Domestication method and treatment process of activated sludge for full-biochemical treatment of alkali-minimization wastewater

Abstract

The invention discloses a domestication method and a treatment process of activated sludge for full-biochemical treatment of alkali-minimization wastewater, and relates to the field of printing and dyeing wastewater treatment. The alkali-minimization wastewater treatment process comprises the following steps: inoculating activated sludge containing salt-tolerant acidizing bacteria and activated sludge containing salt-tolerant anaerobic bacteria in an anaerobic tank, and inoculating activated sludge containing PTA degrading bacteria in an aerobic tank; wastewater to be treated is fed into the anaerobic tank so as to reduce the pH value and COD value of the wastewater, the wastewater subjected to anaerobic treatment enters the aerobic tank, the wastewater is in contact with the PTA degrading bacteria, and the PTA degrading bacteria decompose residual substances in the wastewater so as to further reduce the COD value of the wastewater. According to the method, the activated sludge containing the salt-tolerant acidizing bacteria and the activated sludge containing the salt-tolerant anaerobic bacteria can be directly inoculated into an anaerobic tank of an alkali-minimization wastewater treatment system and have relatively high degradation capacity on organic matters such as PET (Polyethylene Terephthalate) oligomer, PTA (Pure Terephthalic Acid) and ethylene glycol in the wastewater.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment, and in particular to a method for acclimating activated sludge and a wastewater treatment process for the fully biological treatment of alkaline wastewater. Background Technology

[0002] Alkali reduction wastewater mainly originates from the textile printing and dyeing industry, particularly from the alkali reduction treatment of polyester fabrics. This type of wastewater contains high concentrations of sodium terephthalate (PTA-Na), polyethylene terephthalate (PET), and organic compounds such as ethylene glycol. Conventional treatment methods for alkali reduction wastewater include the following: (1) Add strong acid (sulfuric acid or hydrochloric acid) to the wastewater to adjust the pH value of the wastewater to 2-4. Under acidic conditions, PTA-Na is converted into terephthalic acid (PTA), and a solid precipitate is precipitated. The solid is then separated by pressing the filter with a plate and frame filter press. The sludge cake obtained by pressing is transported for disposal. The filtrate is adjusted to neutral pH by alkali adjustment and then mixed with other wastewater for treatment.

[0003] (2) Heat the wastewater to 75-120℃ to hydrolyze polyethylene terephthalate (PET) into sodium terephthalate (PTA-Na) and ethylene glycol (EG), and promote further degradation of organic impurities. Then, most of the terephthalic acid (PTA) is precipitated by adding acid and polyferric sulfate. After solid-liquid separation, it can be recycled. The remaining pollutants are treated by anaerobic and aerobic treatment.

[0004] (3) Pollutants in wastewater are separated by membrane separation technologies such as microfiltration, nanofiltration, and reverse osmosis, and substances such as PTA are recovered. The treated water is discharged in compliance with standards.

[0005] (4) Through Fenton / ozone-H2O2 advanced oxidation, organic macromolecules such as PTA-Na and phenols are oxidized into small molecule organic acids. The wastewater after oxidation is then treated by bipolar membrane electrodialysis and biochemical treatment to achieve the goal of discharge in compliance with standards.

[0006] Methods (1) and (2) both require the addition of acids and other reagents, resulting in high reagent consumption and costs. Methods (3) and (4) involve high equipment investment and electricity costs, as well as high equipment maintenance costs and operational difficulties. Summary of the Invention

[0007] The main purpose of this application is to propose an activated sludge acclimatization method and wastewater treatment process for the full biological treatment of alkali reduction wastewater, aiming to solve the problems of large reagent consumption, high equipment investment and energy consumption, high maintenance costs and high operation difficulty in the treatment of alkali reduction wastewater by existing technologies.

[0008] In a first aspect, this application provides a method for acclimating activated sludge for the fully biological treatment of alkaline reduction wastewater, including a method for acclimating activated sludge containing hydrochloric acid-tolerant bacteria and a method for acclimating activated sludge containing salt-tolerant anaerobic bacteria. The method for acclimating activated sludge containing hydrochloric acid-tolerant bacteria includes the following steps: S1. Provide sludge from the anaerobic tank of the textile printing and dyeing wastewater treatment system and add the sludge to the first anaerobic reactor; S2. Provide textile printing and dyeing production wastewater and introduce carbon dioxide into the wastewater to adjust the pH value of the wastewater to 6.5-7.5. Send the pH-adjusted wastewater and the return liquid flowing out from the upper part of the first anaerobic reactor together into the lower part of the first anaerobic reactor. Mix the wastewater with the sludge and carry out the initial acclimation to obtain the initial acclimated sludge. S3. Gradually increase the pH and influent flow rate of the wastewater fed into the first anaerobic reactor, and gradually decrease the return flow rate of the reflux liquid for subsequent acclimatization, until the pH value rises to 12.0–13.5 and the influent flow rate rises to 17–20 m³ / h. 3 / d, the reflux flow rate of the reflux fluid decreased to 3-7m³ / d. 3 / d, after the later acclimatization is completed, activated sludge containing hydrochloric acid tolerant bacteria is obtained.

[0009] By adopting the above technical solution, the pretreatment wastewater of textile printing and dyeing production (typical water quality: pH≥12.0, COD≥25000mg / L, conductivity≥15000us / cm, TN≤150mg / L) contains a high concentration of organic matter. The system for treating this textile printing and dyeing production wastewater includes an anaerobic tank. The sludge in the anaerobic tank contains acidifying bacteria, organic matter, and other nutrients. Therefore, the sludge (30-40g MLSS / L) in the anaerobic tank of the textile printing and dyeing production wastewater treatment system is used as the sludge to be acclimated. The inoculum amount of the sludge to be acclimated in the first anaerobic reactor is 10–50 v / v%. For example, the ratio of the volume of the sludge to be acclimated to the volume of the first anaerobic reactor can be 10:100 (10 v / v%), 20:100 (20 v / v%), 30:100 (30 v / v%), 40:100 (40 v / v%), or 50:100 (50 v / v%), etc.

[0010] Textile dyeing and printing pretreatment wastewater (typical water quality: pH ≥ 12.0, COD ≥ 25000 mg / L, conductivity ≥ 15000 μS / cm, TN ≤ 150 mg / L) was used as the acclimation stock solution, and carbon dioxide was introduced to adjust the pH value of the acclimation stock solution. During the initial acclimation process, a relatively large amount of carbon dioxide was introduced to lower the pH value of the acclimation stock solution to 6.5–7.5, so that the inoculated unacclimated activated sludge could directly adapt. Furthermore, during the initial acclimation process, the pH-adjusted wastewater and return liquid were fed together into the first anaerobic reactor to promote the full adaptation and utilization of organic matter in the water by microorganisms. After the initial acclimation was completed, the pre-acclimated sludge was obtained.

[0011] During the later stages of acclimatization, the pH value and influent flow rate of the wastewater fed into the anaerobic reactor were gradually increased, while the return flow rate was gradually decreased. This was to allow sufficient growth time for acidifying bacteria, increase their proportion in the activated sludge, and ensure pH stability within the first anaerobic reactor. This process continued until the pH value of the wastewater fed into the first anaerobic reactor reached 12.0–13.5, and the influent flow rate reached 17–20 m³ / h. 3 / d, the reflux flow rate of the reflux fluid decreased to 3-7m³ / d. 3 / d, after the later acclimatization is completed, activated sludge containing hydrochloric acid tolerant bacteria is obtained.

[0012] The activated sludge containing hydrochloric acid-tolerant bacteria obtained using the acclimatization method described in this application can be directly inoculated into the anaerobic tank of an alkali reduction wastewater treatment system, exhibiting strong adaptability to alkali reduction wastewater. Furthermore, the hydrochloric acid-tolerant bacteria in the activated sludge have a strong ability to degrade organic matter such as PET-Na in the wastewater, which is also beneficial to the stable operation of the water treatment system. Using the activated sludge containing hydrochloric acid-tolerant bacteria described in this application to treat wastewater can successfully degrade PTA-Na and COD in the water without adding large amounts of acid, alkali, and physicochemical agents. It requires less reagents, consumes less energy, saves on equipment investment costs, reduces equipment maintenance costs, and is relatively easy to operate.

[0013] It is understandable that "sludge in the anaerobic tank of the textile printing and dyeing production wastewater treatment system" refers to the sludge extracted from the anaerobic tank of the textile printing and dyeing production wastewater treatment system.

[0014] It should be noted that the volume of the first anaerobic reactor is 90–110 m³. 3 The effective water depth is 7–10 m; for example, the volume of the first anaerobic reactor can be 100 m³. 3 The effective water depth can be 9m. Of course, other volumes and effective water depths of the first anaerobic reactor can also be used according to actual needs.

[0015] Optionally, in step S2, the initial acclimatization period is 9 to 11 days; In step S3, the pH value and influent flow rate of the wastewater fed into the first anaerobic reactor are gradually increased, while the reflux flow rate is gradually decreased, including: The pH value of the wastewater fed into the first anaerobic reactor in the next run is controlled to be 0.1 to 0.3 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous run, and the sum of the influent flow rate and the return flow rate is controlled to be 20 to 25 m³. 3 / d.

[0016] By adopting the above technical solution, the initial acclimatization time is controlled to be 9–11 days, so that the microorganisms can fully adapt to and utilize the organic matter in the water. During the later acclimatization process, the pH value and influent flow rate of the wastewater fed into the anaerobic reactor are gradually increased, while the return flow rate of the reflux liquid is gradually decreased, giving acidifying bacteria sufficient growth time, increasing their proportion in the activated sludge, and ensuring the acid-base balance in the first anaerobic reactor.

[0017] Optionally, in step S3, the pH value and influent flow rate of the wastewater fed into the first anaerobic reactor are gradually increased, while the reflux flow rate is gradually decreased, including: The pH of the wastewater was adjusted to 7.1, and the influent flow rate was controlled at 0.2 m³ / h. 3 The rate is increased by / d until the influent flow rate increases to 18m³ / d. 3 / d, the reflux flow rate of the reflux fluid decreased to 4m³ / d. 3 / d; The pH of the wastewater was adjusted to 7.2, and the influent flow rate was controlled at 18 m³ / h. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, acclimatization 2-4 days; The pH value of the wastewater fed into the first anaerobic reactor in the next cycle is controlled to be 0.2 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous cycle, until the pH value increases to 9.0, and the influent flow rate of each pH gradient stage is controlled to be 18 m³ / s. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, acclimatization time is 4-6 days; The pH value of the wastewater fed into the first anaerobic reactor in the next cycle is controlled to be 0.1 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous cycle, until the pH value increases to 13.0, and the influent flow rate of each pH gradient stage is controlled to be 18 m³ / s. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, the acclimatization period is 6 to 10 days.

[0018] By adopting the above technical solution, during the later stage of acclimatization, the pH value of the wastewater fed into the anaerobic reactor is gradually increased while the influent flow rate and return flow rate are controlled, allowing the microorganisms to fully adapt and grow, thus meeting the COD load of the treated influent.

[0019] Optionally, in step S2, the wastewater from textile printing and dyeing production has a pH ≥ 12.0, COD ≥ 25000 mg / L, conductivity ≥ 15000 μS / cm, and TN ≤ 150 mg / L.

[0020] Optionally, the acclimation method for the activated sludge containing salt-tolerant anaerobic bacteria includes the following steps: (1) Provide sludge from the anaerobic tank of the textile dyeing and printing wastewater treatment system and add the sludge to the second anaerobic reactor; (2) Provide textile dyeing and printing wastewater and dilute the wastewater with water to adjust the conductivity of the wastewater to <5000us / cm, and then dilute the wastewater with water at a flow rate of 1-3m³. 3 The influent flow rate of / d is fed into the second anaerobic reactor to mix the wastewater with the sludge for pre-acclimation, resulting in pre-acclimated sludge. (3) The conductivity of the wastewater fed into the second anaerobic reactor is gradually increased for subsequent acclimatization until the conductivity increases to 30,000 to 35,000 μS / cm. The subsequent acclimatization is then completed, and activated sludge containing salt-tolerant anaerobic bacteria is obtained.

[0021] By adopting the above technical solution, sludge (30-35 g MLSS / L) from the anaerobic tank of the textile dyeing and printing wastewater treatment system is used as the sludge to be acclimated. The pretreatment wastewater from textile dyeing and printing (typical water quality: pH ≥ 12.0, COD ≥ 25000 mg / L, conductivity ≥ 15000 μS / cm, TN ≤ 150 mg / L) contains a high concentration of organic matter. The inoculum amount of the sludge to be acclimated in the second anaerobic reactor is 10-40 v / v%. For example, the volume ratio of the sludge to be acclimated to the volume of the second anaerobic reactor can be 10:100 (10 v / v%), 20:100 (20 v / v%), 30:100 (30 v / v%), or 40:100 (40 v / v%), etc.

[0022] Textile dyeing and printing pretreatment wastewater (typical water quality: pH ≥ 12.0, COD ≥ 25000 mg / L, conductivity ≥ 15000 μS / cm, TN ≤ 150 mg / L) was used as the acclimation stock solution. The stock solution was diluted with water to adjust its conductivity. During the initial acclimation process, a relatively large amount of water was added to reduce the conductivity of the stock solution to below 5000 μS / cm, allowing the inoculated unacclimated activated sludge to adapt directly. Furthermore, during the initial acclimation process, the influent flow rate of the stock solution into the anaerobic reactor was controlled to allow the microorganisms to fully adapt and utilize the organic matter in the water. Upon completion of the initial acclimation, pre-acclimated sludge was obtained.

[0023] During the later stages of acclimatization, the conductivity of the wastewater fed into the anaerobic reactor was gradually increased to allow the microorganisms to adapt to the high-salt environment. Acclimatization was completed when the conductivity of the wastewater fed into the anaerobic reactor reached 30,000–35,000 μS / cm, yielding activated sludge containing salt-tolerant anaerobic bacteria.

[0024] The activated sludge containing salt-tolerant anaerobic bacteria obtained by the acclimatization method described in this application can be directly inoculated into the anaerobic tank of an alkali reduction wastewater treatment system. It exhibits strong adaptability to alkali reduction wastewater, and the salt-tolerant anaerobic bacteria demonstrate a strong ability to degrade organic matter such as PET-Na in the wastewater. The hydrochloric acid-tolerant bacteria can decompose some organic matter such as PTA-Na, and the decomposition products can lower the pH value of the wastewater. Further decomposition by the salt-tolerant anaerobic bacteria produces large amounts of methane, carbon dioxide, and other substances. Some of the carbon dioxide produced dissolves in the water, increasing the alkalinity of the water in the anaerobic reaction system and forming a stronger pH buffering capacity, which is beneficial for the stable operation of the water treatment system.

[0025] The activated sludge containing hydrochloric acid-tolerant bacteria of this application, in combination with activated sludge containing salt-tolerant anaerobic bacteria, can be used to treat wastewater without the need to add large amounts of acid, alkali and physicochemical agents. It can successfully degrade PTA-Na and COD in water, with less reagent usage, lower energy consumption, and also saves equipment investment costs, reduces equipment maintenance costs, and is easy to operate.

[0026] It should be noted that the volume of the second anaerobic reactor is 8–10 m³. 3 The effective water depth is 3-5m; for example, the volume of the second anaerobic reactor can be 10m³. 3 The effective water depth can be 4m. Of course, a second anaerobic reactor with other volumes and effective water depths can also be used according to actual needs.

[0027] Optionally, in step (2), the initial acclimatization period is 8 to 10 days; In step (3), during the later acclimatization process, the conductivity of the wastewater fed into the second anaerobic reactor in the next run is 40-60 μS / cm higher than that of the wastewater fed into the second anaerobic reactor in the previous run. When the conductivity of the wastewater is <15000 μS / cm, the acclimatization time for each gradient segment is 22-26 h. When the conductivity of the wastewater is 15000-20000 μS / cm, the acclimatization time for each gradient segment is 18-22 h. When the conductivity of the wastewater is >20000 μS / cm, the acclimatization time for each gradient segment is 24-28 h.

[0028] By adopting the above technical solution, the initial acclimatization time is controlled at 8–12 days to allow the microorganisms to initially adapt to the water quality. During the later acclimatization process, the conductivity of the wastewater fed into the anaerobic reactor is gradually increased, and the acclimatization time of each gradient stage is adjusted to allow the microorganisms to gradually adapt to and tolerate the high-salt environment.

[0029] Optionally, in step (3), when the conductivity of the wastewater is <15000 μS / cm, the influent flow rate into the second anaerobic reactor is controlled to be 1.5–2.5 m³ / min. 3 / d; When the conductivity of the wastewater is ≥15000, the influent flow rate into the second anaerobic reactor should be controlled at 1.3~1.7m³. 3 / d.

[0030] By adopting the above technical solution, during the later stage of acclimatization, the conductivity of the wastewater fed into the anaerobic reactor is gradually increased while the influent flow rate is controlled, allowing the microorganisms to gradually adapt to the COD load.

[0031] Secondly, this application also provides a process for treating alkali-reduction wastewater, comprising the following steps: S1. Inoculate the anaerobic tank with activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria, and inoculate the aerobic tank with activated sludge containing PTA-degrading bacteria. S2. The wastewater to be treated, along with the return liquid flowing from the top of the anaerobic tank, is sent to the bottom of the anaerobic tank. As the wastewater rises, it comes into contact with hydrochloric acid-tolerant bacteria and salt-tolerant anaerobic bacteria. These bacteria decompose some of the substances in the wastewater, reducing its pH and COD values. The anaerobic wastewater then flows out from the outlet at the top of the anaerobic tank. S3. The wastewater flowing from the top of the anaerobic tank is then sent to the aerobic tank. There, it comes into contact with PTA-degrading bacteria, which decompose the remaining substances in the wastewater, further reducing its COD value. The aerobic wastewater then flows out from the outlet at the top of the aerobic tank and enters the sedimentation tank. After sedimentation, the treated water is discharged.

[0032] In step S1, the activated sludge containing hydrochloric acid-tolerant bacteria and the activated sludge containing salt-tolerant anaerobic bacteria are obtained by acclimatization using the acclimatization method described in any of the above-mentioned methods; and the sum of the inoculum amounts of the activated sludge containing hydrochloric acid-tolerant bacteria and the activated sludge containing salt-tolerant anaerobic bacteria is 6-15 g / L.

[0033] By adopting the above technical solution, the typical water quality of the pretreatment wastewater from the dyeing and printing production process is as follows: pH ≥ 12.0, COD ≥ 25000 mg / L, conductivity ≥ 30000 μS / cm, and TN ≤ 150 mg / L. A specific ratio of activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria is inoculated into the anaerobic tank. The hydrochloric acid-tolerant bacteria can decompose some organic matter such as PTA-Na, and the decomposition products include small-molecule organic acids, which can lower the pH value of the wastewater. Further decomposition by the salt-tolerant anaerobic bacteria produces large amounts of methane, carbon dioxide, and other substances. Some of the carbon dioxide produced dissolves in the water, maintaining the alkalinity of the water in the anaerobic reaction system and forming a stronger pH buffering capacity, which is beneficial to the stable operation of the water treatment system. The synergistic treatment of wastewater by activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria can effectively reduce the COD value and pH value of the wastewater.

[0034] Wastewater flowing from the anaerobic tank enters the aerobic tank, where PTA-degrading bacteria decompose the remaining substances in the wastewater to further reduce its COD value. After aerobic treatment, the COD value of the wastewater is further reduced. The wastewater discharged from the aerobic tank is treated by sedimentation in the sedimentation tank, and the supernatant discharged can be used as an alkali source to adjust the pH value of other wastewater. For example, it can be added to the equalization tank of other low-concentration wastewater treatment systems to save on the amount of alkali reagent used.

[0035] In the technical solution of this application, the COD removal rate of the pretreatment wastewater from the dyeing and printing production process can reach more than 95% after treatment in anaerobic and aerobic tanks. Moreover, the amount of reagents used in the entire treatment process is small, the energy consumption is low, and it also saves equipment investment, reduces equipment maintenance costs, and has low operation difficulty.

[0036] It should be noted that "the sum of the inoculum amounts of activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria is 6–15 g / L" refers to the sum of the dry weights of the activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria inoculated into each liter of anaerobic tank being 6–15 g. "Dry weight" refers to the weight of the activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria after being dried separately to constant weight. The activated sludge inoculated into the anaerobic tank is all wet sludge; the corresponding inoculum amount of wet sludge can be obtained by using the dry weight and the moisture content of the wet sludge.

[0037] Optionally, in step S1, the ratio of the inoculum amount of activated sludge containing hydrochloric acid-tolerant bacteria to that of activated sludge containing salt-tolerant anaerobic bacteria is (6-7):(5-6).

[0038] By adopting the above technical solution and further optimizing the inoculation ratio of activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria in the anaerobic tank, the two can fully exert their synergistic effect, effectively reducing the pH value and COD content of wastewater while ensuring the stable operation of the water treatment system and the stability of effluent quality.

[0039] Optionally, in step S1, the activated sludge containing PTA-degrading bacteria includes aerobic sludge from the aerobic tank of a municipal wastewater treatment plant, and PTA-degrading bacteria; the PTA-degrading bacteria are obtained by screening from the bottom sludge of the equalization tank in the dyeing and printing wastewater treatment system. The ratio of the inoculation mass of aerobic sludge to the volume of the aerobic tank is 3–8 g / L, and the inoculation volume of PTA-degrading bacteria is 0.5–5% of the volume of the aerobic tank.

[0040] By adopting the above technical solution, the inoculation amount of activated sludge and PTA-degrading bacteria in the aerobic tank can be controlled to further reduce the COD value of the wastewater. It should be noted that "the ratio of aerobic sludge inoculation mass to aerobic tank volume is 3–8 g / L" means that the dry mass of aerobic sludge inoculated per liter of aerobic tank is 3–8 g. "Dry mass" refers to the mass of the aerobic sludge after drying to constant weight. The aerobic sludge inoculated into the aerobic tank is wet sludge; the inoculation amount of wet sludge can be obtained by measuring its dry mass and moisture content.

[0041] In summary, this application includes at least one of the following beneficial technical effects: 1. The activated sludge containing hydrochloric acid-tolerant bacteria obtained by the acclimation method provided in this application can be directly inoculated into the anaerobic tank of an alkali reduction wastewater treatment system, exhibiting strong adaptability to alkali reduction wastewater. Furthermore, the hydrochloric acid-tolerant bacteria in the activated sludge have a strong ability to degrade organic matter such as PET-Na in the wastewater, which is also beneficial to the stable operation of the water treatment system.

[0042] 2. Activated sludge containing hydrochloric acid-tolerant bacteria, in conjunction with activated sludge containing salt-tolerant anaerobic bacteria, can jointly treat wastewater without the need for large amounts of acid, alkali, and physicochemical agents. It can successfully degrade PTA-Na and COD in water, requiring less reagents, consuming less energy, saving on equipment investment costs, reducing equipment maintenance costs, and being easier to operate.

[0043] 3. After treatment in anaerobic and aerobic tanks, the COD removal rate of the pretreatment wastewater from dyeing and printing production is relatively high. The wastewater discharged from the aerobic tank is further treated by sedimentation in a sedimentation tank. The supernatant discharged from the sedimentation tank can be used as an alkali source to adjust the pH value of other wastewater. For example, it can be added to the equalization tank of other low-concentration wastewater treatment systems to save on the amount of alkali reagent used. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of the first anaerobic reactor in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the structure of the second anaerobic reactor in Embodiment 2 of this application; Figure 3 This is a schematic diagram of the alkali reduction wastewater treatment system in Application Example 1 of this application.

[0045] In the diagram, 1 is the first anaerobic reactor; 11 is the first inlet; 12 is the first three-phase separation zone; 13 is the first gas outlet; 14 is the first outlet; 15 is the first reflux outlet; and 2 is the first effluent collection tank. 3. Anaerobic tank; 31. Third inlet; 32. Second return outlet; 33. Return pipe; 34. Water distribution pipe; 35. Packing layer; 36. Third three-phase separation zone; 37. Third outlet; 4. Aerobic tank; 41. Fourth inlet; 42. Aeration pipe; 43. Fourth outlet; 5. Sedimentation tank; 51. Fifth inlet; 52. Fifth outlet; 6. Second anaerobic reactor; 61. Second inlet; 62. Second three-phase separation zone; 63. Second air outlet; 64. Second outlet; 7. Second effluent collection box. Detailed Implementation

[0046] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] The following are Examples 1-3, Application Examples 1-10, and Comparative Application Examples 1-2 of this application. Examples 1-3 respectively provide a method for acclimating activated sludge containing hydrochloric acid-tolerant bacteria, a method for acclimating activated sludge containing salt-tolerant anaerobic bacteria, and a method for screening PTA-degrading bacteria; Application Examples 1-10 and Comparative Application Examples 1-2 respectively provide an alkali reduction wastewater treatment process.

[0048] Example 1 An acclimatization method for activated sludge containing hydrochloric acid-tolerant bacteria includes the following steps: S1. Sludge (35g MLSS / L) is extracted from the anaerobic tank of the dyeing and finishing wastewater treatment system of a polyester textile enterprise, and the sludge is added to the first anaerobic reactor (volume 100m³). 3 In an effective water depth of 9m, the ratio of the volume of sludge added to the volume of the first anaerobic reactor is 1:5. The structural schematic diagram of the first anaerobic reactor 1 is shown below. Figure 1As shown, it has a first water inlet 11 at the bottom, a first three-phase separation zone 12 and a first return port 15 at the top, and a first water outlet 14 and a first air outlet 13 at the top. The first water outlet 14 is connected to the first water collection tank 2 through a pipe. The first return port 15 is located below the first three-phase separation zone 12 and is connected to the first water inlet 11 through a connecting pipe.

[0049] S2. Wastewater from the pretreatment process of dyeing and printing at a polyester textile company (pH 13.0, COD 28000 mg / L, conductivity 30000 μS / cm, TN 140 mg / L, water temperature 30℃) is provided. Carbon dioxide is introduced into the wastewater to adjust its pH to 7.0. The pH-adjusted wastewater is then discharged at a 2m³ flow rate. 3 A flow rate of / d is fed into the first anaerobic reactor through the first inlet (i.e., the inlet flow rate is 2m³ / d). 3 / d), while the reflux liquid in the upper part of the first anaerobic reactor flows through the first reflux port at a rate of 20m 3 The reflux flow rate is 20 m³ / d, which is returned to the bottom of the anaerobic reactor. 3 / d) to promote the mixing of wastewater and sludge for preliminary acclimatization. The preliminary acclimatization period is 10 days, and the acclimatized sludge is obtained.

[0050] S3. Gradually increase the pH and influent flow rate of the wastewater fed into the first anaerobic reactor, and gradually decrease the return flow rate of the reflux liquid for subsequent acclimatization, until the pH value rises to 13.0 and the influent flow rate rises to 18 m³ / h. 3 / d, the reflux flow rate of the reflux fluid decreased to 4m³ / d. 3 / d, after the later acclimatization is completed, activated sludge containing hydrochloric acid tolerant bacteria is obtained; The pH value and influent flow rate of the wastewater fed into the first anaerobic reactor are increased by gradient, as detailed below: (1) Adjust the pH of the wastewater to 7.1 and control the influent flow rate to 2 m³ / h. 3 / d, the reflux flow rate is 20m³ / d. 3 / d, acclimatization 10d; (2) Maintain the pH of the wastewater at 7.1 and control the influent flow rate at 0.2 m³ / h. 3 The rate was increased by / d until the influent flow rate was increased to 18m³ / d. 3 / d, during which the return flow rate of the reflux liquid is reduced, while maintaining the sum of the influent flow rate and the return flow rate of the reflux liquid at 22m³ / d. 3 / d; (3) Adjust the pH of the wastewater to 7.2 and control the influent flow rate to 18 m³ / h. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, acclimatization for 3d; (4) control the pH value of the wastewater fed into the first anaerobic reactor next time to be 0.2 higher than the pH value of the wastewater fed into the first anaerobic reactor last time, until the pH value of the wastewater fed into the first anaerobic reactor is 9.0, the acclimatization time for each pH gradient segment is 5d, and the influent flow rate for each pH gradient segment is 18m 3 / d, the reflux flow rate is 4m³ / d. 3 / d; (5) Control the pH value of the wastewater fed into the first anaerobic reactor in the next cycle to be 0.1 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous cycle, until the pH value of the wastewater fed into the first anaerobic reactor is 13.0. The acclimatization time for each pH gradient segment is 8 days, and the influent flow rate for each pH gradient segment is 18 m³ / s. 3 / d, the reflux flow rate is 4m³ / d. 3 / d.

[0051] Example 2 An acclimatization method for activated sludge containing salt-tolerant anaerobic bacteria includes the following steps: S1. Sludge (35g MLSS / L) was extracted from the anaerobic tank of the wastewater treatment system of a polyester textile enterprise and added to the second anaerobic reactor (volume 10m³). 3 In an effective water depth of 4m, the ratio of the volume of sludge added to the volume of the anaerobic reactor is 1:10.

[0052] The structural schematic diagram of the second anaerobic reactor 6 is shown below. Figure 2 As shown, it has a second water inlet 61 at the bottom, a second three-phase separation zone 62 at the top, and a second water outlet 64 and a second air outlet 63 at the top. The second water outlet 64 is connected to the second water collection tank 7 through a pipe.

[0053] S2. Wastewater from the dyeing and printing process of a polyester textile company (pH 13.0, COD 28000 mg / L, conductivity 30000 μS / cm, TN 140 mg / L, water temperature 30℃) is provided. The wastewater is diluted with tap water to adjust its conductivity to 4500 μS / cm. The wastewater with adjusted conductivity is then diverted at a flow rate of 1 m³ / min. 3 A flow rate of / d is fed into the second anaerobic reactor through the first inlet to mix the wastewater with the sludge for initial acclimatization. The initial acclimatization period is 9 days, resulting in pre-acclimatized sludge.

[0054] S3. Gradually increase the conductivity of the wastewater fed into the second anaerobic reactor for subsequent acclimatization until the conductivity reaches 30,000 μS / cm. The subsequent acclimatization ends, and activated sludge containing salt-tolerant anaerobic bacteria is obtained. The conductivity of the wastewater fed into the second anaerobic reactor is increased by a gradient, as detailed below: (1) Adjust the conductivity of the wastewater to 4550 μS / cm, and then pour the wastewater with the adjusted conductivity at a flow rate of 2 m... 3 A flow rate of / d is fed into the second anaerobic reactor through the inlet, and the acclimation time is 24h; (2) Control the conductivity of the wastewater fed into the second anaerobic reactor in the next step to be 50 μS / cm higher than that of the wastewater fed into the second anaerobic reactor in the previous step, and the flow rate of the wastewater fed into the second anaerobic reactor in the next step to be the same as that of the wastewater fed into the second anaerobic reactor in the previous step. The acclimatization time for each gradient section is 24 h, until the conductivity of the wastewater fed into the second anaerobic reactor is 14950 μS / cm. (3) Adjust the conductivity of the wastewater to 15000 μS / cm, and then divert the adjusted wastewater at a flow rate of 1.5 m... 3 A flow rate of / d is fed into the second anaerobic reactor through the first inlet, and the acclimation time is 20h; (4) Control the conductivity of the wastewater fed into the second anaerobic reactor in the next step to be 50 μS / cm higher than that of the wastewater fed into the second anaerobic reactor in the previous step, and the flow rate of the wastewater fed into the second anaerobic reactor in the next step to be the same as that of the wastewater fed into the second anaerobic reactor in the previous step. The acclimatization time for each gradient section is 20 h, until the conductivity of the wastewater fed into the second anaerobic reactor is 20000 μS / cm. (5) Adjust the conductivity of the wastewater to 20050 μS / cm, and then divert the adjusted wastewater at a flow rate of 1.5 m... 3 A flow rate of / d is fed into the second anaerobic reactor through the first inlet, and the acclimation time is 26h; (6) Control the conductivity of the wastewater fed into the second anaerobic reactor in the next run to be 50 μS / cm higher than that of the wastewater fed into the second anaerobic reactor in the previous run, and the flow rate of the wastewater fed into the second anaerobic reactor in the next run to be the same as that of the wastewater fed into the second anaerobic reactor in the previous run. The acclimatization time for each gradient section is 26 h, until the conductivity of the wastewater fed into the second anaerobic reactor is 30000 μS / cm.

[0055] Example 3 A method for screening PTA-degrading bacteria includes the following steps: S1. Provide bottom sludge (SVI 120 mL / g) from the equalization tank of the wastewater treatment system in the dyeing and printing production of a polyester textile enterprise. After centrifuging the bottom sludge, discard the supernatant, and inoculate the precipitate into the culture medium (PTA 2 g / L, NH4Cl 1 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.2 g / L, FeSO4·7H2O) at an inoculation rate of 8% (w / v, i.e., the percentage of precipitate mass to culture medium volume). The culture medium (containing 0.01 g / L of anhydrous CaCl2, 0.01 g / L of yeast extract, with the remainder being distilled water, pH 7.1) was incubated at 35°C under aerobic conditions. Changes in PTA levels were monitored. When PTA levels dropped to 0 mg / L, the medium was centrifuged, the supernatant was discarded, and the cells were collected. The cells were then inoculated again into the culture medium at a 10% (w / v) inoculation rate (the composition of this culture medium was based on the previous culture medium, except that the PTA content was increased by 0.2 g / L). This process was repeated for 10 cycles to obtain the PTA-decomposing bacterial solution.

[0056] S2. Dilute the PTA decomposition bacterial solution obtained in step S1 with sterile diluent (0.85 wt% NaCl, balance sterile water) to a concentration of 10. -1 -10 -7 There are 7 dilution gradients. Take 0.1 mL from each dilution gradient and spread it onto solid culture media (PTA 3 g / L, NH4Cl 1 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.2 g / L, FeSO4·7H2O). The culture medium was prepared on plates containing 0.01 g / L of anhydrous CaCl2, 0.01 g / L of yeast extract, 1 g / L of agar powder, 20 g / L of agar powder, with the remainder being distilled water (pH 7.0). Three parallel samples were prepared for each dilution gradient. The plates were incubated at 30°C for 36 h. Single colonies with intact morphology and clear edges were picked from the plates and purified by streak plating to obtain three generations of purified strains. The purified strains were inoculated into LB liquid medium (10 g / L of tryptone, 5 g / L of yeast extract, 10 g / L of sodium chloride, with the remainder being distilled water (pH 7.0)) and incubated at 37°C under aerobic conditions with shaking at 200 rpm for 16 h. An appropriate amount of the bacterial solution was mixed thoroughly with an equal volume of 50% glycerol (glycerol and ddH2O were mixed in equal volumes) and stored at -80°C for long-term storage to obtain purified PTA-decomposing bacterial solution.

[0057] S3. Take 1 mL of the PTA-decomposing bacterial solution preserved in step S2 and place it in a 37℃ water bath for 30 seconds. Then add it to a 100 mL Erlenmeyer flask containing culture medium (NH4Cl 1 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.2 g / L, FeSO4·7H2O 0.01 g / L, anhydrous CaCl2 0.01 g / L, yeast extract 1 g / L, with the remainder being distilled water, pH 7.1). Place the flask in a shaker at 30℃ and 150 rpm for 12 h.

[0058] S4. Inoculate all the culture medium obtained in step S3 into a 1L seed bottle containing culture medium (PTA 2g / L, NH4Cl 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O 0.2g / L, FeSO4·7H2O 0.01g / L, anhydrous CaCl2 0.01g / L, yeast extract 1g / L, the remainder being distilled water, pH 7.1), and place it in a shaker at 30℃ and 200rpm for 16h.

[0059] S5. All the seed culture obtained in step S4 was inoculated into a 20L culture vessel containing culture medium (PTA 2.5g / L, NH4Cl 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O 0.2g / L, FeSO4·7H2O 0.01g / L, anhydrous CaCl2 0.01g / L, yeast extract 1g / L, the remainder being distilled water, pH 7.1), and placed at 30℃ for aeration and culture for 16h.

[0060] S6. All the seed culture obtained in step S5 was inoculated into a 100L culture vessel containing culture medium (PTA 3.0g / L, NH4Cl 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O 0.2g / L, FeSO4·7H2O 0.01g / L, anhydrous CaCl2 0.01g / L, yeast extract 1g / L, the remainder being distilled water, pH 7.1), and placed at 30℃ for aeration and culture for 16h.

[0061] S7. All the seed culture obtained in step S6 was inoculated into a 500L culture vessel containing culture medium (PTA 3.0g / L, NH4Cl 1g / L, K2HPO4 0.5g / L, MgSO4·7H2O 0.2g / L, FeSO4·7H2O 0.01g / L, anhydrous CaCl2 0.01g / L, yeast extract 1g / L, the remainder being distilled water, pH 7.1), and placed at 30℃ for aeration and cultured for 16h to obtain PTA-degrading bacteria culture medium.

[0062] Application Example 1 This application example provides an alkali reduction wastewater treatment system and process.

[0063] See Figure 3 The alkali reduction wastewater treatment system includes an anaerobic tank 3, an aerobic tank 4, and a sedimentation tank 5. A third inlet 31 is provided at the bottom of the anaerobic tank 3. A water distribution pipe 34 is provided in the lower part of the anaerobic tank 3. The inlet of the water distribution pipe 34 is connected to the third inlet 31 through a connecting pipe. An outlet hole is provided at the bottom of the water distribution pipe 34. A packing layer 35 is provided in the middle of the anaerobic tank 3. A third three-phase separation zone 36 is provided in the upper part of the anaerobic tank 3. A third outlet 37 is provided at the top of the anaerobic tank 3. A second return port 32 is provided on the anaerobic tank 3 located between the third three-phase separation zone 36 and the packing layer 35. The second return port 32 is connected to the third inlet 31 through a return pipe 33. Flow regulating valves are provided on both the third inlet 31 and the return pipe 33.

[0064] The aerobic tank 4 is located on one side of the anaerobic tank 3. The top of one side of the aerobic tank 4 is provided with a fourth inlet 41 connected to the third outlet 37. An aeration pipe 42 is provided in the lower part of the aerobic tank 4, and a fourth outlet 43 is provided in the top of the other side of the aerobic tank 4.

[0065] The sedimentation tank 5 is located on one side of the aerobic tank 4. A fifth inlet 51 connected to the fourth outlet 43 is provided on the upper part of one side of the sedimentation tank 5. The fifth inlet 51 is located below the fourth inlet 41. A fifth outlet 52 is provided on the top of the other side of the sedimentation tank 5.

[0066] The wastewater treatment process using the above-mentioned alkali reduction wastewater treatment system includes the following steps: S1. Activated sludge containing hydrochloric acid-tolerant bacteria obtained from Example 1 and activated sludge containing salt-tolerant anaerobic bacteria obtained from Example 2 were inoculated into the anaerobic tank. Activated sludge containing PTA-degrading bacteria was inoculated into the aerobic tank. The inoculation amount of activated sludge containing hydrochloric acid-tolerant bacteria was 4 g / L, and the inoculation amount of activated sludge containing salt-tolerant anaerobic bacteria was 4 g / L. The activated sludge containing PTA-degrading bacteria included aerobic sludge (SVI of 80 mL / g) from the aerobic tank of a municipal wastewater treatment plant, and PTA-degrading bacteria culture medium obtained from Example 3. The inoculation amount of the PTA-degrading bacteria culture medium was 1 v / v% (the inoculation volume of the PTA-degrading bacteria culture medium was 1% of the aerobic tank volume), and the inoculation amount of aerobic sludge was 5 g / L.

[0067] S2. The pretreatment wastewater from the dyeing and printing production of polyester textile enterprises (pH 13.0, COD 25000 mg / L, conductivity 30000 μS / cm, TN 100 mg / L, water temperature 30℃) and the return liquid flowing out of the effluent from the upper part of the anaerobic tank are sent into the anaerobic tank from the inlet at the bottom of the anaerobic tank. The upward flow velocity of the wastewater in the anaerobic tank is controlled at about 2.5 m / h, and the hydraulic retention time is 4 days. During the upward process, the wastewater comes into contact with hydrochloric acid-tolerant bacteria and salt-tolerant anaerobic bacteria. The hydrochloric acid-tolerant bacteria and salt-tolerant anaerobic bacteria decompose some of the substances in the wastewater to reduce the pH and COD values ​​of the wastewater. The anaerobic wastewater flows out from the effluent from the top of the anaerobic tank.

[0068] S3. Wastewater flowing from the top of the anaerobic tank flows into the aerobic tank. The dissolved oxygen (DO) value in the aerobic tank is 2-4 mg / L, and the hydraulic retention time is 4 days. The wastewater comes into contact with PTA-degrading bacteria, which decompose the remaining substances in the wastewater to further reduce the COD value. The wastewater after aerobic treatment flows out from the outlet at the top of the aerobic tank and enters the sedimentation tank. After sedimentation treatment, the supernatant obtained is discharged from the outlet at the top of the sedimentation tank.

[0069] Application Examples 2-3 Application Examples 2 and 3 are based on Application Example 1, with the difference being that in step S1, the inoculum amounts of activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria are different; the other steps remain the same as in Application Example 1. Specifically, in Application Example 2, the inoculum amount of activated sludge containing hydrochloric acid-tolerant bacteria is 6 g / L, and the inoculum amount of activated sludge containing salt-tolerant anaerobic bacteria is 6 g / L.

[0070] In Application Example 3, the inoculum amount of activated sludge containing hydrochloric acid-tolerant bacteria was 7 g / L, and the inoculum amount of activated sludge containing salt-tolerant anaerobic bacteria was 7 g / L.

[0071] Application Examples 4-6 Application Examples 4-6 are based on Application Example 2, with the difference being that in step S1, the sum of the inoculum amounts of activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria is maintained at 12 g / L, and the ratio of their inoculum amounts is adjusted; the other steps remain the same as in Application Example 2. Specifically, in Application Example 4, the inoculum amount of activated sludge containing hydrochloric acid-tolerant bacteria is 5 g / L, and the inoculum amount of activated sludge containing salt-tolerant anaerobic bacteria is 7 g / L.

[0072] In Application Example 5, the inoculum amount of activated sludge containing hydrochloric acid-tolerant bacteria was 7 g / L, and the inoculum amount of activated sludge containing salt-tolerant anaerobic bacteria was 5 g / L.

[0073] In Application Example 6, the inoculum amount of activated sludge containing hydrochloric acid-tolerant bacteria was 8 g / L, and the inoculum amount of activated sludge containing salt-tolerant anaerobic bacteria was 4 g / L.

[0074] Application Examples 7-8 Application Examples 7 and 8 are based on Application Example 5, the difference being that the inoculum size of the aerobic sludge in step S1 has changed, while the other steps remain the same as in Application Example 5. Specifically, In Application Example 7, the inoculum amount of aerobic sludge was 3 g / L.

[0075] In Application Example 8, the inoculum amount of aerobic sludge was 8 g / L.

[0076] Application Examples 9-10 Application Examples 9 and 10 are based on Application Example 5, the difference being that the inoculum size of the PTA-degrading bacteria culture medium changed in step S1, while the other steps remained the same as in Application Example 5. Specifically, In Application Example 9, the inoculum size of the PTA-degrading bacteria culture was 0.5 v / v.

[0077] In Application Example 10, the inoculum size of the PTA-degrading bacteria culture was 2 v / v.

[0078] Application Comparative Examples 1-2 Comparative Examples 1 and 2 are based on Application Example 1, with the difference being that in step S1, activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria are inoculated into the anaerobic tank. Other steps remain the same as in Application Example 1. Specifically, in Comparative Example 1, activated sludge containing salt-tolerant anaerobic bacteria is inoculated into the anaerobic tank at an inoculation rate of 8 g / L, but activated sludge containing hydrochloric acid-tolerant bacteria is not inoculated.

[0079] In Comparative Example 2, activated sludge containing hydrochloric acid-tolerant bacteria was inoculated into the anaerobic tank at an inoculation rate of 8 g / L, while activated sludge containing salt-tolerant anaerobic bacteria was not inoculated.

[0080] Performance Experiment The COD and TN contents of the wastewater treated by the processes in Application Examples 1-10 and Comparative Examples 1-2 were tested, and the results are shown in Table 1 below. The wastewater used for sampling and testing was the supernatant discharged from the sedimentation tank effluent.

[0081] Table 1 Wastewater Treatment Test Results Based on the experimental results of Application Examples 1-10, Comparative Examples 1-2, and Table 1, it can be seen that the activated sludge containing hydrochloric acid-tolerant bacteria, in conjunction with activated sludge containing salt-tolerant anaerobic bacteria, can successfully achieve effective degradation of COD in wastewater. Comparative Examples 1 and 2, because they only inoculated activated sludge containing hydrochloric acid-tolerant bacteria or activated sludge containing salt-tolerant anaerobic bacteria in the anaerobic tank, resulted in higher COD content in the discharged water.

[0082] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater, characterized in that, The invention includes methods for acclimating activated sludge containing hydrochloric acid-tolerant bacteria and methods for acclimating activated sludge containing salt-tolerant anaerobic bacteria. The acclimation method for activated sludge containing hydrochloric acid-tolerant bacteria includes the following steps: S1. Provide sludge from the anaerobic tank of the textile printing and dyeing wastewater treatment system and add the sludge to the first anaerobic reactor; S2. Provide textile printing and dyeing production wastewater and introduce carbon dioxide into the wastewater to adjust the pH value of the wastewater to 6.5~7.

5. Send the pH-adjusted wastewater and the return liquid flowing out from the upper part of the first anaerobic reactor together into the lower part of the first anaerobic reactor. Mix the wastewater with the sludge and carry out the initial acclimation to obtain the initial acclimated sludge. S3. Gradually increase the pH value and influent flow rate of the wastewater fed into the first anaerobic reactor, and gradually decrease the return flow rate of the return liquid for subsequent acclimatization. After the subsequent acclimatization is completed, activated sludge containing hydrochloric acid tolerant bacteria is obtained.

2. The method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater according to claim 1, characterized in that, In step S1, the volume of the first anaerobic reactor is 90~110m³. 3 The effective water depth is 7-10m, and the sludge inoculum in the first anaerobic reactor is 10-50 v / v; and / or, In step S2, the initial acclimatization period is 9-11 days; and / or, In step S3, the pH value and influent flow rate of the wastewater fed into the first anaerobic reactor are gradually increased, while the reflux flow rate is gradually decreased until the pH value rises to 12.0~13.5 and the influent flow rate rises to 17~20 m³ / h. 3 / d, the reflux flow rate of the reflux fluid decreased to 3~7m³ / d. 3 / d, and control the pH value of the wastewater fed into the first anaerobic reactor in the next run to be 0.1~0.3 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous run, and the sum of the influent flow rate and the return flow rate is 20~25m³. 3 / d.

3. The method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater according to claim 2, characterized in that, In step S3, the pH value and influent flow rate of the wastewater fed into the first anaerobic reactor are gradually increased, while the reflux flow rate is gradually decreased, including: The pH of the wastewater was adjusted to 7.1, and the influent flow rate was controlled at 0.2 m³ / h. 3 The rate is increased by / d until the influent flow rate increases to 18m³ / d. 3 / d, the reflux flow rate of the reflux fluid decreased to 4m³ / d. 3 / d; The pH of the wastewater was adjusted to 7.2, and the influent flow rate was controlled at 18 m³ / h. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, acclimatization 2~4d; The pH value of the wastewater fed into the first anaerobic reactor in the next cycle is controlled to be 0.2 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous cycle, until the pH value increases to 9.0, and the influent flow rate of each pH gradient stage is controlled to be 18 m³ / s. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, acclimatization time is 4~6 days; The pH value of the wastewater fed into the first anaerobic reactor in the next cycle is controlled to be 0.1 higher than the pH value of the wastewater fed into the first anaerobic reactor in the previous cycle, until the pH value increases to 13.0, and the influent flow rate of each pH gradient stage is controlled to be 18 m³ / s. 3 / d, the reflux flow rate is 4m³ / d. 3 / d, the acclimatization period is 6~10 days.

4. The method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater according to claim 1, characterized in that, In step S2, the wastewater from textile printing and dyeing production has a pH ≥ 12.0, COD ≥ 25000 mg / L, conductivity ≥ 15000 μS / cm, and TN ≤ 150 mg / L.

5. The method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater according to claim 1, characterized in that, The acclimation method for activated sludge containing salt-tolerant anaerobic bacteria includes the following steps: (1) Provide sludge from the anaerobic tank of the textile printing and dyeing production wastewater treatment system and add the sludge to the second anaerobic reactor; (2) Provide textile printing and dyeing production wastewater and dilute the wastewater with water to adjust the conductivity of the wastewater to <5000us / cm. Send the wastewater after adjusting the conductivity into the second anaerobic reactor so that the wastewater and sludge are mixed and subjected to pre-acclimation to obtain pre-acclimated sludge. (3) The conductivity of the wastewater fed into the second anaerobic reactor is gradually increased for subsequent acclimatization until the conductivity increases to 30,000~35,000 μS / cm. The subsequent acclimatization is then completed, and activated sludge containing salt-tolerant anaerobic bacteria is obtained.

6. The method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater according to claim 5, characterized in that, In step (1), the volume of the second anaerobic reactor is 8~11m³. 3 The effective water depth is 3-5m, and the inoculum size of sludge in the second anaerobic reactor is 10-40 v / v; and / or, In step (2), the wastewater with adjusted conductivity is discharged at a rate of 1-3 m 3 A flow rate of / d is fed into the second anaerobic reactor, with an initial acclimation period of 8-10 days; and / or, In step (3), during the later acclimatization process, when the conductivity of the wastewater fed into the second anaerobic reactor in the next run is 40-60 μS / cm higher than that of the wastewater fed into the second anaerobic reactor in the previous run, and the acclimatization time for each gradient segment is 22-26 h when the conductivity of the wastewater is <15000 μS / cm, the acclimatization time for each gradient segment is 18-22 h when the conductivity of the wastewater is 15000-20000 μS / cm, and the acclimatization time for each gradient segment is 24-28 h when the conductivity of the wastewater is >20000 μS / cm.

7. The method for acclimating activated sludge for the fully biological treatment of alkali-reduction wastewater according to claim 6, characterized in that, In step (3), when the conductivity of the wastewater is <15000 μS / cm, the influent flow rate into the second anaerobic reactor is controlled to be 1.5~2.5 m³ / min. 3 / d; When the conductivity of the wastewater is ≥15000, the influent flow rate into the second anaerobic reactor should be controlled at 1.3~1.7m³. 3 / d.

8. A fully biological treatment process for alkali reduction wastewater, characterized in that, Includes the following steps: S1. Inoculate the anaerobic tank with activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria, and inoculate the aerobic tank with activated sludge containing PTA-degrading bacteria. S2. The wastewater to be treated, along with the return liquid flowing out from the top of the anaerobic tank, is sent to the bottom of the anaerobic tank. As the wastewater rises, it comes into contact with hydrochloric acid-tolerant bacteria and salt-tolerant anaerobic bacteria. The hydrochloric acid-tolerant bacteria and salt-tolerant anaerobic bacteria decompose some of the substances in the wastewater to reduce the pH and COD values ​​of the wastewater. The wastewater after anaerobic treatment flows out from the outlet at the top of the anaerobic tank. S3. Wastewater flowing out from the top of the anaerobic tank is sent into the aerobic tank. The wastewater comes into contact with PTA-degrading bacteria, which decompose the remaining substances in the wastewater to further reduce the COD value of the wastewater. The wastewater after aerobic treatment flows out from the outlet at the top of the aerobic tank and enters the sedimentation tank. After sedimentation, the treated water is discharged. In step S1, the activated sludge containing hydrochloric acid-tolerant bacteria and the activated sludge containing salt-tolerant anaerobic bacteria are obtained by acclimatization using the acclimatization method described in any one of claims 1 to 7.

9. The alkali reduction wastewater full biological treatment process according to claim 8, characterized in that, In step S1, the sum of the inoculation amounts of activated sludge containing hydrochloric acid-tolerant bacteria and activated sludge containing salt-tolerant anaerobic bacteria is 6~15g / L. The ratio of the inoculum size of activated sludge containing hydrochloric acid-tolerant bacteria to that of activated sludge containing salt-tolerant anaerobic bacteria is (6~7):(5~6).

10. The alkali reduction wastewater full biological treatment process according to claim 8, characterized in that, In step S1, the activated sludge containing PTA-degrading bacteria includes aerobic sludge from the aerobic tank of a municipal wastewater treatment plant, as well as PTA-degrading bacteria; the PTA-degrading bacteria are obtained by screening from the bottom sludge of the equalization tank in the dyeing and printing wastewater treatment system. The ratio of the inoculation mass of aerobic sludge to the volume of the aerobic tank is 3~8 g / L, and the inoculation volume of PTA-degrading bacteria is 0.5~5% of the volume of the aerobic tank.

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