System and method for treating petrochemical sewage by aerobic granular sludge continuous flow process

Abstract

According to the system and method for treating petrochemical sewage through the aerobic granular sludge continuous flow process, the shear stress generator, the selective pressure generator and the sludge screener are adopted, the structure of aerobic granular sludge is optimized in a multi-dimensional mode, the aerobic granular sludge in the system is large in particle size, high in impact resistance and rapid in system recovery, and the system can be used for treating petrochemical sewage. And meanwhile, the system adopts a modular and modular design, so that the control is accurate, and the process operation is flexible. According to the sewage treatment method disclosed by the invention, a new process for treating the petrochemical sewage by using the aerobic granular sludge is developed, energy conservation and consumption reduction are realized by adopting a special sludge structure of the granular sludge, multiple targets of land conservation, energy conservation, low carbon and resource recovery of the petrochemical sewage treatment process are realized, and a new thought is provided for energy conservation and carbon reduction of petrochemical sewage treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial wastewater treatment, and particularly relates to a system and method for treating petrochemical sewage by an aerobic granular sludge continuous flow process. Background Art

[0002] Due to the high ammonia nitrogen content of petrochemical sewage, the commonly used treatment processes are A / O biological treatment processes or their modified processes to remove total nitrogen and organic pollutants. According to the morphology of microorganisms, they are divided into activated sludge processes and biofilm processes. These methods have the characteristics of low sludge concentration, complex processes, long flow paths, large floor areas, many power equipment, a large amount of excess sludge, low shock resistance, and high energy consumption, far from meeting the requirements of national scientific and technological development. Therefore, how to reduce operating energy consumption, operating costs, and floor areas has become an urgent problem for petrochemical enterprises.

[0003] Aerobic granular sludge is a granular aggregate formed by the self-aggregation of microorganisms. This technology has the advantages of short flow paths, high loads, multiple functions, shock resistance, fast sedimentation speed, low sludge production, energy conservation, and land saving; multi-strain cooperation, bringing together aerobic, anoxic, and anaerobic microorganisms, especially suitable for the treatment of petrochemical sewage with high concentrations and high total nitrogen; its good application prospects have attracted the research of many domestic scholars, fully meeting the requirements of "carbon emission reduction".

[0004] Patent CN202211598202.1 discloses a system and method for batch treatment of petrochemical sewage with aerobic granular sludge. Compared with traditional processes, it has improved the treatment sludge concentration, reduced the amount of excess sludge, shortened the sedimentation time, eliminated the need for sedimentation tanks, eliminated reflux, and greatly reduced the floor area and energy consumption. However, this patent uses a batch treatment process and cannot achieve continuous reaction. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies of the prior art and provide a system and method for treating petrochemical sewage by an aerobic granular sludge continuous flow process.

[0006] A system for treating petrochemical sewage by an aerobic granular sludge continuous flow process of the present invention includes a sewage regulation and homogenization tower, an aerobic granular sludge full-feed tower, a continuous flow aerobic granular sludge reactor, a shear stress generator, a selection pressure generator, an aerobic granular sludge sieve, a sludge discharge tank, a sludge discharge pump, and a chemical dosing pump; the sewage regulation and homogenization tower, the aerobic granular sludge full-feed tower, the continuous flow aerobic granular sludge reactor, the aerobic granular sludge sieve, and the sludge discharge tank are connected in sequence; the shear stress generator and the selection pressure generator are respectively arranged inside the continuous flow aerobic granular sludge reactor; the sludge discharge pump is connected to the sludge discharge tank, and the chemical dosing pump is connected to the aerobic granular sludge full-feed tower.

[0007] Preferably, a plurality of shear stress generators can be uniformly arranged in the batch aerobic granular sludge reactor according to the scale of the batch aerobic granular sludge reactor.

[0008] A method for treating petrochemical sewage by an aerobic granular sludge continuous flow process of the present invention, using the system for treating petrochemical sewage by the above-mentioned aerobic granular sludge continuous flow process, includes the following steps: 1) The sewage is sent into the sewage regulation and equalization tower, and the sewage is adjusted in water volume and balanced in water quality through the sewage regulation and equalization tower. After adjustment and equalization, the sewage is sent into the aerobic granular sludge satiation tower to satiate the aerobic granular sludge.

[0009] 2) The satiated aerobic granular sludge is sent into the continuous flow aerobic granular sludge reactor, and air is blown into the continuous flow aerobic granular sludge reactor. The aerobic granular sludge is suspended, oxygenated and sheared by the shear stress generator, and the sewage is treated.

[0010] 3) Air is continuously blown into the aerobic granular sludge reactor, and the organic matter concentration in the reactor gradually decreases and gradually reaches a level that cannot be utilized by the microorganisms in the aerobic granular sludge, causing the microorganisms in the aerobic granular sludge to reach a starvation state and converting the aerobic granular sludge into a starvation state of endogenous respiration.

[0011] 4) The sewage and aerobic granular sludge enter the selection pressure generator. After selection, the inferior aerobic granular sludge is discharged with the sewage and enters the next-level sewage treatment device; the qualified aerobic granular sludge is separated from solid and liquid and returned to the aerobic granular sludge satiation tower.

[0012] 5) During the operation of the continuous flow aerobic granular sludge reactor, the aerobic granular sludge is screened by bypass. The qualified aerobic granular sludge is returned to the reactor, and the unqualified aerobic granular sludge is sent to the sludge discharge tank for external discharge.

[0013] Preferably, a dosing device is provided to add medicaments to the aerobic granular sludge satiation tower, including medicaments required for granule formation and medicaments required for microorganism growth.

[0014] Preferably, the sewage in the sewage regulation and equalization tower is sent into the aerobic granular sludge satiation tower by a lift pump or in a gravity flow manner.

[0015] Preferably, the aerobic granular sludge screening device screens out the aerobic granular sludge with a particle size greater than 1.2 mm.

[0016] Preferably, the screening amount of the aerobic granular sludge screening device is 5% - 15% of the designed amount.

[0017] As described above, the sewage regulating and equalizing tower serves to mechanically regulate the sewage volume and equalize the water quality of the whole plant. The sewage in the sewage regulating and equalizing tower can enter the aerobic granular sludge full-feeding tower by means of a lift pump or gravity flow to meet the requirements of the aerobic granular sludge for full feeding and ensure that the microorganisms inside the aerobic granular sludge obtain the same food. After being fully fed, the aerobic granular sludge enters the continuous flow aerobic granular sludge reactor. Air is blown into the continuous flow aerobic granular sludge reactor, and the shear stress generator located inside the reactor shears the aerobic granular sludge to remove the unnecessary microorganisms in the aerobic granular sludge and retain the required microorganisms, ensuring the scientific nature of the aerobic granular sludge flora, making the aerobic granular sludge more compact, and at the same time providing suspension for the aerobic granular sludge and oxygenation for the aerobic granular sludge. Due to the characteristics of the self-generated structure of the aerobic granular sludge, it simultaneously has the functions of an aerobic zone: ammonia oxidation, COD degradation, and biological phosphorus uptake; an anoxic zone: nitrate denitrification and nitrogen removal, and phosphate removal; and an anaerobic zone: hydrolysis of macromolecular organic matter and anaerobic ammonia oxidation. The sewage removes total nitrogen, total phosphorus, and organic pollutants under the action of the aerobic granular sludge, eliminating processes such as the reflux of nitrified water. After the sewage is treated by the aerobic granular sludge, the treatment requirements are met. The concentration of the organic matter serving as the food for the microorganisms in the reactor gradually decreases with the reaction and gradually reaches a level that cannot be utilized by the microorganisms. By continuously aerating and oxygenating, the action time of the microorganisms in the aerobic granular sludge is extended, the organic matter in the microorganisms is consumed, and the microorganisms reach a state of hunger, making the aerobic granular sludge in an endogenous respiration state of hunger. The aerobic granular sludge that has completed the biological reaction process enters the selection pressure generator. The inferior aerobic granular sludge is discharged with the sewage, and the superior aerobic granular sludge is separated from the solid and liquid and returned to the aerobic granular sludge full-feeding tower. The aerobic granular sludge and the sewage are mixed in the aerobic granular sludge full-feeding tower, enabling the microorganisms inside and outside the aerobic granular sludge to absorb sufficient nutrients. During the operation of the continuous flow aerobic granular sludge reactor, the aerobic granular sludge is screened by bypass to avoid the hollowing and fragmentation of the granular sludge. The screened aerobic granular sludge that meets the requirements is returned to the continuous flow aerobic granular sludge reactor, and the unqualified sludge particles are discharged into the sludge discharge bucket and discharged together with the remaining granular sludge as required.

[0018] Beneficial effects

[0019] (1) The aerobic granular sludge sewage treatment method adopted in the present invention is a special biological method without a carrier, which has the advantages of multi-strain cooperation, land saving, energy saving, etc. Compared with the traditional process, it has a longer sludge age, higher sludge concentration in treatment, less surplus sludge, shorter sedimentation time, no need for sedimentation tanks, no reflux, and greatly reduced floor area and energy consumption.

[0020] (2) The present invention adopts a shear stress generator, a selection pressure generator and a sludge sieve to optimize the structure of aerobic granular sludge in multiple dimensions. The aerobic granular sludge in the system has a large particle size, strong shock resistance and fast system recovery. At the same time, the system adopts a modular and device-based design, with precise control and flexible process operation.

[0021] (3) The sewage treatment method of the present invention develops a new process for treating petrochemical sewage with aerobic granular sludge, and adopts the special sludge structure of granular sludge to achieve energy conservation and consumption reduction, realizing multiple goals of land saving, energy conservation, low carbon and resource recovery in the petrochemical sewage treatment process, and providing a new idea for energy conservation and carbon reduction in petrochemical sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings of the specification are schematic diagrams of the process flow of the present invention, and the marks in the figure are: 1. Sewage regulation and homogenization tower; 2. Aerobic granular sludge full-feed tower; 3. Continuous flow aerobic granular sludge reactor; 4. Shear stress generator; 5. Selection pressure generator; 6. Aerobic granular sludge sieve; 7. Sludge discharge tank; 8. Sludge discharge pump; 9. Chemical dosing pump.

[0023] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Such as Figure 1Shown: A method for treating petrochemical sewage by an aerobic granular sludge continuous flow process. The treatment system includes a sewage regulation and homogenization tower 1, an aerobic granular sludge full-feed tower 2, a continuous flow aerobic granular sludge reactor 3, a shear stress generator 4, a selection pressure generator 5, an aerobic granular sludge sieve 6, a sludge discharge tank 7, a sludge discharge pump 8 and a chemical dosing pump 9. Among them, the whole plant sewage is mechanically regulated in terms of water volume and balanced in terms of water quality through the sewage regulation and homogenization tower 1; the sewage in the sewage regulation and homogenization tower 1 enters the aerobic granular sludge full-feed tower 2 by gravity flow to meet the requirements of aerobic granular sludge full-feed. The aerobic granular sludge after being full-fed enters the continuous flow aerobic granular sludge reactor 3; air is blown into the continuous flow aerobic granular sludge reactor from the bottom, and the shear stress generator 4 located in the reactor shears the aerobic granular sludge to remove unnecessary microorganisms on the granular sludge, making the aerobic granular sludge more compact; at the same time, it provides suspension of the aerobic granular sludge and oxygenation of the aerobic granular sludge, and the sewage removes total nitrogen, total phosphorus and organic pollutants under the action of the aerobic granular sludge, eliminating processes such as nitrified water reflux. After the sewage is treated by the aerobic granular sludge, the treatment requirements are completed, and continuous aeration is carried out to make the aerobic granular sludge transform into a starvation state of endogenous respiration, and together with the aerobic granular sludge full-feed tower 2, it completes the starvation-full-feed process of the aerobic granular sludge. The aerobic granular sludge that has completed the biological reaction process enters the selection pressure generator 5, and the superior aerobic granular sludge is separated from solid and liquid and returned to the aerobic granular sludge full-feed tower 2 for cyclic operation; the inferior aerobic granular sludge after passing through the selection pressure generator 5 is discharged together with the sewage. During the operation of the continuous flow aerobic granular sludge reactor, the aerobic granular sludge sieve 6 bypass-sieves the aerobic granular sludge, and the sieving amount is 10% of the designed amount, removing sludge particles with a particle size larger than 1.2 mm and a high proportion of inorganic substances. The screened qualified aerobic granular sludge is returned to the continuous flow aerobic granular sludge reactor 3, and the unqualified sludge particles are discharged into the sludge discharge tank 7 and discharged together with the remaining granular sludge as required;

[0025] The sludge discharge pump 8 is used for the lifting of sewage, sludge and mixed liquid, including saturated sludge, sludge discharge, etc.

[0026] The chemical dosing pump 9 is used for dosing chemicals into the aerobic granular sludge full-feed tower 2 and lifting sludge and sewage.

Claims

1. A system for treating petrochemical sewage by an aerobic granular sludge continuous flow process, characterized in that: It includes a sewage regulation and equalization tower, an aerobic granular sludge satiation tower, a continuous-flow aerobic granular sludge reactor, a shear stress generator, a selection pressure generator, an aerobic granular sludge sieve, a sludge discharge tank, a sludge discharge pump, and a chemical dosing pump; the sewage regulation and equalization tower, the aerobic granular sludge satiation tower, the continuous-flow aerobic granular sludge reactor, the aerobic granular sludge sieve, and the sludge discharge tank are connected in sequence; the shear stress generator and the selection pressure generator are respectively arranged inside the continuous-flow aerobic granular sludge reactor; the sludge discharge pump is connected to the sludge discharge tank, and the chemical dosing pump is connected to the aerobic granular sludge satiation tower.

2. The system for treating petrochemical sewage by an aerobic granular sludge continuous flow process according to claim 1, wherein: A plurality of shear stress generators are evenly arranged in the batch aerobic granular sludge reactor according to the scale of the batch aerobic granular sludge reactor.

3. A method for treating petrochemical sewage by an aerobic granular sludge continuous flow process, using the system for treating petrochemical sewage by the aerobic granular sludge continuous flow process as described in claim 1, characterized in that It includes the following steps: 1) Sewage is sent into the sewage regulation and equalization tower, and the sewage is adjusted in water volume and equalized in water quality through the sewage regulation and equalization tower. After adjustment and equalization, the sewage is sent into the aerobic granular sludge satiation tower to satiate the aerobic granular sludge. 2) The satiated aerobic granular sludge is sent into the continuous-flow aerobic granular sludge reactor, and air is blown into the continuous-flow aerobic granular sludge reactor for aeration. The aerobic granular sludge is suspended, oxygenated, and sheared by the shear stress generator, and the sewage is treated. 3) Air is continuously blown into the aerobic granular sludge reactor for aeration, and the organic matter concentration in the reactor gradually decreases and gradually reaches a level that cannot be utilized by the microorganisms in the aerobic granular sludge, causing the aerobic granular sludge to transform into a starvation state of endogenous respiration. 4) The sewage and aerobic granular sludge enter the selection pressure generator, and after selection, the inferior aerobic granular sludge is discharged with the sewage and enters the next-level sewage treatment device; the qualified aerobic granular sludge is separated from solid and liquid and then returned to the aerobic granular sludge satiation tower. 5) During the operation of the continuous-flow aerobic granular sludge reactor, the aerobic granular sludge is bypass sieved, and the qualified aerobic granular sludge is sieved out and returned to the reactor, while the unqualified aerobic granular sludge is sent to the sludge discharge tank for external discharge.

4. The method for treating petrochemical sewage by an aerobic granular sludge continuous flow process according to claim 3, characterized in that: A chemical dosing device is set to add chemicals to the aerobic granular sludge satiation tower, including chemicals required for particle formation and chemicals required for microorganism growth.

5. The method for treating petrochemical sewage by an aerobic granular sludge continuous flow process according to claim 3, characterized in that: The sewage in the sewage regulation and equalization tower is sent into the aerobic granular sludge satiation tower by using a lift pump or in a gravity flow manner.

6. The method for treating petrochemical sewage by an aerobic granular sludge continuous flow process according to claim 3, characterized in that: The aerobic granular sludge sieve sieves out aerobic granular sludge with a particle size larger than 1.2 mm.

7. A method for treating petrochemical sewage by an aerobic granular sludge continuous flow process according to claim 3, characterized in that: The sieving amount of the aerobic granular sludge sieve is 5% - 15% of the designed amount.

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