in the first anaerobic treatment area and the second anaerobic treatment area, and is discharged through the outlet pipe 8. The generated biogas reaches the gas-liquid separator 7 upward, and enters the biogas cabinet 10 for storage through the exhaust pipe 9. The biogas coming out of the biogas cabinet 10 enters the biogas boiler 11 for use. The hot water in the biogas boiler 11 enters the hot water pipe 13 through the water inlet pump 12. The hot water pipe 13 is connected to the water inlet pipe 3, and flows into the reaction chamber 1 through the water inlet pipe 3 together with the raw water to realize circulation.

[0037] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit thereof, and the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater, comprising an IC anaerobic reactor, a gas-liquid separator (7), a biogas cabinet (10), and a biogas boiler (11), characterized in that: The IC anaerobic reactor comprises a reaction chamber (1), a water distributor (2) is arranged at the bottom of the reaction chamber (1), a water inlet pipe (3) is arranged on the right side of the reaction chamber (1), the water inlet pipe (3) penetrates into the reaction chamber (1) and is connected to the water distributor (2), a primary three-phase separator (4) is arranged above the water distributor (2), a first anaerobic treatment zone is formed between the water distributor (2) and the primary three-phase separator (4), a mud distribution pipe (5) is arranged on the left side of the reaction chamber (1), the mud distribution pipe (5) is connected to the first anaerobic treatment zone, a secondary three-phase separator (6) is arranged above the primary three-phase separator (4), and a second anaerobic treatment zone is formed between the primary three-phase separator (4) and the secondary three-phase separator (6). A gas-liquid separator (7) is installed on the top of the reaction chamber (1); a sedimentation zone is formed between the secondary three-phase separator (6) and the gas-liquid separator (7); a water outlet pipe (8) is arranged on the left side of the sedimentation zone; an exhaust pipe (9) is arranged on the right side of the gas-liquid separator (7); an end of the exhaust pipe (9) away from the gas-liquid separator (7) is connected to a biogas cabinet (10); the biogas cabinet (10) is connected to a biogas boiler (11); an inlet pump (12) is arranged at one end of the biogas boiler (11); a hot water pipe (13) is arranged at one end of the water inlet pump (12) away from the biogas boiler (11); and an end of the hot water pipe (13) away from the water inlet pump (12) is connected to the water inlet pipe (3).

2. The anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater according to claim 1, characterized in that: A heat insulation layer (14) is provided outside the reaction chamber (1), and the material used in the heat insulation layer (14) is rock wool.

3. The anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater according to claim 1, characterized in that: The temperature in the reaction chamber (1) is generally 35 degrees, the pH is 7.3-7.5, and the reaction residence time is 5-6 hours.

4. The anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater according to claim 1, characterized in that: A reflux pipe (15) is provided at the bottom of the gas-liquid separator (7), and the gas-liquid separator (7) is connected to the first anaerobic treatment zone via the reflux pipe (15) at the bottom.

5. The anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater according to claim 1, characterized in that: A biogas lifting pipe (16) is arranged at the bottom of the gas-liquid separator (7), and two biogas lifting pipes (16) are arranged. One end of the two biogas lifting pipes (16) away from the gas-liquid separator (7) is connected to the upper part of the primary three-phase separator (4) and the upper part of the secondary three-phase separator (6), respectively, and a filter screen is arranged at the bottom of the two biogas lifting pipes (16).

6. The anaerobic reactor for anaerobic digestion pretreatment of polyamide production wastewater according to claim 1, characterized in that: The first anaerobic treatment zone and the second anaerobic treatment zone are both filled with anaerobic activated sludge.

Images