Method and device for treating oil-containing nitrogen and phosphorus-containing sewage

Abstract

The present application relates to a kind of oil-containing nitrogen-containing phosphorus sewage treatment method, mainly including two stages of system start and operation, in the start-up stage, in sewage treatment system, activated carbon, activated sludge and special bacteria agent are added, and stewing exposure treatment is carried out;Start-up water, batch operation, water is pretreated after passivation cleaning wastewater;When the ammonia nitrogen concentration of system effluent is less than 8mg / L, the total nitrogen concentration is less than 30mg / L, the total phosphorus concentration is less than 2mg / L, the COD concentration is less than 50mg / L after full load water, complete start-up, enter operation stage, and continuous water feeding mode is used in operation stage.The present application can realize the rapid start-up and stable operation of device, can realize the efficient removal of total nitrogen, total phosphorus, petroleum and COD in the same structure, reduce the treatment burden of subsequent unit, with the advantages of low cost, good comprehensive treatment effect, clear effluent and the like.

Description

Technical Field

[0001] This invention belongs to the field of water pollution control technology, specifically relating to a method and apparatus for treating oily, nitrogenous, and phosphorus-containing wastewater. Background Technology

[0002] Refining and chemical enterprises require regular maintenance and repair of their production facilities, primarily involving chemical cleaning and passivation treatments, which generate large amounts of wastewater. Different production units within the same enterprise use varying cleaning and passivating agents, resulting in complex wastewater compositions. Outsourcing the storage and disposal of this wastewater is prohibitively expensive, so most enterprises opt for pretreatment before discharging it into existing wastewater treatment plants. This wastewater contains not only large amounts of residual passivating agents, cleaning agent reaction products, and suspended solids formed from hard scale and dirt, but also features high salt, high nitrogen, high oil content, high levels of surface-active substances, and recalcitrant organic matter. Some formulations even include phosphorus in their cleaning aids. Even with pretreatment to partially reduce toxicity and inhibitory pollutants, discharging this wastewater into existing wastewater treatment plants still poses certain risks, especially when the existing treatment plants have insufficient capacity, severely impacting system stability.

[0003] Chinese Patent 201811571413.X discloses a method and apparatus for treating chemically passivated oily wastewater. The method includes: pretreating the chemically passivated oily wastewater to reduce the oil content to below 60 mg / L; subjecting the pretreated effluent to flotation treatment to reduce the oil content to below 20 mg / L; and subjecting the flotation-treated effluent to electrocatalytic oxidation treatment to complete the treatment of the chemically passivated oily wastewater. After treatment, the oil content in the chemically passivated oily wastewater is 8 mg / L, the ammonia nitrogen content is 12 mg / L, and the COD is 820 mg / L. However, entering the subsequent biological treatment unit will still increase the treatment burden.

[0004] With increasingly stringent environmental protection requirements, wastewater generated during maintenance and repair at refining and chemical plants poses a major challenge for treatment during shutdowns. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and apparatus for treating oily, nitrogenous, and phosphorus-containing wastewater generated during the maintenance and repair processes of refining and chemical enterprises. This invention enables rapid start-up and stable operation of the apparatus, achieving efficient removal of total nitrogen, total phosphorus, petroleum hydrocarbons, and COD within the same structure, reducing the processing burden on subsequent units, and offering advantages such as low cost, good overall treatment effect, and clear effluent.

[0006] This invention provides a method for treating oily, nitrogenous, and phosphorus-containing wastewater, which mainly includes two stages: system startup and operation. In the startup stage, activated carbon, activated sludge, and special bacterial agents are added to the wastewater treatment system for aeration treatment. Water is then introduced for batch operation, with the influent being pre-treated passivation and cleaning wastewater. When the system effluent concentration is less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L after full-load water intake, the startup is complete, and the system enters the operation stage, which uses a continuous water intake method.

[0007] In this invention, the specific bacterial agent includes *Acinetobacter pittii* PA6, and also includes at least one of *Microbacterium kitamiense* PR and *Aeromicrobacterium tamlense* PW. The cell mass ratio of *Acinetobacter pittii* PA6 to *Microbacterium kitamiense* PR and / or *Aeromicrobacterium tamlense* PW is 1–5:1, preferably 2–4:1. When both *Microbacterium kitamiense* PR and *Aeromicrobacterium tamlense* PW are present, they can be mixed in any ratio, preferably in a cell mass ratio of 1:5 to 5:1.

[0008] In this invention, the specific bacterial agent is added at a concentration of 10-20 μg / L after addition. The agent may also contain nutrients, protectants, and other substances required by the bacteria. More preferably, the specific bacterial agent further includes tetrahydropyrimidine or hydroxytetrahydropyrimidine, with the mass ratio of the added amount to the total amount of the specific bacterial agent being 1-10 μg / kg.

[0009] In this invention, *Acinetobacter pittii* PA6 was deposited on June 27, 2022, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 25181, located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. The main morphological characteristics of this bacterium are as follows: after culturing on TSA medium at 37°C for 18 hours, the colonies are yellow, round, moist, opaque, and have neat edges. Under a microscope, the bacteria are rod-shaped, 0.3-0.5 μm × 0.4-1.0 μm, arranged singly or in pairs, and are Gram-negative.

[0010] In this invention, *Microbacterium kitamiense* PR was deposited on June 27, 2022, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 25182, located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. The main morphological characteristics of this bacterium are as follows: when cultured on TSA medium at 30°C for 3 days, the colonies are yellow, round, moist, opaque, and have neat edges. Under a microscope, the bacteria appear as short rods, 0.4-0.6 μm × 0.7-1.6 μm, arranged singly or in pairs, and are Gram-positive.

[0011] In this invention, *Aeromicrobium tamlense* PW was deposited on June 27, 2022, at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 25183, located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. The main morphological characteristics of this bacterium are as follows: when cultured on TSA medium at 30°C for 3 days, the colonies are yellow, round, moist, opaque, and have neat edges. Under a microscope, the bacteria appear as short rods, 0.4-0.6 μm × 0.6-1.3 μm, arranged singly or in pairs, and are Gram-positive.

[0012] The preparation method of the special bacterial agent of this invention is as follows: first, the bacterial cells are activated; then, seed culture is carried out; finally, the seed culture is scaled up, the bacterial cells are collected, packaged, and stored for later use. Specifically, it may include the following steps:

[0013] (a) The preserved Acinetobacter piezoides PA6, Microbes pr, and Aerobic bacteria PW were inoculated onto LB solid medium and activated in a constant temperature incubator at 20-35℃;

[0014] (b) Using an inoculation loop, take colonies from the plate and inoculate them into LB liquid medium. Shake and culture until the logarithmic phase to obtain liquid bacterial seed culture.

[0015] (c) The above seed liquids are cultured in a large scale, the bacterial cells are collected, and they are mixed in the required proportion to obtain the bacterial agent.

[0016] In the preparation method of the bacterial agent described in this invention, the LB medium formula is: NaCl 5-15 g / L, peptone 5-15 g / L, and yeast extract 3-8 g / L. The solid medium is prepared by adding 15-25 g / L of agar to the liquid medium.

[0017] In the preparation method of the bacterial agent of the present invention, the culture conditions in step (b) are: temperature 20-35℃, pH 6-9, shaking speed 150-240 rpm, and culture time 24-48 h.

[0018] In the preparation method of the bacterial agent of the present invention, the culture conditions in step (c) are: temperature 20-35℃, pH 6-9, dissolved oxygen 0.5-2.5mg / L, and culture time 48-72h.

[0019] In the preparation method of the bacterial agent described in this invention, the bacterial cells are collected by means of filtration, centrifugation, etc. For example, the bacterial cells can be collected by centrifugation at 5000-10000 rpm for 5-10 min.

[0020] In the preparation method of the bacterial agent described in this invention, Acinetobacter piterum PA6 and Microbes kiwi PR and / or Aerobic bacteria PW are mixed at a bacterial mass ratio of 1 to 5:1, preferably 2 to 4:1. When both Microbes kiwi PR and Aerobic bacteria PW are present, they can be mixed in any ratio, preferably at a bacterial mass ratio of 1:5 to 5:1.

[0021] In this invention, the wastewater treatment system can employ conventional bioreactors with aeration functions, such as A / O, SBR, and BAF, with SBR reactors being preferred.

[0022] In this invention, activated carbon is added at 5%-30% of the effective volume of the wastewater treatment system, preferably 10%-15%. The activated carbon is in powder form, with a particle size of 0.2-0.5 mm and a specific surface area of ​​200-1000 m². 2 / g, iodine value is 600-1000mg / g.

[0023] In this invention, activated sludge is added at a post-inoculation concentration of 10-30 g / L, preferably 15-20 g / L. The activated sludge mainly comes from the secondary sedimentation tank of the enterprise's wastewater treatment plant.

[0024] In this invention, after the addition of activated carbon, activated sludge, and special bacterial agents, the mixture is subjected to aeration treatment for 3-5 days under the conditions of dissolved oxygen 2-6 mg / L, pH 7-9, and temperature 25-40℃.

[0025] In this invention, the water intake is first started at 50% of the influent load. During the start-up process, the influent load is gradually increased in batches, with each increase being 5%-15%, until the influent load reaches 100% and the effluent meets the requirements, namely, the effluent ammonia nitrogen concentration is less than 8 mg / L, the total nitrogen concentration is less than 30 mg / L, the total phosphorus concentration is less than 2 mg / L, and the COD concentration is less than 50 mg / L. Then, continuous water intake begins and the system enters the operation phase.

[0026] In this invention, during the start-up and operation phases, the operating conditions of the wastewater treatment system are: dissolved oxygen greater than 2 mg / L, pH value of 7.5-8.5, and temperature of 25-40℃.

[0027] In this invention, the oily, nitrogenous, and phosphorus-containing wastewater is chemically cleaned and passivated wastewater that has undergone oil separation and flotation pretreatment. Its pH value is 6-9, ammonia nitrogen concentration is 30-50 mg / L, total nitrogen concentration is 40-70 mg / L, total phosphorus concentration is 8-15 mg / L, COD concentration is 500-800 mg / L, petroleum content is 15-30 mg / L, and salt content is 15000-20000 mg / L.

[0028] The present invention also provides a treatment device for the above-mentioned oily, nitrogen- and phosphorus-containing wastewater. The treatment device mainly includes a wastewater treatment system and a monitoring system. The wastewater treatment system is filled with activated carbon and inoculated with activated sludge and special bacterial agents for wastewater treatment. The monitoring system is used to monitor the effluent indicators of the system.

[0029] In this invention, the wastewater treatment system can employ conventional bioreactors used in the art, such as A / O, SBR, and BAF, with SBR reactors being preferred.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) In response to the characteristics of oily, nitrogenous, and phosphorus-containing wastewater generated during equipment maintenance, a highly efficient treatment system can be quickly constructed by combining activated sludge, activated carbon, and special bacterial agents. This system integrates oil removal, adsorption and degradation of organic matter, and nitrogen and phosphorus removal. It has strong tolerance to toxins and salts and achieves efficient simultaneous removal of oil, total nitrogen, total phosphorus, and COD from wastewater, reducing the burden on subsequent biochemical treatment units.

[0032] (2) The special bacterial agent provided by this invention is mainly made from aerobic bacterial strains with similar growth environments. The culture conditions of each strain are similar, making the preparation of the bacterial agent simple and easy. In particular, when combined with activated carbon and reagents, the strains multiply rapidly, achieving deep removal of oil and total nitrogen, and further improving the comprehensive treatment effect of wastewater.

[0033] (3) The special bacterial agent of the present invention uses tetrahydropyrimidine or hydroxytetrahydropyrimidine at the same time, which can protect the resistance of the bacteria in the initial addition state, enable the bacteria to quickly adapt to the extreme environment, achieve rapid reproduction in harsh environments, and shorten the start-up time. Detailed Implementation

[0034] The following examples further illustrate the method and effects of the present invention in detail. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following examples.

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following examples were purchased from conventional biochemical reagent stores.

[0036] In this embodiment of the invention, COD concentration was determined using GB11914-89 "Water Quality - Determination of Chemical Oxygen Demand - Dichromate Method"; ammonia nitrogen concentration was determined using GB7478-87 "Water Quality - Determination of Ammonium - Distillation and Titration Method"; total nitrogen concentration was determined using GB11894-89 "Water Quality - Determination of Total Nitrogen - Ultraviolet Spectrophotometry"; petroleum hydrocarbons were determined using HJ970-2018 "Water Quality - Determination of Petroleum Hydrocarbons - Ultraviolet Spectrophotometry"; and total phosphorus concentration was determined using GB11893-89 "Ammonium Molybdate Spectrophotometry".

[0037] In this embodiment of the invention, the oily, nitrogenous, and phosphorus-containing wastewater comes from chemical cleaning and passivation wastewater that has undergone pretreatment via oil separation and flotation during a major overhaul of a refining and chemical enterprise. Testing revealed a pH of 8, an ammonia nitrogen concentration of 45 mg / L, a total nitrogen concentration of 55 mg / L, a total phosphorus concentration of 10 mg / L, a COD concentration of 620 mg / L, petroleum hydrocarbons of 18.9 mg / L, and a salt content of 18000 mg / L. The treatment device mainly includes a wastewater treatment system and a monitoring system. The wastewater treatment system uses an SBR reactor with an effective volume of 50 L. The activated carbon is in powder form with a particle size of 0.2-0.3 mm and a specific surface area of ​​600-700 m². 2 / g, iodine value is 700-800mg / g.

[0038] Example 1

[0039] The LB liquid medium formula is: NaCl 10 g / L, peptone 10 g / L, yeast extract 5 g / L. The solid medium is the liquid medium with 20 g / L agar added.

[0040] Preparation of bacterial agents: (a) Strain activation: Preserved Acinetobacter piezoides PA6, Microbes pr. and Aerobic bacteria PW were inoculated onto LB solid medium, spread evenly, and activated in a constant temperature incubator at 30℃. (b) Seed culture: Colonies of the three strains were picked from the plates using an inoculation loop and inoculated into LB liquid medium. The culture was carried out at 30℃ and 150 rpm for 48 hours with shaking to obtain seed culture. (c) Scale-up culture: The above seed culture was carried out in reactors equipped with aeration equipment at 30℃, dissolved oxygen 2.0-2.5 mg / L, pH 7.0-7.5, and culture time 72 hours to obtain concentrated bacterial solutions of the three strains. The bacterial cells were collected by centrifugation at 10000 rpm for 5 min. The bacterial agents were prepared according to the proportions described in Table 1, as shown in Table 1.

[0041] Table 1 Composition and ratio of the microbial agent

[0042] 1# PA6:PR 3:1 2# PA6:PR 1:1 3# PA6:PW 5:1 4# PA6:PW:PR 4:1:1

[0043] Example 2

[0044] Prepare a 50L SBR wastewater treatment unit. During the start-up phase, first add activated carbon at 15% of the reactor's effective volume. Add activated sludge at a post-inoculation sludge concentration of 20 g / L, and add the special bacterial agent #1 at a post-addition concentration of 20 μg / L. Then, allow the reactor to aerate for 5 days under conditions of dissolved oxygen 5 mg / L, pH 7.5, and temperature 25℃. Afterward, start the reactor at 50% influent load, using a batch-by-batch effluent replacement method, gradually increasing the influent load by 10% with each batch, until the influent load reaches 100% and the effluent ammonia nitrogen concentration is less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L. At this point, the start-up is complete, and the reactor enters the operation phase. The start-up and operation conditions are: dissolved oxygen 2-4 mg / L, pH 7.5-8.0, and temperature 25-30℃. The system operated for 15 days and the treatment effect was stable. The test results were as follows: the effluent ammonia nitrogen concentration was consistently below 6.6 mg / L, the total nitrogen concentration was consistently below 23.3 mg / L, the total phosphorus concentration was consistently below 0.43 mg / L, the petroleum hydrocarbon concentration was consistently below 0.1 mg / L, and the COD concentration was consistently below 35.5 mg / L.

[0045] Example 3

[0046] Prepare a 50L SBR wastewater treatment unit. During the start-up phase, first add activated carbon at 30% of the reactor's effective volume. Add activated sludge at a post-inoculation concentration of 10 g / L, and add the special bacterial agent #2 at a post-addition concentration of 15 μg / L. Then, allow the reactor to aerate for 5 days under conditions of dissolved oxygen 5 mg / L, pH 7.5, and temperature 30℃. Afterward, start the reactor at 50% influent load, using a batch-by-batch effluent replacement method, gradually increasing the influent load by 10% with each batch, until the influent load reaches 100% and the effluent ammonia nitrogen concentration is less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L. At this point, the start-up is complete, and the reactor enters the operation phase. The start-up and operation conditions are: dissolved oxygen 2-4 mg / L, pH 7.5-8.0, and temperature 25-30℃. The system operated for 15 days and the treatment effect was stable. The test results were as follows: the effluent ammonia nitrogen concentration was consistently below 7.8 mg / L, the total nitrogen concentration was consistently below 25.5 mg / L, the total phosphorus concentration was consistently below 0.48 mg / L, the petroleum hydrocarbon concentration was consistently below 0.8 mg / L, and the COD concentration was consistently below 43.2 mg / L.

[0047] Example 4

[0048] Prepare a 50L SBR wastewater treatment unit. During the start-up phase, first add activated carbon at 5% of the reactor's effective volume. Add activated sludge at a post-inoculation sludge concentration of 30 g / L, and add the special bacterial agent #3 at a post-addition concentration of 10 μg / L. Then, allow the reactor to aerate for 5 days under conditions of dissolved oxygen 5 mg / L, pH 7.5, and temperature 25℃. Afterward, start the reactor at 50% influent load, using a batch-by-batch effluent replacement method, gradually increasing the influent load by 10% with each batch, until the influent load reaches 100% and the effluent ammonia nitrogen concentration is less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L. At this point, the start-up is complete, and the reactor enters the operation phase. The start-up and operation conditions are: dissolved oxygen 2-4 mg / L, pH 7.5-8.0, and temperature 25-30℃. The system operated for 15 days and the treatment effect was stable. The test results were as follows: the effluent ammonia nitrogen concentration was consistently below 8.0 mg / L, the total nitrogen concentration was consistently below 25.0 mg / L, the total phosphorus concentration was consistently below 0.46 mg / L, the petroleum hydrocarbon concentration was consistently below 0.6 mg / L, and the COD concentration was consistently below 42.2 mg / L.

[0049] Example 5

[0050] Prepare a 50L SBR wastewater treatment unit. During the start-up phase, first add activated carbon at 15% of the reactor's effective volume. Add activated sludge at a post-inoculation concentration of 20 g / L, and add the special bacterial agent #1 at a post-addition concentration of 20 μg / L. Simultaneously, add tetrahydropyrimidine at a mass ratio of 5 μg / kg to the added special bacterial agent. Then, allow the reactor to aerate for 5 days under conditions of dissolved oxygen 5 mg / L, pH 7.5, and temperature 25℃. Afterward, start the reactor at 50% influent load, using a batch-by-batch effluent replacement method, gradually increasing the influent load by 10% with each batch, until the influent load reaches 100% and the effluent ammonia nitrogen concentration is less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L. At this point, the start-up is complete and the reactor enters the operational phase. The start-up and operation conditions of the wastewater treatment system were: dissolved oxygen 2-4 mg / L, pH 7.5-8.0, and temperature 25-30℃. After 15 days of operation, the system showed stable treatment performance. Test results showed that the effluent ammonia nitrogen concentration was consistently below 4.5 mg / L, total nitrogen concentration was consistently below 22.6 mg / L, total phosphorus concentration was consistently below 0.40 mg / L, petroleum hydrocarbon concentration was consistently undetectable, and COD concentration was consistently below 31.0 mg / L.

[0051] Example 6

[0052] Prepare a 50L SBR wastewater treatment unit. During the start-up phase, first add activated carbon at 15% of the reactor's effective volume. Add activated sludge at a post-inoculation concentration of 20 g / L, and add the special bacterial agent #4 at a post-addition concentration of 20 μg / L. Then, allow the reactor to aerate for 5 days under conditions of dissolved oxygen 5 mg / L, pH 7.5, and temperature 25℃. Afterward, start the reactor at 50% influent load, using a batch-by-batch effluent replacement method, gradually increasing the influent load by 10% with each batch, until the influent load reaches 100% and the effluent ammonia nitrogen concentration is less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L. At this point, the start-up is complete, and the reactor enters the operation phase. The start-up and operation conditions are: dissolved oxygen 2-4 mg / L, pH 7.5-8.0, and temperature 25-30℃. The system operated for 15 days and the treatment effect was stable. The test results were as follows: the ammonia nitrogen concentration in the effluent was consistently below 7.0 mg / L, the total nitrogen concentration was consistently below 24.0 mg / L, the total phosphorus concentration was consistently below 0.45 mg / L, the petroleum hydrocarbon concentration was consistently undetectable, and the COD concentration was consistently below 31.3 mg / L.

[0053] Comparative Example 1

[0054] Similar to Example 2, but without inoculating the specific bacterial agent provided by this invention during the start-up phase. When the reactor reached 100% of the influent load, and the effluent ammonia nitrogen concentration was less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L, the start-up time was 10 days longer than in Example 2. After transitioning to the operational phase, the system underwent a 15-day test, resulting in effluent ammonia nitrogen concentrations of 25.7 mg / L, total nitrogen concentration of 39.8 mg / L, total phosphorus concentration of 6.7 mg / L, petroleum hydrocarbon concentration of 15.8 mg / L, and COD concentration of 118.6 mg / L, indicating that stable operation was not achieved.

[0055] Comparative Example 2

[0056] Similar to Example 2, but with the difference that the specific bacterial agent inoculated during the start-up phase contained only PA6. When the reactor reached 100% of the influent load, and the effluent ammonia nitrogen concentration was less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L, the start-up time was 5 days longer than in Example 2. After transitioning to the operational phase, the system ran for 15 days, and the results showed that the effluent ammonia nitrogen concentration was 18.4 mg / L, total nitrogen concentration was 36.6 mg / L, total phosphorus concentration was 6.1 mg / L, petroleum hydrocarbon concentration was 4.5 mg / L, and COD concentration was 76.1 mg / L, indicating that stable operation had not been achieved.

[0057] Comparative Example 3

[0058] Similar to Example 2, but with the difference that the specific bacterial agent inoculated during the start-up phase contained only PR. When the reactor reached 100% of the influent load, and the effluent ammonia nitrogen concentration was less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L, the start-up time was 5 days longer than in Example 2. After transitioning to the operational phase, the system ran for 15 days, and the results showed that the effluent ammonia nitrogen concentration was 12.2 mg / L, total nitrogen concentration was 28.9 mg / L, total phosphorus concentration was 2.3 mg / L, petroleum hydrocarbon concentration was 13.6 mg / L, and COD concentration was 79.3 mg / L, indicating that stable operation was not achieved.

[0059] Comparative Example 4

[0060] Similar to Example 2, but without the use of activated carbon during the start-up phase. When the reactor reached 100% of the influent load, and the effluent ammonia nitrogen concentration was less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L, the start-up time was 7 days longer than in Example 2. After transitioning to the operational phase, a 15-day test showed the following effluent concentrations: ammonia nitrogen 21.2 mg / L, total nitrogen 34.2 mg / L, total phosphorus 4.4 mg / L, petroleum hydrocarbons 5.8 mg / L, and COD 98.5 mg / L; stable operation was not achieved.

[0061] Comparative Example 5

[0062] Similar to Example 2, but without the addition of activated sludge during the start-up phase. When the reactor reached 100% of the influent load, and the effluent ammonia nitrogen concentration was less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L, the start-up time was 6 days longer than in Example 2. After transitioning to the operational phase, the system ran for 15 days, and the test results showed that the effluent ammonia nitrogen concentration was 22.8 mg / L, total nitrogen concentration was 35.5 mg / L, total phosphorus concentration was 4.7 mg / L, petroleum hydrocarbon concentration was 6.4 mg / L, and COD concentration was 106.3 mg / L, indicating that stable operation was not achieved.

[0063] Comparative Example 6

[0064] Similar to Example 2, but without the initial aeration treatment during startup. When the reactor reached 100% of the influent load, and the effluent ammonia nitrogen concentration was less than 8 mg / L, total nitrogen concentration less than 30 mg / L, total phosphorus concentration less than 2 mg / L, and COD concentration less than 50 mg / L, the startup time was 6 days longer than in Example 2. After transitioning to the operational phase, the system underwent a 15-day test, resulting in effluent ammonia nitrogen concentrations of 21.7 mg / L, total nitrogen concentrations of 33.9 mg / L, total phosphorus concentrations of 4.3 mg / L, petroleum hydrocarbon concentrations of 5.1 mg / L, and COD concentrations of 86.9 mg / L, indicating that stable operation was not achieved.

Claims

1. A method for treating oily, nitrogen- and phosphorus-containing wastewater, characterized in that... The system includes two phases: system startup and operation. During the startup phase, activated carbon, activated sludge, and special bacterial agents are added to the wastewater treatment system for aeration treatment. The system is started with influent, and batch operation is conducted. The influent is pre-treated passivation cleaning wastewater. Start-up is completed and the system transitions to operation when the effluent ammonia nitrogen concentration is less than 8 mg / L, total nitrogen concentration is less than 30 mg / L, total phosphorus concentration is less than 2 mg / L, and COD concentration is less than 50 mg / L after full-load influent. During operation, continuous influent is used. The specific bacterial agent includes Acinetobacter piterum (…). Acinetobacter pittii PA6, which also includes Microbial kiwi ( Microbacterium kitamiense PR and aerobic bacteria ( Aeromicrobiumtamlense At least one of PW; wherein Acinetobacter piezophyllum ( Acinetobacter pittii PA6 has the accession number CGMCC No. 25181, and is a species of Microbes kiwi (Citropa kiwi). Microbacterium kitamiense The accession number for the microorganism is CGMCC No. 25182. Aeromicrobiumtamlense The accession number of PW is CGMCC No. 25183.

2. The method according to claim 1, characterized in that: The cell mass ratio of Acinetobacter piterum PA6 to Microbeobacterium pr and / or Aerobic bacteria PW is 1 to 5:1; when both Microbeobacterium pr and Aerobic bacteria PW are present, they are mixed in any ratio.

3. The method according to claim 2, characterized in that: The cell mass ratio of Acinetobacter piezoides PA6 to Microbeobacterium kiwi PR and / or Microbeobacterium aerogenes PW is 2–4:1; when both Microbeobacterium kiwi PR and Microbeobacterium aerogenes PW are present, they are mixed at a cell mass ratio of 1:5 to 5:

1.

4. The method according to claim 1, 2 or 3, characterized in that: Add the special bacterial agent at a concentration of 10-20 μg / L after addition.

5. The method according to claim 1, 2 or 3, characterized in that: The specific microbial agent also includes tetrahydropyrimidine or hydroxytetrahydropyrimidine, and the mass ratio of the amount added to the amount of specific microbial agent is 1-10 μg / kg.

6. The method according to claim 1, 2 or 3, characterized in that: The preparation method of the special bacterial agent is as follows: first, the bacterial cells are activated, then seed culture is carried out, and finally the seed culture is scaled up, the bacterial cells are collected, packaged and stored for later use.

7. The method according to claim 6, characterized in that: The preparation method of the special bacterial agent is as follows: (a) The preserved Acinetobacter piezoides PA6, Microbes pr, and Aerobic bacteria PW were inoculated onto LB solid medium and activated in a constant temperature incubator at 20-35℃; (b) Using an inoculation loop, take colonies from the plate and inoculate them into LB liquid medium. Shake and culture until the logarithmic phase to obtain liquid bacterial seed culture. (c) The above seed liquids are cultured on a large scale, the bacterial cells are collected, and they are mixed in the required proportion to prepare the bacterial agent.

8. The method according to claim 7, characterized in that: The culture conditions for step (b) are: temperature 20-35℃, pH 6-9, shaking speed 150-240 rpm, and culture time 24-48 h.

9. The method according to claim 7, characterized in that: The culture conditions for step (c) are: temperature 20-35℃, pH 6-9, dissolved oxygen 0.5-2.5 mg / L, and culture time 48-72 h.

10. The method according to claim 1, characterized in that: Activated carbon is added at 5%-30% of the effective volume of the wastewater treatment system; the activated carbon is in powder form with a particle size of 0.2-0.5 mm and a specific surface area of ​​200-1000 m². 2 / g, iodine value is 600-1000mg / g.

11. The method according to claim 10, characterized in that: Activated carbon should be added at a rate of 10%-15% of the effective volume of the wastewater treatment system.

12. The method according to claim 1, characterized in that: Add activated sludge at a concentration of 10-30 g / L after inoculation.

13. The method according to claim 12, characterized in that: Add activated sludge at a concentration of 15-20 g / L after inoculation.

14. The method according to claim 1, 10, 11, 12 or 13, characterized in that: After adding activated carbon, activated sludge, and special bacterial agents, the mixture is subjected to aeration treatment for 3-5 days under conditions of dissolved oxygen 2-6 mg / L, pH 7-9, and temperature 25-40℃.

15. The method according to claim 1, characterized in that: First, start the water intake at 50% of the influent load. During the start-up process, gradually increase the influent load in batches, with each increase being 5%-15%, until the influent load reaches 100% and the effluent meets the requirements, namely, the effluent ammonia nitrogen concentration is less than 8 mg / L, the total nitrogen concentration is less than 30 mg / L, the total phosphorus concentration is less than 2 mg / L, and the COD concentration is less than 50 mg / L. Then, start continuous water intake and enter the operation phase.

16. The method according to claim 1, characterized in that: During the start-up and operation phases, the operating conditions of the wastewater treatment system are: dissolved oxygen greater than 2 mg / L, pH value of 7.5-8.5, and temperature of 25-40℃.

17. The method according to claim 1, characterized in that: The oily, nitrogenous, and phosphorus-containing wastewater is chemically cleaned and passivated wastewater that has undergone oil separation and flotation pretreatment. Its pH value is 6-9, ammonia nitrogen concentration is 30-50 mg / L, total nitrogen concentration is 40-70 mg / L, total phosphorus concentration is 8-15 mg / L, COD concentration is 500-800 mg / L, petroleum content is 15-30 mg / L, and salt content is 15000-20000 mg / L.

18. A treatment apparatus for use in the method for treating oily, nitrogen- and phosphorus-containing wastewater according to any one of claims 1-17, characterized in that: The treatment device mainly includes a wastewater treatment system and a monitoring system; the wastewater treatment system is filled with activated carbon and inoculated with activated sludge and special bacterial agents for wastewater treatment; the monitoring system is used to monitor the effluent indicators of the system.