High-efficiency printing and dyeing wastewater treatment method

Abstract

The invention relates to the technical field of wastewater treatment, and provides a high-efficiency printing and dyeing wastewater treatment method which comprises the following steps: S1, physicochemical pretreatment: sequentially treating printing and dyeing wastewater through an adjusting tank, neutralizing and air floating to obtain pretreated wastewater, and precipitating to obtain primary wastewater; s2, biochemical treatment: treating the primary wastewater by an anaerobic process and an aerobic process to obtain treated wastewater; the anaerobic treatment adopts a pulse water inlet mode, the pH value of the inlet water is 4-6, and the pH value of the outlet water is 6.3-7.5; an A / O process or a complete aeration type activated sludge process is adopted for aerobiotic treatment; when the A / O process is selected in the aerobic process, the reflux ratio of the nitrification liquid in the A / O process is 100-200%; a sedimentation tank is arranged after the aerobic process; the sludge reflux ratio of the sludge in the sedimentation tank to the A / O process is 100-200%. According to the technical scheme, the problem of low removal rate of COD and ammonia nitrogen in printing and dyeing wastewater in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a high-efficiency printing and dyeing wastewater treatment method. Background Art

[0002] The printing and dyeing industry is an important part of the textile industry and plays a key role in the textile production process. However, the printing and dyeing process will produce a large amount of wastewater. The composition of printing and dyeing wastewater is complex, containing a large amount of unreacted dyes, auxiliaries and various organic and inorganic impurities generated in the printing and dyeing process. Therefore, this type of wastewater has the characteristics of great fluctuations in water quality, low biodegradation efficiency, low COD removal rate of biological systems, and high chroma. Therefore, how to improve the treatment efficiency of printing and dyeing wastewater is a problem that needs to be solved at present. Summary of the invention

[0003] The invention provides a high-efficiency printing and dyeing wastewater treatment method, which solves the problem of low removal rate of COD and ammonia nitrogen content in printing and dyeing wastewater in the related art.

[0004] The technical solution of the present invention is as follows: The present invention provides a high-efficiency printing and dyeing wastewater treatment method, comprising the following steps: S1. Physical and chemical pretreatment: the printing and dyeing wastewater is sequentially passed through a regulating tank, neutralized, and flotated to obtain pretreated wastewater, and then precipitated to obtain primary wastewater; S2. Biochemical treatment: the primary wastewater is subjected to anaerobic process and aerobic process to obtain treated wastewater; The anaerobic method adopts pulse water inlet, the pH value of the inlet water is 4-6, and the pH value of the outlet water is 6.3-7.5; The aerobic process adopts A / O process or fully aerated activated sludge process; When the aerobic A / O process is selected, the reflux ratio of the nitrification solution in the A / O process is 100% to 200%; A sedimentation tank is arranged after the aerobic process; the sludge in the sedimentation tank is returned to the A / O process at a sludge return ratio of 100% to 200%.

[0005] In the present invention, the printing and dyeing wastewater is pretreated by combining flotation and sedimentation in series. First, a large amount of surfactants and macromolecular colloidal and insoluble dye pollutants are removed by flotation, and the flotation effluent is further treated by sedimentation. The particles that cannot float during the flotation operation due to water quality fluctuations and the pollutant particles with a larger specific gravity are further separated in the sedimentation tank with the flotation effluent. The pretreatment by combining flotation and sedimentation in series improves the COD removal rate and the mud-water separation effect, lays the foundation for the subsequent biochemical unit, and reduces the load of the subsequent biological treatment. On the other hand, it is also to completely release the residual dissolved gas in the flotation effluent in the sedimentation tank to prevent the impact on the subsequent anaerobic biological unit.

[0006] As a further technical solution, the regulating tank is of baffled type, the printing and dyeing wastewater stays in the regulating tank for 12 to 24 hours, and the regulating tank adopts perforated aeration to stir and mix.

[0007] As a further technical solution, the equipment used for neutralization is a pipeline mixer.

[0008] In the present invention, the neutralization reaction is carried out by a pipeline mixer, and there is no need to build a new neutralization tank, thus saving space and investment.

[0009] As a further technical solution, a coagulant is also added during the flotation, and the coagulant consists of polyferric, cationic polyacrylamide and di(3,5-dicarboxyphenyl)hydroxymethane.

[0010] As a further technical solution, the polyiron includes divalent iron and trivalent iron, and the molar ratio of the divalent iron to the trivalent iron is 1:10-2:1, preferably 1-2:5.

[0011] In the present invention, by adding a polyferric coagulant composed of divalent iron and trivalent iron, the treated wastewater is clear and transparent, and the chroma is significantly reduced, while the COD removal rate of high-chroma dye wastewater is improved.

[0012] As a further technical solution, the order of adding the coagulant is to first add polyferric, and then add cationic polyacrylamide and di(3,5-dicarboxyphenyl)hydroxymethane.

[0013] In the present invention, by first adding polyferric and then adding cationic polyacrylamide and di(3,5-dicarboxyphenyl)hydroxymethane, the COD removal rate can reach 30% to 50%, and the chromaticity is reduced from the original black, (dark) blue, green and other colors to yellow transparent, and the color is significantly reduced. In addition, using polyferric as a coagulant, in addition to decolorization and improving the COD removal rate, it can also reduce the total phosphorus in the wastewater containing phosphorus.

[0014] As a further technical solution, the amount of polyiron added is 0.3%~0.5% of the mass of the printing and dyeing wastewater; the sum of the mass of the cationic polyacrylamide and the di(3,5-dicarboxyphenyl)hydroxymethane added is 0.1%~0.2% of the mass of the printing and dyeing wastewater; the mass ratio of the cationic polyacrylamide to the di(3,5-dicarboxyphenyl)hydroxymethane is 5~30:1, preferably 8~20:1.

[0015] As a further technical solution, the pH value of the pretreated wastewater is 4-6.

[0016] In the present invention, since the pH value of the raw water of printing and dyeing wastewater is generally neutral or strongly alkaline, for strongly alkaline wastewater, acid (sulfuric acid or hydrochloric acid) is required to adjust the pH value to 9-10 before pretreatment, and then a polyferric coagulant is added to react. After the reaction, the pH value reaches 4-6. When the pH value is lower than 4, liquid alkali is required to adjust the pH value to 4-6.

[0017] As a further technical solution, the anaerobic treatment is carried out through an upflow anaerobic reactor, in which a water distributor is arranged, a wastewater collection tank and an overflow weir are arranged on the upper layer, a circulation pump is arranged on the middle and upper layer, and a mud discharge port is arranged in the middle.

[0018] In the present invention, the activated sludge in the upflow anaerobic reactor is in a suspended state through the flow control of the circulation pump, the pretreated wastewater enters from the bottom through the water distributor, the circulation pump draws wastewater from the middle and upper layers of the pool through the water distributor and mixes with the influent water and then enters the bottom, and the wastewater is upflowed from bottom to top, so that sufficient contact between the wastewater and the anaerobic activated sludge is achieved, and 50% to 65% of the COD in the wastewater is removed by anaerobic biodegradation, and at the same time, acid is produced and hydrolyzed for macromolecular organic matter that is difficult to degrade and has low biodegradability, and degraded into small molecular substances, thereby improving its biodegradability and creating conditions for subsequent aerobic treatment.

[0019] As a further technical solution, the rising flow rate of the primary wastewater in the anaerobic upflow anaerobic reactor is 0.8~2m / h, the water temperature is 35~40℃, the HRT is 24~48h, and the operating load is 1.0~2.0kgCOD / m³.d.

[0020] As a further technical solution, the A / O process includes an A pool and an O pool, and the A pool and the O pool are operated in series; the number of the A pools is 1 to 3; the number of the O pools is 3; the pH value of the A pool is 7.8 to 8.5; the pH value of the O pool is 7.0 to 8.0; a submersible agitator is provided in the A pool; and a microporous aeration device is provided in the O pool.

[0021] As a further technical solution, at least one of the following features is also included: The operating control parameter in the A / O process is V A :V O =1:3~2; In the A / O process, DO is 5-6 mg / L, SV 30 500~600ml / L, total HRT is 3~5 days; The water temperature in the A / O process does not exceed 37°C in summer, and the lowest water temperature in winter is not less than 28°C; The operating load in the A / O process is 0.6-1.0 kgCOD / m³.d, and the operating mode is continuous operation with uniform water inflow; The number of aeration tanks in the fully aerated activated sludge process is ≥ 2, and the aeration tanks are operated in series. The pH value in the aeration tanks is 7.0-8.3, the DO is 5.5-6.5 mg / L, and the SV 30 600~700ml / L, total HRT is 1~2 days; The water temperature in the fully aerated activated sludge process is not more than 37°C in summer and not less than 28°C in winter. The sedimentation tank is of radial flow type / vertical flow type, and a sludge return pump is provided in the sedimentation tank; The sludge return ratio of the sludge in the sedimentation tank to the aeration tank is 100% to 200%; The operating load in the fully aerated activated sludge process is 0.8-1.2 kg COD / m³.d, and the operating mode is continuous operation with uniform water inflow.

[0022] In the present invention, for printing and dyeing wastewater with high ammonia nitrogen / total nitrogen, the aerobic A / O process is used; for printing and dyeing wastewater with low ammonia nitrogen and total nitrogen, the aerobic fully aerated activated sludge method is used; the sludge in the sedimentation tank is returned to the first A tank or the first aeration tank water inlet through a sludge return pump, and the remaining sludge is discharged to the sludge storage tank through a sludge discharge pump for dehydration treatment.

[0023] The working principle and beneficial effects of the present invention are: In the present invention, a printing and dyeing wastewater treatment process is provided, which adopts a process technology route combining physical and chemical pretreatment with biochemical treatment, realizes refined treatment through process control parameters of each treatment unit, improves the COD removal rate of each unit, and at the same time achieves that indicators such as ammonia nitrogen and total nitrogen meet industry emission standards, and realizes stable and standard emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0025] Figure 1 It is a specific flow chart of Example 1; Figure 2 This is a comparison chart of the flocculation of printing and dyeing wastewater in Example 1 and Comparative Example 1; In the figure, A is comparative example 1, and B is embodiment 1. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The parameters of the raw materials in the following examples and comparative examples are as follows: Cationic polyacrylamide, particle size: 60~80 mesh.

[0028] Example 1 A high-efficiency printing and dyeing wastewater treatment method comprises the following steps: S1. The printing and dyeing wastewater is passed through a regulating tank to adjust the water quality and quantity of the wastewater. The regulating tank adopts a baffled flow type with a retention time of 12 hours. The bottom of the tank is stirred and mixed by perforated aeration. The wastewater pipeline mixer in the regulating tank is neutralized and the pH value is adjusted to 9. After entering the flotation tank, 0.3wt% polyferric (the molar ratio of divalent iron to trivalent iron is 1:10) is added, and then 0.1wt% cationic polyacrylamide is added for flotation to obtain pretreated wastewater with a pH value of 4. Then, the wastewater enters the sedimentation tank for further separation and removal of sediment to obtain primary wastewater. S2. The primary wastewater is passed through the anaerobic tank and an upflow anaerobic reactor is used. A water distributor is set in the tank, a wastewater collection tank and an overflow weir are set on the upper layer, a circulating pump is set on the middle and upper layers, and a mud outlet is set in the middle. The primary wastewater enters the bottom through the water distributor, and the circulating pump draws wastewater from the middle and upper layers of the tank through the water distributor and mixes with the influent water before entering the bottom. It is upflow from bottom to top to achieve full contact between the wastewater and the anaerobic activated sludge. The upflow velocity is 0.8m / h, the water temperature is 35℃, the HRT is 24h, the operating load is 1.0kgCOD / m³.d, and the effluent pH value is 6.3. S3. The wastewater in the anaerobic tank enters the aerobic tank and is operated using the A / O process. A pool is equipped with a submersible agitator and an O pool is equipped with a microporous aeration device. The A / O process operation control parameters are: V A :V O =1:2 (Vo=Vo1+Vo2), pH value of pool A is 7.8; pH value of pool O is 7.0, DO is 5mg / L, SV 30 The nitrification liquid return ratio is 100%. The wastewater passes through pool A, pool O1 and pool O2 in sequence and then enters the sedimentation tank. The sedimentation tank is a radial flow / vertical flow type. The sedimentation tank is equipped with a sludge return pump to return the sludge at the bottom of the sedimentation tank to the first pool A water inlet. The sludge return ratio is 100%. The remaining sludge is discharged to the sludge storage tank by the sludge pump for dehydration treatment. The supernatant of the sedimentation tank is discharged to the open channel flowmeter and discharged into the designated pipe network after online monitoring to obtain treated wastewater. The operating load is 0.6kgCOD / m³.d.

[0029] Example 2 A high-efficiency printing and dyeing wastewater treatment method comprises the following steps: S1. Physical and chemical pretreatment: The printing and dyeing wastewater is passed through a regulating tank to adjust the water quality and quantity of the wastewater. The regulating tank adopts a baffled flow type with a retention time of 24 hours. The bottom of the tank is stirred and mixed by perforated aeration. The wastewater pipeline mixer in the regulating tank is neutralized and the pH value is adjusted to 10. After entering the flotation tank, 0.5wt% polyferric iron (the molar ratio of divalent iron to trivalent iron is 1:10) is added, and then 0.2wt% cationic polyacrylamide is added for flotation. Liquid alkali is added to obtain pretreated wastewater with a pH value of 6, and then it enters the sedimentation tank for further separation and removal of precipitation to obtain primary wastewater; S2. Biochemical treatment: The primary wastewater is passed through an anaerobic tank and an upflow anaerobic reactor is used. A water distributor is set in the tank, a wastewater collection tank and an overflow weir are set on the upper layer, a circulating pump is set on the middle and upper layers, and a mud outlet is set in the middle. The primary wastewater enters the tank from the bottom through the water distributor, and the circulating pump draws wastewater from the middle and upper layers through the water distributor and mixes it with the influent water before entering the bottom. It is upflow from bottom to top to achieve full contact between wastewater and anaerobic activated sludge. The upflow velocity is 2m / h, the water temperature is 40℃, the HRT is 48h, the operating load is 2.0kgCOD / m³.d, and the effluent pH value is 7.5. S3. The wastewater in the anaerobic tank enters the aerobic tank and is operated using the A / O process. A pool is equipped with a submersible agitator and an O pool is equipped with a microporous aeration device. The A / O process operation control parameters are: V A :V O =1:3 (Vo=Vo1+Vo2+Vo3), pH value of pool A is 8.5; pH value of pool O is 8.0, DO is 6 mg / L, SV 30 The nitrification liquid return ratio is 200%. The wastewater passes through pool A, pool O1, pool O2 and pool O3 in sequence and then enters the sedimentation tank. The sedimentation tank is a radial flow / vertical flow type. The sedimentation tank is equipped with a sludge return pump to return the sludge at the bottom of the sedimentation tank to the first pool A water inlet. The sludge return ratio is 200%. The remaining sludge is discharged to the sludge storage tank by the sludge pump for dehydration treatment. The supernatant of the sedimentation tank is discharged to the open channel flowmeter and discharged into the designated pipe network after online monitoring to obtain treated wastewater. The operating load is 1.0kgCOD / m³.d.

[0030] Example 3 The only difference between this embodiment and embodiment 1 is that the molar ratio of divalent iron to trivalent iron is 2:1.

[0031] Example 4 The only difference between this embodiment and embodiment 1 is that the molar ratio of divalent iron to trivalent iron is 1:5.

[0032] Example 5 The only difference between this embodiment and embodiment 1 is that the molar ratio of divalent iron to trivalent iron is 2:5.

[0033] Example 6 The only difference between this embodiment and embodiment 5 is that the cationic polyacrylamide is replaced by an equal amount of cationic polyacrylamide and di(3,5-dicarboxyphenyl)hydroxymethane in a mass ratio of 5:1.

[0034] Example 7 The only difference between this embodiment and embodiment 6 is that the mass ratio of cationic polyacrylamide to di(3,5-dicarboxyphenyl)hydroxymethane is 30:1.

[0035] Example 8 The only difference between this embodiment and embodiment 6 is that the mass ratio of cationic polyacrylamide to di(3,5-dicarboxyphenyl)hydroxymethane is 8:1.

[0036] Example 9 The only difference between this embodiment and embodiment 7 is that the mass ratio of cationic polyacrylamide to di(3,5-dicarboxyphenyl)hydroxymethane is 20:1.

[0037] Example 10 The only difference between this embodiment and embodiment 1 is that the pH value of the effluent in step S2 is 7.5.

[0038] Embodiment 11 The difference between this embodiment and embodiment 1 is that the reflux ratio of the nitrifying liquid in step S3 is 200%.

[0039] Comparative Example 1 The only difference between this comparative example and Example 1 is that the polyiron is trivalent iron.

[0040] Comparative Example 2 The only difference between this comparative example and Example 1 is that in step S1, liquid alkali is added after flotation to obtain pretreated wastewater with a pH value of 7.77, which then enters a sedimentation tank for further separation and removal of precipitation to obtain primary wastewater; after treatment in the anaerobic tank in step 2, the pH value of the effluent is 7.42.

[0041] Comparative Example 3 The only difference between this comparative example and Example 1 is that in step S1, waste sulfuric acid is added after flotation to obtain pretreated wastewater with a pH value of 3.85, which then enters a sedimentation tank for further separation and removal of precipitation to obtain primary wastewater; after treatment in the anaerobic tank in step 2, the pH value of the effluent is 4.23.

[0042] Comparative Example 4 The only difference between this comparative example and Example 1 is that in step S3, the reflux ratio of the nitrifying liquid is 71%.

[0043] Comparative Example 5 The only difference between this comparative example and Example 1 is that in step S3, the reflux ratio of the nitrifying liquid is 257%.

[0044] The COD removal rate in the primary wastewater obtained after the physical and chemical pretreatment of the printing and dyeing wastewater in Examples 1 to 9 and Comparative Example 1 was tested according to the method listed in Table 4 of GB 4287-2012 "Discharge Standard of Water Pollutants for Textile Dyeing and Finishing Industry", and the COD removal rate was calculated according to the following formula; COD removal rate = (COD before treatment - COD after physical and chemical pretreatment) / COD before treatment × 100%; The test results are shown in Table 1.

[0045] Table 1 COD removal rate test results after physical and chemical pretreatment

[0046] Compared with Comparative Example 1, the polyiron in Example 1 is composed of divalent iron and trivalent iron. As a result, the COD removal rate of the printing and dyeing wastewater in Example 1 after physical and chemical pretreatment is higher than that in Comparative Example 1, indicating that when the polyiron is composed of divalent iron and trivalent iron, the COD removal rate of the printing and dyeing wastewater can be improved.

[0047] Compared with Example 1, the molar ratio of divalent iron to ferric iron was changed in Examples 3 to 5. As a result, the COD removal rates in Examples 4 to 5 were higher than those in Examples 1 and 3, indicating that when the molar ratio of divalent iron to ferric iron in the polyiron was 1 to 5:5, the COD removal rate of printing and dyeing wastewater could be further improved.

[0048] Compared with Example 5, di(3,5-dicarboxyphenyl)hydroxymethane is further added to the coagulant in Examples 6 to 9. As a result, the COD removal rate of the printing and dyeing wastewater in Examples 6 to 9 after physicochemical pretreatment is higher than that in Example 5, indicating that the COD removal rate of the printing and dyeing wastewater can be further improved when di(3,5-dicarboxyphenyl)hydroxymethane is added to the coagulant; by comparing Examples 6 to 9, it is found that the COD removal rate in Examples 8 to 9 is higher than that in Examples 6 to 7, indicating that when the mass ratio of cationic polyacrylamide to di(3,5-dicarboxyphenyl)hydroxymethane is 8 to 20:1, the COD removal rate of the printing and dyeing wastewater can be further improved.

[0049] The COD removal rate of the printing and dyeing wastewater after anaerobic treatment in Example 1, Example 10 and Comparative Examples 2-3 was tested according to the method listed in Table 4 of GB 4287-2012 "Discharge Standard of Water Pollutants for Textile Dyeing and Finishing Industry", and the COD removal rate was calculated according to the following formula; COD removal rate = (COD before anaerobic process - COD after anaerobic process) / COD before anaerobic process × 100%; The test results are shown in Table 2.

[0050] Table 2 Test results of COD removal rate of anaerobic process

[0051] Compared with Comparative Examples 2 to 3, the pH value of the printing and dyeing wastewater in the anaerobic process in Example 1 and Example 10 was controlled to be 6.3 to 7.5. As a result, the COD removal rate of the printing and dyeing wastewater in the anaerobic process in Example 1 and Example 10 was higher than that in Comparative Examples 2 to 3, indicating that when the pH value of the anaerobic process is 6.3 to 7.5, the COD removal rate of the printing and dyeing wastewater can be further improved.

[0052] The COD and ammonia nitrogen content of the effluent of the printing and dyeing wastewater after aerobic treatment in Example 1, Example 11 and Comparative Examples 4 to 5 were tested according to the method listed in Table 4 of GB 4287-2012 "Emission Standard of Water Pollutants for Textile Dyeing and Finishing Industry", wherein the ammonia nitrogen content was tested by Nessler's reagent spectrophotometry, and the test results are shown in Table 3.

[0053] Table 3 Test results of COD and ammonia nitrogen content in effluent after aerobic process

[0054] Compared with Comparative Examples 4 and 5, the reflux ratio of the nitrifying solution in the aerobic process in Example 1 and Example 11 is controlled to be 100%~200%. As a result, the COD and ammonia nitrogen contents of the effluent in Example 1 and Example 11 are lower than those in Comparative Examples 4 and 5, indicating that when the reflux ratio of the nitrifying solution in the aerobic process is 100%~200%, the COD removal rate and ammonia nitrogen removal rate of printing and dyeing wastewater can be further improved.

[0055] In Example 1 and Comparative Example 1, the flocculation of the wastewater after adding the coagulant in step S1 is as follows: Figure 2 shown.

[0056] Depend on Figure 2 It can be seen that polyferric iron is a combination of divalent iron and trivalent iron. The treated wastewater is clear and transparent, and the chromaticity is significantly reduced. This shows that using polyferric iron combined with divalent iron and trivalent iron as a coagulant can improve the treatment effect of printing and dyeing wastewater.

[0057] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-efficiency printing and dyeing wastewater treatment method, characterized in that: The following steps are involved: S1. Physical and chemical pretreatment: the printing and dyeing wastewater is sequentially passed through a regulating tank, neutralized, and flotated to obtain pretreated wastewater, and then precipitated to obtain primary wastewater; S2. Biochemical treatment: the primary wastewater is subjected to anaerobic process and aerobic process to obtain treated wastewater; The anaerobic method adopts pulse water inlet, the pH value of the inlet water is 4-6, and the pH value of the outlet water is 6.3-7.5; The aerobic process adopts A / O process or fully aerated activated sludge process; When the aerobic A / O process is selected, the reflux ratio of the nitrification solution in the A / O process is 100% to 200%; A sedimentation tank is arranged after the aerobic process; The sludge return ratio of the sludge in the sedimentation tank to the A / O process is 100% to 200%.

2. A high-efficiency printing and dyeing wastewater treatment method according to claim 1, characterized in that: A coagulant is also added during the flotation, and the coagulant consists of polyferric, cationic polyacrylamide and di(3,5-dicarboxyphenyl)hydroxymethane.

3. A high-efficiency printing and dyeing wastewater treatment method according to claim 2, characterized in that: The polyiron comprises divalent iron and ferric iron, and the molar ratio of the divalent iron to the ferric iron is 1-2:

5.

4. A high-efficiency printing and dyeing wastewater treatment method according to claim 2, characterized in that: The order of adding the coagulant is to first add polyferric, then add cationic polyacrylamide and di(3,5-dicarboxyphenyl)hydroxymethane.

5. A high-efficiency printing and dyeing wastewater treatment method according to claim 4, characterized in that: The amount of the polyiron added is 0.3% to 0.5% of the mass of the printing and dyeing wastewater; the sum of the mass of the cationic polyacrylamide and the di(3,5-dicarboxyphenyl)hydroxymethane added is 0.1% to 0.2% of the mass of the printing and dyeing wastewater; the mass ratio of the cationic polyacrylamide to the di(3,5-dicarboxyphenyl)hydroxymethane is 8 to 20:

1.

6. A high-efficiency printing and dyeing wastewater treatment method according to claim 1, characterized in that: The pH value of the pretreated wastewater is 4-6.

7. A high-efficiency printing and dyeing wastewater treatment method according to claim 1, characterized in that: The anaerobic treatment is carried out through an upflow anaerobic reactor, in which a water distributor is arranged, a wastewater collecting tank and an overflow weir are arranged on the upper layer, a circulating pump is arranged on the middle upper layer, and a mud discharge port is arranged in the middle.

8. A high-efficiency printing and dyeing wastewater treatment method according to claim 7, characterized in that: The rising flow rate of primary wastewater in the anaerobic upflow anaerobic reactor is 0.8-2 m / h, the water temperature is 35-40° C., the HRT is 24-48 h, and the operating load is 1.0-2.0 kg COD / m³.d.

9. A high-efficiency printing and dyeing wastewater treatment method according to claim 1, characterized in that: The A / O process includes an A pool and an O pool, and the A pool and the O pool are operated in series; the number of the A pools is 1 to 3; the number of the O pools is 3; the pH value of the A pool is 7.8 to 8.5; the pH value of the O pool is 7.0 to 8.0; a submersible agitator is provided in the A pool; and a microporous aeration device is provided in the O pool.

10. A high-efficiency printing and dyeing wastewater treatment method according to claim 9, characterized in that: Also includes at least one of the following features: The operating control parameter in the A / O process is V A :V O =1:2~3; In the A / O process, DO is 5-6 mg / L, SV 30 500~700ml / L, total HRT is 3~5 days; The water temperature in the A / O process does not exceed 37°C in summer, and the lowest water temperature in winter is not less than 28°C; The operating load in the A / O process is 0.6-1.0 kgCOD / m³.d, and the operating mode is continuous operation with uniform water inflow; The number of aeration tanks in the fully aerated activated sludge process is ≥ 2, and the aeration tanks are operated in series. The pH value in the aeration tanks is 7.0-8.3, the DO is 5.5-6.5 mg / L, and the SV 30 600~700ml / L, total HRT is 1~2 days; The water temperature in the fully aerated activated sludge process is not more than 37°C in summer and not less than 28°C in winter. The sedimentation tank is of radial flow type / vertical flow type, and a sludge return pump is provided in the sedimentation tank; The sludge return ratio of the sludge in the sedimentation tank to the aeration tank is 100% to 200%; The operating load in the fully aerated activated sludge process is 0.8-1.2 kg COD / m³.d, and the operating mode is continuous operation with uniform water inflow.

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